JP2578070B2 - Blood cholesterol lowering agent containing bile alcohol sulfate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a blood cholesterol lowering agent containing bile alcohol sulfate.

[0002]

2. Description of the Related Art Hypercholesterolemia promotes arteriosclerosis and eventually causes ischemic heart disease. Therefore, various drugs for lowering blood cholesterol have been developed. These drugs are based on the mechanism of action,
Cholesterol biosynthesis inhibitors and cholesterol absorption inhibitors can be broadly classified into two categories.

[0003] Cholesterol biosynthesis inhibitors are intended to lower blood cholesterol by inhibiting the action of enzymes that act on cholesterol biosynthesis in the body. Inhibits not only the enzyme but also the enzyme system involved in other important biochemical reactions in the body, which may cause unexpected side effects, and also inhibits the biosynthesis of cholesterol in the pathway. However, problems such as accumulation of intermediates which are unfavorable for the human body have been pointed out.

[0004] On the other hand, cholesterol absorption inhibitors inhibit the absorption of cholesterol contained in food from the intestinal tract. When the amount of cholesterol absorbed from the intestinal tract decreases, cholesterol production in the body is correspondingly reduced. Because the synthesis is enhanced, depending on the administration of such drugs,
Blood cholesterol levels often do not drop as expected. In addition, in the category of cholesterol absorption inhibitors, the intestinal absorption of cholesterol is promoted by bile acids, and the effect of bile acids on promoting the aid is prevented by the administration of drugs that adsorb bile acids. Try to inhibit the intestinal absorption of cholesterol. However, bile acids are essential for the digestion and absorption of fats and the absorption of fat-soluble vitamins, and are also substances that exert important physiological actions such as solubilizing cholesterol and preventing gallstone formation. The administration of an acid adsorbent is not preferred because it inhibits the action of bile acids and results in poor digestion and absorption of fat, deficiency of fat-soluble vitamins, and promotion of cholesterol gallstone formation.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to solving the problems of the prior art, based on inhibition of cholesterol biosynthesis, such as conventional blood cholesterol lowering agents, A new category of blood cholesterol that is neither based on inhibition of cholesterol absorption nor on mere adsorption of bile acids (which, as noted above, is undesirable for fat digestion and fat-soluble vitamin absorption). It is intended to provide a reducing agent. More specifically, the present invention differs from conventional blood cholesterol lowering agents by suppressing the absorption of endogenous bile acids from the intestinal tract without impairing the above-mentioned effects brought about by endogenous bile acids. Promotes the de novo biosynthesis of sex bile acids, and thus the conversion of cholesterol to bile acids in the liver, thereby promoting the elimination of cholesterol and thereby safely and effectively lowering blood cholesterol. It is intended to provide a medicament that can be obtained.

[0006]

That is, the present invention provides a compound of the formula (I):

Embedded image (Wherein, R ₁ , R ₂ and R ₃ each independently represent a hydrogen atom, a hydroxyl group or a methyl group, and n represents an integer of 0 to 3). It is a blood cholesterol lowering agent containing an acceptable salt.

Here, bile alcohol sulfate is
It is a natural compound that has been discovered by the present inventors as a main component replacing bile acids in bile such as coelacanth, carp, frog, etc., and it has been revealed that a trace amount is also resident in human bile, We do not yet have a record of being used to treat the disease.

[0008] These bile alcohol sulfates
As shown below, large quantities are available by chemical synthesis from cholic acid (a major component of bovine bile acid) and other commercially available bile acids. For example, in formula (I), 5β-petromizonol sulfate in which R ₁ = α-OH, R ₂ = α-OH, R ₃ = H, and n = 2 (found in the bile of lung fish and also in human bile) It is known that trace amounts exist), Taiju KURAMOTO, Kenji KIHIRA, Naok
o MATSUMOTO and Takahiko HOSHITA, Determination of
the sulfate position in 5β-bufol sulfate by a ca
rbon-13 nuclear magnetic resonance study, Chem. Ph
arm. Bull., 29: 1136-1139 (1981).

That is, specifically, 5β-petromizonol sulfate is obtained according to the following route: 1 g of cholic acid is heated in acetic anhydride / pyridine to obtain triacetylcholic acid. This is reacted with ethyl chlorocarbonate in the presence of triethylamine to form the carboxylic acid residue of triacetylcholic acid in the form of an acid anhydride, which is reduced with sodium borohydride to triacetylcholanol. This is treated with a mixed solution of chlorosulfuric acid and pyridine to form a sulfate, and then three acetyl groups are removed by alkali hydrolysis to obtain 0.24 g of the desired 5β-petromizonol sulfate.

