A composition that helps maintain healthy blood sugar levels and uses thereof

Abstract

The present application belongs to the technical field of pharmaceutical preparations, and particularly relates to a composition for maintaining healthy blood sugar level. The composition comprises DPP IV inhibiting peptide and double-spore mushroom polysaccharide, which can effectively prevent and treat diabetes, improve blood lipid abnormality and key target organ damage caused by diabetes through synergistic effect, and can be applied to the prevention and treatment of diabetes and diabetes complications, and has wide application prospect.

Description

A composition that helps maintain healthy blood sugar levels and its application Technical Field

[0001] This invention belongs to the field of biopharmaceutical formulations, and specifically relates to a composition that helps maintain healthy blood glucose levels and its application. Background Technology

[0002] Diabetes mellitus (DM) is a chronic metabolic disease caused by insulin secretion defects, insulin action disorders, or both, with persistent hyperglycemia as its core pathophysiological feature. Its pathogenesis is influenced by genetic susceptibility, environmental factors (such as lifestyle and obesity), and a variety of other factors. Type 2 diabetes mellitus (T2DM) accounts for approximately 90% of all diabetes cases, and its core pathogenesis lies in insulin resistance accompanied by progressive decline in pancreatic β-cell function to varying degrees. Poor long-term glycemic control can lead to a variety of serious complications, including cardiovascular and cerebrovascular diseases, peripheral neuropathy, diabetic nephropathy, and retinopathy, posing a significant threat to patients' health.

[0003] Agaricus bisporus polysaccharides (ABP) have shown potential value in diabetes intervention. Studies have shown that ABP exerts its hypoglycemic effect through multiple pathways, including improving insulin sensitivity (reducing insulin resistance), protecting pancreatic β-cell function, and regulating gut microbiota. Animal experiments have shown that ABP intervention can significantly reduce fasting blood glucose levels (approximately 15-20%) and improve glucose tolerance. Its natural source endows it with high safety, and compared to some synthetic hypoglycemic drugs, it has a lower risk of adverse reactions. However, single-component Agaricus bisporus polysaccharides are difficult to overcome therapeutic thresholds and functional limitations in glycemic regulation. Currently, there are few studies on the use of Agaricus bisporus polysaccharides in compound hypoglycemic agents, and even fewer reports on the effects and mechanisms of its synergistic regulation of blood glucose with peptides.

[0004] Peptide drugs, due to their high target specificity, low toxicity, and good modifiability, have become an important direction in the research and development of diabetes treatment drugs. Traditional peptide separation and purification techniques (such as ultrafiltration, macroporous adsorption resin chromatography, gel filtration chromatography, reversed-phase high-performance liquid chromatography (RP-HPLC), ion exchange chromatography, etc.) mainly rely on the physicochemical properties of peptide molecules (such as molecular weight, charge, and hydrophobicity) for multi-stage separation, which is relatively cumbersome and time-consuming. With the advancement of bioinformatics and experimental techniques, research strategies based on computer-aided design (such as molecular docking and virtual screening) combined with in vitro activity evaluation (enzyme inhibition, cell models) and in vivo pharmacodynamic verification have significantly improved the discovery efficiency of bioactive peptides and reduced research and development costs and cycles.

[0005] Therefore, the combined application of button mushroom polysaccharides with specific hypoglycemic active peptides is a worthwhile combination therapy option to explore in the field of diabetes treatment. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention aims to propose a composition and its application that helps maintain healthy blood glucose levels. Through synergistic effects, it can effectively prevent and treat diabetes, improve dyslipidemia caused by diabetes and damage to key target organs.

[0007] To achieve the above objectives, in a first aspect, the present invention provides a composition that helps maintain healthy blood glucose levels, the composition comprising a DPPⅣ inhibitory peptide and a button mushroom polysaccharide, wherein the sequence of the DPPⅣ inhibitory peptide is LAFPGSW, and the mass ratio of the DPPⅣ inhibitory peptide to the button mushroom polysaccharide is 1-2:1-2; for example, the mass ratio may be 1:2, 1:1, or 2:1.

