Evaluation of the antioxidant activity of phenolic extracts from pomegranate bark (Punica granatum. L)

Abstract

Pomegranates (Punica granatum) are among the fruits richest in vitamin C and phenolic compounds, in particular anthocyanins and phenolic acids. Sev-eral types of polyphenols with antioxidant properties are present in different parts of the pomegranate such as the stems and bark. This study aims to evaluate the antioxidant properties of extracts from the barks of P. gran-atum L for their use in the therapeutic and nutritional fields. The extraction of phenolic compounds was made using three solvents namely; methanol, ethanol and acetone. The total polyphenol dosing results revealed the meth-anolic extract’s richness in total phenolic composites with a ratio of about 2.940±0.087g EAG/g of lyophilization resultant extract. Likewise, the etha-nolic extract has shown a high concentration, followed by the acetonic extract, with total content of about 2.699 ± 0.057g EAG/g and 2.306 ± 0.026g EAG/g of lyophilization result extract, respectively. Antioxidant activity meas-ured by free root reduction (DDPH) revealed that the methanolic extract presented the most appropriate DPPH-root-inhibiting activity, with an inhib-iting concentration of 50% (IC50) being equal to 0.68 mg/ml. Moreover, the extracts obtained from the three solvents have shown efficiency compared to ascorbic acid (IC50 equal to 0.714±0.004mg/ml). Considering the antioxi-dant activities, it is recommended that P. granatum be used as a functional ingredient in the food industry and pharmaceutical preparations.