Composition for preventing or inhibiting inflammation of nervous system cells

Abstract

The purpose of the present invention is to provide a composition for preventing or suppressing inflammation of nervous system cells, and the like. The present invention relates to a composition for preventing or suppressing inflammation of nervous system cells, which is characterized by containing Cyclo (Phe-Phe) or a salt thereof and Cyclo (Leu-Lys) or a salt thereof as active ingredients.

Description

Technical Field

[0001] The present invention relates to a composition for preventing or suppressing inflammation of nervous system cells, etc. Background Art

[0002] Amyloid-beta (Aβ) is a protein produced in the brain. Aggregation of amyloid-beta occurs to form oligomers or fibrils, thereby exhibiting neurocytotoxicity. Such aggregated amyloid-beta is not excreted from the brain but accumulates, and is considered to be an inducer of the onset of Alzheimer's disease. As one of the pathogenesis of Alzheimer's disease, it is known that amyloid-beta stimulates neural cells and promotes the production of inflammatory cytokines to cause inflammation. Therefore, it is generally considered that preventing or suppressing inflammation of nervous system cells is effective for preventing Alzheimer's disease or suppressing the progression of Alzheimer's disease, for example.

[0003] On the other hand, it has been reported that cyclic dipeptides affect brain function. Patent Document 1 describes an agent for suppressing and / or improving a decrease in cognitive function, which is characterized by containing Cyclo(Gly-Pro).

[0004] Patent Document Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-196686 Summary of the Invention

[0005] An object of the present invention is to provide a composition for preventing or suppressing inflammation of nervous system cells, etc.

[0006] The present inventors conducted in-depth research on the above problems, and as a result, found that a combination of cyclo(phenylalanyl-phenylalanine) (Cyclo(Phe-Phe)) and cyclo(leucyl-lysine) (Cyclo(Leu-Lys)) as cyclic dipeptides is effective for preventing or suppressing inflammation of nervous system cells.

[0007] That is, although not limited thereto, the present invention relates to the following composition for preventing or suppressing inflammation of nervous system cells, etc. [1] A composition for preventing or suppressing inflammation of nervous system cells, which is characterized by containing Cyclo(Phe-Phe) or a salt thereof and Cyclo(Leu-Lys) or a salt thereof as active ingredients. [2] The composition according to the above [1], which is characterized in that the composition further contains Cyclo(Leu-Phe) or a salt thereof as an active ingredient. [3] The composition according to the above [1] or [2], which is characterized in that the composition further contains Cyclo(Leu-Gln) or a salt thereof as an active ingredient. [4] The composition according to any one of [1] to [3] above, characterized in that it inhibits the activation of NF-κB induced by amyloid-β. [5] The composition according to any one of [1] to [4] above, characterized in that it prevents or improves the damage of nerve system cells caused by amyloid-β. [6] The composition according to any one of [1] to [5] above, characterized in that the composition is for oral administration. [7] The composition according to any one of [1] to [6] above, characterized in that the composition is a food or drink or a pharmaceutical product. [8] The composition according to any one of [1] to [7] above, characterized in that the composition is labeled with one or more functions selected from "improve cognitive function", "inhibit the decline of cognitive function", "maintain good cognitive function", "improve memory", "inhibit the decline of memory", "maintain good memory", "improve the accuracy of memory", "prevent memory disorders", "improve memory disorders", "maintain memory as part of cognitive function", "suitable for the function of those who care about memory decline", "improve the accuracy of memory or the correctness of judgment as part of cognitive function", "improve memory retention or integration", "maintain the enhancement of cognitive function", "improve executive function", "promote attention and concentration", "improve learning ability", "maintain and improve orientation ability", "delay the decline of cognitive function with age", "strengthen short-term and long-term memory", and "promote verbal and visual-spatial memory". [9] An application, characterized in that Cyclo(Phe-Phe) or its salt and Cyclo(Leu-Lys) or its salt are used for the manufacture of a composition for preventing or inhibiting inflammation of nerve system cells.

[0008] According to the present invention, a composition for preventing or inhibiting inflammation of nerve system cells can be provided. The composition of the present invention can be used as a food or drink, a pharmaceutical product, etc. for preventing or inhibiting inflammation of nerve system cells. Description of the Drawings

[0009] Figure 1 A chart showing the content of GSH and the activities of CAT and SOD in HT22 cells treated with 0.000504 mg / mL of Cyclo(Val-Pro) under the stimulation of Aβ or in the absence of Cyclo(Val-Pro) for 24 hours. Figure 1 (a) shows the content of GSH, Figure 1 (b) shows the activity of CAT, Figure 1 (c) shows the activity of SOD. Figure 2 A graph showing the concentrations of IL-6, TNF-α, and IL-1β in the medium of HT22 cells. Figure 2 (a) shows the concentration of IL-6, Figure 2 (b) shows the concentration of TNF-α, Figure 2 (c) shows the concentration of IL-1β. Figure 3 A photograph showing the results of Western blot analysis of iNOS, β-actin, p65 NF-κB, p-p65 NF-κB, p38 MAPK, and p-p38 MAPK in HT22 cells. Figure 4 A graph showing the quantitative results of the proteins iNOS, β-actin, p-p65 NF-κB, p65 NF-κB, p-p38 MAPK, and p38 MAPK in HT22 cells. Figure 4 (a) shows the relative intensity of p-p65 NF-κB relative to p65 NF-κB, Figure 4 (b) shows the relative intensity of iNOS relative to β-actin, Figure 4 (c) shows the relative intensity of p-p38 MAPK relative to p38 MAPK, each expressed as the value when the relative intensity in the control group is taken as 1. Figure 5 A heatmap of KEGG pathway analysis performed to study the pathways enriched by Aβ treatment in HT22 cells. Figure 6 A photograph showing the results of Western blot analysis of PI3K, p-PI3K, Akt, p-Akt, p-AMPK, and AMPK in HT22 cells. Figure 7 A graph showing the quantitative results of the proteins p-PI3K, PI3K, p-Akt, Akt, p-AMPK, and AMPK in HT22 cells. Figure 7 (a) shows the relative intensity of p-PI3K relative to PI3K, Figure 7 (b) shows the relative intensity of p-AMPK relative to AMPK, Figure 7 (c) shows the relative intensity of p-Akt relative to Akt, each expressed as the value when the relative intensity in the control group is taken as 1. Figure 8 A graph showing the quantitative results (fluorescence intensity) of the TUNEL-positive regions in HT22 cells. Figure 9 A microscopic photograph showing the results of TUNEL fluorescence staining of HT22 cells. Figure 10 A graph showing the mRNA expression of BDNF, PSD-95, NCAM, and TrκB in HT22 cells. Figure 11 A photograph showing the results of Western blot analysis of p-CREB, CREB, BDNF, and β-actin proteins in HT22 cells. Figure 12 A graph showing the quantitative results of p-CREB, CREB, BDNF, and β-actin proteins in HT22 cells. Figure 12 (a) Shows the relative intensity of p-CREB relative to CREB, Figure 12 (b) Shows the relative intensity of BDNF relative to β-actin, each represented as the value when the relative intensity in the control group is 1. Figure 13 A micrograph showing the results of MAP-2 fluorescence staining in HT22 cells (scale bar: 10 μm). Figure 14 A graph showing the quantification data of MAP-2 fluorescence staining in HT22 cells. Figure 14 (a) Shows the expression level (fluorescence intensity) of MAP-2, Figure 14 (b) Shows the average axon length. Figure 15 A photograph showing the results of Western blot analysis of p-PI3K, PI3K, p-Akt, Akt, Cleaved caspase-3, caspase-3, p-CREB, CREB, BDNF, and β-actin proteins in HT22 cells treated with the PI3K inhibitor LY294002 for 24 hours. Figure 16 A graph showing the quantitative results of p-PI3K, PI3K, p-Akt, Akt, Cleaved caspase-3, caspase-3, p-CREB, CREB, BDNF, and β-actin proteins in HT22 cells treated with the PI3K inhibitor LY294002 for 24 hours. Figure 16 (a) Shows the relative intensity of p-PI3K relative to PI3K, Figure 16 (b) Shows the relative intensity of p-Akt relative to Akt, Figure 16 (c) Shows the relative intensity of Cleaved caspase-3 relative to caspase-3, Figure 16 (d) Shows the relative intensity of p-CREB relative to CREB, Figure 16(e) represents the relative intensity of BDNF relative to β-actin, expressed as the value when the relative intensity in the control group is taken as 1. Figure 17 It is a photograph showing the results of Western blot analysis of p-AMPK, AMPK, Cleaved caspase-3, caspase-3, p-CREB, CREB, BDNF and β-actin in HT22 cells treated with the AMPK inhibitor BML-275 for 24 hours. Figure 18 It is a graph showing the quantitative results of the proteins of p-AMPK, AMPK, Cleaved caspase-3, caspase-3, p-CREB, CREB, BDNF and β-actin in HT22 cells treated with the AMPK inhibitor BML-275 for 24 hours. Figure 18 (a) represents the relative intensity of p-AMPK relative to AMPK, Figure 18 (b) represents the relative intensity of Cleaved caspase-3 relative to caspase-3, Figure 18 (c) represents the relative intensity of p-CREB relative to CREB, Figure 18 (d) represents the relative intensity of BDNF relative to β-actin, expressed as the value when the relative intensity in the control group is taken as 1. Figure 19 It is a micrograph showing the results of TUNEL fluorescence staining of HT22 cells treated for 24 hours under the conditions of the presence or absence of Cyclo(Val-Pro), Cyclo(Val-Pro) and PI3K inhibitor, Cyclo(Val-Pro) and AMPK inhibitor under the stimulation of Aβ. Figure 20 It is a graph showing the quantitative results (fluorescence intensity) of the TUNEL-positive area in HT22 cells treated for 24 hours under the conditions of the presence or absence of Cyclo(Val-Pro), Cyclo(Val-Pro) and PI3K inhibitor, Cyclo(Val-Pro) and AMPK inhibitor under the stimulation of Aβ. Detailed implementation mode

[0010] The composition for preventing or suppressing inflammation of nervous system cells of the present invention contains Cyclo(Phe-Phe) or a salt thereof and Cyclo(Leu-Lys) or a salt thereof. The composition for preventing or suppressing inflammation of nervous system cells of the present invention contains Cyclo(Phe-Phe) or a salt thereof and Cyclo(Leu-Lys) or a salt thereof as active ingredients. In this specification, the composition for preventing or suppressing inflammation of nervous system cells of the present invention may sometimes be referred to as the composition of the present invention. The composition of the present invention can be used for preventing inflammation of nervous system cells and / or suppressing inflammation of nervous system cells.

[0011] Cyclo(Phe-Phe) (cyclophenylalanyl phenylalanine) is a cyclic dipeptide having a structure formed by condensation of two phenylalanine molecules, and Cyclo(Leu-Lys) (cycloleucyl lysine) is a cyclic dipeptide having a structure formed by condensation of leucine and lysine. In this specification, Cyclo(Phe-Phe) and Cyclo(Leu-Lys) may sometimes be respectively referred to as CFF and CLK. In this specification, the so-called "cyclic dipeptide" refers to a compound characterized by having a diketopiperazine structure formed by dehydration condensation of the amino group of the amino acid on the N-terminal side and the carboxyl group of the amino acid on the C-terminal side with amino acids as constituent units. In addition, when the amino acid compositions of cyclic dipeptides are the same, the order of their descriptions may be either one first. For example, Cyclo(Leu-Lys) and Cyclo(Lys-Leu) (cyclolysyl leucine) represent the same cyclic dipeptide.

[0012] The composition of the present invention may further contain at least one selected from Cyclo(Leu-Phe) (cycloleucyl phenylalanine), Cyclo(Leu-Gln) (cycloleucyl glutamine), Cyclo(Pro-Gly) (cycloprolyl glycine), Cyclo(Val-Pro) (cyclovalyl proline), Cyclo(His-Pro) (cyclohistidyl proline) and salts thereof within the range not impairing the effect of preventing or suppressing inflammation of nervous system cells based on Cyclo(Phe-Phe) or a salt thereof and Cyclo(Leu-Lys) or a salt thereof. The above Cyclo(Leu-Phe), Cyclo(Leu-Gln), Cyclo(Pro-Gly), Cyclo(Val-Pro), Cyclo(His-Pro) are respectively cyclic dipeptides having structures formed by condensation of leucine and phenylalanine, leucine and glutamine, proline and glycine, valine and proline, histidine and proline. In this specification, Cyclo(Leu-Phe), Cyclo(Leu-Gln), Cyclo(Pro-Gly), Cyclo(Val-Pro), and Cyclo(His-Pro) are sometimes referred to as CLF, CLQ, CPG, CVP, and CHP, respectively.