[0008] In previous studies, a polypeptide with significant dipeptidyl peptidase-IV (DPP-IV) inhibitory activity (hereinafter referred to as "DPPⅣ inhibitory peptide") was designed through computer simulation, which achieved a good hypoglycemic effect in diabetic model mice.

[0009] Specifically, a novel DPP-IV inhibitory peptide was designed using computer-aided design: based on the PDB crystal structure, the target conformation was optimized through molecular modeling; a virtual library was constructed based on the pharmacophores of natural inhibitors; docking was performed to verify that it formed a stable hydrogen bond network with the active site (ΔG < -7.0 kcal / mol); and the target sequence (LAFPGSW) was obtained through bioinformatics screening. The peptide was synthesized by a professional company using the Fmoc solid-phase method and purified by HPLC-MS.

[0010] In a specific embodiment of the present invention, the button mushroom polysaccharide is obtained by water extraction and alcohol precipitation, ethanol precipitation, protein removal, and DEAE column chromatography purification.

[0011] Specifically, the conditions for water extraction and alcohol precipitation are 100g raw material / 2L water, treated at 90℃ for 3h.

[0012] Furthermore, the mass ratio of the DPPⅣ inhibitory peptide to the button mushroom polysaccharide is 1:1.

[0013] In a second aspect, the present invention provides a product comprising the composition described in the first aspect, wherein the product is a pharmaceutical product.

[0014] Thirdly, the present invention provides the use of the composition described in the first aspect in the preparation of products capable of preventing and treating diabetes.

[0015] Fourthly, the present invention provides the use of the composition described in the first aspect in the preparation of products for the prevention and treatment of diabetes.

[0016] Furthermore, the product in question is a pharmaceutical product.

[0017] Furthermore, the product also includes pharmaceutically acceptable excipients.

[0018] Furthermore, the application includes at least one of the following:

[0019] (1) Application in the preparation of products that can lower blood sugar;

[0020] (2) Application in the preparation of products that can improve glucose tolerance;

[0021] (3) Application in the preparation of products that can improve insulin tolerance;

[0022] (4) Application in the preparation of products that can improve weight loss caused by diabetes;

[0023] (5) Application in the preparation of products that can alleviate polydipsia and polyphagia induced by diabetes.

[0024] (6) Application in the preparation of products that can improve pancreatic tissue damage.

[0025] (7) Application in the preparation of products that can improve liver damage caused by diabetes.

[0026] Furthermore, the application in the preparation of products capable of improving liver damage caused by diabetes includes at least one of the following:

[0027] (1) Application in the preparation of products that can reduce serum alanine aminotransferase levels;

[0028] (2) Application in the preparation of products that can reduce serum aspartate aminotransferase levels.

[0029] Fifthly, the present invention provides the use of the composition described in the first aspect in the preparation of a product capable of improving dyslipidemia caused by diabetes.

[0030] Furthermore, the application includes at least one of the following:

[0031] (1) Application in the preparation of products that can lower serum total cholesterol levels;

[0032] (2) Application in the preparation of products that can lower serum triglyceride levels;

[0033] (3) Application in the preparation of products that can increase serum high-density lipoprotein levels;

[0034] (4) Application in the preparation of products that can reduce serum low-density lipoprotein levels.

[0035] Furthermore, the product in question is a pharmaceutical product.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] (1) The present invention is based on computer-aided design of a novel DPP-IV inhibitory peptide, which has high targeting.

[0038] (2) Based on the problem that the hypoglycemic effect of ABP and DPP-IV inhibitory peptide with specific structure is limited when administered alone, this invention combines ABP and DPP-IV inhibitory peptide and systematically evaluates their synergistic efficacy in treating diabetes. It was found that the two have synergistic effects in preventing and treating diabetes, improving dyslipidemia and organ damage caused by diabetes, and provide an important candidate material basis and theoretical basis for the development of new anti-diabetic drugs or functional health foods. Attached Figure Description

[0039] Figure 1 is a schematic diagram of the docking of the DPPⅣ inhibitory peptide molecule.

