Naringenin confers protection against oxidative stress through upregulation of Nrf2 target genes in cardiomyoblast cells

Cardiovascular diseases are the major health concern and the leading cause of death. Numerous studies have shown that oxidative stress stimuli have been incriminated in the pathogenesis of both acute and chronic heart disease. Though it is well known that bioflavonoids protect cells against reactive oxygen species (ROS)-induced damage, the molecular mechanisms involved are uncertain. Understanding the possible intracellular signaling pathways triggered by flavonoids will help to overcome the cardiac diseases resulting from oxidative stress. In the present study, we investigated whether naringenin (NGN) supplementation would improve the antioxidant defence under oxidative stress through the activation of Nrf2 signaling in cultured cardiomyoblast. NGN pretreatment significantly reduced stress-mediated apoptotic cell death and lipid peroxidation and showed increased level of reduced glutathione in H2O2-treated cardiomyoblast. In addition, NGN inhibited the production of NO and trigged the synthesis of antioxidant marker enzymes. Gene expression studies revealed that NGN upregulated the transcription of Akt and downregulated NF-kappa B and Caspase 3 genes. Notably, transcription of Nrf2 and its target genes was also upregulated. Taken together, the present study revealed that NGN elicits potent cytoprotective effect against oxidative stress by regulating Nrf2 and its target genes. In conclusion, the present work suggests that improving Nrf2 signaling by NGN supplementation would be a rational approach to facilitate ROS detoxification by augmenting both expression and activity of phase II detoxification enzymes for the alleviation of cardiac complications.