In vitro antioxidant activity of stem bark of Trichilia catigua Adr. Juss

Antioxidant activity of the ethanolic extract and fractions from the stem bark of T. catigua was investigated. IC50 (for DPPH scavenging) by T. catigua varied from 9.17 +/- 0.63 to 76.42 +/- 5.87 mu g mL(-1) and total phenolic content varied from 345.63 +/- 41.08 to 601.27 +/- 42.59 mu g GAE g(-1) of dry extract. Fe2+-induced lipid peroxidation was significantly reduced by the ethanolic extract and fractions. Mitochondrial Ca2+-induced dichlorofluorescein oxidation was significantly reduced by the ethanolic extract in a concentration-dependent manner. Ethanolic extract reduced mitochondrial Delta psi(m), only at high concentrations (40-100 mu g mL(-1)), which indicates that its toxicity does not overlap with its antioxidant effects. Results suggest involvement of antioxidant activities of T. catigua in its pharmacological properties.