[0040] Figure 2 shows the high-performance liquid chromatogram of the DPPⅣ inhibitory peptide.

[0041] Figure 3 shows the mass spectrum of the DPPⅣ inhibitory peptide.

[0042] Figure 4 shows the results of the in vitro activity assay of the DPPⅣ inhibitory peptide.

[0043] Figure 5 shows the results of health indicators for each group of mice. A represents body weight, B represents food intake, C represents water intake, D represents fasting blood glucose level, E represents blood glucose level during the insulin tolerance test, F represents blood glucose level during the glucose tolerance test, G represents AUC during the glucose tolerance test, H represents AUC during the insulin tolerance test, I represents serum alanine aminotransferase (ALT) level, J represents serum aspartate aminotransferase (AST) level, K represents serum total cholesterol level, L represents serum triglyceride level, M represents serum high-density lipoprotein (HDL) level, and N represents serum low-density lipoprotein (LDL) level. In the figure, * represents P < 0.05, ** represents P < 0.01, *** represents P < 0.001, **** represents P < 0.0001; # represents P < 0.05, ## represents P < 0.01, ### represents P < 0.001, and #### represents P < 0.0001. In Figures 5E and 5F, different numbers of asterisks represent significant differences between the control group and the model group, and different numbers of # represent significant differences between the model group and the composite group.

[0044] Figure 6 shows the pathological damage to the liver and pancreas of mice in each group. Detailed Implementation

[0045] The following detailed embodiments further illustrate the concept and technical effects of the present invention to fully understand its purpose, features, and effects. Unless otherwise specified, all methods described are conventional methods. Unless otherwise specified, all materials are available from publicly available commercial sources. The illustrative embodiments and descriptions of the present invention are used to explain the invention and do not constitute an undue limitation thereof. It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0046] Example 1: Preparation of bioactive peptides

[0047] 1. Computer-aided drug design of bioactive peptides

[0048] First, the crystal structure of DPP-IV (ID: 4A5S) was obtained from the Protein Database (PDB). Structural optimization was performed using Discovery Studio 2.5 software—missing residues were filled in, the hydrogen bond network was optimized, and key catalytic residues were protonated at physiological pH 7.4 using the ProtonateProtein tool. Based on the characteristics of natural inhibitors (hydroxyl / aromatic ring / positively charged group), a virtual peptide library targeting the active pocket of DPP-IV was constructed using the Peptide Designer module. The binding mode was verified using molecular docking (AutoDock), and the hydrogen bond network (≥3 stable hydrogen bonds) and hydrophobic interactions between the peptide and the target were analyzed to ensure that the binding free energy (ΔG) was significantly lower than the threshold (e.g., <-7.0 kcal / mol). Finally, combined with bioactivity prediction (Peptide Ranker>0.5) and toxicity assessment (ToxinPred), a novel inhibitory peptide sequence with high affinity and low toxicity was successfully designed.

[0049] Using computer-aided drug design combined with molecular docking technology, a peptide with DPP-IV inhibitory potential, sequence LAFPGSW, was designed from a peptide library. Based on molecular docking analysis, the docking affinity (binding energy) between the active peptide and DPP-IV protein crystal was -10.1 kcal / mol, indicating that it has good binding affinity and stable binding ability to DPP-IV. Further analysis of the binding sites and interactions between the active peptide and α-glucosidase, as shown in Figure 1, revealed that LAFPGSW(D1) interacts with DPP-IV at Tyr547, Ser630, Tyr631, Tyr662, Tyr666, Asn710, Val711, His740, and Glu205 via hydrogen bonds, van der Waals forces, and π-stacking within the active peptide docking cassette. Furthermore, according to bioinformatics predictions, the bioactivity of the peptide is 0.868157, and the toxicity prediction using the ToxinPred online tool shows that none of the peptides are toxic, indicating that the designed bioactive peptides have application potential and a certain degree of biosafety.

