New Methoxyflavone from Casimiroa sapota and the Biological Activities of Its Leaves Extract against Lead Acetate Induced Hepatotoxicity in Rats.

Flavonoids are agents with strong antioxidant properties and ameliorate many diseases associated with oxidative stress. Leaves of Casimiroa sapota were investigated for components and antioxidant/anti-inflammatory activities against lead acetate ((AcO)2 Pb) induced hepatotoxicity in rats. Three groups of male albino rats were administrated orally with vehicle or C. sapota (100 and 200 mg/kg b.w/day) for 28 days; other group was injected with sub-acute dose (100 mg/kg b.w/day) of (AcO)2 Pb. Three protective groups were injected with (AcO)2 Pb (100 mg/kg b.w/day) for 7 days at day 22 after treatment with either C. sapota (100 or 200 mg/kg b.w/day) or silymarin (SILY) for 28 days. We isolated and identified, from C. sapota, a new compound for the 1st time in nature; 5,6,2',3'-tetramethoxyflavone in addition to the rare compound 5,6,3'-trimethoxyflavone (second report of isolation from nature) and the known compound 5,6,2',3',4'-pentamethoxyflavone. There is an improvement in all hemato-biochemical parameters, antioxidant defense system and anti-inflammatory cytokines of protective groups, which received C. sapota in dose dependent manner. The percentage of changes in all parameters measured in (AcO)2 Pb groups that received vehicle, CS100, CS200 or SILY were 109.2, 37.3, 12.5%, and 1.2% compared with the healthy control group. The C. sapota groups confer a better antioxidant activity by preventing oxidative stress and inflammation in (AcO)2 Pb treated rats. The compounds isolated are responsible at least in part for the observed protective effects.