Dose-dependent effect of B. pinnata leaf extract and its chromatographic fraction on the viability of human cervical cancer cells. A. HeLa cells incubated in 96 well plate without or with indicated concentration of B. pinnata crude leaf extract or its fraction F3 and F4 were examined for cell viability at 24 h by MTT assay as described in Methods. Percent growth inhibition was measured w.r.t. untreated controls. B and C. HeLa cells incubated with increasing concentration of crude extract (B) and fraction F4 (C) were examined for cell viability at 24 h, 48 h and 72 h and their percent viability was measured by MTT assay. The results are representative of three independent experiments with similar results. Values are mean ± SD of the triplicate cultures. *p < 0.05 versus untreated cultures. #p < 0.05 versus cells treated at similar dose of crude extract or fraction F4 treatment at 48 h or 72 h cultures.