Abstract
Cisplatin (CSP) is a first-line chemotherapeutic for laryngeal squamous cell carcinoma (LSCC), but its clinical effectiveness is limited by resistance and toxicity. Hesperidin (HESP), a citrus flavonoid, may enhance chemotherapeutic efficacy through pro-apoptotic properties. This study investigated the involvement of the transient receptor potential melastatin-2 (TRPM2) channel in the HESP-mediated potentiation of CSP-induced cytotoxicity in human laryngeal carcinoma (Hep-2) cells. Hep-2 cells were treated with CSP (25 µM), HESP (25 µM), or their combination for 24 h. The findings showed that the combined application of HESP and CSP reduced cell viability by approximately 50% (p < 0.001), which was the lowest compared to CSP alone. Western blot analysis revealed that TRPM2 protein expression was higher in the CSP+HESP group compared to the control group (p < 0.001). This synergistic treatment resulted in an increase in ROS production and a decrease in MDA levels, accompanied by a reduction in cellular GSH levels (p < 0.001). Furthermore, the combination therapy increased pro-inflammatory cytokines such as IL-1β and TNF-α (p < 0.001). Functional analyses showed that HESP treatment enhanced CSP-induced Ca(2+) influx and altered mitochondrial membrane potential (p < 0.001). The pharmacological inhibition of TRPM2 with ACA and 2-APB reversed these effects, restoring redox balance and reducing cellular damage. In conclusion, HESP amplifies CSP-induced apoptosis in Hep-2 cells through TRPM2-dependent oxidative stress, Ca(2+) dysregulation, and mitochondrial dysfunction. These findings identify TRPM2 as a mechanistic mediator of HESP-enhanced chemosensitivity in LSCC.