JPH05112596A - Medicine containing bufalin and bufadienolide as effective components - Google Patents

Abstract

PURPOSE: To obtain new compds. useful in the treatment of tumors such as leukemia as antitumorigenic agents because they have strong induced differentiation actions to various tumorous cells.

CONSTITUTION: The new compds. are bufalin, cinobufagin and their analogous compds. of formula I-III (where R¹ is H or OH and R² is H, OH or acetyl). They are obtd. by extraction by a known method from senso useful as domestic drug obtd. by gathering and drying excreta from the position gland of tuna bufo or its close relative.

COPYRIGHT: (C)1993,JPO

Description

Detailed Description of the Invention

FIELD OF THE INVENTION The present invention relates to a drug containing bufadininolide bufalininolide, which has an effect of inducing differentiation of cells such as tumor cells, cinobufagine and related compounds thereof, specifically, treatment of tumors such as leukemia. Regarding medicine.

BACKGROUND OF THE INVENTION Various compounds having a differentiation-inducing action have been studied in the past, and an anti-cancer compound having a differentiation-inducing activity of promoting tumor cell differentiation and decanceration is known. Has been. However, very few compounds have the ability to induce differentiation commonly in tumor cells. The present inventors have conducted research for the purpose of discovering a new compound commonly showing differentiation induction in tumor cells and providing it as an antitumor agent.

[Means and Actions for Solving the Problems] As a result of research, the present inventors have collected and dried the secretions of venom glands of Senso (Rana toad or related species), which have been conventionally used as home remedies and herbal medicines. From the general formula (I)
Bufferin, cinobufagin and similar compounds cardiotonic steroids represented by (II) and (III) are described in M. K
omatsu and S.M. Okano (Analytical Chemistry, 1
5,1115 (1966)),
It was discovered that these compounds are new compounds having a differentiation-inducing ability to promote the differentiation (decanceration) of cancer cells. (L.
Zhang, K .; Nakaya, T .; Yoshida
and Y. Kuroiwa (Biochem. Bio
phys. Res. Commun. , 178 686
(1991)). It was also found that bufarin also shows strong cytotoxicity against various human-derived tumor cells other than leukemia cells. In particular, bufarin has a common differentiation-inducing ability for four human spinal leukemia cells that are developmental offspring, and can be used as an antitumor agent. The bufalin represented by the general formula (I) of the present invention can be administered by formulating it in the form of, for example, an oral preparation or an injectable preparation according to a conventional method. Preferred dosage forms for oral administration include, for example, tablet capsules, granules and solutions. Furthermore, bufarin exhibits an additive or synergistic differentiation-inducing action with known transduction agents such as all-trans-retinoid acid and interferon, and a more effective therapeutic effect can be expected. The pharmacological actions of bufarin and cinobufagin represented by the general formulas (I) and (II) of the present invention and further similar compounds will be described by way of specific test examples. Test Example 1 Cytotoxicity (viability rate) of the compound of the present invention to human myeloid leukemia cells K562 And the ability to reduce nitroblue tetrazolium (NBT) were used to evaluate the activity of the compound of the present invention to induce differentiation of cancer cells. This measurement is based on the K. Tanaka et al. (Can
cer Res. , 42, 5152 (1982)). The compound of the present invention and K562 leukemia cells (1 × 10 ⁵ cells / ml) were incubated for 4 days, and RPHI-1640 + 10 was used as a medium.
% Fetal bovine serum (inactivated by heat treatment at 56 ° C. for 30 minutes) was used and cultured in the gas phase of 5% carbon dioxide and 95% air. The compound of the present invention was dissolved in ethanol in this medium, and the concentration of ethanol in the culture solution was adjusted to 0.1% and added. 2.5 to 10 K562 cells
NBT when incubated with 0 nM bufarin
Differentiated into cells having reducing ability. 10 nM bufarin differentiated about 80% of K562 cells into cells having NBT reducing ability without showing cytotoxicity. From 50 nM to 100 nM bufarin, the survival rate of K562 cells decreased in a dose-dependent manner, and most of the remaining cells had NBT reducing ability. The morphological and biochemical examination of the cells induced to differentiate by bufarin showed that they were differentiated into mature white blood cells. Then, when bufarin and cardiotonic steroid were added, the same differentiation into white blood cells as above was morphologically observed. Among these cardiotonic steroids used, the differentiation-inducing action of bufarin was particularly strong. The experimental results are summarized in Table 1. Test Example 2 As a result of Test Example 1, since the differentiation-inducing activity of bufarin against K562 leukemia cells was the most potent, the results of examining the effects on three types of leukemia cells at different developmental stages are summarized in Table 2. In the same manner as in Test Example 1, HL
-60 cells contain 5 nM bufarin, ML-1 and U9
When 37 cells were incubated with 10 nM bufarin for 4 days, HL-60, similar to K562 cells,
Both ML1 and U937 leukemic cells were NBT
Differentiation was induced (de-cancerous) into macrophage-like cells having virulence.

INDUSTRIAL APPLICABILITY The compound of the present invention has a strong cancer cell differentiation-inducing activity (carcinogenic effect), and also shows a common differentiation-inducing activity for various cancer cells, and is added to conventionally known differentiation-inducing agents. Alternatively, since they show a synergistic effect, they can be expected to be used as excellent cancer chemotherapeutic agents.

Claims (4)

[Claims] 1. A general formula In the formula, R1 is a hydrogen atom or a hydroxyl group, and R2 is a hydrogen atom hydroxyl group or an acetyl group. 2. The medicine according to claim 1, which is a cell differentiation inducer. 3. The differentiation inducer according to claim 2, wherein the cells are tumor cells. 4. The drug according to claim 2 or 3, wherein the cell differentiation inducer is an antitumor agent.