Agent for suppressing decrease in concentration, and agent for alleviating sleepiness

Abstract

The present invention addresses the problem of providing: a novel agent for suppressing decrease in concentration and a novel agent for alleviating sleepiness, each of which contains a component that has not been previously known to be effective in suppressing decrease in concentration and alleviating sleepiness. The present invention provides: an agent for suppressing decrease in concentration, which contains a mulberry-derived component; an agent for alleviating sleepiness, which contains a mulberry-derived component; an agent for suppressing decrease in concentration, which contains a plant-derived component having an effect to suppress increase in a blood glucose level; and an agent for alleviating sleepiness, which contains a plant-derived component having an effect to suppress increase in a blood glucose level.

Description

Concentration suppressant and drowsiness reducer

[0001] The present invention relates to an agent for suppressing decline in concentration and an agent for reducing drowsiness.

[0002] Concentration is important in many areas, including work, learning, exercise, and various tasks. There are various training methods to improve concentration, such as mental training, but improving concentration requires sufficient time.

[0003] Patent Document 1 discloses a composition for improving mental concentration during exercise. However, Patent Document 1 merely discloses that theanine, an amino acid component, is effective for improving mental concentration during exercise.

[0004] JP 2002-322053 JP 2021-137008 JP 2023-110462 JP 2002-65207

[0005] In one embodiment, an object of the present invention is to provide a novel agent for suppressing decline in concentration, which contains a component not previously known to have an effect of suppressing decline in concentration. Also, in another embodiment, an object of the present invention is to provide a novel agent for reducing drowsiness, which contains a component not previously known to have an effect of reducing drowsiness.

[0006] Under these circumstances, the present inventors conducted extensive trial and error with various ingredients and discovered that ingesting mulberry extract to a subject can suppress decline in concentration and alleviate drowsiness. The present invention is based on this novel finding. Accordingly, the present invention provides the following: Item 1. An agent for suppressing decline in concentration, comprising a mulberry-derived component.

[0007] Item 2. A drowsiness relief agent containing a mulberry-derived ingredient.

[0008] Item 3. The agent according to Item 1 or 2, which contains 0.1 mg to 100 mg of a mulberry-derived component in terms of iminosugar.

[0009] Item 4. The agent according to any one of Items 1 to 3, wherein the mulberry-derived component is a mulberry extract.

[0010] Item 5. The agent according to Item 4, wherein the mulberry extract is a mulberry leaf extract or a mulberry fruit extract.

[0011] Item 6. An agent for suppressing decline in concentration, comprising a plant-derived ingredient having an effect of suppressing an increase in blood sugar level.

[0012] Item 7. A drowsiness reducer comprising a plant-derived ingredient having an effect of suppressing an increase in blood glucose level.

[0013] Item 8. The agent according to Item 6 or 7, wherein the plant-derived component having an effect of suppressing an increase in blood glucose level includes water-soluble dietary fiber.

[0014] Item 9. The agent according to any one of Items 6 to 8, wherein the plant-derived component having an effect of suppressing an increase in blood glucose level includes deoxynojirimycin.

[0015] Item 10. The agent according to any one of Items 6 to 9, wherein the plant-derived component having an effect of suppressing an increase in blood glucose level includes iminosugar.

[0016] Item 11. The agent according to any one of Items 1 to 10, which is a food product.

[0017] Item 12. Use of a mulberry-derived ingredient for producing an agent for suppressing decline in concentration.

[0018] Item 13. Use of a mulberry-derived ingredient for producing an agent for reducing drowsiness.

[0019] Item 14. The use according to Item 12, wherein the agent for suppressing decline in concentration contains 0.1 mg to 100 mg of a mulberry-derived component in terms of iminosugar.

[0020] Item 15. The use according to Item 13, wherein the drowsiness-reducing agent contains 0.1 mg to 100 mg of a mulberry-derived component in terms of iminosugar.

[0021] Item 16. The use according to any one of Items 12 to 14, wherein the mulberry-derived ingredient is a mulberry extract.

[0022] Item 17. The use according to Item 16, wherein the mulberry extract is a mulberry leaf extract or a mulberry fruit extract.

