Comparative in vitro study of the effects of the new antitumor drug Ukrainand several cytostatic agents on the thiol groups in the tissue of Guerin carcinoma and its resistance to cisplatin variant

A comparative in vitro study between the effects of Ukrain (a new synthetic thiophosphoric acid derivative of great celandine alkaloids) and alkylatin g antitumor drugs cyclophosphamid and cisplatin on total thiol content in G uerin carcinoma, Guerin/cis-DDP ca,carcinoma, and in animal livers was carr ied out. It is shown that Ukrain action on thiol groups in Guerin carcinoma tissue does not differ from that of cyclophospamid and cisplatin to both o f which Guerin carcinoma is very sensitive. Once tumor resistance to cispla tin has developed, cisplatin does not react with tumor thiol groups and cyc lophosphamid reactions with tumor thiol groups decrease. Reactions of Ukrai n with thiol groups of cisplatin resistant tumors increase. This indirectly indicates the increase of tumor sensitivity to this drug. Therefore, the c ytotoxicity of Ukrain is similar to that of known antitumor drugs and can p robably overcome the cisplatin resistance of the tumor.