JPH06287138A - Agent for prevention and treatment of alzheimer's disease - Google Patents

Abstract

(57) [Summary] [Structure] A drug whose main component is a medium-chain fatty acid triglyceride (MCT) composed of caprylic acid and capric acid. [Effects] By orally or parenterally administering the above-mentioned agents to humans and the like, the constituent free fatty acids of MCT pass through the blood-brain barrier into cerebrospinal fluid and are metabolized to acetyl CoA in brain cells. , Excess acetyl Co
Since A produces acetylcholine together with choline, it is possible to improve the symptoms of Alzheimer's disease patients in which a decrease in acetylcholine content in the brain is observed, and prevent Alzheimer's disease.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a prophylactic / therapeutic agent for Alzheimer's disease, and more particularly to a pharmaceutical agent for preventing and / or treating Alzheimer's disease caused by a decrease in acetylcholine content in the brain.

[0002]

2. Description of the Related Art It is generally known that in patients with Alzheimer's disease, which is one of senile dementia, a decrease in brain acetylcholine content is recognized, and it is an important index for drug development against this disease. There is.

Drugs currently in use or under development are acetylcholine synthesizing enzymes such as an enzyme that synthesizes acetylcholine, an enzyme that suppresses the degradation of acetylcholine, or choline, which is a precursor of acetylcholine, is supplied to the brain. Either by stimulation or by stimulating the receptor with an agonist of the muscarinic acetylcholine receptor.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a preventive and / or therapeutic agent for Alzheimer's disease which has a mechanism of action which is fundamentally different from that of conventional agents.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that the carbon number is 8-10.
Free fatty acid, which is a medium-chain triglyceride (hereinafter referred to as “MCT”) that uses the fatty acid as a constituent fatty acid, passes through the blood-brain barrier to cerebrospinal fluid, is metabolized to acetyl CoA in brain cells, and is excessive. Min acetyl Co
It was found that A produces acetylcholine together with choline, and completed the present invention.

The present invention has been completed based on this new finding, and is an Alzheimer's disease prophylactic / therapeutic agent which contains MCT whose constituent fatty acid is a fatty acid having 8 to 10 carbon atoms as a main component.

The MCT in the present invention has 8 carbon atoms.
Triglycerides composed of ~ 10 saturated fatty acids, for example caprylic acid, capric acid, are used. When the constituent fatty acids of MCT are caprylic acid and capric acid, M
The ratio of caprylic acid to capric acid is preferably 8: 2 to 4: 6 in order to reduce the toxicity of CT. In the present invention, the MCT consists essentially of MCT whose constituent fatty acid is a fatty acid having 8 to 10 carbon atoms. Here, “substantially” means that MCT having a fatty acid having a carbon number other than 8 to 10 as a constituent fatty acid
It means that it may be contained in an amount that does not impair the object of the present invention.

The MCT in the present invention is produced by a method known per se, and can be obtained by an appropriate means such as synthesis from glycerol, partial esterification, transesterification using an enzyme, or fractionation of fats and oils having a high content. For example, it can be obtained by hydrolysis of cocoa butter or palm fat, fractionation of fatty acids by distillation and reselling with glycerol. They also may be extracted from Cuphea species containing 80-90% to C ₁₀ fatty acids. These triglycerides do not necessarily have to be highly pure, and those containing 90% (wt) or more, preferably 95% (wt) or more as a main component are suitable.

The preventive / therapeutic agent for Alzheimer's disease of the present invention is
It contains 1 to 50% by weight, preferably 5 to 15% by weight of MCT, and its dosage form such as solid form, powder form, liquid form and emulsion form is not limited at all. That is, it can be administered orally or parenterally such as injection (eg, intravenous administration, tube administration to stomach, duodenum, jejunum, etc.).

A fat emulsion is mentioned as one dosage form of the preventive / therapeutic agent for Alzheimer's disease of the present invention. Such a fat emulsion is prepared from the above MCT, emulsifier, water, and appropriate additional components by a conventional method.

Examples of emulsifiers include phospholipids (egg yolk phospholipids, soybean phospholipids), nonionic surfactants, etc., which may be purified for medical purposes.