[0013] The composition of the present invention preferably further contains Cyclo(Leu-Phe) (cycloleucylphenylalanine) or a salt thereof as an active ingredient. The composition of the present invention further preferably contains Cyclo(Leu-Gln) (cycloleucylglutamine) or a salt thereof as an active ingredient. In one embodiment, the composition of the present invention may further contain CFF or a salt thereof, CLK or a salt thereof, and CLF or a salt thereof as active ingredients. In addition, in another embodiment, the composition of the present invention may also contain CFF or a salt thereof, CLK or a salt thereof, and CLQ or a salt thereof as active ingredients. One of the preferred embodiments of the present invention is a mode in which the composition of the present invention contains Cyclo(Phe-Phe) or a salt thereof, Cyclo(Leu-Lys) or a salt thereof, and at least one selected from Cyclo(Leu-Phe), Cyclo(Leu-Gln), and salts thereof. A more preferred mode of the composition of the present invention is a mode in which it contains CFF or a salt thereof, CLK or a salt thereof, CLF or a salt thereof, and CLQ or a salt thereof as active ingredients.

[0014] The composition of the present invention further preferably contains CFF or a salt thereof, CLK or a salt thereof, CLF or a salt thereof, CLQ or a salt thereof, as well as CPG or a salt thereof, CVP or a salt thereof, and CHP or a salt thereof as active ingredients. A mode in which the composition of the present invention contains these cyclic dipeptides or salts thereof is one of the preferred embodiments of the present invention.

[0015] As salts of cyclic dipeptides such as CFF and CLK, any salt that is pharmacologically acceptable or acceptable in food and beverages may be used, and there is no particular limitation. It can be either an acidic salt or a basic salt. Examples of acidic salts include inorganic salts such as hydrochloride, sulfate, nitrate, and phosphate; organic salts such as acetate, citrate, maleate, malate, oxalate, lactate, succinate, fumarate, and propionate. Examples of basic salts include alkali metal salts such as sodium salt and potassium salt; alkaline earth metal salts such as calcium salt and magnesium salt. Salts of cyclic dipeptides can be easily prepared by those skilled in the art by any method known in the art.

[0016] There are no particular limitations on the sources and manufacturing methods of CFF, CLK, CLF, CLQ, CPG, CVP, CHP, and their salts. These cyclic dipeptides and their salts can be manufactured according to known methods. These cyclic dipeptides and their salts can be derived from natural products, can be artificially synthesized, can also be manufactured by enzymatic methods or microbial fermentation methods, and can also be synthesized by dehydrating and cyclizing linear dipeptides. For example, heating protein hydrolysates such as collagen hydrolysate can obtain a peptide heat-treated product rich in cyclic dipeptides such as CFF, CLK, CLF, CLQ, CPG, CVP, and CHP. CFF, CLK, CLF, CLQ, CPG, CVP, CHP, and their salts can be formulated into a composition using a protein hydrolysate containing them or its heat-treated product, and can also be formulated into a composition using a concentrate, dry powder of a protein hydrolysate or its heat-treated product, or a substance obtained by improving the purification degree. For example, the composition of the present invention contains a protein hydrolysate or its heat-treated product, and in terms of CFF, CLK, CLF, CLQ, CPG, CVP, CHP, and their salts, it can also be a part of the protein hydrolysate or its heat-treated product. CFF, CLK, CLF, CLQ, CPG, CVP, CHP, and their salts can also use commercially available products.

[0017] Amyloid-β is a peptide sometimes referred to as amyloid-β protein, amyloid-β peptide, or β-amyloid. Amyloid-β is usually a peptide composed of about 40 amino acids, and amyloid-β 1-42 , amyloid-β 1-40 etc. can be cited. Non-aggregated amyloid-β is sometimes also referred to as amyloid-β monomer. Amyloid-β can form aggregates of two or more. For amyloid-β, for example, amyloid-β can form soluble aggregates (amyloid-β oligomers) aggregated by two or more (for example, 2 to 50). As amyloid-β oligomers, amyloid-β 1-42 oligomers, amyloid-β 1-40 oligomers, etc. can be cited. Amyloid-β includes non-aggregated amyloid-β and amyloid-β that forms aggregates such as oligomers.

[0018] Amyloid-β stimulates nerve system cells and activates NF-κB in these cells. NF-κB is a transcription factor for genes encoding various inflammatory cytokines. Due to the activation of NF-κB, the production of inflammatory cytokines is promoted, thereby causing inflammation in nerve system cells. As a result, nerve system cell damage occurs. Therefore, by inhibiting the activation of amyloid-β-induced NF-κB in nervous system cells, the production of inflammatory cytokines can be suppressed, thereby preventing or inhibiting inflammation of nervous system cells. In addition, by preventing or inhibiting inflammation of nervous system cells, damage to nervous system cells can be prevented or improved. In one aspect, the composition of the present invention is preferably a composition for preventing or inhibiting inflammation of nervous system cells caused by amyloid-β. In one aspect, the composition for preventing or inhibiting inflammation of nervous system cells caused by the above amyloid-β may further contain at least one selected from the group consisting of CLF, CLQ, CPG, CVP, CHP, and their salts as an active ingredient.

[0019] The composition of the present invention containing CFF or its salt and CLK or its salt has an inhibitory effect on amyloid-β-induced NF-κB activation. The composition of the present invention can be used for preventing or inhibiting inflammation of nervous system cells by inhibiting NF-κB activation. The composition of the present invention can be used for preventing or improving damage to nervous system cells caused by amyloid-β by inhibiting NF-κB activation. The present invention also includes a composition for inhibiting the activation of amyloid-β-induced NF-κB, which is characterized by containing CFF or its salt and CLK or its salt. The present invention also includes a composition for preventing or improving damage to nervous system cells caused by amyloid-β, which is characterized by containing CFF or its salt and CLK or its salt. In one aspect, the above composition for inhibiting the activation of amyloid-β-induced NF-κB, or the above composition for preventing or improving damage to nervous system cells caused by amyloid-β, may further contain at least one selected from the group consisting of CLF, CLQ, CPG, CVP, CHP, and their salts as an active ingredient.

[0020] In the present invention, "nervous system cells" refers to cells that make up the nervous system, and represents cells other than epidermal cells in tissues derived from the ectoderm. There is no particular limitation on the nervous system cells, but brain nervous system cells are preferred. Examples of brain nervous system cells include glial cells such as microglia, oligodendrocytes, astrocytes, and ependymal cells; Purkinje cells of the cerebellum, raphe neurons, cerebral cortex neurons, hypothalamic neurons, thalamic neurons, brainstem neurons, and hippocampal neurons. Among them, glial cells are preferred, and microglia are more preferred.

[0021] In one aspect, the composition of the present invention can be used to prevent or improve an inflammation-related condition or disease of nervous system cells, preferably an inflammation-related condition or disease of nervous system cells caused by amyloid-β, more preferably an inflammation-related condition or disease of nervous system cells caused by amyloid-β in the brain. As such a condition or disease, there can be mentioned a condition or disease caused by inflammation of nervous system cells. As a condition or disease caused by inflammation of nervous system cells due to amyloid-β in the brain, there can be mentioned, for example, neurodegenerative diseases such as Alzheimer's disease (including dementia of the Alzheimer type), and a part of mild cognitive impairment, etc. The composition of the present invention can be used to prevent or improve the above-mentioned condition or disease, and can preferably be used to prevent the above-mentioned condition or disease. In this specification, the prevention of a condition or disease includes: preventing onset, delaying onset, reducing the incidence rate, reducing the risk of onset, etc. The improvement of a condition or disease includes: restoring an object from the condition or disease, alleviating the symptoms of the condition or disease, improving the symptoms of the condition or disease, delaying or preventing the development of the condition or disease, etc.

[0022] In Alzheimer's disease and mild cognitive impairment, a decrease in cognitive function is known. As symptoms of the decrease in cognitive function in Alzheimer's disease and mild cognitive impairment, there can be mentioned, for example, a decrease in memory, memory impairment (forgetfulness), aphasia (difficulty in naming an item), apraxia, agnosia (getting lost in a place where one should be familiar, etc.), a decrease in orientation ability (the ability to correctly recognize one's own situation such as the place, time, and names of people), a decrease in language and non-verbal learning ability, a decrease in auditory and visual processing, a decrease in executive function, executive dysfunction (becoming unable to make a plan and execute it), a decrease in concentration, a decrease in attention, a decrease in judgment, a decrease in spatial recognition ability, a decrease in cognitive flexibility, a decrease in information processing speed, etc. By preventing or suppressing inflammation of nervous system cells, it can be expected to obtain an effect of preventing a decrease in cognitive function or improving cognitive function, for example, an effect of preventing or improving the above-mentioned symptoms.

[0023] The composition of the present invention can be applied to either a therapeutic use (medical use) or a non-therapeutic use (non-medical use). The so-called non-therapeutic does not include the concept of medical acts, that is, surgery, treatment, or diagnosis of humans. As an example, the composition for preventing or suppressing inflammation of nervous system cells of the present invention can be provided in the form of an agent, but is not limited to this form. The agent can be directly provided as a composition, or provided as a composition containing the agent. In one aspect, the composition for preventing or suppressing inflammation of nervous system cells of the present invention can also be referred to as an anti-inflammatory agent for nervous system cells. In one aspect, the composition of the present invention is preferably an anti-inflammatory agent for nervous system cells caused by amyloid-β. The composition for inhibiting the activation of amyloid-β-induced NF-κB may also be referred to as an inhibitor of amyloid-β-induced NF-κB activation. In one aspect, the composition for preventing or improving damage to nerve cells of the present invention may also be referred to as an agent for preventing or improving damage to nerve cells. In one aspect, the composition of the present invention is preferably an agent for preventing or improving damage to nerve cells caused by amyloid-β.

[0024] The composition of the present invention can be either oral or non-oral. The composition of the present invention is preferably an oral composition. The composition of the present invention can be in the form of, for example, food and drink products, pharmaceuticals, quasi-drugs, feeds, etc., and is preferably food and drink products or pharmaceuticals. The composition of the present invention can also be added to food and drink products, pharmaceuticals, quasi-drugs, feeds, etc. for use. The form of the composition of the present invention is not particularly limited and can be any of solid (e.g., powder, granule, tablet, etc.), liquid, paste, etc.

[0025] The composition of the present invention contains CFF or its salt and CLK or its salt, and further various diluents, acidulants, antioxidants, stabilizers, preservatives, fragrances, emulsifiers, pigments, flavoring agents, pH regulators, nutritional fortifiers, etc. that are permitted as additives to food and drink products, pharmaceuticals, etc. can be added.

[0026] For example, when the composition of the present invention is made into a food and drink product, ingredients that can be used in food and drink products (e.g., food materials, food additives used as needed, etc.) can be formulated into the above-mentioned cyclic dipeptide or its salt used as an active ingredient to make various food and drink products. The food and drink products are not particularly limited, and examples include general food and drink products, health foods, foods with function claims, foods for specified health use, health supplements, food and drink products for patients, etc. The above-mentioned health foods, foods with function claims, foods for specified health use, health supplements, food and drink products for patients, etc. can be used in various preparation forms such as liquid preparations, fine granules, tablets, granules, powders, capsules, chewable tablets, dry syrups, liquid foods, etc.

[0027] When the composition of the present invention is made into a pharmaceutical or quasi-drug, a pharmacologically acceptable carrier can be formulated into the above cyclic dipeptide or its salt, and additives and the like added as needed to make various dosage forms of pharmaceuticals or quasi-drugs. Such carriers, additives, etc. only need to be pharmacologically acceptable substances that can be used in pharmaceuticals or quasi-drugs. For example, one or more of excipients, binders, disintegrants, lubricants, antioxidants, colorants, etc. can be cited. As the administration (ingestion) method of the pharmaceutical or quasi-drug, oral or parenteral (transdermal, transmucosal, enteral, injection, etc.) administration methods can be cited. When the composition of the present invention is made into a pharmaceutical or quasi-drug, it is preferably made into an oral pharmaceutical or oral quasi-drug. As the dosage form for oral administration, for example, liquid preparations, tablets, powders, fine granules, granules, sugar-coated tablets, capsules, suspensions, emulsions, chewable tablets, etc. can be cited. As the dosage form for parenteral administration, for example, injections, drip infusions, ointments, lotions, patches, suppositories, nasal preparations, pulmonary preparations (inhalants), etc. can be cited. The pharmaceutical can also be a pharmaceutical for non-human animals.

