Deciphering the Antioxidant and Free Radical-Scavenging Capacity of Anthocleista vogelii

The empirical survey comparatively explores the antioxidant activity and the free radical-scavenging capacity of various fractions of Anthocleista vogelii leaves. The dried and pulverized leaves of A. vogelii were subjected to cold maceration for 4, 8 and 12 days using 70 % methanol and filtered. The filtrate was concentrated to a slurry crude extract by means of a rotary evaporator at 40ºC with a salvaged yield of 34.10 %. Exactly 0.23 kg of crude extract was defatted and fractionated using two chromatographic techniques in chloroform-methanol-hexane solvent system (3:21 v/v). The fractions were screened qualitatively for polyphenolic compounds. The fractions containing these bioactive compounds were quantified and further subjected to free radical-scavenging activity: DPPH assay, ferric reducing power (FRP) assay, hydrogen peroxide scavenging activity (HPA) and total antioxidant capacity (TAC) respectively. There was marked significant difference (p<0.05) in the total phenolic and flavonoid contents (TPC and TFC) among the fractions with ample amount found in n-hexane fraction. There were marked significant differences (p<0.05) in the IC 50 values among fractions for DPPH, FRP, HPA and TAC assays. Thus, the ample antioxidant activity of n-hexane fraction among other fractions was further validated by the extrapolated IC 50 values. The study inferred that A. vogelii leaves are possible sources of antioxidants with health benefits, especially for disease conditions characterized by oxidative stress. Keywords: Anthocleista vogelii , Antioxidant activity, Free radical-scavenging capacity, IC 50 value, Oxidative stress DOI : 10.7176/JNSR/9-12-09 Publication date :June 30 th 2019