Protective effects of trimetazidine and coenzyme Q10 on cisplatin-induced cardiotoxicity by alleviating oxidative stress and mitochondrial dysfunction Objective: The objective of this study was to investigate the effects of trimetazidine (TMZ) and coenzyme Q10 (CoQ10) on cisplatin-induced cardiotoxicity in rat cardiomyocytes. Methods: Rat cardiomyocytes were isolated and subjected to cisplatin (200 μM) treatment with and without TMZ (200 μM) and CoQ10 (200 mg/L) pretreatment. The cell viability, apoptosis, oxidant and antioxidant indicators, and mitochondrial dysfunction were examined. Results: TMZ or CoQ10 significantly attenuated cisplatin-induced cell viability inhibition (p<0.01) and apoptosis (p<0.001), and the combined use of TMZ and CoQ10 pretreatment exerted a pronounced effect compared to the effects of using each of these agents individually (p<0.05). TMZ or CoQ10 inhibited the levels of reactive oxidative species (ROS, p<0.01) and malondialdehyde (MDA, p<0.001 and p<0.01, respectively), elevated the activities of antioxidant enzymes superoxide dismutase (SOD, p<0.01) and catalase (CAT, p<0.01 and p<0.05, respectively), evidently enhanced nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2, p<0.05), alleviated mitochondrial membrane potential (ΔΨm) loss (p<0.05), and down-regulated the release of cytochrome c (cyto-c) into the cytosol (p<0.01) in cisplatin-treated cells. The combined use of TMZ and CoQ10 treatment was more effective than using either agent alone (p<0.01 for ROS, MDA, CAT, and cytosolic cyto-c; p<0.05 for SOD, nuclear Nrf2, and ΔΨm loss). Conclusion: TMZ and CoQ10 showed protective effects against cisplatin-induced cardiotoxicity via attenuating oxidative stress.