Cytotoxic and antioxidant properties of selected Scutellaria species from the Western Ghats of Peninsular India

Abstract

Context: Scutellaria (Lamiaceae), commonly known as ‘Skullcaps’, has been extensively used in Traditional Chinese Medicine (TCM). Recently, much emphasis has been given to this genus due to the rich source of bioflavonoids that contribute to its biological properties. Therefore, different species of Scutellaria are being explored worldwide.Objectives: Cytotoxic, antioxidant, and phytochemical properties of Scutellaria colebrookiana Benth and S. violacea (Heyne ex Benth) Don collected (October 2009–February 2010) from Western Ghats of India have been analysed.Materials and methods: In vitro cytotoxicity and free radical scavenging effects of root extracts in various solvents were analysed. Spectrophotometric and HPLC methods were performed for phytochemical analysis.Results: Chloroform extract exhibited significant cytotoxicity in Dalton’s Lymphoma Ascites (DLA) and Ehrlich Ascites Carcinoma (EAC) cells with IC50 values 150 and 140 µg/mL for S. colebrookiana and 250 and 280 µg/mL for S. violacea, respectively. Moreover, the extract was effective in scavenging free radicals and inhibiting membrane peroxidation in vitro with IC50 values 158.3 and 167.5 (superoxide), 17.5 and 28.0 (hydroxyl), 76.25 and 69.75 (DPPH), 24.5 and 28.0 (ABTS), 69.75 and 64.6 (lipid peroxidation), 41 and 31.5 µg/mL (erythrocyte hemolysis), respectively. Antioxidant effect observed with acetone extract was also comparable to that of chloroform extract. Phytochemical screening revealed the presence of baicalein.Discussion and conclusion: Scutellaria species of Western Ghats showed cytotoxic and antioxidant potential and the presence of baicalein. This suggests that S. colebrookiana and S. violacea could be used as alternative sources for baicalein in view of the reported scarcity of S. baicalensis.