JP7181695B2 - Antidementia agent and short-term memory impairment improver/suppressor - Google Patents

Description

TECHNICAL FIELD The present invention relates to an antidementia agent and an agent for improving/suppressing short-term memory impairment.

Dementia refers to a state in which brain cells die or function poorly due to various causes, resulting in various disorders and hindrances in daily life. Physical functions may also be lost due to atrophy of the entire brain associated with the onset of dementia.

Therefore, in recent years, extensive research has been conducted on components that have the effect of suppressing dementia. For example, Patent Document 1 discloses that royal jelly exhibits antidementia activity.

WO2017/078175

Journal of Japanese Pharmacology, 130(2), pp112-116, 2007

An object of the present invention is to provide a novel antidementia agent and an agent for improving/suppressing short-term memory impairment.

The present inventors have found from in vivo tests that p-coumaric acid has the effect of improving/suppressing short-term memory impairment caused by accumulation of amyloid β protein.

That is, the present invention provides, as a first aspect, an antidementia agent containing p-coumaric acid as an active ingredient.

As a second aspect, the present invention provides a short-term memory impairment improving/suppressing agent containing p-coumaric acid as an active ingredient.

INDUSTRIAL APPLICABILITY According to the present invention, novel antidementia agents and short-term memory impairment improving/suppressing agents can be provided.

It is a graph which shows the evaluation result in a Y-shaped maze test.

Embodiments of the present invention will be described below. However, the present invention is not limited to the following embodiments.

The antidementia agent of the present invention has an antidementia effect. The "anti-dementia effect" in the present invention is a concept that includes the action of preventing the onset of dementia, the action of delaying the onset of dementia, and the action of recovering from the state of dementia once developed. be. Dementia targeted by the antidementia agent of the present invention may be Alzheimer's dementia. Alzheimer's dementia is divided into pathological conditions caused by loss of acetylcholinergic neurons in the Meynert nucleus of the basal forebrain (choline hypothesis) and pathological conditions caused by accumulation of amyloid β protein (amyloid hypothesis). Both show different pathological conditions, and are not the same pathological condition viewed from different angles. The dementia targeted by the antidementia agent of the present invention may be Alzheimer's dementia based on any theory, preferably Alzheimer's dementia based on the amyloid hypothesis. That is, the dementia targeted by the antidementia agent of the present invention may be Alzheimer's dementia caused by accumulation of amyloid β protein. In other words, the present invention provides a nootropic agent for Alzheimer's dementia, a nootropic for Alzheimer's dementia based on the amyloid hypothesis, or a nootropic for Alzheimer's dementia caused by accumulation of amyloid β protein. It can also be provided.

In Alzheimer's disease based on the amyloid hypothesis, the accumulation of tau protein in addition to amyloid β protein in the brain causes the death of brain neurons, which is thought to impair cognitive function. At the initial stage, accumulation of amyloid β protein begins, and after about 10 years, accumulation of tau protein begins. After that, the accumulation of amyloid β protein and tau protein continues to kill brain nerve cells, causing dementia to develop about 25 years after the initial stage. In another aspect, the antidementia agent of the present invention can be said to have an action to suppress the accumulation of amyloid β protein in the brain and an action to reduce the accumulated amyloid β protein in the brain. It can also be said to have an effect of suppressing accumulation of tau protein in the brain and an effect of reducing tau protein accumulated in the brain.

The present invention can also be said to provide a memory impairment improving/suppressing agent. The memory impairment ameliorating/suppressing agent of the present invention has an effect of improving/suppressing memory impairment. The term "improvement/suppression of memory impairment" in the present invention includes the action of preventing the onset of memory impairment, the action of delaying the onset of memory impairment, and the action of recovering from the state at the time of onset of memory impairment once developed. It is a concept. The memory impairment targeted by the memory impairment improving/suppressing agent of the present invention may be either long-term memory impairment or short-term memory impairment, preferably short-term memory impairment. That is, the present invention can be said to provide an agent for improving/suppressing short-term memory impairment, and can also be said to provide an agent for improving/suppressing short-term memory impairment caused by accumulation of amyloid β protein.

An antidementia agent according to one embodiment contains p-coumaric acid as an active ingredient.

