Piperine, a major ingredient of black and long peppers, protects against AFB1-induced cytotoxicity and micronuclei formation in H4IIEC3 rat hepatoma cells.

We studied the effect of piperine on the cytotoxicity and genotoxicity of aflatoxin B1 (AFB1) in rat hepatoma cells H4IIEC3/G-(H4IIE) using cellular growth and formation of micronuclei as endpoints. Piperine was earlier shown to inhibit cytochrome P-450-dependent aryl hydrocarbon hydroxylase and 7-methoxycoumarin demethylase activities in preparations of these cells with 1/2 maximum inhibition at 30-50 microM (Singh J. and Reen R.K., Current Science, 66, 365-369, 1994). The results of the present study showed that AFB1 inhibited the growth of H4IIE cells with an ED50 of 15 nM. Piperine markedly reduced the toxicity of the mycotoxin. Thus at 100 microM piperine largely restored the rate of growth of the cells. Likewise, piperine reduced the AFB1-induced formation of micronuclei in a concentration-dependent manner. Piperine itself was not toxic to the cells up to a concentration of almost 100 microM. The results suggest, that piperine is capable of counteracting AFB1 toxicity by suppressing cytochromes P-450 mediated bioactivation of the mycotoxin.