Acetaminophen causes mitochondrial dysfunction in heart cardiomyocytes

Acetaminophen (APAP) is a common over-the-counter medication used to treat pain and fever. It can be taken orally, topically, or intravenously and is considered a safe and effective drug when taken at therapeutic doses. However, recent research suggests that taking APAP regularly can result in increased blood pressure and cardiovascular risk. Previous publications found that Non-Steroidal-Anti-Inflammatory-Drugs (NSAIDs) increased Reactive Oxygen Species (ROS) in cardiomyocytes, resulting in cardiac dysfunction. Although APAP is not a NSAID, APAP likely has similar effects. We hypothesized that regular APAP usage resulted in increased ROS levels, leading to potential dysfunction in hearts and other organs. We used the embryonic rat heart cell line H9C2 to test our hypothesis. We conducted a ROS Assay using H9C2 cells treated with dichlorodihydrofluorescein diacetate (DFCDA). The cells were then treated with vehicle, various concentrations of APAP (25μM, 50μM, 100μM, and 200μM), or 100μM hydrogen peroxide for 1.5 hours before measuring the ROS levels of the cells. We also measured the cell viability of H9C2 cells. Cells were treated with 10μM Alamar Blue, then treated with vehicle, various concentrations of APAP (25μM, 50μM, 100μM, and 200μM), or 100μM or 200μM hydrogen peroxide for 48 hours before detecting the percentage of viable cells. The mitochondrial membrane potential (MMP) of cells treated with APAP was also measured. Cells were treated with vehicle, various concentrations of APAP (25μM, 50μM, 100μM, and 200μM), or 250μM p-triflouromethoxyphenylhydrazone (FCCP) for 24 hours before being incubated with JC-10 for one hour. The cells were measured using a fluorescent reader at excitation/emission 490/525 nm and 540/590 nm. For the ROS assay, the cells treated with 100μM APAP, 200μM APAP, and 100μM Hydrogen Peroxide significantly increased total ROS compared to the control. The cell viability assay resulted in a significant decrease in percent viability in cells treated with 200μM APAP, 100μM hydrogen peroxide, and 200μM hydrogen peroxide compared to the control. The MMP Assay resulted in a significant decrease in MMP at all concentrations of APAP and 250μM FCCP compared to the control. These results suggest that treatment of H9C2 cardiac cells with physiological concentrations of APAP causes an increase in intracellular ROS levels, decreased cell viability, and decreased MMP. Overall, APAP causes mitochondrial dysfunction, which is likely to cause cardiomyocyte dysfunction. This research is funded by the NIEHS/Superfund Research Program (P42 ES004699). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.