Antioxidant and Scavenging Activities of Flavonoid Extract (Kolaviron) of Garcinia kola Seeds

Abstract

The antioxidant and scavenging properties of kolaviron, a flavonoid extract of Garcinia kola seeds, were evaluated in a series of in vitro assays involving free radicals and reactive oxygen species. Kolaviron exhibited markedly reducing power and antioxidant activity by inhibiting the peroxidation of linoleic acid. Kolaviron exhibited 57% scavenging effect on superoxide at a concentration of 1 mg/ml and 85% scavenging effect on hydrogen peroxide at a concentration of 1.5 mg/ml. Similarly, kolaviron, at a concentration of 2 mg/ml, elicited an 89% scavenging effect on a,a-diphenyl-ß-picrylhydrazyl radical, indicating that the extract has effective activities as a hydrogen donor and as a primary antioxidant to react with lipid radicals. Kolaviron reacted with hydroxyl radical (·OH) by inhibiting deoxyribose oxidation induced by a Fenton-type reaction system (Fe 3+ + EDTA/H 2 O 2 /ascorbic acid). The second-order rate constant for the reaction with ·OH was approximately 1.1 × 10 10 M -1 sec -1. Kolaviron was ...