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

Abstract

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 IC₅₀ 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 IC₅₀ 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, IC₅₀ value, Oxidative stress

DOI: 10.7176/JNSR/9-12-09

Publication date:June 30^th 2019