JP7601575B2 - Composition for improving brain function - Google Patents

Description

The present invention relates to a composition for improving brain function that contains a specific peptide as an active ingredient.

It is known that peptides consisting of specific sequences exert various functions when orally ingested.
For example, as disclosed in Patent Documents 1 and 2, tripeptides consisting of Leu-Arg-Ala are known to have various physiological actions. Patent Document 1 discloses a composition containing a tripeptide consisting of Leu-Arg-Ala, which is for improving sugar metabolism, suppressing blood glucose level rise, and antidiabetic. Patent Document 2 discloses a composition containing a tripeptide consisting of Leu-Arg-Ala for lowering blood pressure.

JP 2020-14 A JP 2019-99526 A

The object of the present invention is to provide a composition for improving brain function that has excellent effects in improving brain function.

The inventors conducted research to solve the above problems and discovered that a tripeptide consisting of Leu-Arg-Ala has an excellent effect of improving brain function.

In order to achieve the above object, a composition for improving brain function according to one embodiment of the present invention is characterized in that it contains a tripeptide consisting of Leu-Arg-Ala.
In the composition for improving brain function, the improvement of brain function may be improvement of cognitive function.

The composition for improving brain function may be an oral composition.
A food composition or pharmaceutical composition in another aspect of the present invention is characterized by comprising the above-mentioned composition for improving brain function.

The present invention can provide excellent brain function improving effects.

One embodiment of the brain function improving composition (hereinafter also referred to as the composition) of the present invention will be described below. The composition encompassed in this embodiment contains a specific tripeptide (Leu-Arg-Ala). In addition, in this specification, a tripeptide consisting of the amino acid sequence Leu-Arg-Ala may be referred to as "LRA peptide."

The LRA peptide can be prepared by chemical synthesis, for example, using a known peptide synthesis method. Examples of peptide synthesis methods include the azide method, the acid chloride method, the acid anhydride method, the mixed acid anhydride method, the DDC method, the active ester method, the carboimidazole method, and the oxidation-reduction method. These peptide synthesis methods can be performed by either solid-phase synthesis or liquid-phase synthesis.

In the above-mentioned peptide synthesis method, it is preferable to protect the amino group, carboxy group, and/or side chain functional group (e.g., the guanidino group of arginine (Arg)) with a protecting group. The protecting group is not particularly limited and any known protecting group can be used, such as benzyloxycarbonyl group (Cbz), tert-butoxycarbonyl group (Boc), fluorenylmethoxycarbonyl group (Fmoc), benzyl group (Bz), p-toluenesulfonyl group (p-Ts), etc.

In addition, after synthesizing the LRA peptide by the above-mentioned peptide synthesis method, the peptide can be purified by a known method as necessary and used as the LRA peptide.
Alternatively, the LRA peptide may be obtained by hydrolyzing a protein with a protease or the like, followed by purification or crude purification.

A composition containing an LRA peptide exhibits an excellent effect of improving brain function, particularly when taken orally. The composition of this embodiment is applied to improve brain dysfunction, particularly cognitive disorders such as memory disorders, attention disorders, executive dysfunction, and social behavior disorders. Specifically, it is used to treat, improve, and prevent dementia, which develops cognitive disorders.

Specific examples of dementia include Alzheimer's disease, vascular dementia, Lewy body dementia, frontotemporal dementia, and alcohol-related dementia. Improvement of dementia includes not only the improvement of the core symptoms of dementia such as memory impairment, attention disorder, executive dysfunction, and social behavior disorder, but also improvement of peripheral symptoms such as delusions, depression, wandering, insomnia, hallucinations, and decreased motivation.

The application form of the composition is not particularly limited, and may be, for example, a food composition or a pharmaceutical composition. The LRA peptide may be used as it is as a material for a food composition or pharmaceutical composition, or may be made into a product by appropriately mixing with a carrier, additive, etc. that is pharmacologically or food hygienically acceptable.

