10.22376/ijpbs.2019.10.1.p1-12 Volume 3 Issue 4 2012(October - December) Cytotoxicity of Methanolic extracts of lessThan i greaterThan Pisonia lessThan /i greaterThan lessThan i greaterThan aculeata lessThan /i greaterThan (MPA) was evaluated using three human cancer cell lines [Human Laryngeal Epithelial Carcinoma cell (Hep2), Human Colon Cancer cell (HT-29) and Human Breast cancer cells (HBL-100)]. The lessThan i greaterThan in vitro lessThan /i greaterThan cytotoxicity was done by Tryphan blue dye exclusion method, MTT assay and Apoptosis. Cells were treated for 72 hrs with various concentration of MPA (31.25-500 mg/ml), the relative cell survival progressively decreased in a dose dependant manner. The IC lessThan sub greaterThan 50 lessThan /sub greaterThan of the MPA was found to be 280, 200 & 340 mg/ml by Tryphan blue dye exclusion method & 130,100 &170 mg/ml by MTT assay. Among the tested cell lines, MPA was more selective cytotoxic against HT-29 cell line than Hep2 & HBL-100 cells. Extensive apoptotic alterations were observed in MPA (500 µg/ml) by Hoechst staining & more than 30% of cells underwent apoptosis upon a single dose (500 µg/ml) of the MPA after 48 hrs. SHWETA P. GHODE (SHWETA A. CHINTALWAR) , B. RAJKAPOOR AND PRASHANT D. GHODE Cytotoxicity, Pisonia aculeata leaf, Hep2, HT-29 , HBL-100, Human cancer cell lines, MTT, Hoechst staining, Apoptosis. 155-160