[0028] When the composition of the present invention is made into feed, the above cyclic dipeptide or its salt can be formulated into the feed. Feed also includes feed additives. As feed, for example, livestock feed for cattle, pigs, chickens, sheep, horses, etc.; small animal feed for rabbits, rats, mice, etc.; pet foods for dogs, cats, birds, etc. can be cited.

[0029] When the composition of the present invention is made into, for example, food and drink products, pharmaceuticals, quasi-drugs, feed, etc., its manufacturing method is not particularly limited, and the cyclic dipeptide or its salt used as the active ingredient above can be used and manufactured by general methods.

[0030] In one mode, the composition of the present invention is preferably a liquid composition, more preferably a beverage. The beverage can be, for example, a functional beverage. The form of the beverage is not particularly limited and can be a container-packed beverage. The container of the container-packed beverage is not particularly limited, and any form and material of container can be used. For example, metal containers such as aluminum cans and steel cans; resin containers such as PET bottles; paper containers such as paper boxes; glass containers such as glass bottles; wooden containers such as wooden barrels, etc., any of the commonly used containers can be used. By filling the beverage into such a container and sealing it, a container-packed beverage can be obtained.

[0031] The total content (in terms of cyclic dipeptide conversion) of CFF, CLK and their salts contained in the composition of the present invention is not particularly limited and can be set according to its form and the like. In one mode, the total content (in terms of cyclic dipeptide conversion) of CFF, CLK and their salts in the composition of the present invention is, for example, 1×10 -6 wt% or more, preferably 2×10 -6% by weight or more, more preferably 1×10 -5 % by weight or more. Even more preferably 1×10 -4 % by weight or more, particularly preferably 1×10 -3 % by weight or more. In addition, as the above content (in terms of cyclic dipeptide), it is preferably 90% by weight or less, more preferably 50% by weight or less, even more preferably 10% by weight or less, still more preferably 1% by weight or less, still more preferably 1×10 -1 % by weight or less, particularly preferably 1×10 -2 % by weight or less. In one mode, the total content (in terms of cyclic dipeptide) of CFF, CLK and their salts, for example, in the composition of the present invention can be 1×10 -6 ~90% by weight, preferably 2×10 -6 ~90% by weight, more preferably 1×10 -5 ~50% by weight, even more preferably 1×10 -4 ~10% by weight, particularly preferably 1×10 -3 ~1% by weight. In one mode, the total content (in terms of cyclic dipeptide) of CFF, CLK and their salts in the composition of the present invention can be 1×10 -6 ~1×10 -1 % by weight, preferably 1×10 -6 ~1×10 -2 % by weight, more preferably 2×10 -6 ~1×10 -2 % by weight, even more preferably 1×10 -5 ~1×10 -2 % by weight. In one mode, when the composition of the present invention is a liquid composition such as a beverage, the total content (in terms of cyclic dipeptide) of CFF, CLK and their salts in the composition of the present invention is preferably 1×10 -6 ~1×10 -1 % by weight, more preferably 1×10 -6 ~1×10 -2 % by weight, even more preferably 2×10 -6 ~1×10 -2 % by weight, particularly preferably 1×10 -5 ~1×10 -2 % by weight. CFF, CLK and their salts can be quantified by known methods, for example, by liquid chromatography mass spectrometry (LC / MS). The amount converted to a cyclic dipeptide or a similar expression thereof, when it is a cyclic dipeptide such as CFF or CLK, refers to the amount of the cyclic dipeptide, and when it is a salt of a cyclic dipeptide, it refers to the value obtained by multiplying the number of moles of the salt by the molecular weight of the corresponding cyclic dipeptide. For example, when it is a salt of CFF, the amount converted to CFF is obtained by multiplying the number of moles of the salt by the molecular weight of CFF.

[0032] There is no particular limitation on the total content (CFF conversion) of CFF and its salts in the composition of the present invention. For example, it can be 1×10 -6 to 45% by weight, preferably 1×10 -5 to 20% by weight. More preferably, it is 1×10 -4 to 10% by weight, and further preferably 1×10-3 to 1% by weight. In one mode, the total content (CFF conversion) of CFF and its salts in the composition of the present invention can be 1×10 -6 to 1×10-1% by weight, preferably 1×10 -6 to 1×10-2% by weight, and more preferably 1×10 -5 to 1×10-2% by weight. In one mode, when the composition of the present invention is a liquid composition such as a beverage, the total content (CFF conversion) of CFF and its salts in the composition of the present invention is preferably 1×10 -6 to 1×10 -1 % by weight, more preferably 1×10 -6 to 1×10-2% by weight, and further preferably 1×10 -5 to 1×10 -2 % by weight.

[0033] There is no particular limitation on the total content (CLK conversion) of CLK and its salts in the composition of the present invention. For example, it can be 1×10 -6 to 45% by weight, preferably 1×10 -5 to 20% by weight. More preferably, it is 1×10 -4 to 10% by weight, and further preferably 1×10 -3 to 1% by weight. In one mode, the total content (CLK conversion) of CLK and its salts in the composition of the present invention can be 1×10 -6 to 1×10 -1 % by weight, preferably 1×10 -6 to 1×10 -2 % by weight, and more preferably 1×10 -5 to 1×10 -2% by weight. In one embodiment, when the composition of the present invention is a liquid composition such as a beverage, the total content of CLK and its salts (in terms of CLK) in the composition of the present invention is preferably 1×10 -6 to 1×10 -1 % by weight, more preferably 1×10 -6 to 1×10 -2 % by weight, and even more preferably 1×10 -5 to 1×10 -2 % by weight.

[0034] When the composition of the present invention further contains at least one selected from CLF, CLQ, CPG, CVP, CHP, and their salts, the total content of CFF, CLK, CLF, CLQ, CPG, CVP, CHP, and their salts (in terms of cyclic dipeptides) can be, for example, 1×10 -6 to 90% by weight in the composition of the present invention, preferably 2×10 -6 to 90% by weight, more preferably 1×10 -5 to 50% by weight, even more preferably 1×10 -4 to 10% by weight, and particularly preferably 1×10 -3 to 1% by weight. In one embodiment, the total content of CFF, CLK, CLF, CLQ, CPG, CVP, CHP, and their salts (in terms of cyclic dipeptides) in the composition of the present invention can be 1×10 -6 to 1×10 -1 % by weight, preferably 1×10 -6 to 1×10 -2 % by weight, more preferably 2×10 -6 to 1×10 -2 % by weight, even more preferably 1×10 -5 to 1×10 -2 % by weight. In one embodiment, when the composition of the present invention is a liquid composition such as a beverage, the total content of CFF, CLK, CLF, CLQ, CPG, CVP, CHP, and their salts (in terms of cyclic dipeptides) in the composition of the present invention is preferably 1×10 -6 to 1×10 -1 % by weight, more preferably 1×10 -6 to 1×10 -2 % by weight, even more preferably 2×10 -6 to 1×10 -2 % by weight, and particularly preferably 1×10 -5 to 1×10 -2 % by weight.

[0035] The total content (in terms of cyclic dipeptide) of CLF, CLQ, CPG, CVP, CHP and their salts in the composition of the present invention is preferably 0 to 20% by weight, more preferably 1×10 -6 to 15% by weight, still more preferably 1×10 -5 to 10% by weight, even more preferably 1×10 -4 to 5% by weight, and particularly preferably 1×10 -3 to 1% by weight. In one embodiment, the total content (in terms of cyclic dipeptide) of CLF, CLQ, CPG, CVP, CHP and their salts in the composition of the present invention can be 1×10 -6 to 1×10 -1 % by weight, preferably 1×10 -6 to 1×10 -2 % by weight, more preferably 1×10 -5 to 1×10 -2 % by weight. In one embodiment, when the composition of the present invention is a liquid composition such as a beverage, the total content (in terms of cyclic dipeptide) of CLF, CLQ, CPG, CVP, CHP and their salts in the composition of the present invention is preferably 1×10 -6 to 1×10 -1 % by weight, more preferably 1×10 -6 to 1×10 -2 % by weight, still more preferably 1×10 -5 to 1×10 -2 % by weight.

[0036] The composition of the present invention only needs to contain CFF or its salt and CLK or its salt, and the ratio of each cyclic dipeptide is not particularly limited. Each cyclic dipeptide can be contained in the same ratio or in different ratios. Based on the total content (in terms of cyclic dipeptide) of the cyclic dipeptides and their salts contained in the composition of the present invention being 100% by weight, the total content (in terms of cyclic dipeptide) of CFF, CLK and their salts is preferably 5 to 85% by weight, more preferably 10 to 85% by weight. In one embodiment, based on the total content (in terms of cyclic dipeptide) of the cyclic dipeptides and their salts contained in the composition of the present invention being 100% by weight, the total content (in terms of CFF) of CFF and its salts is preferably 5 to 85% by weight, more preferably 5 to 80% by weight. In one embodiment, based on the total content (in terms of cyclic dipeptide) of the cyclic dipeptides and their salts contained in the composition of the present invention being 100% by weight, the total content (in terms of CLK) of CLK and its salts is preferably 5 to 85% by weight, more preferably 5 to 80% by weight.

[0037] The composition of the present invention is preferably taken orally (oral administration). The dosage (also referred to as the intake amount) of the composition of the present invention is not particularly limited. The dosage of the composition of the present invention may be any amount as long as it can achieve the preventive or inhibitory effect on the inflammation of nerve system cells, and can be appropriately set according to the administration form, administration method, body weight of the subject, etc. The dosage of the composition of the present invention is preferably an amount that can achieve the effect of inhibiting the activation of amyloid-β-induced NF-κB.

[0038] In one mode, when the composition of the present invention is taken or administered to a human (adult) subject, the dosage, as the total dosage (cyclic dipeptide conversion) of CFF or its salt and CLK or its salt, is preferably 1 μg or more per day, more preferably 10 μg or more, further preferably 150 μg or more, and in addition, preferably 1000 μg or less, more preferably 500 μg or less, further preferably 300 μg or less. In one mode, when a human (adult) takes or is administered the composition of the present invention, the total dosage (cyclic dipeptide conversion) of CFF or its salt and CLK or its salt is preferably 1 - 1000 μg per day, more preferably 10 - 500 μg, further preferably 150 - 300 μg. When the composition of the present invention further contains at least one selected from CLF, CLQ, CPG, CVP, CHP and their salts, the total dosage (cyclic dipeptide conversion) of CFF, CLK, CLF, CLQ, CPG, CVP, CHP and their salts is preferably in the above range. The total dosage (cyclic dipeptide conversion) of CFF, CLK, CLF, CLQ, CPG, CVP, CHP and their salts, when it is for a human (adult), is preferably 5 - 1000 μg per day, more preferably 20 - 500 μg, further preferably 160 - 300 μg. Preferably, the above amount is divided into one or more times a day, such as once or multiple times a day (for example, 2 - 3 times) for intake or administration. In one mode, it is preferred to orally intake or administer the above amount of CFF or its salt and CLK or its salt. In the case of a human (adult), per day, for every 60 kg of body weight, it is preferably to intake or administer the above amount of CFF or its salt and CLK or its salt. In one mode, the composition of the present invention may be an oral composition for a human to intake or be administered the above amount of CFF or its salt and CLK or its salt per 60 kg of body weight per day.

[0039] The composition of the present invention is preferably taken or administered continuously. By continuously taking or administering CFF or its salt and CLK or its salt, a higher effect is expected to be obtained. In one mode, the composition of the present invention is preferably taken or administered continuously for 1 week or more, more preferably 4 weeks or more, further preferably 8 weeks or more. Cyclic dipeptides such as CFF and CLK and their salts can be ingested as food and beverages, etc., and from the viewpoint of safety, it is considered that there are few problems even with long-term ingestion, for example.

[0040] The subject to which the composition of the present invention is administered (also referred to as the administration subject) is not particularly limited. It is preferably a human or non-human mammal, and more preferably a human. In one mode, as the administration subject of the composition of the present invention, preferably a subject who needs or wishes to prevent or inhibit inflammation of nerve system cells, a subject who needs or wishes to prevent or improve a condition or disease related to inflammation of nerve system cells, etc. In one mode, as the administration subject in the present invention, middle-aged and elderly persons can be cited. Middle-aged and elderly persons include the elderly. Middle-aged and elderly persons can be, for example, humans aged 40 or above. In one mode, among middle-aged and elderly persons, the elderly are preferably the subjects. The elderly can be, for example, humans aged 60 or above or 65 or above. In one mode, the administration subject of the composition of the present invention can also be a healthy person. For example, it can also be used for healthy persons for the purpose of preventing inflammation of nerve system cells caused by amyloid-β in the brain, preventing Alzheimer's disease or mild cognitive impairment, etc.