When used as a food composition, in addition to the LRA peptide as described above, other ingredients may be included as necessary. There are no particular limitations on the other ingredients, and they can be selected appropriately depending on the purpose. Examples of such ingredients include bases, carriers, and additives that are acceptable from a food hygiene perspective, as well as other ingredients and materials that can be used as foods.

When used as a food composition, the intake form is oral intake. In this case, the form of the composition of this embodiment is not particularly limited, and it can be used as a general food, a health functional food, or a food for special uses. Examples include specific health foods, nutritional functional foods, functional foods, foods for the sick, foods for people with swallowing difficulties, dietary supplements, nutritional supplements, hospital foods, nursing care foods, processed foods, beverages, and the like. These can be prepared by conventional methods. When labeling the use of a food composition, examples include labels stipulated by various laws, enforcement regulations, guidelines, and the like. Labeling of use includes labels on packages such as wrapping and containers, as well as labels on advertising media such as pamphlets.

The contents of the display of the use of the composition of this embodiment include, in addition to display of improvement or prevention of brain function, display of improvement or prevention of the above-mentioned core symptoms and peripheral symptoms. Also included are displays suggesting these improvements or preventions. For example, displays of maintaining, supporting, or improving memory, attention, judgment, and spatial awareness, which are part of cognitive function, can be exemplified. More specifically, expressions such as maintaining or supporting the ability to remember and recall information about things seen and heard (memory), such as words, numbers, shapes, colors, location information, and faces, helping to remember information or improving accuracy, maintaining or supporting short-term memory (the ability to hold information in a short time and process it simultaneously), maintaining attention (speed and accuracy of clerical work), and maintaining the efficiency of calculation work can be exemplified.

In addition, the dosage form of the food composition may be, for example, a hard capsule, a soft capsule, a supplement, a chewable tablet, a beverage, a powdered beverage, a granule, a film, etc., or, when used as a food or drink, for example, a beverage such as a tea-based beverage, a sports beverage, a beauty beverage, a fruit juice beverage, a carbonated beverage, an alcoholic beverage, a refreshing drink, a jelly beverage, a concentrated type beverage to be diluted with water, hot water, carbonated water, etc., a powder or granule to be dissolved or suspended in water or hot water, etc., a dry solid such as a tablet, a tablet confectionery, a jelly, a snack, a baked confectionery, a fried confectionery, a cake, a chocolate, a gum, a candy, a gummy candy, etc., a soup, a noodle, a rice dish, a cereal, etc. Of these, in normal life, a supplement type, a chewable tablet, a one-shot drink type, etc. are preferable, and when taken for the purpose of enhancing the effect of exercise, a beverage such as a sports drink is also preferable. In particular, when making it into a health functional food, dietary supplement, or nutritional supplement, it is preferable to make it in the form of, for example, powder, granules, paste, capsule, tablet or pill (including chewable tablets), beverage (powdered beverage, drink, etc.), jelly, etc., to facilitate continuous intake.

When the composition is used as a food additive composition or a food ingredient composition, the form is not particularly limited, and examples of the form include liquid, powder, flake, granule, and paste. More specifically, examples of the form include seasonings (sweeteners, salt substitute compositions, soy sauce, vinegar, miso, sauces, ketchup, dressings, spices, herbs, flakes (furikake, rice cooking additives, etc.), barbecue sauce, roux paste (curry roux paste, etc.)), food premixes, etc.

When the composition is used as a food composition, the amount of LRA peptide in the food composition is not particularly limited as long as the above-mentioned effect of the LRA peptide is exerted, and can be set appropriately.

When the composition of the present invention is used as a food composition, the intake amount, intake interval, and intake target are not particularly limited and can be set appropriately. For example, the intake amount can be set appropriately depending on the age, sex, weight, health condition, and other conditions of the intake target. For example, the intake interval, when the amount described above is taken, may be once or multiple times a day (preferably 2 to 3 times), or once or multiple times every few days to several weeks. In addition to humans, the intake target may be domesticated animals such as pets or livestock, for example, dogs, cats, cows, horses, sheep, llamas, rats, mice, etc.