[0050] 2. Synthesis of bioactive peptides

[0051] The peptide sequence was synthesized in vitro using the Fmoc solid-phase method, following the C-terminal to N-terminal sequence. A dried crude peptide was prepared through amino acid ligation, peptide chain ligation, and peptide chain shearing. The chemically synthesized crude peptide was purified and analyzed using high-performance liquid chromatography coupled with high-resolution mass spectrometry. The purification conditions were as follows: mobile phase A was a 0.065% (v / v) trifluoroacetic acid aqueous solution in pure water; mobile phase B was a 0.05% (v / v) trifluoroacetic acid solution dissolved in acetonitrile; total flow rate: 1 ml / min; detection wavelength: 220 nm. The peptide synthesis was performed at GenScript Inc.

[0052] 3. Inhibition experiment of DPPⅣ active peptide

[0053] First, the peptide sample was dissolved in 100 mM Tris-HCl buffer (pH 8.0) to prepare a 1 mg / mL stock solution, which was then serially diluted to five test concentrations (62.5–1000 μg / mL). The substrate was 1.6 mM Gly-Pro-pNA solution (prepared with the same buffer), and the DPP-IV enzyme solution concentration was 0.01 U / mL. All components were equilibrated at 37°C for 30 minutes before the experiment. The total reaction volume was 100 μL: 25 μL of substrate and 25 μL of sample (or buffer substitute) were added sequentially, followed by 50 μL of enzyme solution. The mixture was incubated at 37°C for 60 minutes. Three control groups were set up: sample group (containing peptide + substrate + enzyme), control group (buffer substitute for peptide), and blank group (buffer substitute for enzyme, substrate volume made up with buffer). After the reaction was terminated, the absorbance (OD value) was measured at 405 nm. The activity was calculated using the formula: Inhibition rate (%) = [(OD_control group - OD_sample group) / (OD_control group - OD_blank group)] × 100%. The data were fitted using a dose-response-inhibition model with GraphPad Prism 10 to finally calculate the IC50 of the peptide. 50 value.

[0054] As shown in Table 1 and Figure 2, the purity of the active peptide is 97.58%. As shown in Figure 3, the mass spectrometry analysis of the DPPⅣ inhibitory peptide indicates a molecular weight of 776.5 Da, suitable for in vitro and in vivo experiments. The in vitro activity assay results are shown in Figure 4, with its IC50 value... 50 It was 183.5 μg / mL.

[0055] Table 1. Peak list of LAFPGSW high performance liquid chromatography

[0056]

[0057] Example 2 Preparation of Polysaccharides from Mushroom Pleurotus ostreatus

[0058] 100 g of dried Agaricus bisporus powder was mixed with 2 vL of distilled water and heated at 90 °C with magnetic stirring for 3 h. The mixture was filtered, and the filtrate was collected. This process was repeated twice. The filtrates were then combined, concentrated under reduced pressure, and an equal volume of 100% (v / v) ethanol was added. The mixture was centrifuged at 4 °C for 12 h and then centrifuged at 4000 × g for 20 min to obtain a precipitate. The precipitate was washed with ethanol (76%, v / v). Proteins were removed first using the Sevage method, and small molecules were removed by dialysis. After purification by DEAE-cellulose 52 column chromatography (4 cm × 19 cm), Agaricus bisporus polysaccharide was obtained by freeze-drying.

[0059] Example 3: Test on the alleviating effect of Agaricus bisporus polysaccharide and polypeptide complex on diabetic mice.

[0060] Experimental approach: A type 2 diabetes mellitus (T2DM) mouse model (fasting blood glucose ≥11.1 mmol / L) was induced using a high-fat diet combined with STZ injection (60 mg / kg bw). Mice were randomly divided into six groups: model group, polypeptide group (200 mg / kg), ABP group (200 mg / kg), complex group (ABP:polypeptide = 1:1, 200 mg / kg), acarbose group, and control group. Mice were administered the medication via gavage for 28 consecutive days, with body weight and fasting blood glucose monitored weekly. An oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) were performed before the end of the experiment. After the last administration, serum samples were collected to measure blood glucose, insulin, liver function (AST / ALT), and lipid levels. Liver and pancreas were harvested for HE staining and pathological analysis.

