Screening of bioconstituents and in vitro cytotoxicity of Clematis gouriana leaves.

Clematis gouriana (Ranunculaceae), a perennial herb, is used by the local inhabitants of the western Himalayan region for its medicinal properties. Major bioconstituents of C. gouriana leaves using different solvent extracts were obtained and analysed. The results revealed promising contents of phenolics (from 18.19 ± 0.10 to 22.17 ± 0.10 mg g(-1)) as gallic acid and flavonoids (from 2.83 ± 0.01 to 6.52 ± 0.08 mg g(-1)) as quercetin equivalent in different extracts. Aqueous acetone extract showed higher antioxidant activity with IC50 value of 129.11 and 25.35 μg mL(-1) against DPPH and ABTS free radicals, respectively. Antioxidant yield ranged from 16.87 ± 0.27 to 24.48 ± 0.13 mg g(-1) of Trolox equivalent in different extracts as measured by the FRAP assay. Furthermore, ethylacetate extract exhibited strong in vitro cytotoxicity against Chinese hamster ovary and glioma cell lines. Proximate composition (proteins, fats, ash and minerals) of C. gouriana leaves was also assessed. Results demonstrated the potential of C. gouriana bioconstituents as nutraceuticals.