[0023] Item 18. Use of a plant-derived ingredient having an effect of suppressing an increase in blood sugar level for the production of an agent for suppressing a decrease in concentration.

[0024] Item 19. Use of a plant-derived ingredient having an effect of suppressing an increase in blood glucose level for the production of an agent for reducing drowsiness.

[0025] Item 20. The use according to Item 17 or 18, wherein the plant-derived component having an effect of suppressing an increase in blood glucose level includes water-soluble dietary fiber.

[0026] Item 21. The use according to any one of Items 17 to 20, wherein the plant-derived component having an effect of suppressing an increase in blood glucose level includes deoxynojirimycin.

[0027] Item 22. The use according to any one of Items 17 to 21, wherein the plant-derived component having an effect of suppressing an increase in blood glucose level includes iminosugar.

[0028] Item 23. The use according to any one of Items 12, 14, 16 to 18, and 20 to 22, wherein the agent for suppressing decline in concentration is a food product.

[0029] Item 24. The use according to any one of Items 13, 15 to 17, and 19 to 22, wherein the drowsiness-reducing agent is a food product.

[0030] Item 25. A method for suppressing a decline in concentration, comprising administering a mulberry-derived component to a subject.

[0031] Item 26. A method for reducing drowsiness, comprising administering a mulberry-derived component to a subject.

[0032] Item 27. The method according to Item 25, comprising administering to a subject an agent for suppressing decline in concentration, which contains 0.1 mg to 100 mg of a mulberry-derived component in terms of iminosugar.

[0033] Item 28. The method according to Item 26, comprising administering to a subject a drowsiness-reducing agent containing 0.1 mg to 100 mg of a mulberry-derived component in terms of iminosugar.

[0034] Item 29. The method according to any one of Items 25 to 28, wherein the mulberry-derived component is a mulberry extract.

[0035] Item 30. The method according to Item 29, wherein the mulberry extract is a mulberry leaf extract or a mulberry fruit extract.

[0036] Item 31. A method for suppressing a decrease in concentration, comprising administering to a subject a plant-derived component having an effect of suppressing an increase in blood glucose level.

[0037] Item 32. A method for reducing drowsiness, comprising administering to a subject a plant-derived component having an effect of suppressing an increase in blood glucose level.

[0038] Item 33. The method according to Item 31 or 32, wherein the plant-derived component having an effect of suppressing an increase in blood glucose level comprises water-soluble dietary fiber.

[0039] Item 34. The method according to any one of Items 31 to 33, wherein the plant-derived component having an effect of suppressing an increase in blood glucose level comprises deoxynojirimycin.

[0040] Item 35. The method according to any one of Items 31 to 34, wherein the plant-derived component having an effect of suppressing an increase in blood glucose level comprises iminosugar.

[0041] Item 36. The method according to any one of Items 25 to 30, which comprises administering to the subject a food product containing a mulberry-derived component.

[0042] Item 37. The method according to any one of Items 31 to 36, comprising administering to the subject a food product containing a plant-derived component that has an effect of suppressing an increase in blood glucose level.

[0043] In one embodiment, the present invention can provide a novel agent for suppressing decline in concentration, which contains a component whose effect of suppressing decline in concentration has not been known until now. Also, in one embodiment, the present invention can provide a novel agent for suppressing drowsiness, which contains a component whose effect of suppressing drowsiness has not been known until now.

[0044] 1 shows an outline of the test schedule in the examples. 2 shows an outline of the area for gaze confirmation in the eye tracking test. (a) shows details of the screen presented to the test subject. (b) shows the area for gaze confirmation. 3 shows the results (fixation time) of the eye tracking test in Example 1. 4 shows the results (eye opening) of the eye tracking test in Example 1. 5 shows the results (fixation time) of the eye tracking test in Example 2. 6 shows the results (eye opening) of the eye tracking test in Example 2. 7 shows the results (fixation time) of the eye tracking test in Example 3. 8 shows the results (eye opening) of the eye tracking test in Example 3.

[0045] The present invention provides an agent for inhibiting decline in concentration, which comprises a component derived from mulberry. The effect of inhibiting decline in concentration in the present invention can be evaluated, for example, by the method described in the examples of the present application.

