Cytotoxic effects of Cochlospermum regium (Mart & Schrank) Pilger aqueous root extract on mammalian cells

We investigated the effect of Cochlospermum regium (Mart & Schrank) Pilger aqueous root extract on Chinese hamster ovarian (CHO)-K1 cells. The extract significantly decreased proliferation of CHO-K1 cells (EC50 = 1.5 mg/mL). Apoptosis induction was analysed by fluorescent microscopy. Cell cultures treated with Cochlospermum regium extract for 4 h contained 13.6% apoptotic cells after 24 h (investigated by fluorescent DNA-microscopy with acridine orange/ethidium bromide staining). Characteristic chromatin condensation and fragmentation, verified by 4′,6-diamidino-2-phenylindole (DAPI) staining, was observed in the cells after treatment with Cochlospermum regium extract. The results confirm the toxicity of Cochlospermum regium root extract to immortal, non-tumorigenic mammalian cells in vitro.