Isofraxidin Alleviates Myocardial Infarction Through NLRP3 Inflammasome Inhibition

Isofraxidin is a well-known coumarin compound refined from traditional Chinese medicines. It has been previously demonstrated to play an anti-inflammatory role in various inflammatory conditions. However, the effect of isofraxidin on myocardial infarction (MI) remains uncovered. In this study, we aimed to investigate the effect of isofraxidin on MI. MI mice was created and triphenyltetrazolium chloride (TTC) staining as well as echocardiographic evaluation were conducted to analyze the severity of MI. Oxygen-glucose deprivation (OGD) was used for the mimics of ischemic stress in murine cardiomyocytes, and Cell Counting Kit-8 (CCK-8), Annexin V, and lactate dehydrogenase (LDH) release assays were conducted for cell viability. Western blot was used for the detection of NOD-like receptor family, pyrin domain containing 3 (NLRP3), and adapter protein apoptosis-associated speck-like protein (ASC) in heart tissues and cardiomyocytes. Real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) were applied for the detection of proinflammatory cytokines. We found that isofraxidin alleviated the severity of MI and produced a cardio-protective effect against OGD damage. Isofraxidin also decreased the overall and local inflammatory reaction in MI. Those effects were through the inhibition of the NLRP3 inflammasome. Taken together, we initially reported the cardio-protective and alleviative effect of isofraxidin on MI and uncovered its underlying mechanism related to the NLRP3 inflammasome inhibition.