Antioxidant activities of Dichrostachys cinerea (L.) Wight et Arn (Leguminosae): Correlations between the Polyphenol Level and the Antioxidant Activity

Abstract

Aims: Free radicals are involved in many diseases. Antioxidants help control them. The overproduction of free radicals or reduction of natural antioxidants promotes the destruction of cells in our body, for example in neurodegenerative diseases. The aim of our study is to evaluate the correlation between the level of polyphenol and antioxidant activity of Dichrostachys cinerea barks he work was carried out at the phytochemistry department of the Institute of Pharmacopoeia and Traditional Medicine (Gabon). Methodology: Different extracts of Dichrostachys cinerea barks were obtained with polarity solvent (dichloromethane, ethyl acetate, butanol, methanol and water).  The antioxidant activity is evaluating using respectively FRAP method (Ferric Reducing Antioxidant Power), antiradical activity by the method of inhibition of DPPH radical (2.2-diphenyl-1-picrylhydrazyl), cations ABTS radical (2.2'-azinobis-[3-acid-6-sulfonic ethylenzothiazoline]). Results: Ethyl acetate and dichloromethane extract have the higher value for polyphenolic compounds, respectively 52,27±0,66 mg EAG / g and 49,72±0,55 mg EAG / g. Aqueous extract have the lower value 20,67±1,05 mg EAG / g. The different fractions of Dichrostachys cinerea have antioxidant effect, and this effect is in correlation with its constituents: polyphenols, tannins and flavonoids. Results were compared to standard antioxidants such as ascorbic acid and quercetin. Conclusion: This study confirms higher is the level of polyphenols greater is the antioxidant power.