In particular, when the subject of administration is a human, the amount of LRA peptide administered (ingested) is, for example, preferably about 10 to 5,000 μg per day for an adult (60 kg), and more preferably about 100 to 4,000 μg per day. In addition, the administration (ingestion) period is not particularly limited, but may be, for example, 3 days to 12 weeks, or may be longer.

There are no particular limitations on the human subject to intake, but it is preferable for the human subject to intake to be a human who has a desire or need for improvement or prevention of brain function.
When the subject of intake is a domestic animal, the form, intake amount, intake interval, etc. can be appropriately determined with reference to the case when the subject of intake is a human.

Pharmaceutical compositions include drugs and quasi-drugs. When the composition of this embodiment is used as a pharmaceutical composition, the administration method is not particularly limited, and it is possible to adopt oral administration (oral ingestion), enteral administration, intravascular administration (particularly intravenous injection), etc. When applied as a pharmaceutical composition, in addition to the LRA peptide as described above, other components may be included as necessary. The other components are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include pharma- ceutically acceptable bases, carriers, and/or additives (e.g., solvents, dispersants, emulsifiers, buffers, stabilizers, excipients, binders, disintegrants, lubricants, etc.). The blending amount of the other components can be appropriately set depending on the purpose.

The dosage form of the pharmaceutical composition is not particularly limited, and examples thereof include tablets such as orally disintegrating tablets, chewable tablets, effervescent tablets, dispersible tablets, and dissolving tablets; troches; powders; suspensions; emulsions; elixirs; lemonades; syrups; lotions; granules; capsules such as hard capsules and soft capsules; creams; ointments; suppositories; poultices, tapes, microneedles, transdermal/mucosal administration agents such as iontophoresis and electroporation; and aerosols. These forms can be prepared by combining the LRA peptide with the other components described above as necessary in a conventional manner.

The amount of the LRA peptide in the pharmaceutical composition is not particularly limited as long as the amount is such that the above-mentioned effects of the LRA peptide are exerted, and can be set appropriately.
When used as a pharmaceutical composition, the dosage, administration interval, administration subject, etc. are not particularly limited and can be set appropriately. For example, the dosage can be set appropriately depending on the age, sex, weight, health condition, and other conditions of the administration subject. In addition, for example, the administration interval may be once or multiple times a day (preferably 2 to 3 times), or once or multiple times every few days to weeks. In addition, the administration subject may be a human, or a domestic animal such as a pet or livestock, for example, a dog, a cat, a cow, a horse, a sheep, a llama, a rat, a mouse, etc.

In particular, when the subject of administration is a human, the amount of LRA peptide administered (ingested) is, for example, preferably about 10 to 5,000 μg per day for an adult (60 kg), and more preferably about 100 to 4,000 μg per day. In addition, the administration (ingestion) period is not particularly limited, but may be, for example, 3 days to 12 weeks, or may be longer.

When the subject of administration is a domestic animal, the administration form, dosage form, dosage amount, administration interval, etc. can be appropriately determined with reference to the case where the subject of administration is a human.
The effects of the composition for improving brain function of this embodiment will be described.

(1) In this embodiment, the composition contains an LRA peptide. Therefore, it can exert an excellent effect of improving brain function. It is particularly effective in improving cognitive function. Furthermore, in cases where cognitive function has declined due to lifestyle habits such as a high-fat diet, short-term intake can contribute to the recovery of cognitive function.

The above embodiment may be modified as follows.
The composition of the above embodiment is not only intended to be administered to patients for the purpose of improving symptoms related to brain function, but also to be taken by healthy individuals for the purpose of preventing the worsening of symptoms, delaying the reduction in symptoms, and preventing the reduction in brain function.

