Selective antiproliferative activity of spinasterol from Physospemum verticillatum against A549 and COR-L23 cancer cells.

Several plants have been screened for their potential antitumor properties in order to identify putative compounds with novel structures and/or mechanism of action. Three triterpene saponins, saikosaponin a, buddlejasaponin IV, and songarosaponin D, were isolated from the roots of Physospermum verticillatum Waldst & Kit (Apiaceae) and exhibited a strong cytotoxic activity against COR-L23 cell line. In the present study spinasterol was isolated as main component from the ethyl acetate-soluble fraction of the methanol extract of P. verticillatum and was examined for its antiproliferative activity against a panel of human cancer cell lines including ACHN, C32, Caco-2, COR-L23, A375, A549, LNCaP, and Huh-7D12. The cytotoxicity was evaluated using the sulforhodamine B (SRB) assay. Ethyl acetate-soluble fraction was active against COR-L23 and Caco-2 cells (IC50 values of 74.2 and 84.6 µg/ml, respectively). Spinasterol exhibited an higher activity than the positive control vinblastine against COR-L23 and A549 cell lines with IC50 values of 16.2 and 36.6 µM, respectively. A selective activity against tumor cells was demonstrated since spinasterol not affect the proliferation of skin fibroblasts (142BR) used as control cell line.