P-coumaric acid is a kind of hydroxycinnamic acid, and can be obtained as a lignin decomposition product, separated from natural essential oils, or as a synthetic reaction product. Lignin, which is a raw material for lignin decomposition products, may be derived from gramineous plants, or may be derived from sugarcane or bagasse. Commercially available p-coumaric acid may be used.

The antidementia agent according to the present embodiment may consist of only p-coumaric acid, which is an active ingredient, and may further contain materials that can be used for foods, quasi-drugs, or pharmaceuticals. Materials that can be used for foods, quasi-drugs, or pharmaceuticals are not particularly limited, but examples include amino acids, proteins, carbohydrates, fats and oils, sweeteners, minerals, vitamins, flavors, excipients, and binders. , lubricants, disintegrants, emulsifiers, surfactants, bases, solubilizers, suspending agents and the like.

Proteins include, for example, milk casein, whey, soybean protein, wheat protein, egg white and the like. Carbohydrates include, for example, corn starch, cellulose, pregelatinized starch, wheat starch, rice starch, potato starch and the like. Fats and oils include, for example, salad oil, corn oil, soybean oil, safflower oil, olive oil, palm oil and the like. Sweeteners include, for example, sugars such as glucose, sucrose, fructose, high-fructose corn syrup, high-fructose corn syrup, sugar alcohols such as xylitol, erythritol, and maltitol, and artificial sweeteners such as sucralose, aspartame, saccharin, and acesulfame K. sweeteners, stevia sweeteners, and the like. Minerals include, for example, calcium, potassium, phosphorus, sodium, manganese, iron, zinc, magnesium, and salts thereof. Examples of vitamins include vitamin E, vitamin C, vitamin A, vitamin D, B vitamins, biotin, niacin and the like. Excipients include, for example, dextrin, starch, lactose, crystalline cellulose and the like. Examples of binders include polyvinyl alcohol, gelatin, hydroxypropylmethylcellulose, hydroxypropylcellulose, sodium carboxymethylcellulose, polyvinylpyrrolidone and the like. Lubricants include, for example, magnesium stearate, calcium stearate, talc and the like. Examples of disintegrants include crystalline cellulose, agar, gelatin, calcium carbonate, sodium hydrogencarbonate, dextrin and the like. Examples of emulsifiers or surfactants include sucrose fatty acid esters, citric acid, lactic acid, glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, propylene glycol fatty acid esters, and lecithin. Bases include, for example, cetostearyl alcohol, lanolin, polyethylene glycol and the like. Examples of solubilizing agents include polyethylene glycol, propylene glycol, sodium carbonate, sodium citrate and the like. Suspending agents include, for example, glyceryl monostearate, polyvinyl alcohol, polyvinylpyrrolidone, methylcellulose, hydroxymethylcellulose, sodium alginate and the like. You may use these individually by 1 type or in combination of 2 or more types.

When the anti-dementia agent contains other materials, the content of the active ingredient p-coumaric acid may be appropriately set according to the form of the anti-dementia agent described later, the purpose of use, etc. From the viewpoint of exhibiting the disease effect more effectively, it is preferably 1% by mass or more, more preferably 3% by mass or more, and still more preferably 5% by mass or more, based on the total amount of the nootropic agent. and is preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably 30% by mass or less.

Antidementia agents can be used as foods, quasi-drugs, or pharmaceuticals. Foods may be provided in the form of, for example, health foods, foods for specified health uses, functional foods, functional foods, and supplements.

Antidementia agents can also be used as feeds and feed additives. Feeds include companion animal feeds such as dog food and cat food, livestock feeds, poultry feeds, farmed fish and shellfish feeds, and the like. "Food" includes anything orally ingested by an animal for nutritional purposes. More specifically, when classified in terms of nutrient content, it includes all of rough feed, concentrated feed, mineral feed, and special feed, and in terms of official standards, it includes all of compound feed, mixed feed, and single feed. encompasses In addition, when classified from the aspect of feeding method, it includes all feeds that are directly fed, feeds that are mixed with other feeds, and feeds that are added to drinking water to supplement nutrients.

The nootropic agent may be in any form such as solid (powder, granules, etc.), liquid (solution, suspension, etc.), paste, etc., and may be powders, pills, granules, tablets, capsules, lozenges, etc. It may be in any dosage form such as a drug, liquid, suspension, and the like.

