Evaluation of the Antioxidant Activity of the Stem Bark Extracts of Anacardium occidentale (Linn) Anacardiaceae
Chidimma M. Iheanacho, Paschal C. Akubuiro, Irene O. Oseghale, Vincent O. Imieje, Osayemwenre Erharuyi, Kennedy O. Ogbeide, Arthur N. Jideonwo, Abiodun Falodun
Abstract
Anacardium occidentale is a known Nigerian indigenous plant used in folklore medicine in the management of various ailments. The antioxidant properties of A.occidentale was investigated via the evaluation of the radical scavenging activity of the various fractions of the extracts using 2, 2-diphenyl-1-picrylhydrazyl and 2,4,6-tri[2-pyridyl]-5-triazine assays. Phytochemical screening was conducted on the extract to ascertain the presenceof vital phytoconstituents, and the phenol and flavonoid contents of the various fractions of the extracts were quantified spectrophotometrically. The results obtained revealed that A.occidentale contains vital phytoconstituents with the highest total phenol contents of 130.630.89 GAE/mg of extract in the crude sample, while the lowest value of 11.190.21 GAE/mg of extract was obtained in 50:50 n-hexane/ethylacetate fraction respectively. The total flavonoid content was highest in the crude sample (62.29 ± 3.81 mg QE/g extract dry weight) and least in the methanol fraction 0.31 ± 0.07 mg QE/g of dry extract. The Ferric Reducing Antioxidant Power (FRAP) assay shows that the extract and fractions showed a considerable antioxidant effect from the absorbance of 0.208nm to 1.276 nm with 100% methanol having the highest value. Similarly, the DPPH assay result of the extracts and fractions was concentration-dependent. DPPH radical scavenging activity revealed that the highest radical scavenging was observed in 90% Methanol-10% Water fraction with an IC50 value of 0.43μg/mL. These findings validate A.occidentale as a rich source of antioxidant and could be recommended for therapeutic use in the management of oxidative related ailments.