As the phospholipid, a purified phospholipid such as egg yolk lecithin or soybean lecithin is suitable, and it can be prepared by a conventional fractionation method using an organic solvent. It is mainly composed of phosphatidylcholine and phosphatidylethanolamine, and also contains phosphatidylinositol, phosphatidylserine, sphingomyelin and the like as other phospholipids.

As the phospholipid, one containing no phosphatidylethanolamine may be used. This product can be obtained by subjecting commonly available phospholipids such as egg yolk and soybeans to organic solvent fractionation by a conventional method and then purifying with an inorganic absorbent such as silica gel or alumina. The phospholipid thus obtained is mainly composed of phosphatidylcholine, and may contain phosphatidylinositol, phosphatidylserine, and sphingomyelin as other phospholipids. Furthermore, phosphatidylcholine itself may be used.

The water to be used varies depending on the dosage form, and water suitable for intravenous injection (for example, distilled water for injection, purified water for injection, etc.) or water suitable for oral administration (for example, purified water) is used.

The content of each component of the fat emulsion is, for example, 1 to 50% (w / v) of the oil component (MCT), preferably 5 to 15% (w / v), and 100 parts of the oil component. On the other hand, an emulsifier composed of 1 to 500 parts (preferably 10 to 50 parts) and an appropriate amount of water is exemplified.

In addition, if necessary, an emulsification auxiliary agent (for example, fatty acid having 6 to 22 carbon atoms, preferably 12 to 20 carbon atoms in an amount up to 0.3% (w / v) or a pharmacologically acceptable salt thereof. Salt, etc.], stabilizer [eg 0.5% (w / v)
Below, preferably 0.1% (w / v) or less cholesterol, or 5% (w / v) or less, preferably 1%
(W / v) or less amount of phosphatidic acid, etc.], polymeric substance (for example, 0.1 to 5% (w / v), preferably 0.1.
5 to 1% (w / v) albumin, dextran, vinyl polymer, nonionic surfactant, gelatin, hydroxyethyl starch, etc.], tonicity agent (eg, glycerin,
Glucose, etc.), fragrance, etc. can also be added.

Any fatty acid having 6 to 22 carbon atoms as an emulsification aid can be used as long as it can be added to a pharmaceutical product. This fatty acid may be linear or branched,
It is preferable to use linear stearic acid, oleic acid, linoleic acid, palmitic acid, linolenic acid, myristic acid and the like. These salts include physiologically acceptable salts such as alkali metal salts (for example, sodium salt,
Potassium salt etc.), alkaline earth metal salt (eg calcium salt, magnesium salt etc.) and the like can be used.

Further, an aliphatic amine may be used as an emulsification aid. Specifically, those having 2 to 22 carbon atoms are exemplified. Any of these aliphatic amines can be used as long as they can be added to pharmaceutical products. This aliphatic amine is linear,
It may be branched, but it is preferable to use linear ethylamine, propylamine, octylamine, stearylamine, oleylamine or the like. The amount added is, for example, about 0.0001 to 0.01% (w / v). If the emulsification is insufficient, various known emulsification aids may be used.

Cholesterol, phosphatidic acid and the like as the stabilizer are not particularly limited as long as they can be used for medicinal purposes. In addition, albumin is preferably of human origin because of the problem of antigenicity, and examples of vinyl polymers include polyvinylpyrrolidone and polyvinyl alcohol. As the nonionic surfactant, polyalkylene glycol (e.g., polyethylene glycol having an average molecular weight of 1,000 to 10,000, preferably 4,000 to 6,000) and polyoxyalkylene copolymer (e.g., average molecular weight of 1,000 to 20,000, preferably 6, 00
0-10,000 polyoxyethylene-polyoxypropylene copolymer), hydrogenated castor oil polyoxyalkylene derivative (for example, hydrogenated castor oil polyoxyethylene- (20)-
Ether, same- (40) -ether, same- (100) -ether and the like], castor oil polyoxyalkylene derivative (for example, castor oil polyoxyethylene- (20) -ether, same- (40) -ether, same) -(100) -ether and the like] can be used.

