JP3486778B2 - Alzheimer's disease preventive / treatment agent - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prophylactic and / or therapeutic agent for Alzheimer's disease, and more particularly to a prophylactic and / or therapeutic agent for Alzheimer's disease caused by a decrease in brain acetylcholine content. For drugs. [0002] It is generally known that acetylcholine content in the brain is reduced in patients with Alzheimer's disease, which is one of the senile dementias, and is an important index for drug development for this disease. It has become. [0003] Drugs currently used or being developed are enzymes that synthesize acetylcholine, enzymes that inhibit the degradation of acetylcholine, or acetylcholine synthesis that supplies choline, a precursor of acetylcholine, to the brain. Either by stimulating or by stimulating the receptor with an agonist of the muscarinic acetylcholine receptor. [0004] An object of the present invention is to provide a prophylactic and / or therapeutic agent for Alzheimer's disease whose action mechanism is fundamentally different from that of conventional drugs. The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have found that the number of carbon atoms is 8 to 10;
The free fatty acids of the medium-chain fatty acid triglyceride (hereinafter referred to as “MCT”), which contains the fatty acids of the present invention, pass through the blood-brain barrier to the cerebrospinal fluid and are metabolized to acetyl-CoA in the brain cells. Minute acetyl Co
A found that A produced acetylcholine together with choline, and completed the present invention. The present invention has been completed on the basis of such new findings, and is an agent for preventing or treating Alzheimer's disease containing MCT whose constituent fatty acid is a fatty acid having 8 to 10 carbon atoms as a main component. [0007] In the present invention, the MCT has a carbon number of 8
Triglycerides composed of up to 10 saturated fatty acids such as caprylic acid and capric acid are used. When the constituent fatty acids of MCT are caprylic acid and capric acid,
In order to reduce the toxicity of CT, the ratio of caprylic acid to capric acid is preferably from 8: 2 to 4: 6. In the present invention, the MCT consists essentially of only the MCT containing fatty acids having 8 to 10 carbon atoms as constituent fatty acids. Here, “substantially” means that MCT having a fatty acid other than 8 to 10 carbon atoms as a constituent fatty acid,
It means that it may be contained in an amount that does not impair the purpose of the present invention. [0008] The MCT of 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 a high-content fat or oil. For example, it can be obtained by hydrolysis of cocoa butter or palm fat, fractionation of fatty acids by distillation, and re-eswellation 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 have high purity, and those containing, for example, at least 90% (by weight), preferably at least 95% (by weight) as a main component are suitable. The preventive and therapeutic agent for Alzheimer's disease of the present invention comprises
It contains MCT in an amount of 1 to 50% by weight, preferably 5 to 15% by weight, and its dosage form such as solid form, powder form, liquid form and emulsified form is not limited at all. That is, it can be administered orally or parenterally such as by injection (eg, intravenous administration, tube administration to the stomach, duodenum or jejunum, etc.). One dosage form of the prophylactic / therapeutic agent for Alzheimer's disease of the present invention includes a fat emulsion. Such a fat emulsion is prepared from the above-mentioned MCT, emulsifier, water, and appropriate additives by a conventional method. Examples of the emulsifier include phospholipids (egg yolk phospholipids, soybean phospholipids), nonionic surfactants and the like, and any emulsifier may be used as long as it is purified for medical use. As the phospholipid, purified phospholipids such as egg yolk lecithin and soybean lecithin are suitable, and can be prepared by a conventional fractionation method using an organic solvent. It is mainly composed of phosphatidylcholine and phosphatidylethanolamine, and also contains other phospholipids such as phosphatidylinositol, phosphatidylserine, sphingomyelin and the like. As the phospholipid, those not containing phosphatidylethanolamine may be used. This product can be obtained by subjecting generally available phospholipids such as egg yolk and soybean to organic solvent fractionation by a conventional method, and then purifying the resultant with an inorganic absorbent such as silica gel or alumina. The phospholipid thus obtained is mainly composed of phosphatidylcholine, and may contain phosphatidylinositol, phosphatidylserine, sphingomyelin as other phospholipids. Further, phosphatidylcholine itself may be used. The water to be used varies depending on the administration mode, and water suitable for intravenous injection (eg, distilled water for injection, purified water for injection, etc.) or water suitable for oral use (eg, purified water) is used. The content of each component of the fat emulsion is, for example, 1 to 50% (w / v), preferably 5 to 15% (w / v) of the oil component (MCT), and 100 parts of the oil component. The emulsifier comprises 1 to 500 parts (preferably 10 to 50 parts) and an appropriate amount of water. In addition, if necessary, an emulsifying aid (for example, a fatty acid having 6 to 22 carbon atoms, preferably 12 to 20 carbon atoms or an pharmaceutically acceptable salt thereof in an amount of up to 0.3% (w / v)). Salt, etc.), stabilizer [eg, 0.5% (w / v)
