Panaxynol ameliorates cardiac ischemia/reperfusion injury by suppressing NLRP3-induced pyroptosis and apoptosis via HMGB1/TLR4/NF-κB axis.

BACKGROUND AND PURPOSE: Panaxynol (PNN) is a common natural minor component in Umbelliferae plants. Many clinical studies have shown that PNN exhibits nutritional value and anti-inflammatory and other pharmacological activities. However, whether PNN can mediate cardiac ischemia/reperfusion injury (IRI) remains unclear. Here, we aimed to determine the potential effects of PNN on myocardial IRI.

METHODS

Myocardial IRI was stimulated in a mouse IRI model, and neonatal rat ventricle myocytes (NRVMs) were exposed to hypoxia/reoxygenation to construct in an vitro model. Myocardial infarction size, myocardial tissue injury, myocardial apoptotic index, hemodynamic monitoring, pyroptosis-related proteins, cardiac enzyme activities and inflammatory responses were examined to assess myocardial injury.

RESULTS

It was found that PNN administration markedly reduced myocardial infarct size and apoptosis, suppressed myocardial damage and cell pyroptosis, attenuated pro-inflammatory cytokines and neutrophil infiltration via NLRP3 inhibitor. More importantly, PNN treatment remarkably decreased the expression of TLR4/NF-κB pathway-associated proteins and NLRP3-related pyroptosis proteins by HMGB1 inhibitor. PNN also enhanced cell viability, reduced cardiac enzyme activities, suppressed apoptosis and attenuated inflammation in the isolated NRVMs. Furthermore, vitro studies indicated that MCC950 (a NLRP3 inhibitor) increased the anti-inflammatory and anti-apoptotic effects of PNN on NRVMs via HMGB1/TLR4 pathway.

CONCLUSION

To sum up, our results demonstrate that PNN exhibits a cardioprotective effect by modulating heart IRI-induced apoptosis and pyroptosis via HMGB1/TLR4/NF-κB pathway, thereby inhibiting NLRP3 inflammasome stimulation.