The Synergistic effect of nicotinamide mononeuclutide and melatonin on infarct size, expression of mitochondrial (Fox1, SIRT3) and apoptotic genes (Bax, Bcl2, Casp3) and histopathological changes in miocardium of aged male rats with ischemia-reperfusion injury

Abstract

It has been shown that aging is associated with higher risk of cardiovascular complications such as ischemia/reperfusion (IR). In this study, we aimed to investigate the effects of melatonin (Mel) and nicotinamide mononucleotide (NMN) treatment separately or in combination on apoptotic markers, mRNA expression of SIRT3 and FOXO1, infarct size, and also histophatological changes of the aged myocardium injured by IR. Sixty aged Wistar rats were randomly divided into five groups including sham, IR, NMN-IR, Mel-IR, and combination therapy (NMN+IR+Mel). Isolated hearts were mounted on a Langendorff apparatus and were subsequently subjected to a 30-min regional ischemia followed by 60-min reperfusion. NMN (100 mg/kg/day/i.p.) was administered for every other day for 28 days before IR. Melatonin was added to perfusion solution 5 minutes before reperfusion up to 15 minutes early reperfusion. The infarct size was assessed by a computerised planimetry. Moreover, mRNA expression of SIRT3, FOXO1 and also expression genes BCL2, BAX, and Caspase-3 were investigated by Real time PCR. Histopathological changes were also assessed by hematoxylin-eosin staining. All treatments could reduce infarct size. In addition, melatonin and NMN increased Bcl‐2 expression and decreased Bax, and Caspase‐3, in response to myocardial IR (p<0.001) . Combination of NMN and melatonin upregulated SIRT3 and FOXO1 expression (p<0.001). These findings indicate that combined administration of NMN and melatonin is able to protect the aged heart against IR injury by decreasing apoptosis and activation of SIRT3/FOXO1. Also combination treatment improved the damaged tissue following IR injury.