Abstract A64: Chemopreventive potential of Bauhinia variegata against DMBA-induced skin papillomagenesis in Swiss albino mice

Abstract

Abstract The present study is an attempt to evaluate the cancer chemopreventive potential of Bauhinia variegata bark against DMBA-induced skin papillomagenesis in mice. We investigated chemopreventive effect of three different doses (2%, 4% and 6% w/w) of test diets of bark of B. variegata during DMBA-induced skin papillomagenesis in mice and tumor cell proliferation and apoptosis. Its effect was also studied in a short-term animal protocol on carcinogen metabolizing enzymes in liver. DMBA and croton oil was used to induce and promote skin papillomagenesis, respectively. Skin papillomagenesis study was done by using three different doses of B. variegata before, during and after the DMBA treatment to mice till termination of the experiment (120 days). In addition, the expression of proliferation [proliferating cell nuclear antigen (PCNA), glutathione-S-transferse (GST-π) and apoptosis were analyzed in the skin tumors by immunohistochemistry. For biochemical studies, mice were given with the same doses of B. variegata in the test diet for two weeks. The specific activities/levels of phase-I and phase-II enzymes, antioxidant enzymes, lactate dehydrogenase, glutathione content, and peroxidative damage were determined in the liver of the mice. Results showed a significant reduction in the skin tumors in B. variegata treated animals, as compared to the control group of animals. The tumor incidence in case of control group of animals was 100% whereas it was 90%, 70% and 99% in groups treated with 2%, 4% and 6% test diets, respectively. Tumor multiplicity in control group was 12±3.9 whereas it was reduced to 8±3.7, 3±2.9 and 4±2.4 by the lower, intermediate and higher dose of B. variegata treatment. The dietary administration of three different doses of B. variegata significantly decreased the expression of PCNA, GST-π, Bcl-2 and VEGF and on the other hand significantly increased the expression of Bax and total Caspase 3 as compared to DMBA and croton oil treated group of animals. The effect of 2 weeks of dietary feeding of B. variegata inhibited phase I, activated phase II and antioxidant enzymes in the mouse liver. The content of reduced glutathione was significantly elevated whereas the peroxidative damage and specific activity of lactate dehydrogenase exhibited a significant reduction with all the doses of test diets, respectively. All these findings were indicative of that Bauhinia variegata has chemopreventive potential against DMBA-induced skin carcinogenesis. It would be of interest to investigate for active cancer chemopreventive agents in Bauhinia variegata for its future implication in cancer prevention and control. Citation Information: Cancer Prev Res 2010;3(1 Suppl):A64.