Cholesterol in an amount of no more than 0.1% (w / v), or no more than 5% (w / v), preferably 1%
(W / v) or less of phosphatidic acid or the like], a high molecular substance [for example, 0.1 to 5% (w / v), preferably
5 to 1% (w / v) of albumin, dextran, vinyl polymer, nonionic surfactant, gelatin, hydroxyethyl starch, etc.], tonicity agent (for example, glycerin,
Glucose and the like), flavors and the like can also be added. Any fatty acid having 6 to 22 carbon atoms as an emulsifying aid can be used as long as it can be added to pharmaceuticals. 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 (eg, sodium salt,
Potassium salt), alkaline earth metal salts (eg, calcium salt, magnesium salt, etc.) and the like can be used. Further, an aliphatic amine may be used as an emulsifying 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 pharmaceuticals. This aliphatic amine is linear,
It may be branched, but it is preferable to use linear ethylamine, propylamine, octylamine, stearylamine, oleylamine and the like. The addition amount is, for example, about 0.0001 to 0.01% (w / v). When the emulsification is insufficient, various known emulsification aids can be further used. Cholesterol and phosphatidic acid as stabilizers are not particularly limited as long as they can be used for medicine. Albumin is preferably derived from humans due to the problem of antigenicity, and vinyl polymers include polyvinylpyrrolidone and polyvinyl alcohol. Examples of the nonionic surfactant include polyalkylene glycols (for example, polyethylene glycol having an average molecular weight of 1,000 to 10,000, preferably 4,000 to 6,000), and polyoxyalkylene copolymers (for example, an average molecular weight of 1,000 to 20,000, preferably 6, 00
0 to 10,000 polyoxyethylene-polyoxypropylene copolymer), hydrogenated castor oil polyoxyalkylene derivative [for example, hydrogenated castor oil polyoxyethylene- (20)-
Ether, same- (40) -ether, same- (100) -ether, etc.), castor oil polyoxyalkylene derivative (e.g., castor oil polyoxyethylene- (20) -ether, same- (40) -ether, same as above) -(100) -ether etc.]. 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, heated to form a solution, and homogenized using a conventional homogenizer (eg, a high-pressure injection homogenizer, an ultrasonic homogenizer, etc.). Thus, a water-in-oil dispersion is prepared, and then water containing a required amount of an isotonic agent, a stabilizer and the like is added thereto, and the mixture is homogenized again with the homogenizer to convert it into an oil-in-water emulsion. Can be manufactured. 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 has an average fat particle size of about 0.05 to 0.5 μm.
And its storage stability is very good. The above-mentioned fat emulsion may contain a long-chain fatty acid triglyceride (hereinafter referred to as "LCT"), and a fatty acid triglyceride containing a saturated or unsaturated fatty acid having 16 to 18 carbon atoms as a constituent fatty acid is preferable. As an example. LCT is a substance containing the LCT as a main component, for example, a vegetable oil containing the LCT at 95% (by weight) or more, preferably at least 99% (eg, cottonseed oil, soybean oil, corn oil, peanut oil, safflower oil) Etc.). Preferred LCTs include soybean oil. High-purity refined soybean oil is suitably used as soybean oil, and more preferably refined soybean oil obtained by further refining refined soybean oil by, for example, a steam distillation method (purity: containing 99.9% or more as triglyceride). Is used. Fatty acids constituting LCT include, for example, palmitic acid, stearic acid, linoleic acid, linolenic acid,
Oleic acid and the like can be mentioned. When LCT is contained, the weight ratio of MCT to LCT is from 4: 1 to 1: 4, preferably from 2: 1 to 1: 2, and more preferably 1: 1. MCT contained in the Alzheimer's disease preventive / remedy of the present invention is generally rapidly and easily absorbed from intestinal epithelial cells after administration, transported to the liver via the portal vein, oxidized by the liver, and used as energy. It is used as a nutrient as a high calorie energy source that is easy to absorb. Therefore, the preventive and therapeutic agent for Alzheimer's disease of the present invention includes proteins, amino acids,
Peptides, plant lipids, carbohydrates, minerals, vitamins,
Further, other known additives (for example, an emulsifier, a stabilizer) and the like may be appropriately compounded. Examples of the protein include vegetable protein, whey protein and low-lactose milk protein, and amino acids such as valine, leucine, isoleucine, threonine, lysine, and the like.
