In vitro antioxidant activities of ethanolic stem bark extract of Brachystegia eurycoma
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The Faculty of Basic Medical Sciences, College of Medicine of the University of Lagos.
Background: Reactive oxygen species (ROS) and free radicals are involved in the pathophysiology of diverse disease conditions and medicinal plants with antioxidant activity may be useful in the treatment of these ailments. Brachystegia eurycoma Harms (Caesalpiniaceae) is a medicinal plant used for various ethnomedical purposes, including gastrointestinal disorders in Nigeria. Objective: The study aimed at evaluating the antioxidant effect of ethanolic stem bark extract of B. eurycoma. Materials and Methods: The extract was screened for in vitro antioxidant capacity using five complementary tests, viz: 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical-scavenging, lipid peroxidation, metal chelating and ferric reducing antioxidant power (FRAP) assays in comparison with known antioxidants such as tocopherol and quercetin. Polyphenolic contents in the plant extract were also quantified. Results: Various degrees of the antioxidant activity were recorded for B. eurycoma. The extract scavenged both DPPH and hydroxyl radicals with IC50 value of 23.076 and 0.404 g/ml, respectively. The effect of the extract in scavenging hydroxyl radical was significantly higher than that of quercetin (IC50 = 0.828 g/ml) and tocopherol (IC50 = 12.092 g/ml). The chelating rate of the extract reached 52.35± 0.017% at 100 μg/ml. In FRAP assay, the activity of the extract (324.56±0.05 mol Fe 2+/g) was significantly higher (p<0.05) than that of catechin (263.72±0.08 mol Fe 2+/g) and tocopherol (217.61±0.08 mol Fe 2+/g), respectively. The inhibition of lipid peroxidation was moderate with 34.39% inhibition at 100 µg/ml. The extract possessed considerable amount of total phenols (62.83±0.02 mg GAE/g of extract), flavonoids (6.58 ± 0.00 mg QE/g of extract) and proanthocyanidins (12.58 ± 0.01 mg CE/g of extract). Conclusion: The results obtained in this study indicate that ethanolic stem bark extract of B. eurycoma possess significant antioxidant effect and may be useful against reactive species-mediated diseases.
Antioxidant activity , Brachystegia eurycoma , Radical scavenging , Total phenol , Flavonoids , Research Subject Categories::PHARMACY::Pharmacognosy
Sofidiya M.O., Familoni O. B. (2016). In vitro antioxidant activities of ethanolic stem bark extract of Brachystegia eurycoma. University of Lagos Journal of Basic Medical Sciences, 4 (7), 31-36.