Original Articles
Ajiboye, Clement Odunayo, Moro
Abstract
Inability of antioxidants to scavenge effect of free radicals generated in the body results in various health disorders for which free radicals have been implicated. The increasing quest for plant based novel compounds of medicinal relevance led to the comparative study of antioxidant activities of extracts from different parts of the ethno-medicinally utilized Blighia unijugata. Samples were collected and authenticated (Department of Botany) at University of Ibadan, Ibadan, Nigeria and separated into leaf, stem bark, root, flower and fruit. Flower and fruit were extracted separately in methanol (labeled MBuFM and MBuFsM respectively), the leaf, stem bark and root extracts were obtained sequentially first with 100% hexane (MBuLH, MBuSH, and MBuRH), and then with equal mixture of ethyl acetate and methanol (MBuLf1, MBuSt1, and MBuRt1). Antioxidant activity evaluations was done using hydrogen peroxide assay. Their 50% inhibitory concentration (IC50) values were determined by regression analysis on Microsoft excel. % inhibition of hydrogen peroxide was between 52.28% - 82.41% which is comparable to that of the two standards: Vitamin C and Butylhydroxyl Anisole (BHA) used (58.05%-85.63%). IC50 values for the hydrogen peroxide scavenging activities of all the extracts studied gave the following trend: MBuFM>MBuSt1=MBuSH=MBuRt1>MBuLH>MBuFsM=MBuLf1>MBuRH, with their corresponding IC50 values being 0.0056 > 0.0057 = 0.0057 = 0.0057 > 0.0059 > 0.0060 = 0.0060 > 0.0064 (mg/ml) respectively. Our results indicate that the five parts studied are potential good sources of free-radical scavenging compounds, which support the ethno-medicinal application of Blighia unijugata as anti-ageing agent.