Protective effects of curcumin and quercetin during benzo(a)pyrene induced lung carcinogenesis in mice

Phytochemicals is one such family of chemopreventive agents that is being researched extensively the world over for its efficacies against several cancer pathways. Curcumin and quercetin belong to the family of phytochemicals and have anti-oxidative and anti-carcinogenic properties. In the present study, chemopreventive efficacy of curcumin and quercetin was investigated against benzo(a)pyrene (BP) induced lung carcinogenesis.

The mice were segregated into five groups which included normal control, BP treated, BP+curcumin treated, BP+quercetin treated and BP+curcumin+quercetin treated groups. Lung carcinogenesis was induced by a single intra-peritoneal (IP) injection of BP (100 mg/kg body weight). Curcumin was supplemented to mice at a dose level of 60 mg/kg body weight in drinking water and quercetin was given at a dose level of 40 mg/kg body wt in drinking water.

The BP treatment resulted in a significant increase in LPO and ROS levels. GSH levels and the activities of SOD, GST as well as GR were found to be significantly decreased following BP treatment. Further, BP treatment brought about a significant increase in the activities of drug metabolizing enzymes (cytochrome P450 and b5). Curcumin and quercetin treatments to mice were able to decrease significantly the levels of LPO, ROS, as well as activities of SOD, GST. Also, the activities of drug metabolizing were markedly decreased by the administration of phytochemicals.

The results of this study suggest that combined treatment with curcumin and quercetin proved beneficial on antioxidant status and drug metabolizing enzymes during experimentally induced lung carcinogenesis in mice.