GOMISIN-A, A LIGNAN COMPONENT OF SCHIZANDORA FRUITS, INHIBITS DEVELOPMENT OF PRENEOPLASTIC LESIONS IN RAT-LIVER BY 3'-METHYL-4-DIMETHYLAMINO-AZOBENZENE

The effects of gomisin A, a lignan component of Schizandra fruits, on development of preneoplastic lesions in the liver after a short-term ( 3 weeks) feeding of 3'-methyl-4-dimethyl-aminoazobenzene (3'-MeDAB) to male Donryu rats were investigated, and compared with the effects of phenobarbital. Gomisin A inhibited both increases of the level of glut athione-S-transferase placental form (GST-P) and the number and size o f GST-P positive foci in the liver increased after treatment with 3'-M eDAB. Moreover, although the population of diploid nuclei was increase d and that of tetraploid nuclei was decreased by pretreatment with 3'- MeDAB, gomisin A returned this to near the normal ploidy pattern. But phenobarbital increased the level of GST-P and the number and size of GST-P positive foci with little affect on the ploidy population change d by 3'-MeDAB. Thus, the effect of gomisin A on hepatocarcinogenesis w as inhibitory in contrast with that of phenobarbital. This study sugge sts that gomisin A is a candidate for a chemopreventive drug inhibitin g the promotion process in hepatocarcinogenesis.