[0061] 1. Establishment of a mouse model of type 2 diabetes mellitus (T2DM)

[0062] Six-week-old C57BL / 6J mice were purchased and acclimatized for 7 days under laboratory conditions (22±2 °C, 50±5%, 12h light / dark cycle). After 7 days, the mice were divided into two groups: one group was fed a conventional diet as the control group (NC), and the other group was fed a high-fat diet to induce a type 2 diabetes mellitus (T2DM) model as the experimental group. After 6 weeks of high-fat diet, the experimental group mice were fasted for 12 hours but allowed free water, and then received three consecutive intraperitoneal injections of streptozotocin (STZ, 60 mg / kg bw). The control group received an equal volume of citrate buffer. Three days after STZ injection, the mice were fasted for 12 hours but allowed free water, and blood glucose levels were measured by tail blood sampling. Mice with fasting blood glucose (FBG) ≥11.1 mmol / L were selected and continued to be fed for another week. The remaining mice with blood glucose levels below the target were again intraperitoneally injected with STZ (70 mg / kg bw). Mice with FBG ≥11.1 mmol / L were designated as T2DM model mice. T2DM model mice were fed a high-fat diet throughout the experimental period.

[0063] 2. Grouping and administration of experimental animals

[0064] Mice with established T2DM models were randomly divided into 5 groups using a randomized grouping method: diabetes group (model group), DPPⅣ inhibitory peptide intervention group (DPPⅣ inhibitory peptide group), *Tricholoma matsutake* polysaccharide intervention group (*Tricholoma matsutake* polysaccharide group), DPPⅣ inhibitory peptide-*Tricholoma matsutake* polysaccharide complex intervention group (complex group), and acarbose group (positive control). Mice fed with conventional diet served as a blank control group.

[0065] (1) Blank control group: The same amount of physiological saline was administered by gavage daily;

[0066] (2) Model group: The same amount of physiological saline was administered by gavage daily;

[0067] (3) Acarbose group: Acarbose was administered by gavage at a dose of 200 mg / kg·bw;

[0068] (4) DPPⅣ inhibitory peptide group: DPPⅣ inhibitory peptide group prepared by gavage in Example 1, at a dose of 200 mg / kg·bw;

[0069] (5) Twin mushroom polysaccharide group: Twin mushroom polysaccharide prepared by gavage in Example 2, at a dose of 200 mg / kg·bw;

[0070] (6) Complex group: Agaricus bisporus polypeptide and DPPⅣ inhibitory peptide were compounded at a mass ratio of 1:1 and administered by gavage at a dose of 200 mg / kg·bw.

[0071] Mice were allowed free access to food and water during the rearing period. Body weight and fasting blood glucose (FBG) were recorded every 7 days. For 12 hours prior to body weight and FBG measurements, mice were fasted but allowed free water. On day 28, after 12 hours of fasting but with free water, blood was collected from the eyeballs and placed in ice-cold blood collection tubes. The tubes were kept on ice for half an hour, then centrifuged at 4°C (1000 g / min, 10 min). The supernatant serum was aliquoted and frozen at -80°C for later use. After blood collection, mice were euthanized by cervical dislocation. The liver, kidneys, pancreas, and other tissues were rapidly dissected. A portion was rapidly frozen in liquid nitrogen and stored at -80°C for later use, while the other portion was preserved in 4% paraformaldehyde for histological analysis.

[0072] 3. Indicator Testing Methods

[0073] 3.1 Fasting blood glucose measurement

[0074] Before the experiment, mice were fasted for 6 hours (with free access to water). Blood glucose levels were measured using a portable blood glucose meter via tail tip sampling. Before blood collection, the tail tip was wiped to avoid contamination, and the tail was gently pressed to promote blood flow. A small amount of whole blood (approximately 1 μL) was dropped into the test strip's detection area, and a stable reading (unit: mg / dL) was recorded. Each group was measured three times, and the average value was taken. Standards were simultaneously used to calibrate the instrument to ensure data reliability.