The fat emulsion in the present invention is produced, for example, by the following method. That is, a predetermined amount of oil component (M
CT), an emulsifier (preferably phospholipid) and other additives described above are mixed and heated to form a solution, and homogenized using a conventional homogenizer (eg, high-pressure jet homogenizer, ultrasonic homogenizer, etc.) To prepare a water-in-oil dispersion, and then add water containing necessary amounts of isotonicity agents, stabilizers, etc., and homogenize again with the homogenizer to convert into an oil-in-water emulsion. Can be manufactured by. Depending on the production convenience, additives such as a stabilizer and a tonicity agent may be added after the formation of the fat emulsion (see JP-A-58-222014).

The fat emulsion thus produced is extremely fine, and the average particle size of fat particles is about 0.05 to 0.5 μm.
And its storage stability is extremely good.

The fat emulsion may contain a long-chain fatty acid triglyceride (hereinafter referred to as "LCT"), and a fatty acid triglyceride having a saturated or unsaturated fatty acid having 16 to 18 carbon atoms as a constituent fatty acid is preferable. It is illustrated as one. LCT contains the LCT as a main component, for example, vegetable oil containing 95% (weight) or more, preferably 99% or more of the LCT (eg, cottonseed oil, soybean oil, corn oil, peanut oil, safflower oil). Etc.) and the like. A preferred LCT is soybean oil. As the soybean oil, highly purified purified soybean oil is preferably used, and more preferably, the highly purified purified soybean oil obtained by further purifying the purified soybean oil by, for example, a steam distillation method (purity: containing 99.9% or more as triglyceride) Is used. Examples of the fatty acid that constitutes LCT include palmitic acid, stearic acid, linoleic acid, linolenic acid,
Examples thereof include oleic acid. When LCT is included, the weight ratio of MCT and LCT is 4: 1 to 1: 4, preferably 2: 1 to 1: 2, and more preferably 1: 1.

The MCT contained in the Alzheimer's disease prophylactic / therapeutic agent of the present invention is generally, after administration, rapidly and easily absorbed from intestinal epithelial cells, transported to the liver through the portal vein, oxidized in the liver and used as energy. Therefore, it is used as a nutritional supplement as a high-calorie energy source that can be easily absorbed. Therefore, the Alzheimer's disease prophylactic / therapeutic agent of the present invention includes proteins, amino acids, and the like used in ordinary nutritional supplements.
Peptides, vegetable lipids, sugars, minerals, vitamins,
Further, other known additives (for example, an emulsifier, a stabilizer) and the like may be appropriately mixed.

Examples of the protein include vegetable protein, whey protein and low-lactose milk protein, and the amino acids include valine, leucine, isoleucine, threonine, lysine,
Examples of methionine, phenylalanine, tryptophan, as plant lipids, safflower oil, corn oil, soybean oil, cottonseed oil, sunflower oil, linoleic acid such as linseed oil, lipids containing linolenic acid are exemplified, as the sugar , Glucose, mannose, galactose, monosaccharides such as fructose, lactose, sucrose, disaccharides such as maltose, dextrin, polysaccharides such as pregelatinized starch, and the like, minerals include sodium, potassium, calcium, magnesium, Iron, zinc, chlorine, phosphorus, copper,
Examples of manganese, cobalt, molybdenum, chromium, selenium, and the like include vitamins A (A ₁ , A ₁ ,
A ₂ , retinene, provitamin A), vitamin B ₁ (thiamine, anoylin), vitamin B ₂ (riboflavin,
Lactoflavin), vitamin B ₆ (pyridoxine, pyridoxal, pyridoxamine, pyridoxal phosphate), pantothenic acid, nicotinic acid amide, biotin, folic acid, vitamin B ₁₂ , vitamin C, vitamin D (D ₂ , D)
₃ , provitamin D), vitamin E (tocopherol), vitamin K (K ₁ , K ₂ , K ₃ ) and the like.