In the pharmacological / animal experiments described below, ursodesoxycholanol sulfate, a compound of the formula (I) wherein R ₁ = β-OH, R ₂ = H, R ₃ = H and n = 2, is used. Hereinafter, it is abbreviated as “UDC sulfate”.)
(Not yet found in nature.), But this compound was synthesized from ursodesoxycholic acid in the same manner as described above.

As a pharmaceutically acceptable salt of the compound represented by the formula (I), an alkali metal salt such as a sodium salt and a potassium salt, or an alkaline earth metal salt such as a calcium salt and a magnesium salt is particularly preferably used. .

The blood cholesterol-lowering agent of the present invention is orally administered to a patient. The preferred dose is usually 300 to 60 as bile alcohol sulfate.
The range is 0 mg / day. However, in general, the dose should be appropriately set in accordance with the severity of the disease, the patient's age, physique, constitution, and treatment policy. Therefore, other doses can be used as appropriate. . The form of the preparation is preferably a tablet or capsule (hard capsule or soft capsule) most commonly used for oral administration, but is not particularly limited thereto.

In the production of oral preparations such as tablets and capsules, commonly used excipients, binders, disintegrants,
Components such as lubricants can be used. Examples of excipients include, for example, lactose, sucrose, starch, microcrystalline cellulose,
As a binder such as calcium carbonate, for example, gelatin,
Gum arabic, hydroxypropylcellulose and the like, as disintegrants, for example, starch, sodium carboxymethylcellulose, calcium carboxymethylcellulose,
Lubricants such as sodium bicarbonate include, for example, magnesium stearate, calcium stearate, talc, macrogol and the like.

The effects and effects of the cholesterol-lowering agent of the present invention have been confirmed by an absorption experiment using the inverted intestinal tract of hamsters and a breeding experiment of hamsters, as shown below.

[Experiment Using Hamster Inverted Intestinal Tract] <Method>: The ileum of a male Golden Syrian hamster (body weight: 75 to 85 g) is taken out, inverted, and the upper and lower ends are tied to form a sausage-like bag (length 6 cm). Then, one of the following culture solutions a to c is put in the inside thereof, and it is suspended in a beaker filled with the same culture solution, and oxygen: carbon dioxide (95:
After incubating at 5 ° C. for 1 hour while aerating 5), [ ¹⁴ C] radioactivity in the internal solution and the external solution was measured to determine the amount of cholyltaurine absorbed. Culture solution a: 200 μM [ ¹⁴ C] cholyltaurine-containing sodium bicarbonate buffer (pH 7.4). Culture solution b: Culture solution a + 200 μM UDC sulfate. Culture solution c: Culture solution a + 400 μM UDC sulfate.

<Results>

[Table 1]

As shown in the column of culture solution a in Table 1, cholyltaurine is transferred from the external solution to the internal solution by the inverted intestinal tract of the hamster. Since the compositions of the inner solution and the outer solution are the same at the beginning of the experiment, this shift is performed against the concentration gradient and is absorbed by active transport. As can be seen from the culture solutions b and c in Table 1, the amount of absorption was reduced to about す る と when the same concentration (200 μmol) of UDC sulfate as cholyltaurine was present, and the double concentration (400 μmol) of UDC sulfate was observed.
When DC sulfate coexisted, it became about 1/4. This result indicates that the absorption of cholyltaurine decreases depending on the increase in the concentration of UDC sulfate, indicating that the absorption of cholyltaurine, an endogenous bile acid, from the ileum,
It has been demonstrated that the cholesterol-lowering agent of the present invention suppresses.

[Breeding Experiments] As shown in the following test examples, it was also confirmed that continuous oral administration of bile alcohol sulfate to hamsters fed a normal diet or a cholesterol diet, respectively, lowered blood cholesterol levels. . Therefore, it was confirmed that the cholesterol-lowering agent of the present invention exerts its effects not only in guinea pig inversion ileum experiments but also in oral administration. At this time, it was also confirmed that the activity of cholesterol-7α-hydroxylase, an enzyme that determines the rate of conversion of cholesterol to endogenous bile acids, was enhanced. This is because the intestinal reabsorption of bile acids is suppressed by bile alcohol sulfate, which results in the promotion of excretion of endogenous bile acids, thereby alleviating negative feedback in the liver and reducing cholesterol. This is presumed to be due to the promotion of the new biosynthesis pathway of bile acids. The absorption of lipids from the intestinal tract was not affected by the administration of bile alcohol sulfate. This indicates that inhibition of endogenous bile acid absorption by bile alcohol sulfate is performed in a competitive manner. The fact that the absorption of lipids is not affected is a problem in the digestion and absorption of lipids and the absorption of fat-soluble vitamins, which can be a problem with conventional bile acid adsorbents.
Indicates that it would not occur with sulfate.

