Antioxidant activity and DNA damage inhibition in vitro by a methanolic extract of Carissa carandas (Apocynaceae) leaves

The aim of this study was to determine the antioxidant and DNA damage inhibition potential of a methanolic extract of Carissa carandas leaves. The extract had significant (p < 0.05), dose-dependent DPPH radical scavenging activity (median inhibitory concentration, 73.1 μg/ml), total antioxidant activity, H2O2 scavenging activity (median inhibitory concentration, 84.03 μg/ml) and reducing power activity. The extract also completely protected pBR322 plasmid DNA from free radical-mediated oxidative stress in a DNA damage inhibition assay. The antioxidant and DNA damage inhibition properties of C. carandas can be attributed to a high content of phenolic compounds (84.0 mg gallic acid equivalents/g dry weight of extract), estimated in the Folin–Ciocalteau assay. The high antioxidant and DNA damage inhibiting potential of C. carandas could be used to develop antioxidant compounds for therapeutic applications.