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.

Chemomodulatory effect of Moringa oleifera, Lam, on hepatic carcinogen metabolising enzymes, antioxidant parameters and skin papillomagenesis in mice.

The modulatory effects of a hydro-alcoholic extract of drumsticks of Moringa oliefera Lam at doses of 125 mg/kg bodyweight and 250 mg/ kg body weight for 7 and 14 days, respectively, were investigated with reference to drug metabolising Phase I (Cytochrome b(5) and Cytochrome p(450) ) and Phase II (Glutathione-S- transferase) enzymes, anti-oxidant enzymes, glutathione content and lipid peroxidation in the liver of 6-8 week old female Swiss albino mice. Further, the chemopreventive efficacy of the extract was evaluated in a two stage model of 7,12 - dimethylbenz(a)anthracene induced skin papillomagenesis. Significant increase (p<0.05 to p<0.01) in the activities of hepatic cytochrome b(5), cytochrome p(450), catalase, glutathione peroxidase ( GPx ), glutathione reductase (GR), acid soluble sulfhydryl content (-SH ) and a significant decrease ( p<0.01 ) in the hepatic MDA level were observed at both dose levels of treatment when compared with the control values. Glutathione-S- transferase ( GST )activity was found to be significantly increased (p<0.01 ) only at the higher dose level. Butylated hydroxyanisol (BHA ) fed at a dose of 0.75% in the diet for 7 and 14 days (positive control ) caused a significant increase (p<0.05 to p<0.01) in the levels of hepatic phase I and phase II enzymes, anti- oxidant enzymes, glutathione content and a decrease in lipid peroxidation. The skin papillomagenesis studies demonstrated a significant decrease (p<0.05 ) in the percentage of mice with papillomas, average number of papillomas per mouse and papillomas per papilloma bearing mouse when the animals received a topical application of the extract at a dose of 5mg/ kg body weight in the peri-initiation phase 7 days before and 7 days after DMBA application, Group II ), promotional phase (from the day of croton oil application and continued till the end of the experiment, Group III ) and both peri and post initiation stages (from 7 days prior to DMBA application and continued till the end of the experiment, Group IV) compared to the control group (Group I ). The percentage inhibition of tumor multiplicity has been recorded to be 27, 72, and 81 in Groups II, III, and IV, respectively. These findings are suggestive of a possible chemopreventive potential of Moringa oliefera drumstick extract against chemical carcinogenesis.