Apoptosis, DNA damage, and cell cycle arrest: The anticancer mechanisms of quercetin in human cervix epithelioid carcinoma cells

Objectives: The objectives of the study are to investigate the anti-cancer properties of quercetin, a widely distributed phytochemical, and assess its potential as a chemopreventive and therapeutic agent for cervical cell carcinoma. Methods: The study employed cell viability assays for cytotoxicity, flow cytometry for cell cycle arrest, comet assays for DNA damage, nuclear morphology to assess apoptosis, and Western blotting to measure caspase 3 expression, a key apoptosis-related marker. Results: Notably, a significantly lower half-maximal inhibitory concentration (25.5 mu M) at 48 h compared to 24 h highlights the time-dependent nature of quercetin's cytotoxic effects. Quercetin significantly (P < 0.001) inhibited human cervix epithelioid carcinoma (HeLa) cell viability compared to the control group, indicating its cytotoxic potential. Morphological changes observed in quercetin-treated cells further supported its cytotoxic effects. Quercetin-induced substantial increase in the percentage of cells in the sub-G0/G1 phase relative to controls (P < 0.001) reveals cell cycle arrest and the initiation of apoptosis. In addition, quercetin caused notable DNA damage, as evidenced by the significant increase (P < 0.001) in the comet tail length, highlighting the genotoxic effects of quercetin. Moreover, quercetin treatment significantly (P < 0.001) upregulated the expression of caspase-3, suggesting the activation of the intrinsic apoptotic pathway. Conclusion: The findings of the current study suggest that quercetin can effectively inhibit HeLa cell viability, induce cell cycle arrest, promote DNA damage, and activate caspase-mediated apoptosis. This underscores quercetin's therapeutic potential against cervical cancer and highlights caspase-mediated apoptosis as a promising strategy. Prolonged exposure may further enhance its efficacy, offering valuable insights into its potential for longterm cancer treatment.