[0041] The composition of the present invention can also be labeled with a function exerted by preventing or inhibiting inflammation of nerve system cells. Such a label is also called a functional label. The above label is not particularly limited. As such a label, for example, those selected from "improve cognitive function", "inhibit the decline of cognitive function", "maintain good cognitive function", "improve memory", "inhibit the decline of memory", "maintain good memory", "improve the accuracy of memory", "prevent memory disorders", "improve memory disorders", "maintain memory as part of cognitive function", "suitable for functions of those who care about memory decline", "improve the accuracy of memory or the correctness of judgment as part of cognitive function", "improve memory retention or integration", "maintain enhanced cognitive function", "improve executive function", "promote attention and concentration", "improve learning ability", "maintain and improve orientation ability", "delay the decline of cognitive function with age", "strengthen short-term and long-term memory", and "promote verbal and visuospatial memory", and labels or functional labels that can be regarded as equivalent thereto can be cited. In one mode of the present invention, the composition of the present invention is preferably a food or beverage labeled with one or more of the above labels. In addition, the above label can also be a label indicating the meaning of using the above composition to obtain the above function. This label can be attached to the composition itself or to the container or packaging of the composition.

[0042] The present invention also includes the following methods and applications. A method for preventing or suppressing inflammation of nervous system cells, characterized by administering Cyclo(Phe-Phe) or a salt thereof and Cyclo(Leu-Lys) or a salt thereof. A method for inhibiting the activation of amyloid-β-induced NF-κB, characterized by administering Cyclo(Phe-Phe) or a salt thereof and Cyclo(Leu-Lys) or a salt thereof. A method for preventing or improving damage to nervous system cells, characterized by administering Cyclo(Phe-Phe) or a salt thereof and Cyclo(Leu-Lys) or a salt thereof.

[0043] An application, characterized by using Cyclo(Phe-Phe) or a salt thereof and Cyclo(Leu-Lys) or a salt thereof for preventing or suppressing inflammation of nervous system cells. An application, characterized by using Cyclo(Phe-Phe) or a salt thereof and Cyclo(Leu-Lys) or a salt thereof for inhibiting the activation of amyloid-β-induced NF-κB. The above methods can be therapeutic methods or non-therapeutic methods. The above applications can be therapeutic applications or non-therapeutic applications.

[0044] In one mode, Cyclo(Phe-Phe) or a salt thereof and Cyclo(Leu-Lys) or a salt thereof can be used for preventing and / or suppressing inflammation of nervous system cells. In one mode, Cyclo(Phe-Phe) or a salt thereof and Cyclo(Leu-Lys) or a salt thereof can be used for preventing and / or suppressing inflammation of nervous system cells by inhibiting the activation of amyloid-β-induced NF-κB.

[0045] In the above methods and applications, in addition to the above CFF or a salt thereof and CLK or a salt thereof, at least one selected from CLF, CLQ, CPG, CVP, CHP and their salts can also be administered or used.

[0046] In the above methods and applications, it is preferred to administer or give the subject CFF or a salt thereof and CLK or a salt thereof more than once a day, for example, once to multiple times a day (such as 2 to 3 times). The above application is preferably for humans or non-human mammals, and more preferably for humans. In one mode, Cyclo(Phe-Phe) or a salt thereof and Cyclo(Leu-Lys) or a salt thereof can be used for preventing or improving a state or disease related to inflammation of nervous system cells by inhibiting the activation of amyloid-β-induced NF-κB. A method for preventing or improving a state or disease related to inflammation of nervous system cells by administering CFF or a salt thereof and CLK or a salt thereof is also included in the present invention.

[0047] In the above methods and applications, CFF or its salt and CLK or its salt in an amount capable of obtaining a preventive or inhibitory effect on inflammation of nervous system cells (also referred to as an effective amount) may be used. The above effective amount is preferably an amount capable of obtaining a preventive or inhibitory effect on inflammation of nervous system cells. The preferred dosage, administration method, administration target, etc. of CFF or its salt and CLK or its salt are the same as those of the composition of the present invention described above. CFF or its salt and CLK or its salt can be directly ingested or administered, or can be ingested or administered as a composition containing them. For example, the composition of the present invention can also be ingested or administered.

[0048] CFF or its salt and CLK or its salt can be used to manufacture food and beverages, pharmaceuticals, quasi-drugs, feeds, etc. for preventing or inhibiting inflammation of nervous system cells. In one aspect, the present invention also includes the use of CFF or its salt and CLK or its salt in the manufacture of a composition for preventing or inhibiting inflammation of nervous system cells. The present invention also includes the use of CFF or its salt and CLK or its salt in the manufacture of a composition for inhibiting the activation of amyloid-β-induced NF-κB. CFF or its salt and CLK or its salt can be used to manufacture a composition for preventing or improving a condition or disease related to inflammation of nervous system cells.

[0049] This specification also discloses the following compositions for neuroprotection, etc. [A1] A composition for neuroprotection, characterized by containing Cyclo(Val-Pro) or its salt as an active ingredient. [A2] The composition according to [A1] above, characterized in that the composition is a composition for preventing or improving damage to nervous system cells caused by amyloid-β. [A3] The composition according to [A1] or [A2] above, characterized in that the composition is for oral administration. [A4] The composition according to any one of [A1] to [A3] above, characterized in that the composition is a food and beverage or a pharmaceutical. [A5] The composition according to any one of [A1] to [A4] above is characterized in that the composition is attached with a label selected from one or more of the functions of "enhancing cognitive function", "inhibiting the decline of cognitive function", "maintaining good cognitive function", "enhancing memory", "inhibiting the decline of memory", "maintaining good memory", "enhancing the accuracy of memory", "preventing memory disorders", "improving memory disorders", "maintaining memory as part of cognitive function", "suitable for the function of those who care about memory decline", "enhancing the accuracy of memory or the correctness of judgment as part of cognitive function", "improving memory retention or integration", "maintaining the enhancement of cognitive function", "improving executive function", "promoting attention and concentration", "improving learning ability", "maintaining and improving orientation ability", "delaying the decline of cognitive function with age", "strengthening short-term and long-term memory", and "promoting verbal and visual-spatial memory". [A6] An application, characterized in that Cyclo(Val-Pro) or a salt thereof is used for the manufacture of a neuroprotective composition. [A7] A method for protecting nerves, characterized by administering Cyclo(Val-Pro) or a salt thereof.

[0050] The inventors have found that cyclo(valyl-proline) (Cyclo(Val-Pro)), a cyclic dipeptide, or a salt thereof is effective for nerve protection. Thus, a neuroprotective composition and the like can be provided. The neuroprotective composition of the present invention can be used as a food, drink, pharmaceutical, etc. for nerve protection.

[0051] The neuroprotective composition of the present invention contains Cyclo(Val-Pro) or a salt thereof. The neuroprotective composition contains Cyclo(Val-Pro) or a salt thereof as an active ingredient. The neuroprotective composition can be used for nerve protection.

[0052] Cyclo(Val-Pro) (cyclo(valyl-proline)) is a cyclic dipeptide having a structure in which valine and proline are condensed. Cyclo(Val-Pro) is sometimes referred to as CVP. In this specification, the so-called "cyclic dipeptide" refers to a compound characterized by having a diketopiperazine structure formed by dehydration condensation of the amino group of the N-terminal side amino acid and the carboxyl group of the C-terminal side amino acid with amino acids as constituent units. In addition, in this specification, when the amino acid compositions of cyclic dipeptides are the same, the order of their descriptions may be either one first. For example, Cyclo(Val-Pro) and Cyclo(Pro-Val) (cyclo(prolyl-valine)) represent the same cyclic dipeptide.

[0053] As a salt of CVP, any pharmaceutically acceptable salt or food additive salt can be used without particular limitation, and it can be either an acidic salt or a basic salt. Examples of acidic salts include inorganic salts such as hydrochloride, sulfate, nitrate, and phosphate; and organic salts such as acetate, citrate, malate, oxalate, lactate, succinate, fumarate, and propionate. Examples of basic salts include alkali metal salts such as sodium salt and potassium salt; and alkaline earth metal salts such as calcium salt and magnesium salt. The salt of CVP can be easily prepared by those skilled in the art by any method known in the art.

[0054] There are no particular limitations on the sources and manufacturing methods of CVP and its salts. CVP and its salts can be manufactured according to known methods. CVP and its salts can be derived from natural products, synthesized artificially, manufactured by enzymatic methods or microbial fermentation methods, or synthesized by dehydrating and cyclizing linear dipeptides. For example, heating protein hydrolysates such as collagen hydrolysate can obtain a peptide heat-treated product rich in CVP. CVP and its salts can be formulated into a neuroprotective composition using protein hydrolysates containing them or their heat-treated products, or concentrates, dry powders, or substances with improved purity of protein hydrolysates or their heat-treated products. For example, a neuroprotective composition contains a protein hydrolysate or its heat-treated product, and for CVP and its salts, it can also be a part of the protein hydrolysate or its heat-treated product. CVP and its salts can also use commercially available products.

[0055] The neuroprotective composition of the present invention can be used to protect nerve system cells. Neuroprotection includes preventing or improving damage to nerve system cells, inhibiting nerve system cell death (apoptosis or necrosis), etc. The neuroprotective composition can be used to protect nerves from damage to nerve system cells, nerve system cell death, states or diseases associated with damage or cell death of nerve system cells, etc. Preventing or improving damage to nerve system cells also helps to inhibit the degeneration of nerve system cells. In one mode, the neuroprotective composition is a nerve system cell protective composition. In one mode, the neuroprotective composition is a composition for preventing or improving damage to nerve system cells. A composition for preventing or improving damage to nerve system cells can be used to prevent and / or improve damage to nerve system cells. Further, in one mode, the neuroprotective composition is a composition for preventing or improving damage to nerve system cells caused by amyloid-β. A composition for preventing or improving damage to nerve system cells caused by amyloid-β can be used to prevent and / or improve damage to nerve system cells caused by amyloid-β. In addition, in one mode, the composition for neuroprotection is also a composition for preventing or suppressing inflammation of nervous system cells. The composition for preventing or suppressing inflammation of nervous system cells can be used to prevent inflammation of nervous system cells and / or suppress inflammation of nervous system cells. Further, in one mode, the composition for neuroprotection is also a composition for preventing or suppressing inflammation of nervous system cells caused by amyloid-β. The composition for preventing or suppressing inflammation of nervous system cells caused by amyloid-β can be used to prevent inflammation of nervous system cells caused by amyloid-β and / or to suppress inflammation of nervous system cells caused by amyloid-β. In one mode, the composition for neuroprotection is preferably a composition for preventing or improving damage to nervous system cells caused by amyloid-β.

[0056] Amyloid-β is a peptide sometimes referred to as amyloid-β protein, amyloid-β peptide, or β-amyloid. Amyloid-β is generally a peptide composed of about 40 amino acids, and examples of amyloid-β include 1-42 , amyloid-β 1-40 and the like. Non-aggregated amyloid-β is sometimes also referred to as amyloid-β monomer. Amyloid-β can form aggregates of two or more. For amyloid-β, for example, amyloid-β can form soluble aggregates (amyloid-β oligomers) aggregated from two or more (e.g., 2 to 50). Examples of amyloid-β oligomers include amyloid-β 1-42 oligomers, amyloid-β 1-40 oligomers and the like. Amyloid-β includes non-aggregated amyloid-β and amyloid-β that forms aggregates such as oligomers.

[0057] Amyloid-β stimulates nervous system cells and changes the gene expression related to AMPK signaling and / or PI3K-Akt signaling in these cells. AMPK signaling is the main signaling pathway that regulates cellular energy homeostasis. PI3K-Akt signaling is an important signaling pathway related to controlling various cellular processes such as cell growth, proliferation, survival, and metabolism. When the gene expression of the pathways related to AMPK signaling and / or PI3K-Akt signaling changes, it promotes the production of inflammatory cytokines, thereby triggering inflammation in nervous system cells. As a result, damage occurs to nervous system cells. As shown in the test examples described below, CVP or its salt can exert a neuroprotective effect through pathways related to AMPK signaling and / or PI3K-Akt signaling. For example, CVP or its salt can inhibit the production of inflammatory cytokines and prevent or inhibit inflammation of nervous system cells through pathways related to AMPK signaling and / or PI3K-Akt signaling. In addition, by preventing or inhibiting inflammation of nervous system cells, damage to nervous system cells can be prevented or improved. Further, by preventing or inhibiting inflammation of nervous system cells or preventing or improving damage to nervous system cells, nerves can be protected.

[0058] In addition, amyloid-β induces apoptosis of nervous system cells, thereby causing damage to nervous system cells. Therefore, by inhibiting apoptosis of nervous system cells caused by amyloid-β, damage to nervous system cells can be prevented or improved. Further, by preventing or improving damage to nervous system cells, nerves can be protected.