[0046] Mulberry-derived components are not particularly limited as long as they are derived from mulberry, and examples include mulberry extract, mulberry juice, and dried or crushed mulberry leaves. Examples of mulberry extract include mulberry leaf extract and mulberry extract, with mulberry leaf extract being preferred. These mulberry-derived components may be used alone or in combination of two or more. The varieties, production areas, harvest times, etc. of mulberry leaves, mulberry, mulberry stalks, mulberry roots, etc. used as extraction raw materials are not particularly limited. Furthermore, mulberry leaves, mulberry, mulberry stalks, mulberry roots, etc., used as extract raw materials, may be subjected to processing such as shredding or crushing. Mulberry leaf extracts obtained using common methods for extracting extracts from plants can be used. Commercially available mulberry leaf extracts can also be used. For example, mulberry leaves can be extracted with water containing 0 to 30% by mass of alcohol. Extraction conditions can be adjusted appropriately within the range typically used for plant extract extraction. Commercially available mulberry leaf extracts can be used as is. Alternatively, extracts obtained by the method described in Patent Document 2, for example, can also be used. More specifically, for example, mulberry leaf extract can be obtained by a method comprising the following steps 1 and 2. Step 1: A step of extracting mulberry leaves with water containing 0 to 30% by mass of a lower alcohol to obtain an extract having a ratio of absorbance A320 at a wavelength of 320 nm to absorbance A300 at a wavelength of 300 nm (A320 / A300) of 0.97 or less. Step 2: A step of subjecting the extract obtained in Step 1 to an activated carbon treatment.

[0047] The mulberry extract is not particularly limited, and can be obtained by a general method for producing concentrated fruit juice. Specifically, examples of the method for producing concentrated fruit juice include the method described in Figure II.A.2.1 of "Encyclopedia of Fruit Juices and Fruit Drinks (Asakura Publishing), edited by the Japan Fruit Juice Association, first edition, October 1, 1997."

[0048] The mulberry juice is not particularly limited, and can be produced using a general method for producing fruit juice. Specifically, the mulberry juice can be produced in the same manner as the method described in the above-mentioned "Encyclopedia of Fruit Juices and Fruit Drinks," except that the concentration step is not performed.

[0049] Examples of dried or pulverized mulberry leaves include mulberry leaf powder and mulberry tea leaves. Mulberry leaf powder and mulberry tea leaves can be produced using a general method for producing plant powders and tea leaves. Mulberry leaf powder can be produced by drying and pulverizing mulberry leaves. For example, it can be produced using the method described in "Iwate Prefectural Sericulture Experiment Station Bulletin No. 17, pp. 60-65 (1994)." Furthermore, mulberry tea leaves can be produced using a method used for producing ordinary tea leaves. For example, it can be produced by shredding fresh mulberry leaves, steaming them, rolling them, and drying them.

[0050] In the present invention, the mulberry-derived component, which is the active ingredient of the present invention, may be used as an agent for suppressing decline in concentration itself, or the mulberry-derived component may be used as a composition in which the mulberry-derived component is combined with various carriers that are pharmaceutically acceptable or can be added to foods (e.g., isotonicity agents, chelating agents, stabilizers, pH adjusters, preservatives, antioxidants, solubilizers, thickeners, excipients, binders, etc.). In this embodiment, the content of the mulberry-derived component in the composition for suppressing decline in concentration is not limited and can be set appropriately within the range of 0.0001% by mass to 100% by mass. For example, 0.0001 mass% or more, 0.0005 mass% or more, 0.001 mass% or more, 0.005 mass% or more, 0.01 mass% or more, 0.05 mass% or more, 0.1 mass% or more, 0.5 mass% or more, 1 mass% or more, 3 mass% or more, 5 mass% or more, 7 mass% % or more, 10 mass% or more, 15 mass% or more, 20 mass% or more, 30 mass% or more, 40 mass% or more, 50 mass% or more, 60 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, 95 mass% or more, 99 mass% or more. The upper limit of the content of the mulberry-derived component is not limited, and can be, for example, 100% by mass, or can be set appropriately within ranges such as 99% by mass or less, 95% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, 7% by mass or less, 5% by mass or less, 3% by mass or less, 1% by mass or less, or 0.1% by mass or less.