The preventive / therapeutic agent for Alzheimer's disease of the present invention is
In the case of oral administration, the standard adult dose is 100 g to 300 g per day.
(For example, if it is a 10% w / v solution, 1,000 ml to 3,000 m
l) is given in several divided doses, and 10% if given parenterally
Dosage rate 100-150 as w / v-30% w / v solution
It is continuously administered to the stomach, duodenum, or jejunum at a rate of ml / hour, or divided into several times a day by instillation or intravenous administration. The dose, dose concentration, and dose rate may be appropriately increased or decreased according to age, symptoms, body weight, and the like.

[0026]

According to the preventive / therapeutic agent for Alzheimer's disease of the present invention, MC containing a fatty acid having 8 to 10 carbon atoms as a constituent fatty acid
Since T is contained as the main component, the constituent free fatty acids of MCT pass through the blood-brain barrier and are transferred to the cerebrospinal fluid, and are metabolized to acetyl-CoA in the brain cells. Produces acetylcholine.

[0027]

EXAMPLES In order to explain the present invention in more detail, examples and experimental examples will be given below, but the present invention is not limited thereto.

[Raw material] MCT; MCT is 77% caprylic acid, 23% capric acid
Is a medium-chain fatty acid triglyceride that is randomly esterified with glycerin at a ratio of. It is a colorless to pale yellow transparent liquid. Solubility in water 60mg / dl, freezing point -14
℃, the amount of heat is 8.3kcal / g.

Example 1 50 g of purified soybean oil (LCT), 50 g of MCT, 22.1 g of Japanese Pharmacopoeia glycerol and an appropriate amount of distilled water for injection were mixed with 12 g of egg yolk phospholipid as an emulsifier, and the total amount was adjusted to 1 liter using a homomixer. And coarse emulsification was performed. Further, using a Manton-Gaulin homogenizer, a total pressure of 200 to 25
It was emulsified for 10 minutes under a pressure of 0 kg / cm ² . Extremely fine LCT / MCT emulsion (pH 6.3) homogenized by this
Got The average grain size of this emulsion was 0.2 to 0.4 μm. The LCT / MCT emulsion was placed in a glass bottle of appropriate quality and then heat-sterilized by a conventional method to obtain a milk-like intravenous Alzheimer's disease prophylactic / therapeutic agent.

Example 2 In Example 1, M without refined soybean oil (LCT) was used.
An MCT emulsion (pH 6.3) was obtained in the same manner as in Example 1 except that 100 g of CT was used. The average grain size of this emulsion is 0.2-0.
It was 4 μm. This MCT emulsion was placed in a glass bottle of appropriate quality, and then heat-sterilized by a conventional method to obtain a milk-like intravenous prophylactic / therapeutic agent for Alzheimer's disease.

Example 3 50 g of purified soybean oil (LCT), 50 g of MCT, 22.1 g of Japanese Pharmacopoeia glycerin, 50 g of sucrose, a small amount of flavor and a suitable amount of distilled water for injection were taken, and 12 g of egg yolk phospholipid was mixed as an emulsifier, The total amount was set to 1 liter and rough emulsification was performed using a homomixer. Thereafter, emulsification was performed in the same manner as in Example 1. This gave a homogenized very fine LCT / MCT emulsion (pH 6.3). The average grain size of this emulsion is 0.2-0.
It was 4 μm. The LCT / MCT emulsion was placed in a glass bottle of appropriate quality and then heat-sterilized by a conventional method to obtain a milk-like intravenous Alzheimer's disease prophylactic / therapeutic agent.

Example 4 19.7 g of acid casein was dissolved in an appropriate amount of an aqueous solution of sodium carbonate or potassium carbonate, 12 g of MCT and 3 g of safflower oil were added to this aqueous solution, and the mixture was homogenized and then dried by spray drying or freeze drying. Let Next, 0.3 g of DL-methionine, 64 g of dextrin, 1 g of vitamins and 5 g of minerals were mixed in a V blender to obtain a powdery oral therapeutic agent for Alzheimer's disease.

Example 5 MCT 5.4 g, safflower oil 1.3 g, casein hydrolyzate 8.87 g, DL-methionine 0.14 g, dextrin 28.8
g, Japanese Pharmacopoeia 0.2 g glycerin, 1 g vitamins, 5 g minerals and 0.2 g egg yolk phospholipid in 100 ml purified water
The resulting mixture was mixed with a homogenizer to give a liquid prophylactic / therapeutic agent for Alzheimer's disease for tube.

