L-ascorbic acid and α-tocopherol attenuate arsenic trioxide-induced toxicity in H9c2 cardiomyocytes by the activation of Nrf2 and Bcl2 transcription factors

Arsenic trioxide (As2O3) is a potent drug for the treatment of acute promyelocytic leukemia (APL) and has achieved remarkable remissions in patients. Unfortunately, clinical reports have shown that the treatment is associated with cardiotoxicity. Many efforts have been made to mitigate drug-mediated cardiac damage using naturally occurring antioxidant compounds possessing free radical scavenging activity. The present investigation aims to explore protective role of L-ascorbic acid (L-AA) and alpha-tocopherol (alpha-TOC) from As2O3-induced oxidative stress in H9c2 cardiomyocytes through the evaluation of Nrf2 (nuclear factor erythroid 2-related factor 2) and Bcl-2 (B-cell lymphoma 2) transcription factors. The in vitro study was conducted using H9c2 cardiomyocytes. The evaluation of total antioxidant capacity, mitochondrial membrane potential, cellular calcium concentration and reactive oxygen species generation was performed. Oxidative stress (Nrf2) and anti-apoptotic (Bcl2) signaling indicators were measured by reverse transcriptase polymerase chain reaction. A depletion of the total antioxidant capacity and mitochondrial transmembrane potential were observed in As2O3-treated cardiomyocytes. In addition, the cellular calcium concentration and ROS generation were found to be increased on treatment with As2O3 with the alterations in the activity of transcription factors, Nrf2 and Bcl2. Co-treatment of antioxidant vitamins with As2O3 resulted in a significant reversal of oxidative stress and alteration on the antioxidant defense through the activation of Nrf2 and Bcl2. L-AA and alpha-TOC alleviates As2O3-induced oxidative stress in cardiac cells by activating Nrf2 and Bcl2 transcription factors that results in increased cell survival and prevents apoptosis.