[0051] Examples of the isotonicity agent include sugars such as glucose, trehalose, lactose, fructose, mannitol, xylitol, and sorbitol, polyhydric alcohols such as glycerin, polyethylene glycol, and propylene glycol, and inorganic salts such as sodium chloride, potassium chloride, and calcium chloride. These isotonicity agents can be used alone or in combination of two or more.

[0052] Examples of the chelating agent include edetate salts such as disodium edetate, calcium disodium edetate, trisodium edetate, tetrasodium edetate, and calcium edetate, ethylenediaminetetraacetate, nitrilotriacetic acid or a salt thereof, sodium hexametaphosphate, citric acid, etc. These chelating agents may be used alone or in combination of two or more.

[0053] The stabilizer may, for example, be sodium hydrogen sulfite.

[0054] Examples of pH adjusters include acids such as hydrochloric acid, carbonic acid, acetic acid, and citric acid, as well as alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates or hydrogen carbonates such as sodium carbonate, alkali metal acetates such as sodium acetate, alkali metal citrates such as sodium citrate, and bases such as trometamol. These pH adjusters can be used alone or in combination of two or more.

[0055] Examples of preservatives include sorbic acid, potassium sorbate, parahydroxybenzoic acid esters such as methyl parahydroxybenzoate, ethyl parahydroxybenzoate, propyl parahydroxybenzoate, and butyl parahydroxybenzoate, quaternary ammonium salts such as chlorhexidine gluconate, benzalkonium chloride, benzethonium chloride, and cetylpyridinium chloride, alkylpolyaminoethylglycine, chlorobutanol, polyquad, polyhexamethylene biguanide, and chlorhexidine. These preservatives can be used alone or in combination of two or more.

[0056] Examples of antioxidants include sodium hydrogen sulfite, dry sodium sulfite, sodium pyrosulfite, concentrated mixed tocopherols, etc. These antioxidants may be used alone or in combination of two or more.

[0057] Examples of solubilizing agents include sodium benzoate, glycerin, D-sorbitol, glucose, propylene glycol, hydroxypropylmethylcellulose, polyvinylpyrrolidone, macrogol, D-mannitol, etc. These solubilizing agents can be used alone or in combination of two or more.

[0058] Examples of thickeners include polyethylene glycol, methyl cellulose, ethyl cellulose, carmellose sodium, xanthan gum, sodium chondroitin sulfate, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, polyvinylpyrrolidone, polyvinyl alcohol, etc. These thickeners may be used alone or in combination of two or more.

[0059] Examples of excipients include lactose, corn starch, L-cysteine, trehalose, maltitol, sorbitol, etc. These excipients may be used alone or in combination of two or more.

[0060] Examples of binders include crystalline cellulose, starch, sucrose, hydroxypropyl cellulose, gelatin, powdered gum arabic, polyvinylpyrrolidone, pullulan, dextrin, cyclodextrin, methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, polyvinyl alcohol, polyethylene glycol, etc. These binders can be used alone or in combination of two or more.

[0061] In addition to the mulberry-derived component, the composition may further contain a substance known to have an effect of suppressing decline in concentration. Examples of substances known to have an effect of suppressing decline in concentration include theobromine, ginkgo leaf-derived flavonoid glycosides, and ginkgo leaf-derived terpene lactones. These substances may be used alone or in combination of two or more.

[0062] The mulberry-derived component preferably contains an iminosugar. In a preferred embodiment, examples of the iminosugar include 1-deoxynojirimycin (DNJ), fagomine, and 2-O-α-D-galactopyranosyl-1-deoxynojirimycin (GAL-DNJ). A particularly preferred component is deoxynojirimycin. These iminosugars can be used alone or in combination of two or more. In an embodiment containing an iminosugar, the concentration decline suppressant of the present invention preferably contains 0.1 mg to 100 mg of iminosugar, more preferably 0.5 mg to 50 mg, and even more preferably 1.0 mg to 30 mg. Of these, 1.5 mg to 10 mg is even more preferred, and 2 mg to 5 mg is particularly preferred. In an embodiment containing deoxynojirimycin, the concentration decline inhibitor of the present invention preferably has a deoxynojirimycin content of 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, even more preferably 30% by mass or more, and most preferably 50% by mass or more, relative to the total amount of iminosugars contained in the concentration decline inhibitor.

