Extraction of bioactive compounds and determination of antioxidant activity of ethanolic and acetonic extracts of Mentha aquatique leaves

Mentha aquatique is one of important species of Labiatae family and commonly found in the North of Iran. Despite Mentha species are widely used for various purposes, the antioxidant potential of Iranian species are still lacking. In this study, extraction of total phenolic compounds from Mentha aquatique by Acetone and Ethanol solvents in three different concentrations (pure, 50% and 70%) were investigated. Total phenolic contents were determined by Folin-Ciocaltue assay and were expressed as mg of gallic acid per g of extract. Then the antioxidant capacity of extracts were assessed by DPPH radical-scavenging activity, total antioxidant capacity and reducing power assay and compared with BHT. In all extracts, the highest total phenolic contents was observed in 50 percentage concentration. In these conditions, total phenolic contents of acetonic and ethanolic extracts were obtained as 53.41 and 40.36 mg gallic acid equivalents (GAE)/g extract, respectively, (P<0.05). Extracts showed antioxidant activity in a dose-dependent manner. Acetonic extract had more antioxidant activity than ethanolic exrtact. In total antioxidant capacity assay in all concentrations the extraction had better antioxidant activity than BHT. Hence the Mentha aquatique can be used as a potential source of phenolic compounds and natural antioxidant and can be used in food formulation.