Interaction of piperine with rat liver microsomes.

Pretreatment of adult male albino rats with piperine did not induce cytochrome P-450 whereas safrole did cause such induction. Piperine and safrole interacted with different forms of cytochrome P-450 as indicated by their in vivo effect on drug metabolising enzymes and mixed function oxidases and electrophoretic patterns. Incubation of piperine or safrole with dithionite- or NADPH-reduced microsomes from untreated rats resulted in a modified type II difference spectrum with an absorption maximum at 427 nm and a trough at 408 nm.