Piperine as an adjuvant increases the efficacy of curcumin in mitigating benzo(a)pyrene toxicity.

In the present study, the antioxidative and anticlastogenic effects of curcumin and piperine separately and in combination have been investigated against benzo(a)pyrene (BaP)-mediated toxicity in mice. Male Swiss albino mice were pretreated with curcumin (100 mg kg(-1) body weight) and piperine (20 mg kg(-1) body weight) separately as well as in combination orally in corn oil for 7 days; and subsequently, after 2 h of pretreatment, BaP was administered orally in corn oil (125 mg kg(-1) body weight). A single dose of BaP in normal mice increased the levels of lipid peroxidation (LPO), protein carbonyl content (PCC), and frequency of bone marrow micronucleated polychromatic erythrocytes (MNPCEs) but decreased significantly the levels of endogenous antioxidants such as superoxide dismutases (SODs), glutathione peroxidase (GPx), glutathione reductase (GR), catalase (CAT) and reduced glutathione (GSH) in the liver. Pretreatments with curcumin and curcumin plus piperine before administration of single dose of BaP significantly decreased the levels of LPO, PCC, and incidence of MNPCEs but elevated the level of GSH and enzyme activities of GPx, GR, SOD, CAT, and glutathione-S-transferase (GST) when compared to the BaP-treated group. The effect of curcumin plus piperine is more pronounced as compared to curcumin in attenuating BaP-induced oxidative insult and clastogenicity.