When the product containing the antidementia drug is intensively ingested, the intake of the product (intake or dosage per day) is preferably 50 to 3,000 mg/day based on the total amount of p-coumaric acid. kg (body weight), more preferably 100 to 2,000 mg/kg (body weight). For daily long-term intake, the intake of the above product (daily intake) is preferably 1 to 500 mg/kg (body weight) based on the total amount of p-coumaric acid.

The antidementia agent of the present embodiment can be used for humans or animals with accumulated amyloid β protein. In addition, the antidementia agent of the present embodiment can be used for humans or animals suffering from dementia (or Alzheimer's dementia), humans or animals suffering from memory impairment (or short-term memory impairment), Dementia and memory impairment may result from the accumulation of amyloid beta protein. The antidementia agent of the present embodiment is a human or animal that has not developed dementia (or Alzheimer's dementia), or a human or animal that has not developed memory impairment (or short-term memory impairment). It can be used to forestall the onset of dementia or memory impairment, and can also be used to delay the onset of dementia or memory impairment.

Specific aspects of the short-term memory impairment improving/suppressing agent according to one embodiment may be the same as those of the antidementia agent described above. That is, the short-term memory impairment improving/suppressing agent according to one embodiment may be read as "short-term memory impairment improving/suppressing agent" instead of "anti-dementia agent" in the description of the anti-dementia agent described above. .

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.

In the following description regarding the dosage of p-coumaric acid, for example, "100 mg/kg" means that 100 mg was administered per 1 kg of body weight. "Amyloid β protein" may be simply referred to as "amyloid β".

<Preparation of test solution>
p-Coumaric Acid (trans-p-Coumaric Acid, Tokyo Chemical Industry Co., Ltd.) was stored at room temperature (controlled temperature: 18.0 to 28.0° C.) until the test. Water for injection (Otsuka distilled water, Otsuka Pharmaceutical Factory Co., Ltd.) was prepared as a medium for dissolving p-coumaric acid. A required amount of p-coumaric acid was weighed, dissolved in water for injection, diluted to a predetermined concentration, and used as a test solution.

<Preparation of amyloid β solution>
Amyloid-β protein (25-35, Polypeptide Laboratories) used in the amyloid-β solution was stored frozen (controlled temperature: -30°C to -20°C) until testing. It was dissolved to 2 mM to prepare an amyloid β solution.

<Test animals>
Male Slc:ddY mice (SPF, Japan SLC, Inc.) were used as test animals. Five-week-old mice were obtained as the mice. The mouse is an animal species commonly used for behavioral pharmacological tests, and its lineage maintenance is clear. Mice weight ranged from 23.8 to 30.0 g on day 1 after acquisition. A 5-day preliminary breeding period was provided for the obtained mice.

(Breeding conditions)
Mice were kept at a controlled temperature of 20.0 to 26.0°C, controlled humidity of 40.0 to 70.0%, 12 hours of light and dark (lighting: 6:00 am to 6:00 pm), ventilation rate of 12 times/hour (with a filter). The animals were housed in an animal care room maintained with fresh air.
From the preliminary rearing period to the day of grouping, groups of up to 10 animals per cage were reared using plastic cages (W: 310 x D: 360 x H: 175 mm), and after grouping, 5 animals per cage. They were reared in groups of up to 100 animals. Solid feed (MF, Oriental Yeast Co., Ltd.) was freely given as feed, and tap water was given as drinking water.

<Test operation>
(Group composition and amount of liquid administered)
The groups were divided by random sampling on the first day of administration of the test solution so that the average body weight of each group was almost uniform. The groups consisted of three groups: a sham operation group, a vehicle control group, and a p-coumaric acid administration group. For the p-coumaric acid-administered group, the amount of liquid to be administered was calculated at 10 mL/kg based on body weight on the day of administration so that the dose of p-coumaric acid per mouse was 100 mg/kg. 10 mL/kg of 0.5% (w/v) methylcellulose solution was administered to the sham-operated group and the vehicle control group.

(Experiment schedule)
The administration start date of the test solution was defined as the first day of administration, and the test solution was administered once a day, and on the eighth day of administration, the amyloid β solution was injected into the mice. After that, the Y-maze test was performed on the 14th day of administration. Each procedure will be described later.

