Antioxidant Activity and Assessment of Total Phenolic and Flavonoid Contents of Caesalpinia pulcherrima leaf Extract and Fractions

Abstract

Oxidative stress has been shown to play an important role in the development of many diseases. Indeed, the increase in total antioxidant status is imperative in the recuperation from these diseases. The antioxidant activity, total phenolic and flavonoid contents of Caesalpinia pulcherrima leaves were determined in this study. The powdered dried leaves of C. pulcherrima were screened for their effect on 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). Total phenolic and flavonoid contents of the extract and fractions were estimated using established methods. Concentrations of the plant extracts required for 50% inhibition of DPPH radical scavenging effect (IC50) were recorded as 3.20, 48.11, 33.12, 9.15, 27.26, 17.90, 272.18 and 55.51μg/ml for Ascorbic acid, 100% n-hexane, 50% n-hexane: 50% ethyl acetate, 100% ethyl acetate, 50% ethyl acetate:50% methanol, 100% methanol, 90% methanol:10% water fractions and crude extract, respectively. Total phenolic and flavonoid contents were highest for 100% ethyl acetate fraction. The leaf extract and fractions of C. pulcherrima exhibited notable radical scavenging activity and therefore corroborate its use as a natural plant antioxidant by preventing free radical damage.