[0063] Ingestion of the concentration decline inhibitor of the present invention by a subject (preferably a mammal such as a human) provides the effect of inhibiting concentration decline. The amount of the concentration decline inhibitor of the present invention to be ingested is not limited, but the amount of the active ingredient, mulberry-derived component, to be ingested per administration is preferably 0.1 mg to 200 mg, more preferably 0.5 mg to 100 mg, and even more preferably 1.0 mg to 60 mg. Of these, 1.5 mg to 20 mg is even more preferred, and 2 mg to 10 mg is particularly preferred. In embodiments containing iminosugar, the amount of the mulberry-derived component to be ingested per administration can be appropriately set, for example, in the range of 0.1 mg to 100 mg, preferably 0.5 mg to 50 mg, more preferably 1.0 mg to 30 mg, especially 1.5 mg to 10 mg, and particularly 2 mg to 5 mg, in terms of iminosugar. Furthermore, the number of times per day to be taken of the concentration decline inhibitor of the present invention is not limited, but can be appropriately set within the range of 1 to 4 times, 1 to 3 times, etc. Furthermore, the concentration decline inhibitor of the present invention may be taken before, during, or after a meal, but is preferably taken before and / or during a meal. If taken before a meal, it is preferably taken within 3 hours of the start of the meal, more preferably within 1 hour. It is even more preferably within 30 minutes, and particularly preferably within 15 minutes. If taken after a meal, it is preferably taken within 3 hours of the end of the meal, more preferably within 1 hour. It is even more preferably within 30 minutes, and particularly preferably within 15 minutes. The number of times of intake is sufficient as long as it is taken at least once at any timing, and it may also be taken multiple times at any timing during the above period. In one embodiment, the present invention may be in the form of an oral composition containing a mulberry-derived component. Accordingly, in this embodiment, the present invention provides an oral composition containing the mulberry-derived component. Oral compositions include food and beverage compositions, pharmaceutical compositions, etc. In the present invention, the food and beverage compositions also include health functional foods (nutrient functional foods, foods for specified health uses, foods with functional claims), etc. Examples of food and beverage compositions include beverages such as tea drinks, vegetable juice drinks, fruit juice drinks, mixed vegetable and fruit juice drinks, fermented milk drinks, and almond-containing drinks; and foods such as ice creams, frozen desserts, almond-containing foods, biscuits, chocolates (including semi-chocolate), and fermented milk foods (yogurt, cheese).In the present invention, among these foods and beverages, beverages such as tea drinks are preferred. The food and beverage compositions of the present invention also include supplements. Supplements are preferably in powder, tablet, or other form. Details of the mulberry-derived component as an active ingredient in an embodiment of the oral composition, its intake amount, etc., are the same as those described above in the description of the concentration decline inhibitor. In this embodiment, the mulberry-derived component content and iminosugar content in the oral composition are also the same as those described above.

[0064] In another embodiment, the present invention provides an agent for suppressing decline in concentration, comprising a plant-derived component having the effect of suppressing an increase in blood glucose level. Examples of plant-derived components having the effect of suppressing an increase in blood glucose level include iminosugars, water-soluble dietary fiber, salacinol, anthocyanins, proanthocyanidins, wheat albumin, 5-aminolevulinic acid phosphate, and GABA. Examples of iminosugars include deoxynojirimycin. Examples of water-soluble dietary fiber include indigestible dextrin, inulin, guar gum hydrolyzate, isomaltodextrin, water-soluble soybean polysaccharides, polydextrose, sodium alginate, psyllium, fucoidan, laminaran, sodium carboxymethylcellulose, pullulan, curdlan, and low-molecular-weight hemicellulose. These plant-derived components may be used alone or in combination of two or more. The effect of these plant-derived components in suppressing an increase in blood glucose level can be evaluated, for example, by the methods described in Patent Document 3 or Patent Document 4. For example, a plant-derived component is preferred that, when administered to humans or mice, significantly suppresses the rise in blood glucose levels compared to humans or mice that have not been administered the plant-derived component.