(Administration route and administration method of test solution)
The route of administration was oral administration. As for the administration method, the test solution was orally administered using a polypropylene disposable syringe (Terumo Corporation) equipped with a disposable oral sonde for mice (Fuchigami Kikai Co., Ltd.) according to the usual method used at the test facility. did. During the administration operation, the test solution was mixed by inversion every time one animal was administered, and then sucked into the syringe. On the day of amyloid β solution injection, the test solution was administered after the amyloid β solution was injected, and on the Y-maze test day, the test solution was administered 30 minutes before the measurement.

(Method of injecting amyloid β)
Mice were anesthetized by intraperitoneally administering 40 mg/kg sodium pentobarbital (Tokyo Kasei Kogyo Co., Ltd.) (administration volume: 10 mL/kg). After anesthesia, levobupivacaine hydrochloride (Bobskine (registered trademark) 0.25% injection, Maruishi Pharmaceutical Co., Ltd.) was subcutaneously administered (0.1 mL) to the scalp. An incision was made in the scalp to expose the skull, and a hole for inserting a stainless steel pipe was made in the skull 1 mm laterally (right side) and 0.2 mm posteriorly from bregma using a dental drill. A stainless steel pipe connected to a silicon tube with an outer diameter of 0.5 mm and a microsyringe was vertically inserted to a depth of 2.5 mm from the bone surface. To the p-coumaric acid-administered group and the vehicle control group, 3 μL of amyloid β solution (6 nmol/3 μL) was injected into the ventricle over 3 minutes with a microsyringe pump. On the other hand, the sham operation group was injected with 3 μL of water for injection in the same manner. After the injection, the stainless steel pipe was left in place for 3 minutes, and then the stainless steel pipe was slowly removed. Thereafter, the cranial hole was closed with a non-absorbable bone marrow hemostat (Nestop (registered trademark), Alfresser Pharma Inc.), and the scalp was sutured.

(Evaluation by Y-shaped maze test)
A Y-shaped maze test (for example, Non-Patent Document 1), which is a method for evaluating learning and memory behavior and is particularly known as a method for evaluating short-term memory, was performed. The test consisted of a plastic Y-shape with one arm length of 39.5 cm, floor width of 4.5 cm, wall height of 12 cm, and three arms each diverging 120 degrees. A maze (Unicom Co., Ltd.) was used.
Prior to evaluation, the illuminance on the floor surface of the apparatus was adjusted to 10-40 lux. Evaluations were performed 30 minutes after administration of the test solution. Mice were placed in either arm of the Y-maze and allowed to explore the maze freely for 8 minutes. The order of the arms to which the mice moved within the measurement time was recorded, and the number of times the mice moved to the arms was counted as the total number of entries. Next, combinations in which three different arms were selected in succession were examined, and this number was defined as the number of spontaneous alternation behaviors. Then, the spontaneous alternation behavior rate was calculated using the following formula.
Spontaneous replacement behavior rate (%) = [number of spontaneous replacement behaviors/(total number of entries - 2)] x 100

A Y-shaped maze test was performed on each group of mice, and the average value and standard error of the total number of entries, the number of spontaneous alternations, and the rate of spontaneous alternations were calculated. In the significance test, comparison was made between the sham operation group and the vehicle control group, and between the vehicle control group and the p-coumaric acid administration group. For comparison between two groups, the homoscedasticity test was performed by F test, Student's t-test was performed in the case of homoscedasticity, and Aspin-Welch test was performed in the case of unequal variances. The significance level was set to 1%. A commercially available statistical program (SAS system, SAS Institute Japan Co., Ltd.) was used for the significance test. The results are shown in Table 1 and FIG. As shown in Table 1 and FIG. 1, the rate of spontaneous alternation behavior was lower in the vehicle control group than in the sham-operated group, indicating a significant difference (p<0.01). In addition, the p-coumaric acid-administered group had a higher spontaneous alternation behavior rate than the vehicle control group, showing a significant difference (p<0.01).

Claims (2)

An antidementia agent for Alzheimer's dementia caused by accumulation of amyloid β protein , containing p-coumaric acid as an active ingredient . An agent for improving/suppressing short-term memory impairment caused by accumulation of amyloid β protein , containing p-coumaric acid as an active ingredient .

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