Nicotinic Acid Riboside Regulates Nrf-2/P62-Related Oxidative Stress and Autophagy to Attenuate Doxorubicin-Induced Cardiomyocyte Injury.

Doxorubicin (Dox) is an effective chemotherapeutic drug for the treatment of various cancers. Due to its potential fatal cardiotoxic side effects, the clinical application is often limited. Dexrazoxane (Dex) is the only drug approved by the Food and Drug Administration (FDA) for the prevention of Dox-induced cardiotoxicity but has side effects. Thus, more protective strategies should be explored. If NAD(+) plays a role in maintaining heart function, its precursor prospectively alleviates Dox-induced cellular injury. Here, we studied the protective effects of nicotinic acid riboside (NAR) on Dox-induced cardiotoxicity in vivo and in vitro. We found that NAR significantly improved the cardiac function of Dox-treated mice by restoring ejection fraction (EF), fractional shortening (FS), and serum level of cardiac troponin (cTnI). NAR not only reduced malondialdehyde (MDA), lactate dehydrogenase (LDH), and reactive oxygen species (ROS) levels in Dox-treated cardiomyocytes but also further promoted the activities of cardiac superoxide dismutase (SOD) and glutathione (GSH). Following exposure to 5 μM Dox, cotreatment with NAR exhibited increased cell viability with a decrease in the apoptosis cell population. Moreover, the levels of apoptosis-related proteins, as well as proteins involved in oxidative stress and autophagy, were altered after NAR treatment. Collectively, these findings underline the protective potential of NAR against Dox-induced cardiomyocyte injury by regulating Nrf-2/P62-related oxidative stress and autophagy, which could potentially promote survival.