Methionine, phenylalanine, tryptophan are exemplified, examples of vegetable lipids include linoleic acid such as safflower oil, corn oil, soybean oil, cottonseed oil, sunflower oil, and linseed oil, and lipids containing linolenic acid. Monosaccharides such as glucose, mannose, galactose and fructose, lactose, sucrose, disaccharides such as maltose, dextrin, polysaccharides such as pregelatinized starch are exemplified, and as minerals, sodium, potassium, calcium, magnesium, Iron, zinc, chlorine, phosphorus, copper,
Manganese, cobalt, molybdenum, chromium, selenium and the like are exemplified. As the vitamins, vitamin A (A ₁ ,
A ₂ , retinene, provitamin A), vitamin B ₁ (thiamine, anoiline), vitamin B ₂ (riboflavin,
Lactoflavin), vitamin B ₆ (pyridoxine, pyridoxal, pyridoxamine, pyridoxal phosphate), pantothenic acid, nicotinamide, 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 and therapeutic agent for Alzheimer's disease of the present invention
In the case of oral administration, 100 g to 300 g per day as an adult standard amount
(For example, for a 10% w / v solution, 1,000 ml to 3,000 m
l) is divided into several doses, 10% for parenteral administration
As a w / v to 30% w / v solution, the administration rate is 100 to 150%.
The drug is continuously administered to the stomach, duodenum, or jejunum at a rate of ml / hour, or divided into several times a day by infusion via tube or intravenously. In addition, the dose, the concentration, and the administration rate are appropriately increased or decreased according to the age, symptoms, body weight, and the like. According to the agent for preventing and treating Alzheimer's disease according to the present invention, MC comprising a fatty acid having 8 to 10 carbon atoms as a constituent fatty acid
Since T is contained as a main component, the constituent free fatty acids of MCT migrate to the cerebrospinal fluid through the blood-brain barrier and are metabolized to acetyl-CoA in brain cells. Produces acetylcholine. EXAMPLES The present invention will be described in more detail with reference to the following Examples and Experimental Examples, which by no means limit the present invention. [Raw materials] MCT; MCT contains 77% of caprylic acid and 23% of capric acid
Is a medium-chain fatty acid triglyceride that is randomly esterified with glycerin. It is a colorless to slightly yellow transparent liquid. Solubility in water is 60mg / dl, freezing point is -14
° C, calorie is 8.3 kcal / g. Example 1 50 g of refined soybean oil (LCT), 50 g of MCT, 22.1 g of glycerin of the Japanese Pharmacopoeia and an appropriate amount of distilled water for injection were mixed, and 12 g of egg yolk phospholipid was mixed as an emulsifier. To perform coarse emulsification. Furthermore, using a Menton-Gaulin type homogenizer, the total pressure was 200 to 25.
The emulsion was emulsified under a pressure of 0 kg / cm ² for 10 minutes. A very fine LCT / MCT emulsion homogenized by this (pH 6.3)
Got. The average grain size of this emulsion was 0.2 to 0.4 .mu.m. This LCT / MCT emulsion was placed in a glass bottle of an appropriate quality, and then heat-sterilized by a conventional method to obtain a milk-like intravenous prophylactic and therapeutic agent for Alzheimer's disease. Example 2 In Example 1, M was used without using refined soybean oil (LCT).
