Evaluation of Antioxidant Activity of Ethanol Extract of Root and Stem Bark of Moringa oleifera (MO) obtained from Utu Ikpe, Ikot Ekpene Local Government Area, Nigeria

Abstract

Patrick. G. Udofia^*,  Philippa. C.  Ojimelukwe, A. O. Olaoye, Anthony. N. Ukom, Moses L. Ekanem and I. I. Okparauka

The work studied free radical scavenging activities of ethanol extract of the stem bark and root bark of MO.  They are used by the local population to manage common health problems.  Antioxidant activities of the plant parts extracts were studied spectrophotometrically using DPPH (1,1-dimethyl-2-picrylhydrazyl radical), (FRAP) ferric reducing antioxidant power, (H2O2) hydrogen peroxide, ABTS (2,2’azinobis (3-ethylbenzthiozoline-6-sulphonic acid), (NO) nitric oxide as basic free radicals. The result of phytochemical screening and quantitative content of the plant parts revealed a yield of (2.84%) and 4.34% for the stem and root barks respectively.  Alkaloids (2.47%), saponin (0.169%), tannins (3.35%), flavonoids (1.34%) and Alkaloids (1.01%), saponin (0.03%) tannins (1.87%), flavonoids (traces) were estimated in the stem bark and root bark respectively.  The total phenolic contents in the stem and root barks were (25.21 GAE/g) and (13.37 RE/g) of the dry samples respectively. The stem and root barks of the samples showed 5.30 AAE/g and 4.90 AAE/g respectively.  Models of extracts on the basic free radicals were significant (p<0.05; R2>90%) and acted linearly as a function of the phytochemical content and the free radicals’ models in use. The IC50 of the stem bark and root bark on FRAP was 21.41±0.01 and 59.20±0.11 AAE/g respectively compared with ascorbic acid (40.56). The result indicated that ethanol extract of the plant parts may constitute a good source of natural compounds with antioxidant capability in the food and general health sector.