title: Evaluation of antioxidant properties of Mallotus oppositifolium in in-vitro, in-vivo and ex-vivo model systems.
abstract: The protective effect of antioxidants and naturally occurring substances against oxidative stress damage has recently attracted much attention. The leaves of Mallotus oppositifolium, a shrub of the family Euphorbiacea that grows in many parts of Africa, are used in folk medicine and herbal preparations for the treatment of dysentery, worms and malaria. The study investigated the antioxidant properties of the methanolic extract of the leaves of Mallotus oppositifolium (MEMO) in comparison with butylated hydroxyl anisole (BHA) as a standard antioxidant using three free radical generators viz hydrophilic radical generator 2,2-azobis(2-amidino propane) dihydrochloride (AAPH), hydrophobic radical generator 2,2-azobis(2,4-dimethylvaleronitrile) (AMVN) and hydroxyl radical and non-specific radical generator Fe2+/ascorbate system in an in vitro, in vivo and ex-vivo model systems. Phytochemical analysis of the leaves extract was also assessed. Phytochemical analysis of the powdered leaves revealed the presence of alkaloids, tannins, cardenolides and saponins. In vitro study indicated that while MEMO failed to inhibit lipid peroxidation (LPO) induced by AAPH, while BHA offered 55.5% inhibition. In addition, while AMVN-induced LPO was inhibited by 17.7% and 29.4% by MEMO and BHA respectively, Fe2+/ascorbate system-induced LPO was inhibited by 57.9% and 78.9% by MEMO and BHArespectively. Ex-vivo studies showed that MEMO at 100mg/kg bw reduced malondialdehyde and protein carbonyl levels by 34.5% and 12.0% respectively compared with the control. In vivo, MEMO increased (P<0.05) superoxide dismutase and catalase activities by 408.0% and 295.0% respectively. Taken together, this study demonstrates that MEMO exhibits antioxidant, radical scavenging and enhancement of enzymatic antioxidant capacity and as such could intervene in toxicological processes mediated by free radical mechanisms.
authors.affiliation: Drug Metabolism and Toxicology Research Laboratories, Department of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, Nigeria.
authors.forename: I A
authors.initials: IA
authors.lastname: Adedara
authors.forename: O A
authors.initials: OA
authors.lastname: Adesanoye
authors.forename: E O
authors.initials: EO
authors.lastname: Farombi
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D016166:Free Radical Scavengers / Q000032:analysis / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects / Q000502:physiology; D036461:Mallotus Plant / Q000737:chemistry*; D000432:Methanol; D008954:Models, Biological; D010084:Oxidation-Reduction / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D050050:Protein Carbonylation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D010936:Plant Extracts; D000432:Methanol