- In the composition of the above embodiment, the amount of LRA peptide contained in the food composition or pharmaceutical composition is not particularly limited as long as the effect of the present invention is obtained, and can be configured to contain, for example, 0.1 to 100% by mass, preferably 1 to 90% by mass, of the solid content.

In this specification, the term "comprising" includes "consisting essentially of" and "consisting of." In addition, the present invention includes any combination of the constituent elements described in this specification.

Furthermore, the various characteristics (properties, structures, functions, etc.) described for each embodiment of the present invention above may be combined in any way to identify the subject matter encompassed by the present invention. In other words, the present invention encompasses all subject matter consisting of any combination of the combinable characteristics described in this specification.

The above-mentioned embodiment will be described in more detail below with reference to test examples, but the present invention is not limited thereto.
(Synthesis of LRA peptide)
Production Example 1: Synthesis of tripeptide by Fmoc method A tripeptide consisting of Leu-Arg-Ala was synthesized by solid phase synthesis using the Fmoc method. The obtained LRA peptide was purified by HPLC, and the sequence was analyzed using a protein sequencer. As a result, it was confirmed that the tripeptide consisted of Leu-Arg-Ala.

Production Example 2: Synthesis of tripeptide by Boc method Synthesis of a tripeptide consisting of Leu-Arg-Ala by the Boc method was requested to Peptide Institute, Inc. The delivered LRA peptide was confirmed to be a tripeptide consisting of Leu-Arg-Ala by RP-HPLC, mass spectrometry and amino acid analysis.

(Measurement of cognitive function)
The test method was based on the mouse object recognition test method (Marianne. Leger et al., Nature Protocols 8 (12), 2531-2537, 2013).

The mice used in the study were 11-week-old male ddY mice, which were fed a high-fat diet for one week to acclimate them, and then divided into two groups. Both groups were kept on a high-fat diet for one week (free food and water intake). One group (LRA peptide group) was orally administered LRA peptide prepared in saline using a Teflon tube at 1 mg/kg, and the other control group was orally administered the same amount of saline on the 5th, 6th, and 7th days of the week.

The high-fat diet used was HFD-60 (manufactured by Oriental Bio Co., Ltd.), which consists of the ingredients shown in Table 1.

On the sixth day of rearing, one mouse from each group was placed in a box of a given size and allowed to acclimate to the environment for five minutes (acclimatization 1). After 24 hours, the mouse was placed in a box with two substances, one on each side, and allowed to move until the total exploration time for both substances reached 20 seconds, after which it was removed from the box and returned to its cage (acclimatization 2). At this time, both substances in the box were the same, either building blocks or flasks. After another hour, the mouse was placed in a box in which one of the two substances had been replaced with a substance of a different shape, and allowed to move until the total exploration time for both substances reached 20 seconds, and the proportion (%) of the exploration time for the replaced novel substance was calculated.

Whether the novel substance was on the right or left side was completely random during the test. The test box was placed in an area separated by a partition, and the tester observed the behavior of the mice from outside the partition using a video camera installed above the box, without being seen by the mice. All tests were conducted in a facility set at 23°C with a 12-hour light and 12-hour dark cycle.

The average value ± standard deviation was calculated for each test group. The results for each group are shown in Table 2. There were no significant differences in body weight between the groups during the test period. * indicates vs. Control: p<0.05 (Tukey's multiple test).

As shown in Table 2, the group of subjects to which the LRA peptide was added in a high-fat diet showed a significantly increased proportion of time spent exploring a novel substance compared to the control group.

Claims (3)

A composition for improving brain function, comprising a tripeptide consisting of Leu-Arg-Ala, wherein the improvement of brain function is improvement of cognitive function . The composition for improving brain function according to claim 1, which is an oral composition. A food composition or pharmaceutical composition for improving cognitive function, comprising the composition for improving brain function according to claim 1 or 2 .