Prevention of skin tumors induced by 7,12-dimethylbenz(a)anthracene in mice by black seed oil

The effect of topical application of black seed oil on 7,12-dimethylbenz(a)anthracene (DMBA)-induced skin tumors in BALB/c mice was investigated. Topical application of chemically extracted oil (C.O.) and naturally extracted oil (N.O.) highly prevented the appearance of skin tumors in experimental animals. Skin tumors (papillomas and carcinomas) were initiated by application of 300 mu g DMBA (on days 1,8) followed by applying 0.5 mg croton oil, biweekly until the end of the experiment (25 weeks). The application of N.O. completely prevented the appearance of skin tumors in mice of group 3 versus a tumor incidence of 78.9% in animals of group 1 (carcinogenic control) (cc). Painting the skin of mice with C.O. (group 2) significantly reduced the tumor incidence to 14.2%. Moreover, a significant decrease was observed in number of mice bearing tumors, and number of tumors per mouse in group 2. Multiplicity was also decreased but insignificantly in the same group. The treatment with C.O. and N.O. insignificantly increased the rate of mice survival as compared to that of animals of group 1.