Antioxidant activity and phytochemical screening of Nepeta nepetella aqueous and methanolic extracts from Algeria.

ABSTRACT

Plant phenolics constitute one of the major groups of components that act as primary antioxidant free radical terminators. This paper reports the antioxidative activity of methanolic and water extract of Nepeta nepetella. Phytochemical screening of the crude extracts of stems, leaves and flowers revealed the presence of different kind of chemical groups such as flavonoids, tannins, alkaloids, saponins and carbohydrates. The amounts of total phenolics solvent extracts (methanol and water extract) for the three parts of plant were determined spectrometrically. From the analyses, leaves methanolic extract had the highest total phenolic content (58.11± 1.24 mg GAE/g), the highest DPPH scavenging ability with the lowest IC50 value (1.45 ± 0.07 mg/ml), the same tendency was observed with ferric reducing power. Concerning β-carotene bleaching assays results showed that the stems methanolic extract exhibited the highest antioxidant ability with an IC50 higher than standards (0.148 ± 0.003 mg/ml).