EFFECTS OF KAMPO (JAPANESE HERBAL) MEDICINE SHO-SAIKO-TO ON DNA-SYNTHESIZING ENZYME-ACTIVITY IN 1,2-DIMETHYLHYDRAZINE-INDUCED COLONIC CARCINOMAS IN RATS

Sho-Saiko-To (SST) is a modified Japanese traditional Chinese herbal m edicine containing seven medical plants: Bupleuri radix, Pinelliae tub er, Suxtallariae radix, Zizyphi fructus, Ginseng radix, Glycyrrhizae r adix, and Zingiberis recens rhizoma. This preparation has been used in the treatment of some inflammatory diseases of the respiratory system and chronic hepatitis. In the present study, the effects of SST were investigated on the activities of DNA-synthesizing enzymes in 1,2-dime thylhydrazine (DMH)-induced colonic carcinomas in rats. Six-week admin istration of SST prevented nearly 100 % of the body weight loss and th e final number of the colonic carcinomas compared to those in the rats treated with DMH alone, and suppressed the enhanced activities of thy midylate synthetase (TS) and thymidine kinase (TK) which were involved in the de novo and salvage pathways of pyrimidine synthesis, respecti vely, in DMH-induced colonic carcinomas. These results indicate that S ST may show directly and/or indirectly inhibitory effects on the devel opment of colonic carcinomas.