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 particle size of this emulsion is 0.2 to 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 and therapeutic agent for Alzheimer's disease. Example 3 50 g of refined soybean oil (LCT), 50 g of MCT, 22.1 g of glycerin of the Japanese Pharmacopoeia, 50 g of sucrose, a small amount of flavor and an appropriate amount of distilled water for injection were mixed with 12 g of yolk phospholipid as an emulsifier, Coarse emulsification was performed using a homomixer with the total amount being 1 liter. Thereafter, emulsification was carried out in the same manner as in Example 1. As a result, a homogenized very fine LCT / MCT emulsion (pH 6.3) was obtained. The average particle size of this emulsion is 0.2 to 0.
It was 4 μm. This LCT / MCT emulsion was placed in a glass bottle of an appropriate quality, and then heat-sterilized by a conventional method to obtain a milk-like intravenous prophylactic and therapeutic agent for Alzheimer's disease. Example 4 19.7 g of acid casein was dissolved in an appropriate amount of an aqueous solution of sodium carbonate or potassium carbonate, and 12 g of MCT and 3 g of safflower oil were added to the aqueous solution, homogenized, and then dried by spray drying or freeze drying. I let it. 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 remedy 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, glycerin 0.2 g of the Japanese Pharmacopoeia, vitamins 1 g, minerals 5 g and egg yolk phospholipids 0.2 g in purified water 100 ml
And mixed by a homogenizer to obtain a liquid tube-feeding preventive / treatment agent for Alzheimer's disease. Example 6 12 g of MCT, 3 g of safflower oil, 19.7 g of acid casein, 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 mixed homogeneously and solidified with a molding machine or extruder capable of humidification and warming to obtain a solid oral preparation. 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 intravenously to rats.
The time course of acetylcholine and choline content in the brain homogenate was examined. 1. Animals used 80 male rats of 4 weeks of age were used for the test. The weight at the time of using the test was 81.3 g to 97.3 g. 2. Administration group composition, dose and administration rate The administration group was the MCT emulsion administration group only. The dose and administration rate were 20 ml / kg, 4 ml / min / animal. Five animals were used for each test. 3. Test Items (1) Quantification of Acetylcholine Rats were decapitated before administration of the pretreatment, 10 minutes, 30 minutes, 1 hour and 2 hours after administration, and the brain was immediately removed to measure the brain wet weight. Next, 500 μl of 0.2 M perchloric acid (containing 100 μM EDTA2Na) was added to 100 mg of the 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 place in ice for 30 minutes to complete the Xu protein.
After centrifugation at 10,000g for 15 minutes at 0 ° C,
200 μl of 0.2 M KHCO ₃ was added to 200 μl for neutralization. Further, after standing 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] Acetylcholine and choline content The acetylcholine and choline content in the brain homogenate is shown in Table 1 below. [Table 1] Acetylcholine increased at 10 minutes after administration, gradually increased until 30 minutes after administration, and returned to the pre-dose value 2 hours after administration. On the other hand, choline, contrary to acetylcholine, decreased at 10 minutes after administration, but recovered at 30 minutes after administration. At 1 hour and 2 hours after administration, no change was observed as compared to the value before administration. The reason that acetylcholine is increased is that MCT
It is thought that octanoic acid, which is one of the constituent free fatty acids, is transferred to cerebrospinal fluid, so that octanoic acid is metabolized into acetyl-CoA in brain cells and excess acetyl-CoA is synthesized into acetylcholine together with choline. Can be Accordingly, the prophylactic / therapeutic agent for Alzheimer's disease according to the present invention stimulates the synthesis of acetylcholine or stimulates the receptor with an agonist of muscarinic acetylcholine receptor, like a conventional drug for Alzheimer's disease. The mechanism of action is fundamentally different from that of acetylcholine, which increases acetyl-CoA, which is also a source of acetylcholine, and produces acetylcholine in the brain, and is useful as a prophylactic and / or therapeutic agent for Alzheimer's disease. is there. Effects of the Invention [0045] Oral or parenteral administration of the agent for preventing or treating Alzheimer's disease according to the present invention to humans or the like produces acetylcholine in brain cells. Can be used for the purpose of improving the symptoms of Alzheimer's disease patients in which Alzheimer's disease is observed and preventing Alzheimer's disease.

Claims (1)

(57) [Claim 1] An agent for preventing or treating 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.