In vitro antioxidant and anticancer activity studies on drosera indica L. (Droseraceae)

The aim of present in vitro studies was performed to examine the antioxidant and anticancer activities of ethanol and aqueous extracts of Drosera indica L.

Different concentrations (5 - 640mcg/ml) of the ethanol (EEDI) and aqueous (AEDI) extracts of D.indica L were used in various antioxidant assay methods such as hydroxyl radicals, DPPH, super oxide radical scavenging activity, chelating ability of ferrous ion, nitric oxide radical inhibition, ABTS and reducing power. Ascorbic acid (AA) was used as the standard antioxidant for the free radical scavenging assays. Dalton's Ascitic Lymphoma (DAL) and Ehrlich Ascitic Carcinoma (EAC) cell lines were used as the in vitro cancer models for the tryphan blue dye and LDH leakage assays, where 5 to 250mcg /ml of both EEDI and AEDI were tested.

EEDI showed antioxidant activities with the minimum IC50 values of 34.8±0.43 mcg/ml in scavenging of hydroxyl radical and moreover AEDI showed minimum IC50 values of 94.51±0.84 mcg/ml in Fe(2+)chelating assay. EEDI on the reducing power assay and ABTS showed higher IC50 than standard AA. IC50 values of AEDI on Fe(2+) chelating assay and super oxide radical assay was lesser than IC50 value of AA. Both extracts at 250mcg/ml dose showed remarkable increase in the percentage of dead cancer cells (90% by EEDI and 86% by AEDI in DAL model and 89% by EEDI and 80% by AEDI in EAC model).

It is concluded from this study that D.indica L exhibited excellent antioxidant activity against the different in vitro antioxidant models and anticancer activity against the two different cell lines tested.