[0065] In this embodiment, the plant-derived component, which is the active ingredient of the present invention, may be used as an agent for suppressing decline in concentration, or the plant-derived component may be used as a composition in which the plant-derived component is combined with various carriers that are pharmaceutically acceptable or can be added to foods. The types of components to be combined with the plant-derived component, such as various carriers, are the same as those described above. In this embodiment, the content of the plant-derived component in the concentration decline suppressant composition is not limited, and can be appropriately set within ranges such as 0.0001% by mass or more, 0.0005% by mass or more, 0.001% by mass or more, 0.005% by mass or more, 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 3% by mass or more, 5% by mass or more, 7% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 99% by mass or more, etc. The upper limit of the content of the plant-derived component is not limited, but may be, for example, 100% by mass, or may be set appropriately within the range of 99% by mass or less, 95% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, 7% by mass or less, 5% by mass or less, 3% by mass or less, 1% by mass or less, or 0.1% by mass or less. The intake amount of the concentration decline inhibitor of the present invention is not limited, but the amount of the plant-derived component as an active ingredient per administration is preferably, for example, 0.1 mg to 200 mg, more preferably 0.5 mg to 100 mg, and even more preferably 1.0 mg to 60 mg. Of these, 1.5 mg to 20 mg is even more preferred, and 2 mg to 10 mg is particularly preferred. When the plant-derived component contains an iminosugar, the daily intake of the plant-derived component per serving can be appropriately set within the range of, for example, 0.1 mg to 100 mg, preferably 0.5 mg to 50 mg, more preferably 1.0 mg to 30 mg, even more preferably 1.5 mg to 10 mg, and particularly preferably 2 mg to 5 mg, in terms of iminosugar. Examples of iminosugars include 1-deoxynojirimycin (DNJ), fagomine, and 2-O-α-D-galactopyranosyl-1-deoxynojirimycin (GAL-DNJ).Among these, deoxynojirimycin is a particularly preferred component. These iminosugars can be used alone or in combination of two or more. When the plant-derived component contains deoxynojirimycin, the deoxynojirimycin content relative to the total amount of iminosugars is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, even more preferably 30% by mass or more, and most preferably 50% by mass or more. In this embodiment, the number of times per day the agent for suppressing decline in concentration of the present invention is taken is not limited, but can be appropriately set within a range of 1 to 4 times a day, 1 to 3 times a day, etc. In this embodiment, the preferred timing for taking the agent for suppressing decline in concentration of the present invention is the same as that described above.

[0066] Drowsiness Reducing Agent In one embodiment, the present invention provides a drowsiness reducing agent. Specifically, the present invention provides a drowsiness reducing agent, for example, comprising a mulberry-derived component. In one embodiment, the present invention provides a drowsiness reducing agent, for example, comprising a plant-derived component having an inhibitory effect on blood glucose levels. Details of the active ingredients (mulberry-derived component, plant-derived component having an inhibitory effect on blood glucose levels), their intake amounts, intake timing, etc. in the embodiment of the drowsiness reducing agent are the same as those described above in the description of the concentration decline inhibitor. In the present invention, the drowsiness reducing effect can be evaluated, for example, by the method described in the Examples of the present application. In this embodiment, in addition to the mulberry-derived component and the plant-derived component having an inhibitory effect on blood glucose levels, a substance known to have a drowsiness reducing effect may be further contained. Examples of substances known to have a drowsiness reducing effect include caffeine, L-menthol, and mint extract. These substances can be used alone or in combination of two or more.

[0067] Specific embodiments of the present invention will be described in more detail below using examples, but the present invention is not limited to the following examples.

[0068] Example 1 Mulberry Leaf Extract <Eye Tracking Test> Thirty minutes after finishing the test food or control food, subjects underwent an eye tracking test (Figure 1). Subjects were instructed to observe a cross in the center of the screen for 30 minutes, and the subject's gaze position and eye opening were measured using an eye tracker. The time the subject spent looking at the Size 2 and Other areas (areas other than the area around the cross) in Figure 2 was counted as time of loss of concentration, and the percentage of time spent looking at the cross relative to the time spent looking at the screen was calculated. Eye opening was measured by measuring the diameter of the largest sphere that could fit between the upper and lower eyelids, and used as an index of sleepiness.

