Chemopreventive action of Boerhaavia diffusa on DMBA-induced skin carcinogenesis in mice.

Boerhaavia diffusa, Linn (Fam: Nyctagenaceae), is widely used for the treatment of Jaundice in various parts of India. In the present study, cancer chemopreventive property of B. diffusa was evaluated on 7,12-dimethyl benz(a)anthracene (DMBA) induced skin papillomagenesis in male Swiss albino mice (6-7 weeks old). A single topical application of 7,12-dimethyl benz(a)anthracene (50 microg/50 microl of acetone), followed 2 weeks later by repeated application of croton oil (1% in acetone three times a week) and continued till the end of the experiment exhibited 100% tumor incidence. In contrast, mice treated topically on the shaven backs with the Boerhaavia diffusa extract at either the peri-initiational phase (i.e. 7 days before and 7 days after the application of DMBA; Group II), post initiational phase (i.e. from the day of start of croton oil treatment and continued till the end of the experiment; Group III) or continuously at the peri- and post-initiational stages (i.e. 7 days prior to DMBA application and continued till the end of the experiment; Group IV), a significant reduction in the values of tumor incidence (Group II - 65%; Group III - 30%; Group IV - 25%), average number of tumors per tumor bearing mouse (Group II - 2.8; Group III - 0.75; Group IV - 0.35) and papillomas per papilloma bearing mouse (Group II - 3.1; Group III - 2.5; Group IV - 1.2) were observed.