<Test Method> Male Golden Syrian hamsters (body weight 75-85 g) were bred for 4 weeks in the following diet for 7 weeks, and then the blood cholesterol concentration, hepatic cholesterol concentration, and hepatic cholesterol-7α-hydroxylase level were measured. The activity was measured in each case.

Feed: Group 1: Standard diet. Group 2: Standard diet + 0.1% UDC sulfate. Group 3: Standard diet + 0.1% cholesterol. Group 4: Standard diet + 0.1% UDC sulfate + 0.1%
cholesterol. Here, the standard diet is a powder feed (manufactured by Oriental Yeast) consisting of 24.6% protein, 5.6% fat, 52.3% carbohydrate, 6.4% ash, 3.1% fiber, and 8.0% moisture.

Measurement of blood cholesterol concentration: A commercially available kit for measuring serum cholesterol (manufactured by Boehringer Mannheim, using cholesterol oxidase) was used. Measurement of hepatic cholesterol concentration: A part of the liver was lyophilized, extracted with hexane, and the extract was subjected to gas chromatography.

Cholesterol-7α hydroxylase activity:
The microsomal fraction prepared from the liver homogenate by centrifugation was incubated at 37 ° C. for 20 minutes in the presence of NADPH, and 7α-hydroxycholesterol generated from cholesterol present in the microsomal fraction was removed.
Quantification was performed by gas chromatography / mass spectrometry, and the enzyme activity was determined from the data.

<Test Results> The blood cholesterol concentration, hepatic cholesterol concentration and cholesterol-7α-hydroxylase activity are shown in Table 2 below.

[0024]

[Table 2]

For each measurement in the first group (standard diet), a second
As is clear from comparison of those in the group (with UDC sulfate added to the standard diet), in the second group with addition of UDC sulfate, both blood and hepatic cholesterol decreased, while the activity of cholesterol-7α-hydroxylase was decreased. Is observed. Group 3 (cholesterol-containing diet)
Similarly, in the comparison of the fourth group (adding UDC sulfate) to the above, in the fourth group to which UDC sulfate was added, a decrease in both cholesterol levels and an increase in enzyme activity were observed.

[0026]

EXAMPLES [Example 1] Tablets UDC sulfate 100 mg Lactose 75 mg Corn starch 22 mg Magnesium stearate 3 mg The above components are taken as one tablet, and the required amount of each component is collected, mixed, and manufactured into a tablet using a tableting machine. I do.

Example 2 Tablets UDC Sulfate 80 mg Lactose 90 mg Microcrystalline Cellulose 27 mg Magnesium Stearate 3 mg The above components are taken as one tablet, the required amount of each component is sampled, mixed, and the tablet is made using a tableting machine. To manufacture.

Example 3 Tablets UDC Sulfate 50 mg Corn Starch 90 mg Hydroxypropyl Cellulose 30 mg Magnesium Stearate 5 mg The above components are taken as one tablet, and the required amount of each component is collected.
First, UDC sulfate and corn starch are mixed.
Hydroxypropylcellulose is dissolved in an appropriate amount of alcohol, added to the mixture, kneaded, granulated using a granulator, and dried. Magnesium stearate is added to the granules and mixed, and tablets are produced using a tableting machine.

Example 4 Capsule UCD Sulfate 50 mg Corn Starch 15 mg Lactose 14 mg Microcrystalline Cellulose 20 mg Talc 0.5 mg Magnesium Stearate 0.5 mg The above components are taken as one capsule, and the required amount of each component is collected. And filled into capsules.

Claims (1)

(57) [Claims] (1) a compound represented by the formula (I): (Wherein, R ₁ , R ₂ and R ₃ each independently represent a hydrogen atom, a hydroxyl group or a methyl group, and n represents an integer of 0 to 3). A blood cholesterol lowering agent containing an acceptable salt.