Effects of Solvents on the In-vitro Antioxidant Activity of Dennettia tripetala G. Baker and Milicia excelsa (Welw.) C. Berg Root Extracts

Background and The root extracts of Dennettia tripetala G. Baker and Milicia excelsa (Welw.) C. Berg was investigated for their in-vitro antioxidant activities. The pulverized roots of Dennettia tripetala and Milicia excelsa were extracted separately by cold maceration using ethyl acetate, methanol, n-butanol and water respectively as the extracting solvents. In-vitro antioxidant, the activity of root extracts was then investigated using DPPH model. The results obtained was analyzed using One-way Analysis of Variance (ANOVA) involving GraphPad Prism 5 Software. The antioxidant assay of various extracts, using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging model, revealed that the ethanol and n-butanol extracts of D. tripetala had better radical scavenging activity with IC50 values of 2.02 and 0.631 µg/mL for ethanol and n-butanol extracts, respectively. The methanol and ethanol extracts of M. excelsa showed higher radical scavenging capacity with IC50 of 0.194 and 8.84 µg/mL compared to that of the ascorbic acid which had IC50 value of 4.60 µg/mL. The radical scavenging ability of the extracts could be attributed to the presence of flavonoids and phenolics.