Phellinus rimosus (Berk.) pilat attenuates 7,12-dimethylbenz[a] anthracene induced and croton oil promoted skin papilloma formation in mice.

The roles of 7,12-dimethylbenz[a]anthracene (DMBA), a polycyclic aromatic hydrocarbon (PAH), and 12-O-tetradecanoylphorbol-13-acetate (TPA) a skin tumor promoter present in croton oil, are clearly implicated in the formation of skin papilloma. The effect of ethyl acetate extract of Phellinus rimosus, a polypore macro fungus, against croton oil-induced skin inflammation, lipid peroxidation and tumor promotion was studied. The antiinflammatory and lipid peroxidation inhibiting activities were determined by topical application of extract of P. rimosus (10 and 20 mg) prior to the application of 0.1 ml of 50% croton oil in acetone. The tumor promotion inhibiting effect of P. rimosus was evaluated against DMBA-initiated, croton oil promoted two-stage carcinogenesis model in mouse skin. The results showed that topical application of the extract (10 and 20 mg) significantly (p < 0.01) and dose dependently attenuate the inflammatory edema as well as lipid peroxidation induced by croton oil. Similarly, topical application of extract (1 and 5 mg) effectively ameliorated the croton oil promoted skin papilloma formation. The results of this study concluded that ethyl acetate extract of P. rimosus showed antitumor activity against DMBA initiated, croton oil promoted skin papilloma formation which can be partially ascribed to the antiperoxidative and anti-inflammatory effects of the extract.