[0059] A neuroprotective composition containing CVP or its salt has a nerve-protecting effect, for example, through pathways related to AMPK signaling and / or PI3K-Akt signaling. A neuroprotective composition can be used, for example, to prevent or inhibit inflammation of nervous system cells caused by amyloid-β through pathways related to AMPK signaling and / or PI3K-Akt signaling. A neuroprotective composition can be used, for example, to prevent or improve damage to nervous system cells caused by amyloid-β through pathways related to AMPK signaling and / or PI3K-Akt signaling.

[0060] A neuroprotective composition containing CVP or its salt has the effect of inhibiting apoptosis of nervous system cells caused by amyloid-β. A neuroprotective composition can prevent or improve damage to nervous system cells caused by amyloid-β by inhibiting apoptosis of nervous system cells caused by amyloid-β. A composition for inhibiting apoptosis of nervous system cells containing CVP or its salt is also disclosed in this specification.

[0061] The so-called "nerve (nervous system)" refers to the central nervous system. The so-called "nervous system cells" are cells that make up the nervous system and refer to cells other than epidermal cells in tissues derived from the ectoderm. Nervous system cells include nerve cells. There is no particular limitation on the above-mentioned nervous system cells, but brain nervous system cells are preferred. As cells of the brain nervous system, examples include glial cells such as microglia, oligodendrocytes, astrocytes, ependymal cells, etc.; Purkinje cells of the cerebellum, raphe nucleus neurons, cerebral cortex neurons, hypothalamic neurons, thalamic neurons, brainstem neurons, and hippocampal neurons. Among them, raphe nucleus neurons, cerebral cortex neurons, hypothalamic neurons, thalamic neurons, brainstem neurons, and hippocampal neurons are preferred, and hippocampal neurons are more preferred.

[0062] In one aspect, the composition for neuroprotection can be used for the prevention or improvement of a state or disease accompanied by damage to nervous system cells, or a state or disease accompanied by cell death of nervous system cells. In one aspect, the composition for neuroprotection can be used for the prevention or improvement of a state or disease related to inflammation of nervous system cells, preferably a state or disease related to inflammation of nervous system cells caused by amyloid-β, more preferably a state or disease related to inflammation of nervous system cells caused by amyloid-β in the brain. As such a state or disease, a state or disease caused by inflammation of nervous system cells can be cited. As a state or disease caused by inflammation of nervous system cells caused by amyloid-β in the brain, for example, neurodegenerative diseases such as Alzheimer's disease (including Alzheimer's type dementia), and some cases of mild cognitive impairment, etc. can be cited. The composition for neuroprotection can be used for the prevention or improvement of the above-mentioned state or disease, preferably for the prevention of the above-mentioned state or disease. In this specification, the prevention of a state or disease includes: preventing the onset, delaying the onset, reducing the incidence rate, reducing the risk of onset, etc. The improvement of a state or disease includes: restoring the subject from the state or disease, alleviating the symptoms of the state or disease, improving the symptoms of the state or disease, delaying or preventing the development of the state or disease, etc.

[0063] In Alzheimer's disease and mild cognitive impairment, a decrease in cognitive function is known. As symptoms of the decrease in cognitive function in Alzheimer's disease and mild cognitive impairment, for example, a decrease in memory, memory impairment (forgetfulness), aphasia (difficulty naming objects), apraxia, agnosia (getting lost in a familiar place, etc.), a decrease in orientation ability (the ability to correctly identify one's own situation such as place, time, name of people, etc.), a decrease in language and non-verbal learning ability, a decrease in auditory and visual processing, a decrease in executive function, executive function disorder (becoming unable to make a plan and execute it), a decrease in concentration, a decrease in attention, a decrease in judgment, a decrease in spatial recognition ability, a decrease in cognitive flexibility, a decrease in information processing speed, etc. can be cited. By preventing or improving the damage of nervous system cells or preventing or inhibiting the inflammation of nervous system cells, it can be expected to obtain the prevention of the decrease in cognitive function or the improvement effect of cognitive function, such as the prevention or improvement effect of the above-mentioned symptoms.

[0064] The composition for neuroprotection can be applicable to either therapeutic use (medical use) or non-therapeutic use (non-medical use). By non-therapeutic, it means not including medical acts, that is, the concepts of surgery, treatment, or diagnosis of humans. As an example, the composition for neuroprotection can be provided in the form of an agent, but is not limited to this form. The agent can be directly provided as a composition or as a composition containing the agent. In one mode, the composition for neuroprotection can also be referred to as a neuroprotective agent. In one mode, the composition for preventing or improving damage to nervous system cells can also be referred to as an agent for preventing or improving damage to nervous system cells. In one mode, the composition for preventing or suppressing inflammation of nervous system cells can also be referred to as an agent for preventing or suppressing inflammation of nervous system cells.

[0065] The composition for neuroprotection can be either oral or non-oral. The composition for neuroprotection is preferably an oral composition. The composition for neuroprotection can be made into forms such as food and drink products, pharmaceuticals, quasi-drugs, feeds, etc., and is preferably food and drink products or pharmaceuticals. The composition for neuroprotection can also be added to food and drink products, pharmaceuticals, quasi-drugs, feeds, etc. for use. The form of the composition for neuroprotection is not particularly limited and can be any of solid forms (e.g., powder form, granular form, tablet form, etc.), liquid form, paste form, etc.

[0066] The composition for neuroprotection contains CVP or its salt, and various diluents, acidulants, antioxidants, stabilizers, preservatives, fragrances, emulsifiers, pigments, flavoring agents, pH regulators, nutritional fortifiers, etc. that are permitted as additives to food and drink products, pharmaceuticals, etc. can further be added.

[0067] For example, when the composition for neuroprotection is made into a food and drink product, ingredients that can be used in food and drink products (e.g., food materials, food additives used as needed, etc.) can be formulated into the CVP or its salt used as an active ingredient to make various food and drink products. The food and drink products are not particularly limited, and examples include general food and drink products, health foods, foods with functional claims, foods for specified health uses, health supplements, foods for patients, etc. The above health foods, foods with functional claims, foods for specified health uses, health supplements, foods for patients, etc. can be used in various preparation forms such as liquid preparations, fine granule preparations, tablet preparations, granule preparations, powder preparations, capsule preparations, chewable preparations, dry syrup preparations, liquid foods, etc.

[0068] When preparing the neuroprotective composition into a pharmaceutical or quasi-drug, a pharmacologically acceptable carrier can be formulated with CVP or its salt, and additives, etc. added as needed to prepare various dosage forms of pharmaceuticals or quasi-drugs. Such carriers, additives, etc. only need to be pharmacologically acceptable substances that can be used in pharmaceuticals or quasi-drugs. For example, one or more of excipients, binders, disintegrants, lubricants, antioxidants, colorants, etc. can be cited. As the administration (ingestion) method of the pharmaceutical or quasi-drug, oral or non-oral (transdermal, transmucosal, transintestinal, injection, etc.) administration methods can be cited. When preparing the neuroprotective composition into a pharmaceutical or quasi-drug, it is preferably prepared into an oral pharmaceutical or oral quasi-drug. As the dosage form for oral administration, for example, liquid preparations, tablets, powders, fine granules, granules, sugar-coated tablets, capsules, suspensions, emulsions, chewable tablets, etc. can be cited. As the dosage form for non-oral administration, for example, injections, drip infusions, ointments, lotions, patches, suppositories, nasal preparations, pulmonary preparations (inhalants), etc. can be cited. The pharmaceutical can also be a pharmaceutical for non-human animals.

[0069] When preparing the neuroprotective composition into feed, it is only necessary to formulate CVP or its salt into the feed. Feed also includes feed additives. As feed, for example, livestock feed for cattle, pigs, chickens, sheep, horses, etc.; small animal feed for rabbits, rats, mice, etc.; pet foods for dogs, cats, small birds, etc. can be cited.

[0070] When preparing the neuroprotective composition into, for example, food and drink products, pharmaceuticals, quasi-drugs, feed, etc., its manufacturing method is not particularly limited, and CVP or its salt used as an active ingredient can be used and manufactured by general methods.

[0071] In one mode, the neuroprotective composition is preferably a liquid composition, more preferably a beverage. The beverage can be, for example, a functional beverage. The form of the beverage is not particularly limited and can be a container-packed beverage. The container of the container-packed beverage is not particularly limited, and any form and material of container can be used. For example, metal containers such as aluminum cans and steel cans; resin containers such as PET bottles; paper containers such as paper cartons; glass containers such as glass bottles; wooden containers such as wooden barrels, etc., any of the commonly used containers can be used. By filling the beverage into such a container and sealing it, a container-packed beverage can be obtained.

[0072] The total content (in terms of CVP conversion) of CVP and its salt contained in the neuroprotective composition is not particularly limited and can be set according to its form, etc. For example, it can be 1×10 -6 ~45% by weight, preferably 1×10 -5 ~20% by weight. More preferably 1×10 -4 ~10% by weight, and further preferably 1×10 -3 ~1% by weight. In one mode, the total content of CVP and its salts (in terms of CVP) in the neuroprotective composition may be 1×10 -6 to 1×10 -1 wt%, preferably 1×10 -6 to 1×10 -2 wt%, more preferably 1×10 -5 to 1×10 -2 wt%. In one mode, when the neuroprotective composition is a liquid composition such as a beverage, the total content of CVP and its salts (in terms of CVP) in the neuroprotective composition is preferably 1×10 -6 to 1×10 -1 wt%, more preferably 1×10 -6 to 1×10 -2 wt%, and further preferably 1×10 -5 to 1×10 -2 wt%. CVP and its salts can be quantified by a known method, for example, by liquid chromatography mass spectrometry (LC / MS). The amount in terms of CVP or a similar expression means the amount of CVP when it is CVP, and when it is a salt of CVP, it means the value obtained by multiplying the number of moles of the salt by the molecular weight of CVP.

[0073] As long as the neuroprotective composition contains CVP or its salt, it may also contain other cyclic dipeptides. When two or more other cyclic dipeptides are contained, the ratio of each cyclic dipeptide is not particularly limited, and each cyclic dipeptide may be contained in the same ratio or in different ratios. Taking the total content of the cyclic dipeptides and their salts contained in the neuroprotective composition (in terms of cyclic dipeptides) as 100 wt%, the total content of CVP and its salts (in terms of CVP) is preferably 5 to 85 wt%, more preferably 5 to 80 wt%.

[0074] The neuroprotective composition is preferably administered orally. The dosage of the neuroprotective composition (also referred to as the intake amount) is not particularly limited. The dosage of the neuroprotective composition only needs to be an amount that can achieve the neuroprotective effect, and can be appropriately set according to the dosage form, administration method, body weight of the subject, etc. The dosage of the neuroprotective composition is preferably an amount that can achieve the restoration effect of the pathway related to AMPK signaling and / or PI3K-Akt signaling concentrated by amyloid-β. In addition, the dosage of the neuroprotective composition is preferably an amount that can achieve the inhibitory effect on apoptosis of nervous system cells caused by amyloid-β.

[0075] In one mode, when a neuroprotective composition is ingested or administered to a human (adult), the dosage thereof, in terms of the dosage of CVP or its salt (converted to CVP), is preferably 1 μg or more, more preferably 10 μg or more, still more preferably 150 μg or more per day, and preferably 1000 μg or less, more preferably 500 μg or less, still more preferably 300 μg or less per day. In one mode, when a neuroprotective composition is ingested or administered to a human (adult), the total dosage thereof, in terms of the dosage of CVP or its salt (converted to CVP), is preferably 1 to 1000 μg, more preferably 10 to 500 μg, still more preferably 150 to 300 μg per day. Preferably, the above dosage is divided into one or more times a day, for example, once or multiple times a day (such as 2 to 3 times), for ingestion or administration. In one mode, it is preferred to orally ingest or administer the above dosage of CVP or its salt. In the case of a human (adult), per day, it is preferred to ingest or administer the above dosage of CVP or its salt per 60 kg of body weight. In one mode, the neuroprotective composition can be an oral composition for a human to ingest or for administering the above dosage of CVP or its salt per 60 kg of body weight per day.

[0076] The neuroprotective composition is preferably continuously ingested or administered. By continuously ingesting or administering CVP or its salt, a higher effect is expected to be obtained. In one mode, the neuroprotective composition is preferably continuously ingested or administered for 1 week or more, more preferably 4 weeks or more, still more preferably 8 weeks or more. CVP and its salts can be ingested as food or drink, etc., and from the viewpoint of safety, it is considered that there are few problems even in the case of long-term ingestion, for example.

