Thymoquinone from Nigella sativa was more potent than cisplatin in eliminating of SiHa cells via apoptosis with down-regulation of Bcl-2 protein

► Cytotoxicity assays showed that TQ was more potent towards SiHa cells and less cytoxic towards 3T3-L1 and Vero cells as compared to cisplatin. ► TQ caused morphological changes in SiHa cells at higher concentration of TQ (30 μg/mL). ► Cell cycle analysis, Annexin V-FITC/PI and AO/PI tests indicated that TQ was cytotoxic towards SiHa cells by involving apoptosis. ► Cytotoxicity of TQ in SiHa cells involved a significant elevation of the level of the p53 activity and the Bax to Bcl-2 ratio.