[Influence of silymarin and (+)-cyanidanol-3 on the HCB-induced porphyria in rats (author's transl)].

Adult female Wistar rats were fed continuously over a period of 65 days with a diet containing 0.05% hexachlorobenzene (HCB), silymarin (100 mg/kg) or (+)-cyanidanol-3 (150 mg/kg) alone or together with HCB. On day 49 the porphyrins were increased in the cyanidanol-HCB-group in contrast to the silymarin-HCB- and the HCB-group which showed lower levels during the whole experiment. Compared with the other groups--aminolevulinic acid and porphobilinogen were increased in the cyanidanol/HCB-group. Silymarin and cyanidanol had no effect on the formation of experimental porphyria. On the other hand, silymarin is a stronger inducer of the mixed function monooxygenase system than cyanidanol. The type of the cytochrome P-450 induced by the substances could not be identified with the help of different type-specific inhibitors.