Evaluation of the in vitro anti-oxidant activity of Alternanthera brasiliana leaves

Abstract

Abstract Background and aim Alternanthera brasiliana belongs to the family, Amaranthaceae and is popularly known as Brazilian joyweed. It is a medicinal plant famous for its therapeutic effects in Brazil, South Africa and Nigeria amongst other countries. In the present study, the ethanol extract of the leaves of A. brasiliana was evaluated for its potential anti-oxidant activity. Methods This was carried out by determining the concentration of total phenols in the extract as well as using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging, iron (II)-chelating, nitric oxide radical-scavenging, ferrous sulphate and carbon tetrachloride-induced lipid peroxidation assays. Results The results show that the concentration of total phenols in the extract was 0.031 ± 0.006 μg/ml of the extract. In addition, the percentage inhibition of DPPH radical exhibited by the increasing concentrations of the extract, iron (II)-chelating and nitric oxide radical-scavenging activities (in percent), percentage inhibitions of ferrous sulphate and carbon tetrachloride-induced lipid peroxidation by the extract ranged from 96.29% to 99.59%, 51.43% to 78.78%, 53.43% to 94.85%, 25.00% to 37.90% and 96.26% to 99.50% respectively. Results of the assays were comparable to those of the standard anti-oxidant (ascorbic acid). Conclusion The above data provide evidences that the ethanol extract of the leaves of A. brasiliana is rich in natural anti-oxidants and thus justify its use in folk medicine especially in the management of free radical-mediated disorders.