Selective Cytotoxicity and G2/M Cell Cycle Arrest Induced by Taxus sumatrana (Miq.) de Laub. Leaf Extract in HeLa Cervical Cancer Cells: A Comparative Study with Paclitaxel

Cervical cancer remains a significant health challenge, particularly in regions with limited access to targeted therapies. Taxus sumatrana, traditionally used in Indonesian herbal medicine, has limited scientific evidence supporting its anticancer activity. This study aimed to evaluate the selective cytotoxicity of T. sumatrana leaf extract against cervical cancer cells. The extract was tested in HeLa cells, normal Vero epithelial cells, and RAW 264.7 cells. Cytotoxicity was assessed using the MTT assay, while flow cytometry was employed to analyse cell cycle distribution and Cyclin D1 protein expression. The extract exhibited preferential cytotoxicity toward HeLa cells, with normal cells showing markedly higher tolerance, resulting in a favourable selectivity index. Cell cycle analysis revealed G2/M phase arrest accompanied by Sub-G1 accumulation, suggesting apoptotic induction. Cyclin D1 protein modulation showed a similar trend to that of paclitaxel treatment, though to a lesser extent. These findings suggest that T. sumatrana leaf extract may exert antiproliferative activity by disrupting mitotic progression while sparing non-cancerous cells. The selective action observed highlights its potential as a safer phytopharmaceutical candidate or adjunct anticancer therapy, warranting further in vivo validation.