Effect of Aegle marmelos on biotransformation enzyme systems and protection against free-radical-mediated damage in mice

The effect of hydroalcoholic (80% ethanol, 20% water) extract of leaves of Aegle marmelos was examined on carcinogen-metabolizing phase-I and phase-II enzymes, antioxidant enzymes, glutathione content, lactate dehydrogenase a nd lipid peroxidation, using two doses of dried extract (50 and 100 mg kg(- 1) daily for 14 days), in the liver of mice. The modulatory effect of the e xtract was also examined on extrahepatic organs (lung, kidney and fore-stom ach) for effects on the activity of glutathione S-transferase, DT-diaphoras e, superoxide dismutase and catalase. Extract treatment significantly increased the basal levels of acid-soluble sulphydryl (-SH) content, cytochrome P450, NADPH-cytochrome P450 reductase, cytochrome b5, NADH-cytochrome b5 reductase, glutathione S-transferase, DT -diaphorase, superoxide dismutase, catalase, glutathione peroxidase and glu tathione reductase in the liver. Aegle acted as a bifunctional inducer sinc e it induced both phase-I and phase-II enzyme systems. Both doses significa ntly decreased the activity of lactate dehydrogenase and formation of malon dialdehyde in liver, suggesting a role in cytoprotection as well as protect ion against pro-oxidant-induced membrane damage. Butylated hydroxyanisole ( positive control) induced almost all the antioxidative parameters measured in this study. The extract was effective in inducing glutathione S-transfer ase, DT-diaphorase, superoxide dismutase and catalase in lung, glutathione S-transferase, DT-diaphorase and superoxide dismutase in fore-stomach, and DT-diaphorase and superoxide dismutase in lung. These significant changes in the levels of drug-metabolizing enzymes and an tioxidative profiles are strongly indicative of the chemopreventive potenti al of this plant, especially against chemical carcinogenesis.