Anticancer potentials of root extract of Polygala senega against benzo[a]pyrene-induced lung cancer in mice

To evaluate anticancer potentials of Polygala senega on lung cancer induced by benzo[a]pyrene (B[a]P) in mice.

Swiss albino mice were divided into five groups with each containing six animals. Group 1 served as control, and the animals received olive oil as vehicle. Group 2 animals were treated with B[a]P (50 mg/kg body weight dissolved in olive oil) orally twice a week for four consecutive weeks. Group 3 animals were fed B[a]P as in group 2 and 48% alcohol (since the vehicle of the remedy was alcohol). Group 4 animals were B[a]P-intoxicated mice (as in group 2) which were additionally fed ethanolic extract of Polygala senega (EEPS) daily for 16 weeks. EEPS treatment started after the first dose of B[a]P. Group 5 animals were treated with EEPS alone for 16 weeks to test cytotoxicity of EEPS if any. Mice were sacrificed after 16 weeks and the following parameters were assessed: the anti-oxidant activity measured by 2,2-diphenyl-1-picrylhydrazyl free radical assay, tumor incidence, lung weight and body weight, DNA damage evaluation by comet assay and enzyme-linked immunosorbent assay (ELISA); toxicity biomarkers like catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, lipid peroxidation (LPO) and total thiol content were also detected.

Treatment with EEPS increased the final body weight and significantly decreased the lung weight in group 4 mice (P<0.01) compared with group 3 mice. Comet assay showed that EEPS-treated mice in group 4 presented a decrease of DNA damage significantly (P<0.01) in lung tissues. There was a significant increase observed in the level of p53 in group 4 as compared with group 3 (P<0.01) detected by ELISA. A highly significant increase in tissue LPO with concomitant decrease in the activity of anti-oxidants was observed in group 2 and group 3 mice (P<0.05) compared with the control mice. These adverse changes were reversed significantly in group 4 mice (P<0.01).

Chemopreventive potentials of Polygala senega against chemically induced lung cancer in mice are confirmed.