[0075] 3.2 Glucose tolerance test

[0076] Before the experiment, mice were fasted for 6 hours (with free access to water) and administered 20% glucose solution by gavage at a dose of 2 g / kg body weight. Blood glucose levels were measured by tail tip blood sampling before administration (0 min) and at 15, 30, 60, 90, and 120 min after administration. Data were recorded using a blood glucose meter (calibrated daily), and the area under the curve (AUC) was calculated to assess glucose tolerance.

[0077] 3.3 Insulin Tolerance Test

[0078] Before the experiment, mice were fasted for 4 hours (with free access to water) and injected intraperitoneally with conventional human insulin (0.75 U / kg body weight). Blood glucose levels were measured by tail tip blood sampling before injection (0 min) and at 15, 30, 60, 90, and 120 min after injection. Data were recorded using a calibrated blood glucose meter, and insulin sensitivity was assessed by area under the curve (AUC).

[0079] 3.4 HE staining of tissues

[0080] Fresh liver and pancreatic tissues were fixed overnight in 4% fixative, dehydrated sequentially with ethanol (50%, 75%, and 95%), and embedded in paraffin. After dewaxing and hydration, the tissue sections were stained with hematoxylin and eosin (H&E), and images were captured using an optical microscope for morphological examination (scale bar 50 μm).

[0081] 3.5 Liver function index measurement

[0082] Mouse blood samples were collected into anticoagulant tubes and incubated at 4°C for 4 h. The samples were then centrifuged at 1000g for 15 min at 4°C. The supernatant was aliquoted and stored at -20°C. 50 mg of liver tissue was accurately weighed and added to 500 μL of PBS. A 10% tissue homogenate (w / v) was prepared under ice-water bath conditions. The homogenate was centrifuged at 2500 rpm for 10 min at 4°C. The supernatant was aliquoted and stored at −20°C for further analysis. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were measured using commercially available kits.

[0083] 3.6 Serum marker determination

[0084] The levels of the corresponding indicators in serum were detected using triglyceride assay kits, total cholesterol assay kits, high-density lipoprotein assay kits, and low-density lipoprotein assay kits.

[0085] 4. Test Results

[0086] As shown in Figure 5A, the body weight of diabetic mice (model group) was significantly lower than that of the control group. The acarbose, DPP-IV inhibitory peptide, twin mushroom polysaccharide and complex groups could significantly restore the body weight of diabetic mice. Among them, the complex group had a better effect on improving the body weight of diabetic mice than acarbose. Moreover, the recovery level of the complex group was significantly higher than that of the two single-component intervention groups, the DPP-IV inhibitory peptide group and the twin mushroom polysaccharide group, indicating that the DPP-IV inhibitory peptide and twin mushroom polysaccharide have a synergistic effect in improving the weight loss caused by diabetes.

[0087] As shown in Figures 5B and 5C, compared with the normal control group, diabetic mice exhibited polydipsia and polyphagia. Acarbose, DPP-IV inhibitory peptide, twin mushroom polysaccharide, and the complex group could all alleviate this phenomenon to some extent. Among them, the improvement effect of the complex was significantly better than that of twin mushroom polysaccharide and DPP-IV inhibitory peptide, indicating that DPP-IV inhibitory peptide and twin mushroom polysaccharide have a synergistic effect in alleviating polydipsia and polyphagia induced by diabetes.

[0088] As shown in Figure 5D, the fasting blood glucose level of diabetic mice was significantly higher than that of the normal control group. DPPⅣ inhibitory peptide and button mushroom polysaccharide could reduce the fasting blood glucose level of diabetic mice to a certain extent. The complex group and acarbose group could significantly reduce the fasting blood glucose of diabetic mice. Among them, the improvement effect of the complex group was better than that of acarbose, and significantly better than that of the DPPⅣ inhibitory peptide group and the button mushroom polysaccharide group, indicating that DPPⅣ inhibitory peptide and button mushroom polysaccharide have a synergistic effect in reducing blood glucose.