[0077] The subject for ingesting or administering the neuroprotective composition (also referred to as the administration subject) is not particularly limited. It is preferably a human or a non-human mammal, more preferably a human. In one aspect, the subject for administration of the composition for neuroprotection is preferably a subject who needs or desires to prevent or improve damage to nerve cells, a subject who needs or desires to prevent or inhibit inflammation of nerve cells, a subject who needs or desires to prevent or improve a condition or disease associated with damage to nerve cells, a subject who needs or desires to prevent or improve a condition or disease related to inflammation of nerve cells, and the like. In one aspect, the subject for administration of the composition for neuroprotection may include middle-aged and elderly individuals. Middle-aged and elderly individuals include the aged. Middle-aged and elderly individuals may be, for example, humans aged 40 years or older. In one aspect, among middle-aged and elderly individuals, the aged are preferably the subjects. The aged may be, for example, humans aged 60 years or older or 65 years or older. In one aspect, the subject for administration of the composition for neuroprotection may also be a healthy subject. For example, it may be used for a healthy subject for the purpose of preventing damage to nerve cells caused by amyloid-β in the brain, preventing inflammation of nerve cells caused by amyloid-β, preventing Alzheimer's disease or mild cognitive impairment, and the like.

[0078] The composition for neuroprotection may also be labeled with a function exerted by protecting nerves. Such a label is also referred to as a functional label. The above label is not particularly limited. As such a label, for example, there may be mentioned a label selected from one or more functions of "improving cognitive function", "inhibiting decline in cognitive function", "maintaining good cognitive function", "improving memory", "inhibiting decline in memory", "maintaining good memory", "improving memory accuracy", "preventing memory impairment", "improving memory impairment", "maintaining memory as part of cognitive function", "suitable for the function of those who are concerned about memory decline", "improving the accuracy of memory or the correctness of judgment as part of cognitive function", "improving memory retention or integration", "maintaining enhanced cognitive function", "improving executive function", "promoting attention and concentration", "improving learning ability", "maintaining and improving orientation ability", "delaying age-related decline in cognitive function", "enhancing short-term and long-term memory", and "promoting verbal and visuospatial memory", and a label or functional label that can be regarded as equivalent thereto. In one aspect of the present invention, the composition for neuroprotection is preferably a food or drink labeled with one or more of the above labels. In addition, the above label may also be a label indicating the meaning of using the above composition to obtain the above function. The label may be attached to the composition itself or to the container or packaging of the composition.

[0079] This specification also discloses the following methods and applications. A method for protecting nerves, characterized by administering Cyclo(Val-Pro) or a salt thereof. A method for preventing or suppressing inflammation of nervous system cells, characterized by administering Cyclo(Val-Pro) or a salt thereof. A method for preventing or improving damage to nervous system cells, characterized by administering Cyclo(Val-Pro) or a salt thereof. An application, characterized by using Cyclo(Val-Pro) or a salt thereof to protect nerves. An application, characterized by using Cyclo(Val-Pro) or a salt thereof to prevent or suppress inflammation of nervous system cells. An application, characterized by using Cyclo(Val-Pro) or a salt thereof to prevent or improve damage to nervous system cells. The above methods can be therapeutic or non-therapeutic methods. The above applications can be therapeutic or non-therapeutic applications.

[0080] In one mode, Cyclo(Val-Pro) or a salt thereof can be used to prevent and / or improve damage to nervous system cells caused by amyloid-β. In one mode, Cyclo(Val-Pro) or a salt thereof can be used to prevent and / or suppress inflammation of nervous system cells caused by amyloid-β. In one mode, Cyclo(Val-Pro) or a salt thereof can be used to prevent and / or improve damage to nervous system cells through pathways related to AMPK signaling and / or PI3K-Akt signaling. In one mode, Cyclo(Val-Pro) or a salt thereof can be used to prevent and / or suppress inflammation of nervous system cells through pathways related to AMPK signaling and / or PI3K-Akt signaling. In one mode, Cyclo(Val-Pro) or a salt thereof can be used to prevent and / or improve damage to nervous system cells by inhibiting apoptosis of nervous system cells.

[0081] In the above methods and applications, in addition to CVP or its salt, other cyclic dipeptides or their salts can also be administered or used.

[0082] In the above methods and applications, it is preferred to administer CVP or its salt to the subject more than once a day, for example, once to multiple times a day (such as 2 to 3 times), and the subject ingests or is administered CVP or its salt. The above application is preferably for humans or non-human mammals, and more preferably for humans. In one mode, CVP or its salt can be used to prevent or improve an inflammation-related condition or disease of nervous system cells through a pathway related to AMPK signaling and / or PI3K-Akt signaling. A method for preventing or improving an inflammation-related condition or disease of nervous system cells by administering CVP or its salt is also disclosed in this specification.

[0083] In the above methods and applications, an amount of CVP or its salt that can achieve a neuroprotective effect (which may also be referred to as an effective amount) can be used. The above effective amount is preferably an amount that can achieve a neuroprotective effect. The preferred dosage, administration method, administration subject, etc. of CVP or its salt are the same as those of the above-described neuroprotective composition of the present invention. CVP or its salt can be directly ingested or administered, or can be ingested or administered as a composition containing it. For example, the above-described neuroprotective composition can also be ingested or administered.

[0084] CVP or its salt can be used to manufacture foods and beverages, pharmaceuticals, quasi-drugs, feeds, etc. for protecting nerves. In one mode, this specification also discloses the application of Cyclo(Val-Pro) or its salt in the manufacture of a neuroprotective composition; the application of CVP or its salt in the manufacture of a composition for preventing or improving damage to nervous system cells caused by amyloid-β. In one mode, this specification also discloses the application of CVP or its salt in the manufacture of a composition for preventing or suppressing inflammation of nervous system cells caused by amyloid-β. In one mode, this specification also discloses the application of CVP or its salt in the manufacture of a composition for inhibiting apoptosis of nervous system cells caused by amyloid-β. CVP or its salt can be used to manufacture a composition for preventing or improving an inflammation-related condition or disease of nervous system cells.

[0085] In this specification, a numerical range represented by a lower limit value and an upper limit value, that is, "lower limit value to upper limit value", includes these lower limit values and upper limit values. For example, the range represented by "1 to 2" means 1 or more and 2 or less, and includes 1 and 2. In this specification, the upper limit and the lower limit can be set as a range based on any combination. Examples

[0086] Hereinafter, the present invention will be further described in detail by way of examples, but the scope of the present invention is not limited thereby.

[0087] <Examples 1 to 6 and Comparative Examples 1 to 3> (Evaluation of the Activity of Amyloid-β-Induced NF-κB) A. Reagents The cyclic dipeptides used as test compounds were purchased from Bachem and Peptide Institute, Inc. Aβ 1-42 Peptides were purchased from rPeptide. 1,1,1,3,3,3-Hexafluoro-2-propanol (HFIP) and dimethyl sulfoxide (DMSO) were purchased from Sigma Aldrich. DMEM / F12 medium, penicillin-streptomycin, and Lipofectamine® 3000 transfection reagent (0.3 μL / well) were purchased from Thermo Fisher Scientific. Fetal bovine serum was purchased from Merck-Millipore. The NanoLuc® reporter gene vector containing the NF-κB response element (100 ng / well) and the Nano-Glo® luciferase assay system (100 μg / well) were purchased from Promega.

[0088] B. Cell culture BV-2 mouse microglial cells (RRID: CVCL_0182, hereinafter referred to as BV-2 microglial cells) were cultured in DMEM / F12 medium supplemented with 10% fetal bovine serum (very low endotoxin level < 0.05 EU / mL) and 1% penicillin-streptomycin. The culture was carried out in a humidified atmosphere of 37 °C, 5% CO2, and 95% air, and subcultured when the cell density reached 80% confluence (every 2-3 days).

[0089] C. Aβ 42 Oligomer (Aβ 42 O) preparation Aβ 1-42 peptide was dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) at a concentration of 1 mM and incubated at room temperature for 30 minutes. The resulting Aβ 42 -HFIP solution was evaporated overnight without heating to dryness to remove residual trace amounts of HFIP and moisture, obtaining an Aβ 42 membrane. Subsequently, the Aβ 42 membrane was reconstituted with DMSO to a concentration of 5 mM, vortexed for 30 seconds, and sonicated using a bath-type sonicator for 10 minutes. The resulting Aβ 42 -DMSO solution was diluted with ice-cold growth medium and stored at 4 °C for 24 hours before use.

[0090] D. Transfection of plasmid DNA, cell treatment, and measurement of NF-κB-driven luciferase activity BV-2 mouse microglial cells were seeded in a 96-well culture plate at a density of 25,000 cells / well and cultured using 100 μL / well of proliferation medium. Sixteen hours after seeding, the NanoLuc (registered trademark) reporter gene vector with NF-κB response elements was introduced using Lipofectamine (registered trademark) 3000 transfection reagent. Forty-eight hours after transfection, Aβ 42 O and the test compound were prepared to make the proliferation medium for culture. The concentration of Aβ 42 O in the proliferation medium was 20 μM, and the concentrations of the test compounds in Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Table 1. The test compound and its concentration in Example 5 were the same as those in Example 4. The test compounds and their concentrations in Example 6 were: CFF 4.4 μg / mL, CLK 34.4 μg / mL, CLF 19 μg / mL, CLQ 20.6 μg / mL, CPG 15 μg / mL, CVP 7.6 μg / mL, CHP 6.2 μg / mL. After incubation for 24 hours, the cells were lysed. The NF-κB-driven luciferase activity was detected using the Nano-Glo (registered trademark) luciferase assay system. The reaction mixture composed of the cell lysate and the detection reagent was transferred to a 96-well white / clear bottom microplate (Thermo Fisher Scientific), and the fluorescence intensity was measured using a multimode microplate reader (BioTek). The experiment was carried out with n = 8, and the average value of the fluorescence intensity of the reaction mixture was used as the measured value. In this system, the stronger the fluorescence intensity, the stronger the activation degree of NF-κB.

[0091] [Table 1] CFF (μg / mL) CLK (μg / mL) CLF (μg / mL) CLQ (μg / mL) Example 1 4.4 34.4 - – Example 2 4.4 34.4 19 - Example 3 4.4 34.4 - 20.6 Example 4 4.4 34.4 19 20.6 Comparative Example 1 4.4 - 19 - Comparative Example 2 - 34.4 19 - Comparative Example 3 - - 19 20.6

[0092] E. Statistical analysis Statistical analysis was performed using Prism software (version 7.0a, GraphPad Software Inc., San Diego, California, USA). The results were expressed as mean ± standard deviation. The difference analysis between two independent groups was carried out by Student's t-test. When the P value was p < 0.05, the data was considered significant. To analyze the differences between more than three independent groups, multiple comparisons using Dunnett's test were performed after one-way ANOVA.

[0093] (Results) The results are shown in Table 2 and Table 3. The results are expressed as mean ± standard deviation (n = 8). * indicates relative to the control (without Aβ 42The treatment of either O or the test compound showed a significant difference at the p < 0.05 level. ** indicates a significant difference at the p < 0.01 level, *** indicates a significant difference at the p < 0.001 level, and **** indicates a significant difference at the p < 0.0001 level. # indicates relative to Aβ 42 The O treatment group (without treatment with the test compound) showed a significant difference at the p < 0.05 level. ## indicates a significant difference at the p < 0.01 level, indicates a significant difference at the p < 0.001 level, and # indicates a significant difference at the p < 0.0001 level. The luciferase activities shown in Table 2 and Table 3 are relative values of the luciferase activity when using the test compound (the fluorescence intensity of the reaction mixture containing the cell lysate treated with the test compound) with the luciferase activity of the control (the fluorescence intensity of the reaction mixture of the control) set to 100.

[0094] [Table 2]

[0095] [Table 3]

[0096] The results in Table 2 clearly showed that the combination of CFF and CLK significantly inhibited NF-κB activation compared to the case without treatment with the test compound. Furthermore, the results in Table 3 confirmed that when combining CFF, CLK, CLF, CLQ, CPG, CVP, and CHP (7DKP), the inhibitory effect on NF-κB activation was greater than when only combining CFF, CLK, CLF, and CLQ (4DKP).