[0069] <Test Menu> The test food was a solution of mulberry leaf extract (3.6 g, iminosugar content 15.3 mg, DNJ content 7.5 mg) mixed with 340 ml of water, while two rice balls with salt (Seven-Eleven) were ingested over 10 minutes. The mulberry leaf extract was prepared according to the method described in Test Example 1 of Patent Document 2. The control food was a solution of mulberry leaf extract not mixed with mulberry leaf extract, while two rice balls with salt were ingested over 10 minutes. The nutritional values ​​of the rice balls with salt are shown in Table 1.

[0070]

[0071] <Study Overview> - Subjects: Healthy men and women - Number of subjects: 2 - Test method: Open crossover test - Intake period: Single intake Of the two subjects (Subject A and Subject B), Subject A ingested the test food in Intake Period I and the control food in Intake Period II. Subject B ingested the control food in Intake Period I and the test food in Intake Period II (Table 2). Subjects were instructed not to significantly change the contents of their breakfast between the Intake Period I and Intake Period II tests (breakfast should be eaten at least two hours before arrival). They were also instructed not to go to bed beyond their usual bedtime the day before the test.

[0072]

[0073] The results of the eye tracking test are shown in Figures 3 and 4. As shown in Figure 3, when the test food was ingested, compared to when the control food was ingested, the time spent looking at areas other than the area around the cross (areas of Size 2 and Other) was shorter, indicating higher concentration. Of the present examples (Examples 1 to 3), Example 1 had the greatest inhibitory effect on decline. Furthermore, as shown in Figure 4, when the test food was ingested, the eyes were opened wider, indicating suppression of drowsiness, compared to when the control food was ingested.

[0074] Example 2 Mulberry Extract <Eye Tracking Test> Thirty minutes after finishing the test food or control food, subjects underwent an eye tracking test (Figure 1). Subjects were instructed to observe a cross in the center of the screen for 30 minutes, and the subject's gaze position and eye opening were measured using an eye tracker. The time the subject spent looking at the "Other" area in Figure 2 (area other than the area around the cross) was counted as the time when their concentration was lost, and the proportion of time spent looking at the cross relative to the time spent looking at the screen was calculated. Eye opening was measured by measuring the diameter of the largest sphere that could fit between the upper and lower eyelids, and was used as an index of sleepiness.

[0075] <Test Menu> The test food was a solution of mulberry extract (10 g, iminosugar content 15.3 mg, DNJ content 1.2 mg) mixed with 340 ml of water, while two rice balls with salt (Seven-Eleven) were ingested over 10 minutes. The mulberry extract was prepared according to the method described in Figure II.A.2.1 of "Encyclopedia of Fruit Juice and Fruit Drinks (Asakura Publishing), supervised by the Japan Fruit Juice Association, first edition October 1, 1997." The control food was 340 ml of water without mulberry extract, while two rice balls with salt were ingested over 10 minutes. The nutritional values ​​of the rice balls with salt are as shown in Table 1 above.

[0076] <Study Overview> ・Subjects: Healthy men and women ・Number of subjects: 2 ・Test method: Open crossover test ・Intake period: Single intake Two subjects (Subject A and Subject B) were included. Subject A consumed the test food during Intake Period I and the control food during Intake Period II. Subject B consumed the control food during Intake Period I and the test food during Intake Period II (see Table 2 above). Subjects were instructed not to significantly change the breakfast they ate between Intake Period I and Intake Period II (breakfast was consumed at least two hours before arrival). They were also instructed not to sleep past their usual bedtime the day before the test. The results of the eye-tracking test are shown in Figures 5 and 6. As shown in Figure 5, subjects who consumed the test food spent less time looking at areas other than the cross (the "Other" area) compared to those who consumed the control food, demonstrating higher concentration. Furthermore, as shown in Figure 6, subjects who consumed the test food opened their eyes wider, demonstrating reduced drowsiness compared to those who consumed the control food.

