Antioxidants ameliorates glucose/glucose oxidase-induced myocardial damage through mitochondrial and MAPK Pathway

Objective Diabetes is characterized by high blood glucose concentration which leads to oxidative stress by auto-oxidation, resulting in pathological conditions like myocardial complications. This study is focused on evaluation of the protective potential of antioxidants against glucose/glucose oxidase (G/GO)-induced oxidative stress and cardiac cell damage. Methods H9c2 cells which is derived from cardiac muscles were exposed to 33mM glucose and 1.6 milliunits glucose oxidase for induction of oxidative stress. Apoptosis was evaluated through markers like phosphatidylserine accumulation, DNA damage, and esterase activity. Reactive oxygen and nitrogen species production, mitochondrial membrane potential loss, and cytochrome-c release assessed using confocal microscopy and FACS analysis. Antioxidants such as N-Acetyl Cysteine, catalase, and glutathione were tested for their protective effects. Western blot analysis was used to evaluate anti-apoptotic protein expression and MAPK pathway activation. Results G/GO exposure led to apoptosis in H9c2 cells, as evidenced by phosphatidylserine accumulation, DNA damage, and increased esterase activity. Reactive oxygen and nitrogen species production resulted in mitochondrial membrane potential loss and cytochrome-c release. Antioxidants successfully reduced free radical production, restored mitochondrial membrane potential, and prevented cytochrome-c release. Cell death inhibition, caspase activation and PARP cleavage was also done by the antioxidant. Furthermore, antioxidants restored levels of anti-apoptotic proteins (Bcl-2, Bcl-xL, cFLIP, XIAP, survivin) and inhibited Raf1, MEK1, and ERK1/2 activation in the MAPK pathway. Pharmacological inhibition of Raf1 reduced apoptosis. Conclusion Antioxidants exhibit strong protective efficacy against G/GO-induced oxidative stress by preventing mitochondrial dysfunction and inhibiting MAPK-mediated pathways, offering potential therapeutic benefits for oxidative stress-related cardiac damage in diabetes.