JPS6352014B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an immunomodulator comprising mecobalamin [α-(5,6-dimethylbenzimidazolyl)-Co-methyl-cobamide]. Biochemically, mecobalamin is involved in transmethylation reactions as coenzyme B ₁₂ present in the blood, and has the highest in vivo activity among B ₁₂ homologs in nucleic acid, protein, and lipid metabolism. . Furthermore, pharmacologically, it has been proven that it promotes myelination and nerve regeneration, and clinically it has been established to be effective against neurological diseases such as diabetic neuropathy and polyneuritis, and peripheral neuropathy. It is used as a therapeutic agent. The present inventors have discovered that mecobalamin has an immunomodulatory effect. The present invention is based on this knowledge. Therefore, mecobalamin can be used as a therapeutic agent for diseases caused by or accompanied by abnormal immune function. Examples of such diseases include cancer, infectious diseases, allergic diseases, autoimmune diseases, and the like. Furthermore, some anticancer drugs, anti-inflammatory drugs, antibacterial drugs, and other drugs cause a decline in immune function as a side effect when administered. In particular, cancer chemotherapeutic agents generally have such a tendency. Mecobalamin is also useful for preventing the side effects of such drugs. Examples of drugs that cause immune dysfunction as a side effect include cyclophosphamide, cortisone acetate, vinblastine, vincristine, 6-mercaptopurine, 5-fluorouracil, mitomycin C, chloramphenicol, and adriamycin. Next, pharmacological tests and acute toxicity tests regarding the immunomodulatory effects of mecobalamin will be shown. (1) Antibody-producing cell proliferation effect (in vitro) Lymphocytes were separated from the mouse spleen by specific gravity centrifugation (Immunology Experimental Procedures, p. 265, edited by the Japanese Society of Immunology). By a modification of the method of Mishell et al. (Immunology Experimental Procedures, p. 353, edited by the Japanese Society of Immunology), 0.2 of a lymphocyte solution of 1×10 ⁷ /ml was obtained.
Add 0.2ml of sheep blood cells 1× ¹⁰⁶ cells/ml to ml,
Add mecobalamin to this at a predetermined concentration (1 μg/ml,
10 μg/ml, 100 μg/ml) and cultured for 5 days. Then, the method of Cunningham et al.
The number of antibody-producing cells was measured using the following method (p. 129, edited by the Japanese Society of Immunology). As a control, one without mecobalamin was selected. As shown in Table 1, addition of mecobalamin causes antibody-producing cells to proliferate. This indicates that mecobalamin has an immunoenhancing effect.

[Table] (2) Effect of concanavalin A on enhancing blastogenesis of mouse T lymphocytes (in vitro) Mouse lymphocytes were isolated using the method described in (1) above, and the method of Specter et al.
Obimmunology (J.Immunol.), Volume 120,
487, 1978], the degree of juvenileization of mouse T lymphocytes was measured. That is, 0.2 ml of lymphocyte fluid 2 × 10 ⁶ cells/ml and concanavalin.
Mix 0.02ml of A25μg/ml, then add mecobalamin to the specified concentration (1μg/ml, 10μg/ml)
I added it so that it becomes . After culturing for 2 days, ³ H
- After adding 0.5 μC of thymidine and culturing for another day, lymphocytes were separated and their radioactivity was measured. As a control, one without mecobalamin was selected. As shown in Table 2, those containing mecobalamin have high radioactivity of lymphocytes. This indicates that mecobalamin has an effect of enhancing the juvenile development of suppressor T cells, and further indicates that mecobalamin also has an immunosuppressive effect.

[Table] (3) Effect of recovery from decreased immune function after treatment with cyclophosphamide 1 mg/mouse of cyclophosphamide was administered intraperitoneally to BDF ₁ mice (female, 7 weeks old).
Two days later, 5×10 ⁸ sheep red blood cells/0.25 ml were intravenously injected. From the next day, a predetermined amount of mecobalamin (0 μg, 1 μg, 10 μg, 100 μg) was administered into the recovery cavity four times daily. On the fifth day after intravenous injection of sheep red blood cells, the spleen of the mouse was removed, and the number of antibody-producing cells (nucleated cells: 10 ⁶
Mice without administration of cyclophosphamide or mecobalamin were selected as controls. As shown in Table 3, mecobalamin has the effect of restoring the weakened immune function caused by cyclophosphamide administration.

[Table] (4) Effect of recovery from decreased immune function in mice treated with cortisone acetate. The test was conducted in the same manner as method (3). However, 2.5 mg/mouse of cortisone acetate was used instead of cyclophosphamide in (3). As the results are shown in Table 4, mecobalamin has the effect of restoring the weakened immune function caused by administration of cortisone acetate.

[Table] (5) Inhibitory effect on cancer cell growth in mice with bile cancer Mouse ascites tumor cells (180 Sarcoma ^cells /mouse/0.2ml) were subcutaneously transplanted, and from day 3 to day 14 after transplantation. Mecobalamin (10 μg/mouse/day) was administered intraluminally. The size of the solid cancer was measured on the 9th and 14th day after cancer transplantation. The measurement was performed by measuring the long and short axes of the cancer and multiplying them to calculate the area. As a control, one without mecobalamin administration was selected. As shown in Table 5, mecobalamin has a growth inhibiting effect on solid cancer.

[Table] (6) Acute toxicity An acute toxicity test for mecobalamin was conducted. The results are shown in Table 6. The unit in the table is mg/Kg.

[Table] There were no deaths at the above doses, and no effects suggestive of toxicity were observed. As shown above, mecobalamin has an immunomodulating effect, and its toxicity is also low compared to the administered dose. The dosage of mecobalamin per day for adults is approximately
It is 10 μg to 50 mg and is administered orally or parenterally. Dosage forms include powders, fine granules, granules, tablets, capsules, and injections (ampoules, vials).
These can be produced by conventional methods. However, since mecobalamin is unstable to light, it is desirable that the production be carried out in a light-shielded environment, and that each preparation be packaged in a manner that can shield it from light. Next, a pharmaceutical formulation will be shown as an example. Example 1 Capsules Mecobalamin 250 μg Starch 50 mg Crystalline cellulose 50 mg The above powders were mixed and filled into No. 4 hard gelatin capsules to prepare capsules. Example 2 Injection 250 μg of mecobalamin and 10 mg of mannitol were dissolved in 11 ml of distilled water, sterilized, and freeze-dried. This was sealed in a brown vial. When using
Dissolve in 2 c.c. of distilled water for injection and inject.

Claims (1)

[Claims] 1. An immunomodulator comprising mecobalamin. 2. The immunomodulator according to claim 1, which is used as a cancer therapeutic agent. 3. The immunomodulator according to claim 1, which is used as a side effect preventive agent for a drug that causes a decrease in immune function as a side effect.