RESUMEN
The chemotherapeutic agents used to treat nasopharyngeal cancer (NPC) exhibit low efficacy. Strobilanthes crispa Blume is widely used for its anticancer, diuretic and antidiabetic properties. The present study aimed to determine the cytotoxic and apoptogenic effects of S. crispa on CNE1 NPC cells. A 3(4,5dimethylthiazol2yl)2,5 diphenyl tetrazolium bromide assay was used to evaluate the cytotoxic effects of S. crispa against CNE1 cells. The rate of apoptosis was determined using propidium iodide staining and caspase assays. Ethyl acetate, hexane and chloroform extracts of S. crispa leaves all exhibited cytotoxic effects on CNE1 cells, at a half maximal inhibitory concentration (IC50) of 119, 123.5 and 161.7 µg/ml, respectively. In addition, hexane, chloroform and ethyl acetate extracts of S. crispa stems inhibited CNE1 cell proliferation, at a IC50 of 49.4, 148.3 and 163.5 µg/ml, respectively. Flow cytometric analysis revealed an increased proportion of cells in the sub G1 phase and a decreased proportion of cells in the G2/M phase, following treatment with the extracts. However, the extracts did not alter the activities of caspase 3/7, 8 and 9. No cytotoxic effect was observed when the cells were treated with the methanol and water extracts of S. crispa stems and leaves. In conclusion, the S. crispa extracts were cytotoxic against CNE1 cells and these extracts were able to induce apoptosis, independent of caspase activation.