Anti-inflammatory activity of carvacrol protects the heart from lipopolysaccharide-induced cardiac dysfunction by inhibiting pyroptosis via NLRP3/Caspase1/Gasdermin D signaling axis

Aims: Lipopolysaccharide (LPS) is a well-known agent to induce septic conditions. Sepsis-induced cardiomyop-athy has an overwhelming death rate. Carvacrol (CVL), a monoterpene phenol, has anti-inflammatory and antioxidant properties. This research aimed to investigate the effect of CVL on LPS-induced dysfunction in the heart. In this study, we evaluated the effect of CVL in LPS-stimulated H9c2 cardiomyoblast cells and Balb/C mice. Main methods: LPS was used to induce septic conditions in H9c2 cardiomyoblast cells in vitro and in Balb/C mice. A survival study was conducted to assess the survival rate of mice after LPS and/or CVL treatment. Key findings: In vitro studies indicated that CVL inhibits reactive oxygen species (ROS) generation and abates pyroptosis mediated by NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome in H9c2 cells. In mice, CVL intervention improved the survival rate in septic conditions. The CVL administration mark-edly improved the echocardiographic parameters and alleviated the LPS-induced reduction in the ejection fraction (%) and fraction shortening (%). The CVL intervention restored the myocardial antioxidants and his-topathological alterations and decreased the pro-inflammatory cytokine contents in the heart. Further findings disclosed that CVL reduced the protein levels of NLRP3, apoptosis-associated speck-like protein (ASC), caspase 1, interleukin (IL)-18, IL-18, and the pyroptosis-indicative protein, gasdermin-D (GSDMD) in the heart. The autophagy-indicative proteins, beclin 1 and p62 in the heart were also restored in the CVL-treated group. Significance: Altogether, our findings demonstrated that CVL has a beneficial effect and can be a potential molecule against sepsis-induced myocardial dysfunction.