Combined conditioning with nicotinamide mononucleotide and alpha-lipoic acid as a potential approach in cardioprotection and mitochondrial improvement in rats with doxorubicin-induced cardiotoxicity

Abstract

Doxorubicin (DOX) is a cytotoxic anthracycline drug used to treat various cancers. One of the most important side effects of doxorubicin is cardiotoxicity, which causes cardiac dysfunction, cardiomyopathy, heart failure, and ultimately increased mortality. Given that mitochondrial dysfunction/biogenesis and the subsequent exacerbation of inflammatory responses have been proposed as the main culprits of doxorubicin cardiotoxicity. Nicotinamide mononucleotide (NMN) is essential for mitochondrial activity. Alpha-lipoic acid (ALA) itself also has a wide range of effects in the body, from reducing oxidative stress to influencing many mitochondrial functions. Therefore, the aim of the present study was to investigate the protective effects of combined conditioning with NMN and ALA on cardioprotection in rats subjected to doxorubicin cardiotoxicity by examining cardiac histological changes, serum LDH levels, mitochondrial function/biogenesis, and inflammatory responses. Methods: In this study, 30 male Wistar rats weighing 250-300 g were used. The animals were randomly divided into 5 groups (6 animals per group): (1) healthy control (Control), (2) DOX (3) receiving nicotinamide mononucleotide (DOX+NMN), (4) receiving alpha-lipoic acid (DOX+ALA), and (5) receiving nicotinamide mononucleotide and alpha-lipoic acid (DOX+NMN+ALA). Histopathological changes of the heart were assessed using hematoxylin-eosin (H&E) staining and light microscopy, serum LDH levels were assessed using a specific kit and ELISA, mitochondrial membrane depolarization by JC-1 staining and fluorometric technique, mitochondrial ROS production by DCFH-DA dye using fluorometric method, ATP levels by the relevant specific kit, mitochondrial biogenesis gene expression (PGC-1α, NRF1, TFAM) by Real-time PCR, and inflammatory cytokines (TNF-α, IL-1β, IL-6) by ELISA. Results: Co-administration of NMN and ALA, both alone and together, significantly reduced LDH levels and improved cardiac histological changes in mice exposed to DOX cardiotoxicity. NMN and ALA in combination significantly increased mitochondrial potential and ATP and decreased ROS levels in the heart tissue of rats exposed to DOX (P<0.05). NMN and ALA in combination increased the expression of genes involved in mitochondrial biogenesis including PGC-1α, NRF1, TFAM (P<0.05). Also, combined administration of NMN and ALA significantly reduced the levels of inflammatory proteins TNF-α, IL-1β, IL-6 compared to the DOX group (P<0.05).