[0089] As shown in Figures 5E and 5H, insulin tolerance in diabetic mice was severely impaired. The acarbose group, DPP-IV inhibitory peptide, button mushroom polysaccharide, and the complex could significantly improve insulin tolerance in diabetic mice. Among them, the complex showed better improvement than DPP-IV inhibitory peptide and button mushroom polysaccharide, indicating that DPP-IV inhibitory peptide and button mushroom polysaccharide have a synergistic effect in improving insulin tolerance.

[0090] As shown in Figures 5F and 5G, glucose tolerance in diabetic mice was severely impaired. The acarbose group, DPPⅣ inhibitory peptide, button mushroom polysaccharide, and the complex could improve glucose tolerance in diabetic mice. Among them, the complex showed a significantly better improvement effect than DPPⅣ inhibitory peptide and button mushroom polysaccharide, indicating that DPPⅣ inhibitory peptide and button mushroom polysaccharide have a synergistic effect in improving glucose tolerance.

[0091] As shown in Figure 5I, the serum alanine aminotransferase (ALT) level in the diabetic group was higher than that in the normal control group. Acarbose, DPP-IV inhibitory peptide, button mushroom polysaccharide, and the complex significantly reduced serum ALT levels. The complex was significantly more effective than acarbose, DPP-IV inhibitory peptide, and button mushroom polysaccharide, indicating a synergistic effect between DPP-IV inhibitory peptide and button mushroom polysaccharide in reducing serum ALT levels. As shown in Figure 5J, the serum aspartate aminotransferase (AST) level in the diabetic group was significantly higher than that in the control group. Acarbose, DPP-IV inhibitory peptide, button mushroom polysaccharide, and the complex significantly reduced serum AST levels. The complex also showed a better improvement effect than acarbose to some extent, and significantly better than DPP-IV inhibitory peptide and button mushroom polysaccharide, indicating a synergistic effect between DPP-IV inhibitory peptide and button mushroom polysaccharide in reducing serum AST levels.

[0092] As shown in Figure 5K, the serum total cholesterol level of diabetic mice was significantly higher than that of the control. Acarbose, DPP-IV inhibitory peptide, button mushroom polysaccharide and the complex could significantly reduce the serum total cholesterol level, and the improvement effect of the complex was significantly better than that of DPP-IV inhibitory peptide, acarbose and button mushroom polysaccharide, indicating that DPP-IV inhibitory peptide and button mushroom polysaccharide have a synergistic effect in reducing serum total cholesterol level.

[0093] As shown in Figure 5L, the serum triglyceride level in diabetic mice was higher than that in the normal control group. Acarbose, DPP-IV inhibitory peptide, button mushroom polysaccharide and the complex could significantly reduce the serum triglyceride level in diabetic mice, and the improvement effect of the complex was better than that of the acarbose group, button mushroom polysaccharide and DPP-IV inhibitory peptide, indicating that DPP-IV inhibitory peptide and button mushroom polysaccharide have a synergistic effect in reducing serum triglycerides.

[0094] As shown in Figure 5M, the serum high-density lipoprotein (HDL) level in diabetic mice was significantly lower than that in the normal control group. The complex significantly restored serum HDL levels, and the improvement effect was significantly higher than that of the acarbose group, DPPⅣ inhibitory peptide, and button mushroom polysaccharide, indicating that DPPⅣ inhibitory peptide and button mushroom polysaccharide have a synergistic effect in improving serum HDL levels.

[0095] As shown in Figure 5N, the low-density lipoprotein (LDL) level in diabetic mice was significantly higher than that in the normal control group. Acarbose, DPP-IV inhibitory peptide, button mushroom polysaccharide, and the complex significantly reduced serum LDL levels, and the complex showed better improvement than acarbose, DPP-IV inhibitory peptide, and button mushroom polysaccharide, indicating that DPP-IV inhibitory peptide and button mushroom polysaccharide have a synergistic effect in reducing serum LDL levels.

