Cytotoxicity of oleanane type triterpene from leaf extract of Pterospermum acerifolium (in vitro) and theoretical investigation of inhibitory signaling pathway

OBJECTIVE: To evaluate the cytotoxic activity of taraxerol isolated from the leaves of Pterospermum acerifolium and its EtOH extract against human breast, colon, and lung cancer cell lines and docking studies. METHODS: The structures of the isolated compounds were elucidated by several spectroscopic methods such as (1)H-NMR, (13)C-NMR, DEPT-135, COSY, HSQC, and HMBC. The extract and isolated compound were analyzed for cytotoxic activity on MDA-MB-231, BT-549, A-549, and SW-480 cancer cell lines by MTT assay. Molecular docking was performed on software such as Chem3D pro 12.0.2.1076, Discovery Studio Visualizer, Auto Dock Tools-1.5.6 and Auto dock vina. RESULTS: The extract and isolated compound taraxerol both displayed excellent inhibitory activity (IC(50): 80 µg/mL for extract and 160 µg/mL for compound) on breast cancer cell (MDA-MB-231). The docking studies show a strong affinity with PI3K (-9.8 Kcal/mol) and mTOR (-10.0 Kcal/mol). CONCLUSION: The results confirm that the extract and compound exhibited strong cytotoxicity on the MDA-MB-231 cancer cell. So, the extract and the compound may be useful in human chemotherapies.