Evaluation of antioxidant activity of leave extract of Bauhinia rufescens Lam. (Caesalpiniaceae)

Abstract

Antioxidant evaluation of Bauhinia rufescens used in Northern Nigerian traditional medicine, was carried out using 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH) and reducing power assay on the methanolic extract of the leaves. The results of the DPPH scavenging activity indicate a concentration dependent antioxidant activity with no significant difference (p < 0.05) at 50, 125 and 250 µgml-1 with those of the standard ascorbic and gallic acids. The total phenolic content was determined and found to be 68.40 ± 0.02 mg/g gallic acid equivalent (GAE) and the reducing power of 0.071 ± 0.03 nm was obtained. The phytochemical screening revealed the presence of flavonoids, tannins and saponins whose synergistic effect may be responsible for the strong antioxidant activity. It indicates that the methanolic extract of the leave may have promising antioxidant agents and may also help in the treatment of the diseases caused by free radicals.   Key words: Antioxidants, free radicals, Bauhinia rufescens, DPPH, reducing power, total phenolics.