[0097] <Test Example 1> (Evaluation of the neuroprotective effect of Cyclo(Val-Pro)) A. Cell culture and treatment HT22 cells (mouse hippocampal neuron cell line) (Chuanqiu Biotechnology Co., Ltd.) were cultured in DMEM (Dulbecco’s Modified Eagle Medium) containing 10% (vol / vol) fetal bovine serum (Chuanqiu Biotechnology Co., Ltd.) supplemented with 1% penicillin / streptomycin solution (Gibco) in a humidified environment (5% CO2, 95% air, 37°C). For amyloid-β (Aβ) treatment, HT22 cells were treated with Aβ (10 μmol / L, Adooq BioScience) for 24 hours (Aβ treatment group). In the Aβ treatment, cells were cultured in a medium supplemented with Aβ. In the Cyclo(Val-Pro) treatment group, HT22 cells were treated with both Aβ (10 μmol / L) and Cyclo(Val-Pro) (Bachem) for 24 hours. Specifically, cells in the Cyclo(Val-Pro) treatment group were cultured in a medium supplemented with Aβ and Cyclo(Val-Pro) (the concentration of Cyclo(Val-Pro) was 0.000504 mg / mL). Cells in the control group were not treated with either Aβ or Cyclo(Val-Pro). Cells in the control group were cultured in a medium without the addition of Aβ and Cyclo(Val-Pro). The following evaluations were performed on the cells in the Aβ treatment group, Cyclo(Val-Pro) treatment group, and control group. In addition, in the experiment studying the mechanism of action of Cyclo(Val-Pro), cells obtained by the following treatment were also used for evaluation. To inhibit PI3K (phosphatidylinositol 3-kinase) and AMPK (AMP-activated protein kinase), HT22 cells were treated with 10 μmol / L Aβ and 0.000504 mg / mL Cyclo(Val-Pro) for 24 hours in the presence of 20 μM PI3K inhibitor LY294002 (Adooq BioScience) or 10 μM AMPK inhibitor BML-275 (Adooq BioScience).

[0098] B. ELISA method and enzyme activity assay The activities of superoxide dismutase (SOD) and catalase (CAT) and the amount of reduced glutathione (GSH) in HT22 cells were measured using the corresponding kits (Jiancheng Institute of Biotechnology Co., Ltd.). Cytokines in the culture medium such as tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and IL-6 were measured using commercially available ELISA kits according to the instructions of the manufacturer (Multi Sciences (Lianke) Biotech, Co., Ltd.).

[0099] C. RT-qPCR Total RNA was extracted from cells using Biozol reagent (Vazyme), and the RNA concentration was evaluated using a Nano-3000 instrument (Aosens). cDNA was synthesized using a high-capacity cDNA reverse transcriptase kit (Tsingke Co., Ltd.), and qPCR was performed using the method described in Ma et al. (Gut Microbes, 2020, 12(1), 1832857) with SYBR Green Real-time PCR Master Mix (Tsingke Co., Ltd.) on a CFX Connect Real-Time PCR System (Bio-rad). The transcription of β-actin was used as a housekeeping gene for data normalization.

[0100] D. Western blot HT22 cells were lysed in RIPA lysis buffer (Radioimmunoprecipitation Buffer), and the protein concentration was measured using a BCA-Protein Quantitative Kit (Beyotime) according to the manufacturer's instructions. Cell lysates containing 30 μg of protein were subjected to SDS-PAGE and transferred to a PVDF membrane (Millipore) with a KPL Detector TMAfter blocking for 1 hour at room temperature (RT) by Block (SeraCare Life Sciences), it was incubated overnight at 4 °C with the first antibody. After washing thoroughly with Tris-buffered saline, the membrane was further incubated with an appropriate HRP-conjugated second antibody (Cell Signaling Technology). The bands were visualized by a chemiluminescence imaging workstation (Tanon) and quantified by ImageJ.

[0101] E. Immunofluorescence and TUNEL staining HT22 cells were cultured on coverslips (size: 10 mm × 10 mm; thickness: 0.13 - 0.17 mm) in 24-well culture plates until reaching 70 - 80% confluence. The cells were fixed with 4% paraformaldehyde (PFA) at RT for 10 minutes, permeabilized with 0.5% Triton X-100 (Sigma-Aldrich), and blocked with 5% FBS / PBS. Then, the first antibody against microtubule-associated protein-2 (MAP-2, HUABIO) was added to the cells and incubated overnight at 4 °C in a humid chamber. After washing, appropriate second antibodies (Alexa Fluor488 and Alexa Fluor 594, Thermo Fisher Scientific) were applied to the cells and incubated for 1 hour at RT. In TUNEL staining, the coverslips were incubated in terminal deoxynucleotidyl transferase (TdT) reaction buffer for 10 minutes and further incubated in TdT reaction mixture for 1 - 2 hours in a humid chamber at 37 - 40 °C. The coverslips were treated with stop rinse buffer for 10 minutes and rinsed with PBS-Tween 20 for 6 minutes. For detection, the coverslips were incubated with streptavidin-HRP in PBS at room temperature for 20 minutes and then incubated with 3,3'-diaminobenzidine (DAB) for 2 minutes.

[0102] F. Transcriptome analysis Total RNA was isolated from HT22 cells and used with NanoDrop TMThe concentration, mass, and integrity were determined using a spectrophotometer (Thermo Fisher Scientific). The sequencing library was constructed by Novogene and verified using an Agilent 2100 Bioanalyzer (Agilent Technologies), and quantified by ultraviolet spectrophotometry using PicoGreen dsDNA quantification reagent (Yeasen). Transcriptome sequencing was performed on an Illumina Novaseq 6000 system (LC-Bio Technology Co., Ltd.) using paired-end sequencing (PE150) with 2 × 150 bp reads. To measure gene expression, Fragments per kilobase of exon per million mapped reads (FPKM) values were used, and mRNAs with fold change > 2 or fold change < 0.5 and P value < 0.05 were screened using the R software package DESeq2. Further analysis included gene heatmap and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. Visualization of the Complex Heatmap was performed according to the instructions of Complex Heatmap (URL: https: / / bioconductor.org / packages / ComplexHeatmap / ).

[0103] G. Statistical analysis All data are presented as mean ± standard error of the mean (SEM). Comparisons between different groups were analyzed by one-way analysis of variance (ANOVA) followed by Tukey-Kramer test. A P value < 0.05 or < 0.01 was considered statistically significant.

[0104] H. Results 1. Screening of Cyclo(Val-Pro) with anti-inflammatory and antioxidant effects To investigate the anti-inflammatory and antioxidant effects of Cyclo(Val-Pro), the antioxidant enzyme activities and the concentrations of secreted cytokines were measured. Figures 1 - 4 The effects of Cyclo(Val-Pro) on inflammation and oxidative stress in HT22 cells are shown.

[0105] Figure 1A graph showing the content of GSH, and the activities of CAT and SOD in HT22 cells treated with 0.000504 mg / mL of Cyclo(Val-Pro) under the stimulation of Aβ, or treated for 24 hours in the absence of Cyclo(Val-Pro). Figure 1 (a) shows the GSH content, Figure 1 (b) shows the CAT activity, Figure 1 (c) shows the SOD activity. The antioxidant enzyme activities decreased by amyloid-β (Aβ) treatment were restored by Cyclo(Val-Pro) treatment ( Figure 1 ).

[0106] Figure 2 A graph showing the concentrations of IL-6, TNF-α and IL-1β in the culture medium of HT22 cells. Figure 2 (a) shows the concentration of IL-6, Figure 2 (b) shows the concentration of TNF-α, Figure 2 (c) shows the concentration of IL-1β. According to the ELISA results, the concentrations of the cytokines IL-6, TNF-α and IL-1β secreted were all increased by Aβ treatment, but decreased by Cyclo(Val-Pro) treatment ( Figure 2 ).

[0107] Next, the effects of Cyclo(Val-Pro) on the inflammatory and oxidative stress pathways were verified by immunoblotting. Figure 3 A photograph showing the results of Western blot analysis of inducible nitric oxide synthase (iNOS), β-actin, p65 NF-κB, p-p65 NF-κB (phosphorylated p65 NF-κB), p38 mitogen-activated protein kinase (MAPK) and p-p38 MAPK (phosphorylated p38 MAPK) in HT22 cells. Figure 4 A graph showing the quantitative results of the proteins of iNOS, β-actin, p-p65 NF-κB, p65 NF-κB, p-p38 MAPK and p38 MAPK in HT22 cells. Here, the quantitative results are represented by the relative intensity of p-p65 NF-κB to p65 NF-κB (the ratio of the signal intensity (protein amount) of the Western blot band), the relative intensity of p-p38 MAPK to p38 MAPK, and the relative intensity of iNOS to β-actin, respectively. Figure 4 (a) shows the relative intensity of p-p65 NF-κB to p65 NF-κB, Figure 4 (b) shows the relative intensity of iNOS to β-actin, Figure 4(c) represents the relative intensity of p-p38 MAPK with respect to p38MAPK, expressed as the value when the relative intensity in the control group is taken as 1. As a result, due to Aβ treatment, the phosphorylation of p65 NF-κB and p38 MAPK was significantly activated, and at the same time, the amount of iNOS increased significantly, but all of these were attenuated by Cyclo(Val-Pro) treatment ( Figure 3 and Figure 4 ).

[0108] Figure 1 , Figure 2 and Figure 4 In, the data are expressed as mean ± standard error (N = 6). * represents p < 0.05 relative to the control group (untreated with either Aβ or Cyclo(Val-Pro)), ** represents p < 0.01. # represents p < 0.05 relative to the Aβ-treated group (untreated with Cyclo(Val-Pro)), ## represents p < 0.01. In addition, in the drawings of this specification, Con represents the control group, Aβ represents the Aβ-treated group, and CVP represents the CVP-treated group (treated with Aβ and Cyclo(Val-Pro)).

[0109] 2. Effects of Cyclo(Val-Pro) on gene profiles and regulated different signaling pathways in HT22 cells To further investigate the mechanism of Cyclo(Val-Pro) on Aβ-induced inflammation in HT22 cells, transcriptome analysis was performed. Figure 5 The results of KEGG pathway analysis for the effects of Cyclo(Val-Pro) are shown. Figure 5 A heat map of KEGG pathway analysis performed to study the pathways enriched by Aβ treatment in HT22 cells. These generally show that in the KEGG pathway analysis of regulated genes, due to Aβ treatment, pathways related to MAPK signaling, apoptosis, AMPK signaling, PI3K-Akt signaling, and NF-κB signaling were enriched. On the other hand, due to Cyclo(Val-Pro) treatment, the AMPK and PI3K-Akt signaling pathways changed significantly ( Figure 5 ). Here, Figure 5 the values in represent the Enrichment score (-Log10(p value)). The Enrichment score takes values from 0 to 32, and the larger the value, the more relevant the pathway is to the effects of Aβ treatment and Cyclo(Val-Pro) treatment.

[0110] To verify the effects of Cyclo(Val-Pro) on the AMPK signaling pathway and the PI3K-Akt signaling pathway, Western blot analysis was performed on specific markers contained in these pathways. Figures 6 - 9 The effects of Cyclo(Val-Pro) on these pathways are shown.

[0111] Figure 6 A photograph showing the results of Western blot analysis of PI3K, p-PI3K (phosphorylated PI3K), Akt, p-Akt (phosphorylated Akt), p-AMPK, and AMPK in HT22 cells. Figure 7 A graph showing the quantitative results of the proteins p-PI3K, PI3K, p-Akt, Akt, p-AMPK, and AMPK in HT22 cells. Here, the quantitative results are represented by the relative intensity of p-PI3K relative to PI3K (the ratio of the signal intensity (protein amount) of the band in the Western blot), the relative intensity of p-Akt relative to Akt, and the relative intensity of p-AMPK relative to AMPK. Figure 7 (a) represents the relative intensity of p-PI3K relative to PI3K, Figure 7 (b) represents the relative intensity of p-AMPK relative to AMPK, Figure 7 (c) represents the relative intensity of p-Akt relative to Akt, each expressed as the value when the relative intensity in the control group is taken as 1. As a result, the phosphorylation of PI3K, Akt, and AMPK was attenuated by Aβ treatment, while the phosphorylation of these proteins was promoted by Cyclo(Val-Pro) and these changes were reversed ( Figure 6 and Figure 7 ).

[0112] Figure 8 A graph showing the quantitative results (fluorescence intensity) of the TUNEL-positive regions in HT22 cells. Figure 9 A microscopic photograph showing the results of TUNEL fluorescence staining of HT22 cells. The nuclei of TUNEL-positive (apoptotic) cells appear green. By TUNEL staining, it was found that the apoptotic cells increased by Aβ were decreased by Cyclo(Val-Pro) ( Figure 8 and Figure 9 ). Figure 8 The results shown are represented by the relative intensity when the fluorescence intensity of the control group is taken as 1.

[0113] Figure 7 and Figure 8Data are expressed as mean ± standard error (N = 4). * indicates p < 0.05 compared to the control group (untreated with either Aβ or Cyclo(Val-Pro)), ** indicates p < 0.01. # indicates p < 0.05 compared to the Aβ-treated group (untreated with Cyclo(Val-Pro)), ## indicates p < 0.01. In addition, in Figure 9 , Merge represents an image in which cells stained with DAPI for nuclear staining are overlapped with cells stained with TUNEL.

