In Vitro Cytotoxic Activity of Clinacanthus nutans Leaf Extracts Against HeLa Cells

OBJECTIVE: This study was conducted to investigate the antiproliferative activity of extracts of Clinacanthus nutans leaves against human cervical cancer (HeLa) cells. METHODS: C. nutans leaves were subjected to extraction using 80% methanol or water. The methanol extract was further extracted to obtain hexane, dichloromethane (DCM), and aqueous fractions. The antiproliferative activity of the extracts against HeLa cells was determined. The most cytotoxic extract was furthered analyzed by apoptosis and cell cycle assays, and the phytochemical constituents were screened by gas chromatography-mass spectrometry (GC-MS). RESULTS: All of the extracts were antiproliferative against HeLa cells, and the DCM fraction had the lowest IC(50 )value of 70 µg/mL at 48 h. Microscopic studies showed that HeLa cells exposed to the DCM fraction exhibited marked morphological features of apoptosis. The flow cytometry study also confirmed that the DCM fraction induced apoptosis in HeLa cells, with cell cycle arrest at the S phase. GC-MS analysis revealed the presence of at least 28 compounds in the DCM fraction, most of which were fatty acids. CONCLUSION: The DCM fraction obtained using the extraction method described herein had a lower IC(50) value than those reported in previous studies that characterized the anticancer activity of C. nutans against HeLa cells.