Inhibition of lung cancer in diethylnitrosamine-induced mice by Rhizoma paridis saponins.

Lung cancer is the foremost cause of cancer mortality and a growing economic burden worldwide. Rhizoma paridis saponins (RPS) have been reported to exhibit potential anti-tumor effects on many kinds of tumor models. The present study was designed to investigate the mechanism-based chemopreventive nature of RPS against DEN-induced lung carcinogenesis in Kunming mice. As a result, the treatment with RPS reduced the severity of pulmonary histopathology. The mechanism of its antitumor effect involved in (a) reducing oxidative stress injury through up-regulating activities of CAT and SOD; (b) down-regulating the levels of inflammatory factors, like TNF-α, IL6, COX-2, and PGE2; (c) activation of caspase-3 and up-regulating the pro-apoptotic protein Bax; (d) decreasing the expression of PCNA; (e) depressing the expression of cancer stem cells marker CD133; (f) suppressing aberrant expression of cytokeratin 8 and 18; and (g) inhibiting EGFR/ PI3 K/Akt, EGFR/Ras/Erk and NF-κB pathways. Taken together, RPS would be a potent agent inhibiting lung tumor in the future.