Abstract

MEASUREMENT OF ANTIOXIDANT ACTIVITY OF AFRICAN MANGO (Irvingia wombolu) KERNEL PEELS

Rosane Matsinkou Soh*, William Dakam, Boris Gabin Kingue Azantsa, Judith Laure Ngondi, Julius Oben

Abstract

Background: Oxidation of macromolecules by free radicals leads to cellular oxidative damage implicated in several chronic human diseases. Natural antioxidants have become the target of a great number of research studies. Objective: This study was aimed at assessing in vitro inhibiting effects of Irvingia wombolu peel extracts on lipid peroxidation and free radicals. Materials and methods: Phenol contents of the extracts (aqueous and hydroethanolic) was measured by Folin-Ciocalteu assays. Inhibition of Fe2+-induced lipid peroxidation (LPO) in liver homogenates, 1,1-diphenyl-2- picrylhydrazyl (DPPH), 2,2’-azinobis (3-ethyl-benzothiazoline-6- sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP), metal chelating activity, nitric oxide and hydroxyl (OH-) radical scavenging activities were evaluated. Results: Hydroethanolic extracts of peel (HEP) showed significantly higher level of phenolic compounds (228.91±35.47 mg catechin equiv/g) and exhibited the higher antioxidant activity by the FRAP assay. However, the highest scavenging activities on DPPH, ABTS, hydroxyl radical, nitric oxide and chelating effect on ferrous ions were obtained with aqueous extract (AEP) as evidenced by low IC50 value. Ascorbate/FeSO4-induced lipid peroxidation was inhibited by AEP and HEP. Moreover, the percentage inhibition of these extracts decreased with increasing concentrations. IC50 values for AEP and HEP was found to be 0.50 mg/ml and 0.61 mg/ml respectively. Conclusion: The results obtained in the present study indicate that peel extracts of Irvingia wombolu can be used as potential source of natural antioxidant.

Keywords: natural antioxidant, free radicals, Irvingia wombolu peel, oxidative stress.