[0077] Example 3 Indigestible Dextrin <Eye Tracking Test> Thirty minutes after finishing the test food or control food, subjects underwent an eye tracking test (Figure 1). Subjects were instructed to observe a cross in the center of the screen for 30 minutes, and the subject's gaze position and eye opening were measured using an eye tracker. The time the subject spent looking at the "Other" area in Figure 2 (area other than the area around the cross) was counted as the time when the subject lost concentration, and the proportion of time spent looking at the cross relative to the time spent looking at the screen was calculated. Eye opening was measured by measuring the diameter of the largest sphere that could fit between the upper and lower eyelids, and was used as an index of sleepiness.

[0078] <Test Menu> The test food was a solution of resistant dextrin (25g) mixed with 340ml of water, and two rice balls with salt (Seven-Eleven) were consumed over 10 minutes. The control food was a solution of resistant dextrin (25g) mixed with 340ml of water, and two rice balls with salt (Seven-Eleven) were consumed over 10 minutes. The nutritional values ​​of the rice balls with salt are shown in Table 1 above.

[0079] <Test overview> - Test subjects: Healthy men and women - Number of test subjects: 2 - Test method: Open crossover test - Intake period: Single intake Of the two test subjects (Test subject A and Test subject B), Test subject A took the test food in Intake Period I and the control food in Intake Period II. Test subject B took the control food in Intake Period I and the test food in Intake Period II (Table 2 above). The test subjects were instructed not to significantly change the contents of their breakfast between the Intake Period I test and the Intake Period II test (breakfast should be eaten at least two hours before arrival). They were also instructed not to go to bed beyond their usual bedtime the day before the test.

[0080] The results of the eye tracking test are shown in Figures 7 and 8. As shown in Figure 7, when subjects ingested the test food, they spent less time looking at areas other than the cross (other areas) compared to when they ingested the control food, demonstrating higher concentration. Also, as shown in Figure 8, when subjects ingested the test food, they opened their eyes more widely, demonstrating reduced drowsiness compared to when they ingested the control food.

Claims

1. An agent that prevents loss of concentration and contains ingredients derived from mulberry.

2. A drowsiness-reducing agent that contains ingredients derived from mulberry.

3. The agent according to claim 1 or 2, containing 0.1 mg to 100 mg of mulberry-derived components in terms of iminosugar.

4. The agent according to claim 1 or 2, wherein the mulberry-derived ingredient is a mulberry extract.

5. The agent according to claim 1 or 2, wherein the mulberry-derived ingredient is mulberry leaf extract or mulberry fruit extract.

6. An agent for preventing loss of concentration that contains plant-derived ingredients that have the effect of suppressing blood sugar levels.

7. A drowsiness-reducing agent that contains plant-derived ingredients that have the effect of suppressing blood sugar levels.

8. The agent according to claim 6 or 7, wherein the plant-derived component having the effect of suppressing blood glucose level elevation comprises water-soluble dietary fiber.

9. The agent according to claim 6 or 7, wherein the plant-derived ingredient having the effect of suppressing blood glucose level elevation comprises deoxynojirimycin.

10. The agent according to claim 6 or 7, wherein the plant-derived ingredient having the effect of suppressing blood glucose level elevation comprises iminosugar.

11. The agent according to claim 1, 2, 6 or 7, which is a food product.

12. A method for suppressing a decline in concentration, comprising administering a mulberry-derived ingredient to a subject.

13. A method for reducing drowsiness, comprising administering a mulberry-derived ingredient to a subject.

14. Use of a mulberry-derived ingredient for producing an agent for suppressing concentration decline.

15. Use of a mulberry-derived ingredient for producing an agent for reducing drowsiness.

16. A method for suppressing a decline in concentration, comprising administering to a subject a plant-derived ingredient having the effect of suppressing an increase in blood sugar levels.

17. A method for reducing drowsiness, comprising administering to a subject a plant-derived ingredient having the effect of suppressing blood sugar level elevation.

18. Use of a plant-derived ingredient having an effect of inhibiting an increase in blood sugar level in the manufacture of an agent for inhibiting a decrease in concentration.

19. Use of a plant-derived ingredient having an inhibitory effect on blood sugar levels in the manufacture of an agent for reducing drowsiness.

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