[0114] 3. Protective effect of Aβ produced by Cyclo(Val-Pro) on neuronal function in HT22 cells Next, the effect of Cyclo(Val-Pro) on neuronal function was investigated. Figures 10 - 14 Shows the effect of Cyclo(Val-Pro) on neuronal function in HT22 cells. Figure 10 Is a graph showing the mRNA expression (relative mRNA amount) of brain-derived neurotrophic factor (BDNF), postsynaptic density protein 95 (PSD-95), neural cell adhesion molecule (NCAM), and tropomyosin receptor kinase B (TrκB) in HT22 cells. Figure 10 The results shown are expressed as relative mRNA amounts with the mRNA expression level of the control group taken as 1. Through qPCR analysis of BDNF, PSD-95, NCAM, and TrκB, genes related to neurodegenerative diseases, it was found that the expression of these genes, which was dysregulated by Aβ treatment, was basically restored by Cyclo(Val-Pro) treatment ( Figure 10 ).

[0115] Figure 11 Is a photograph showing the results of Western blot analysis of cAMP response element-binding protein (CREB), p-CREB (phosphorylated CREB), BDNF, and β-actin in HT22 cells. Figure 12 Is a graph showing the quantitative results of the proteins p-CREB, CREB, BDNF, and β-actin in HT22 cells. Here, the quantitative results are expressed as the relative intensity of p-CREB relative to CREB (the ratio of the signal intensity (protein amount) of the band in the Western blot) and the relative intensity of BDNF relative to β-actin, respectively. Figure 12 (a) Represents the relative intensity of p-CREB relative to CREB, Figure 12(b) represents the relative intensity of BDNF relative to β-actin, expressed as the value when the relative intensity in the control group is taken as 1. The phosphorylation of CREB and the protein amount of BDNF decreased due to Aβ treatment but increased due to Cyclo(Val-Pro) treatment ( Figure 11 and Figure 12 ).

[0116] Figure 13 The figure is a micrograph showing the results of immunofluorescence staining of microtubule-associated protein 2 (MAP-2) in HT22 cells (scale bar: 10 μm). Figure 14 The figure is a graph showing the quantification data of MAP-2 immunofluorescence staining in HT22 cells. Figure 14 (a) represents the expression level (fluorescence intensity) of MAP-2, Figure 14 (b) represents the average axon length. Through immunofluorescence staining of MAP-2, it was found that Aβ treatment significantly decreased the expression of MAP-2 and the average axon length, but both were increased by Cyclo(Val-Pro) treatment ( Figure 13 and Figure 14 ).

[0117] Figure 10 , Figure 12 and Figure 14 In, data are expressed as mean ± standard error (N = 3). * indicates p < 0.05 compared to the control group (untreated with either Aβ or Cyclo(Val-Pro)), ** indicates p < 0.01. # indicates p < 0.05 compared to the Aβ-treated group (untreated with Cyclo(Val-Pro)), ## indicates p < 0.01. In addition, in Figure 13 , DAPI represents a micrograph of cells stained with DAPI, MAP-2 represents a photo of immunofluorescence staining of MAP-2, and Merge represents an image obtained by overlapping DAPI and MAP-2.

[0118] 4. Neuroprotective and anti-apoptotic effects of Cyclo(Val-Pro) via the PI3K-Akt and AMPK pathways To further clarify the basic mechanisms of Cyclo(Val-Pro) in neuronal function and apoptosis, a PI3K inhibitor (LY294002) and an AMPK inhibitor (BML-275) were used. As Figures 15 - 18 shown, Cyclo(Val-Pro) exerts neuroprotective and anti-apoptotic effects through the AMPK and PI3K / Akt pathways. In addition, as Figures 19 - 20 shown, the anti-apoptotic effect of Cyclo(Val-Pro) was reduced by inhibiting PI3K / Akt or AMPK signaling.

[0119] Figure 15 Photograph showing the results of Western blot analysis of p-PI3K, PI3K, p-Akt, Akt, Cleaved caspase-3, caspase-3, p-CREB, CREB, BDNF and β-actin in HT22 cells treated with the PI3K inhibitor LY294002 for 24 hours. Figure 16 Graph showing the quantitative results of the proteins p-PI3K, PI3K, p-Akt, Akt, Cleaved caspase-3, caspase-3, p-CREB, CREB, BDNF and β-actin in HT22 cells treated with the PI3K inhibitor LY294002 for 24 hours. Here, the quantitative results are represented by the relative intensity of p-PI3K relative to PI3K (ratio of the signal intensity (protein amount) of the band in the Western blot), the relative intensity of p-Akt relative to Akt, the relative intensity of Cleaved caspase-3 relative to caspase-3, the relative intensity of p-CREB relative to CREB, and the relative intensity of BDNF relative to β-actin. Figure 16 (a) shows the relative intensity of p-PI3K relative to PI3K, Figure 16 (b) shows the relative intensity of p-Akt relative to Akt, Figure 16 (c) shows the relative intensity of Cleaved caspase-3 relative to caspase-3, Figure 16 (d) shows the relative intensity of p-CREB relative to CREB, Figure 16 (e) shows the relative intensity of BDNF relative to β-actin, each represented as the value when the relative intensity in the control group is 1. Treatment with the PI3K inhibitor not only blocked the phosphorylation of PI3K / Akt induced by Cyclo(Val-Pro), but also abolished the promotion of CREB phosphorylation and the decrease in Cleaved caspase-3 induced by Cyclo(Val-Pro), and significantly reduced the induction of BDNF amount induced by Cyclo(Val-Pro) ( Figure 15 and Figure 16 ).

[0120] Figure 17 Photograph showing the results of Western blot analysis of p-AMPK, AMPK, Cleaved caspase-3, caspase-3, p-CREB, CREB, BDNF and β-actin in HT22 cells treated with the AMPK inhibitor BML-275 for 24 hours. Figure 18Chart showing the quantitative results of proteins p-AMPK, AMPK, Cleaved caspase-3, caspase-3, p-CREB, CREB, BDNF and β-actin in HT22 cells treated with the AMPK inhibitor BML-275 for 24 hours. Here, the quantitative results are represented by the relative intensity of p-AMPK relative to AMPK (the ratio of the signal intensity (protein amount) of the band in the western blot), the relative intensity of Cleaved caspase-3 relative to caspase-3, the relative intensity of p-CREB relative to CREB, and the relative intensity of BDNF relative to β-actin. Figure 18 (a) shows the relative intensity of p-AMPK relative to AMPK, Figure 18 (b) shows the relative intensity of Cleaved caspase-3 relative to caspase-3, Figure 18 (c) shows the relative intensity of p-CREB relative to CREB, Figure 18 (d) shows the relative intensity of BDNF relative to β-actin, each represented as the value when the relative intensity in the control group is 1. Similarly to the above, by inhibiting AMPK signaling with the AMPK inhibitor, the effects of Cyclo(Val-Pro) on the phosphorylation of Cleaved caspase-3 and CREB can be offset, and the effect of Cyclo(Val-Pro) on the amount of BDNF can be alleviated ( Figure 17 and Figure 18 ).

[0121] Figure 16 and Figure 18 In, the data are represented as mean ± standard error (N = 3). * indicates p < 0.05 relative to the control group (untreated with any of Aβ, Cyclo(Val-Pro) and the inhibitor), ** indicates p < 0.01. # indicates p < 0.05 relative to the Aβ-treated group (untreated with any of Cyclo(Val-Pro) and the inhibitor), ## indicates p < 0.01. + indicates p < 0.05 relative to the Cyclo(Val-Pro)-treated group (untreated with the inhibitor), ++ indicates p < 0.01. In addition, ns indicates no significant difference. Figure 15 and Figure 16 In, PI3K-INH represents the PI3K inhibitor, and CVP+PI3K-INH represents the CVP+PI3K-INH treatment group (treated with Aβ, Cyclo(Val-Pro) and the PI3K inhibitor). Figure 17 and Figure 18In this study, AMPK-INH represents an AMPK inhibitor, and CVP+AMPK-INH represents the CVP+AMPK-INH treatment group (treated with Aβ, Cyclo(Val-Pro), and an AMPK inhibitor).

[0122] Figure 19 This is a micrograph showing the results of TUNEL fluorescence staining of HT22 cells treated for 24 hours under the stimulation of Aβ, in the presence or absence of Cyclo(Val-Pro), Cyclo(Val-Pro) and a PI3K inhibitor, Cyclo(Val-Pro) and an AMPK inhibitor. The nuclei of TUNEL-positive (apoptotic) cells appear green. Figure 20 This is a graph showing the quantitative results (fluorescence intensity) of the TUNEL-positive area in HT22 cells treated for 24 hours under the stimulation of Aβ, in the presence or absence of Cyclo(Val-Pro), Cyclo(Val-Pro) and a PI3K inhibitor, Cyclo(Val-Pro) and an AMPK inhibitor. Evaluated by TUNEL staining, when PI3K / Akt or AMPK signaling was inhibited, the anti-apoptotic effect of Cyclo(Val-Pro) was also reduced ( Figure 19 and Figure 20 ).

[0123] Figure 19 In this figure, Merge represents the image of overlapping the cells stained with DAPI for nuclear staining and the cells stained with TUNEL. Figure 20 In this figure, the data are expressed as mean ± standard error (N = 3). * indicates p < 0.05 compared to the control group (untreated with any of Aβ, Cyclo(Val-Pro), and inhibitors), ** indicates p < 0.01. # indicates p < 0.05 compared to the Aβ treatment group (untreated with any of Cyclo(Val-Pro) and inhibitors), ## indicates p < 0.01. + indicates p < 0.05 compared to the Cyclo(Val-Pro) treatment group (untreated with inhibitors). In addition, PI3K-INH represents a PI3K inhibitor, AMPK-INH represents an AMPK inhibitor, CVP+PI3K-INH represents the CVP+PI3K-INH treatment group (treated with Aβ, Cyclo(Val-Pro), and a PI3K inhibitor), and CVP+AMPK-INH represents the CVP+AMPK-INH treatment group (treated with Aβ, Cyclo(Val-Pro), and an AMPK inhibitor).

[0124] I. Conclusion Based on all of the above in vitro experiments, it was initially found that Cyclo(Val-Pro) exerts anti-inflammatory, antioxidant stress, and anti-apoptotic effects in HT22 cells. Through further analysis based on KEGG pathways and Western blot analysis, it was found that the effects of Cyclo(Val-Pro) can be exerted through different pathways. Further, the neuroprotective and anti-apoptotic effects of Cyclo(Val-Pro) can be partially controlled through the PI3K / Akt and AMPK pathways.

Claims

1. A composition for preventing or suppressing inflammation of nervous system cells, characterized in that, Containing Cyclo(Phe-Phe) or its salt and Cyclo(Leu-Lys) or its salt as active ingredients.

2. The composition according to claim 1, characterized in that, The composition further contains Cyclo(Leu-Phe) or its salt as an active ingredient.

3. The composition according to claim 1 or 2, characterized in that, The composition further contains Cyclo(Leu-Gln) or its salt as an active ingredient.

4. The composition according to claim 1 or 2, characterized in that, Inhibiting the activation of amyloid-β-induced NF-κB.

5. The composition according to claim 1 or 2, characterized in that, Preventing or improving damage to nerve system cells caused by amyloid-β.

6. The composition according to claim 1 or 2, characterized in that, The composition is for oral administration.

7. The composition according to claim 1 or 2, characterized in that, The composition is a food or drink product or a pharmaceutical.

8. The composition according to claim 1 or 2, characterized in that, The composition is labeled with one or more functions selected from "enhancing cognitive function", "inhibiting the decline of cognitive function", "maintaining good cognitive function", "enhancing memory", "inhibiting the decline of memory", "maintaining good memory", "enhancing the accuracy of memory", "preventing memory impairment", "improving memory impairment", "maintaining memory as part of cognitive function", "suitable for functions of those who are concerned about memory decline", "enhancing the accuracy of memory or the correctness of judgment as part of cognitive function", "improving memory retention or integration", "maintaining enhanced cognitive function", "improving executive function", "promoting attention and concentration", "improving learning ability", "maintaining and improving orientation ability", "delaying the decline of cognitive function with age", "strengthening short-term and long-term memory", and "promoting verbal and visual-spatial memory".

9. An application, characterized in that, Using Cyclo(Phe-Phe) or its salt and Cyclo(Leu-Lys) or its salt for the manufacture of a composition for preventing or inhibiting inflammation of nerve system cells.

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