Assessment of In-vitro Antioxidant Activities and Genotoxicity in E. coli of Ethanol Extracts of Vitellaria paradoxa (Gaertn. F)

Abstract

Medicinal plants grossly contain bioactive phytochemicals. Phytochemical such as polyphenols, flavonoids, saponins, vitamin C, E have antioxidant potentials; they therefore act as protecting agent when used in the right perspective. The objective of this study is to evaluate the in vitro antioxidant and genotoxic properties of ethanol extracts of Vitellaria paradoxa. To achieve this, different antioxidant assays were used whereas SOS chromotest was used for the assessment of genotoxicity. Using ascorbic acid as a standard, the leaf extract had a 1.4 fold higher level total antioxidant when compared to seed. At 800 μg/ml, the leaf extract compared well to the standard in reducing power but that of the seed extract was significantly lower. The % inhibition of 1,1-diphenyl-2-picrylhydrazyl (DPPH) for leaf and seed extracts at 50 μg/ml are 79.95 ± 0.31 and 82.52 ± 0.31 respectively which are significantly low compared to value by ascorbic acid (93.04 ± 2.07). The phytochemical analysis showed the total phenolic content was (83.46 ± 0.72 and 68.88 ± 7.50) μgGAE/ml for leaf and seed extracts respectively. The leaf extract total flavonoid content was equally significantly higher in comparison to the seed using quercetin as a standard compound. The genotoxic assay, SOS chromotest, showed both extracts to be non-genotoxic at concentrations < 800 μg/ml in comparison to 4-Nitroquinoline-1- oxide (4-NQO). However at 800 μg/ml the extracts showed marginal genotoxicity. Findings from this study showed both extracts of Vitellaria paradoxa have antioxidant properties. The leaf extract showed a more promising antioxidant potential and high level of flavonoid. The marginal genotoxicity observed at 800 μg/ml calls for caution on the medicinal application of the plant.