Example 6 MCT 12 g, safflower oil 3 g, acid casein 19.7 g, D
0.3 g of L-methionine, 54 g of α-corn starch, 10 g of sucrose, 1 g of vitamins and 5 g of minerals are homogeneously mixed and solidified with a molding machine or extruder capable of humidification and heating to give a solid oral form. An agent for preventing and treating Alzheimer's disease was obtained.

Experimental Example 1 MCT 10%, egg yolk phospholipid 1.8% and glycerin 2.21
% MCT emulsion was prepared and administered to rats intravenously,
The time course of acetylcholine and choline content in brain homogenate was examined.

1. Animals used Eighty-four-week-old male rats were used in the test. The weight at the time of test use was 81.3 g to 97.3 g.

2. Administration group composition, dose and administration rate The administration group is MCT emulsion administration group only, and the administration dose of MCT emulsion was confirmed to cause toxicity symptoms 20 ml / kg, 4 ml / min / animal. Five animals were used for each test.

3. Test Items (1) Acetylcholine Quantification Pretreatment Before administration, 10 minutes, 30 minutes, 1 hour, and 2 hours after administration, the rats were decapitated, and the brain was immediately removed to measure the wet weight of the brain. Next, 500 μl of 0.2 M perchloric acid (containing 100 μM EDTA2Na) was added to 100 mg of brain, and 10 ⁻⁴ M ethyl homocholine was added as an internal standard to perchloric acid.
After adding 100 μl per 500 μl, the mixture was homogenized with a Potter type Teflon homogenizer at 1,000 rpm under ice cooling. Then, put on ice for 30 hours to complete the protein.
After standing for 10 minutes, centrifuge at 10,000g x 15 minutes at 0 ° C, and remove the supernatant.
200 μl of 0.2 M KHCO ₃ was added to neutralize the mixture. After leaving it in ice for 30 minutes, the supernatant was filtered through a 0.45 μm filter and injected into a high performance liquid chromatograph equipped with an electrochemical detector.

Measurement Items Measurements were performed on acetylcholine and choline.

[Test Results] 1. Acetylcholine and Choline Content The acetylcholine and choline content in brain homogenate is shown in Table 1 below.

[0041]

[Table 1]

Acetylcholine increased 10 minutes after administration, gradually increased until 30 minutes after administration, and recovered to the pre-administration value 2 hours after administration. On the other hand, choline decreased contrary to acetylcholine at 10 minutes after administration, but recovered at 30 minutes after administration. No change was observed at 1 and 2 hours after administration, compared with the pre-administration value.

The reason why acetylcholine increases is that MCT
Octanoic acid, which is one of the constituent free fatty acids of cis, is transferred to the cerebrospinal fluid, so it is thought that octanoic acid is metabolized to acetyl-CoA in brain cells, and excess acetyl-CoA is synthesized with acetylcholine along with choline. To be

Therefore, the prophylactic / therapeutic agent for Alzheimer's disease according to the present invention stimulates the synthesis of acetylcholine, as in the case of conventional agents for Alzheimer's disease, or stimulates the receptor with an agonist of muscarinic acetylcholine receptor. The mechanism of action is fundamentally different from that of acetylcholine, which increases acetyl-CoA, which is also a raw material of acetylcholine, and produces acetylcholine in the brain, which is useful as a preventive and / or therapeutic agent for Alzheimer's disease. is there.

[0045]

EFFECTS OF THE INVENTION By the oral or parenteral administration of the Alzheimer's disease prophylactic / therapeutic agent according to the present invention to humans or the like, acetylcholine is produced in brain cells. It can be used for the purpose of improving the symptoms of Alzheimer's disease patients and preventing Alzheimer's disease.

Claims (1)

[Claims] 1. A preventive / therapeutic agent for Alzheimer's disease, which comprises a medium-chain fatty acid triglyceride whose constituent fatty acid is a fatty acid having 8 to 10 carbon atoms as a main component.