[0096] As shown in Figure 6, the hepatocytes of the normal control group mice were normal in morphology and size, and the liver tissue structure was intact. In contrast, the hepatocytes of diabetic mice were swollen, enlarged, and structurally disordered, with indistinct nuclei and numerous vacuoles of varying sizes around them. Gavage administration of acarbose, DPP IV inhibitory peptide, button mushroom polysaccharide, and the complex showed some improvement in the liver of diabetic mice. The complex significantly reduced vacuoles around the nuclei, and the hepatocyte structure tended to be normal. Compared to the normal group, the pancreatic tissue of the diabetic group showed severe atrophy and degeneration of the islets, with irregular shapes, indistinct boundaries, fewer insulin cells, and irregular and loosely arranged peripheral β cells. After intervention with acarbose, DPP IV inhibitory peptide, button mushroom polysaccharide, and the complex, the damage to the pancreatic tissue was alleviated to varying degrees. The recovery of the pancreatic tissue in the complex and acarbose groups was close to that in the normal group, with a significant increase in islet area and number of islet cells, and intact structure with clear boundaries.

[0097] In summary, the DPPⅣ inhibitory peptide and the button mushroom polysaccharide complex can improve the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and hepatocytes, indicating that the DPPⅣ inhibitory peptide and button mushroom polysaccharide can effectively and synergistically improve liver damage caused by diabetes. The DPPⅣ inhibitory peptide and the button mushroom polysaccharide complex can improve the dyslipidemia in diabetic mice by reducing serum total cholesterol, serum triglyceride, and low-density lipoprotein levels and increasing serum high-density lipoprotein levels. The DPPⅣ inhibitory peptide and the button mushroom polysaccharide can synergistically alleviate the condition of diabetes by improving the body weight, food intake, water intake, blood glucose, blood lipids, glucose tolerance, insulin tolerance, and target organ damage in mice.

[0098] The embodiments described above are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

Claims

1. A composition for maintaining healthy blood glucose levels, characterized in that, The composition comprises a DPPⅣ inhibitory peptide and a button mushroom polysaccharide, wherein the sequence of the DPPⅣ inhibitory peptide is LAFPGSW, and the mass ratio of the DPPⅣ inhibitory peptide to the button mushroom polysaccharide is 1:

1.

2. A product, characterized in that, The product includes the composition of claim 1, the product is a pharmaceutical product, and also includes pharmaceutically acceptable excipients.

3. The use of the composition of claim 1 in the preparation of a product for maintaining healthy blood glucose levels in patients with type II diabetes, wherein the product is a pharmaceutical product.

4. The use of the composition of claim 1 in the preparation of a product for treating type II diabetes, wherein the product is a pharmaceutical product.

5. The application according to claim 4, characterized in that, The applications include at least one of the following: (1) application in the preparation of products for lowering blood sugar; (2) application in the preparation of products for improving glucose tolerance; (3) application in the preparation of products for improving insulin tolerance; (4) application in the preparation of products for improving weight loss caused by type II diabetes; (5) application in the preparation of products for alleviating polydipsia and polyphagia induced by type II diabetes; (6) application in the preparation of products for improving pancreatic damage induced by type II diabetes; and (7) application in the preparation of products for improving liver damage caused by type II diabetes.

6. The application according to claim 5, characterized in that, The application in the preparation of products that improve liver damage caused by type II diabetes includes at least one of the following: (1) application in the preparation of products that reduce serum alanine aminotransferase levels; (2) application in the preparation of products that reduce serum aspartate aminotransferase levels.

7. The use of the composition of claim 1 in the preparation of a product for improving dyslipidemia in patients with type II diabetes, wherein the product is a pharmaceutical product.

8. The application according to claim 7, characterized in that, The application includes at least one of the following: (1) application in the preparation of a product that lowers serum total cholesterol levels; (2) application in the preparation of a product that lowers serum triglyceride levels; (3) application in the preparation of a product that increases serum high-density lipoprotein levels; and (4) application in the preparation of a product that lowers serum low-density lipoprotein levels.

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