Artemisinin is known for its pharmaceutical effect against malaria and received increased attention for its other potential function. Mounting evidence suggest that artemisinin could also exert cardioprotective effects while the understanding of its regulatory mechanism is still limited. This study is designed to investigate the role of artemisinin in myocardial ischemia/reperfusion (I/R) injury and the involvement of NLRP3 inflammasome. Artemisinin was administrated for 14 consecutive days intragastrically before I/R injury. Cardiac function was assessed by echocardiography. Infarct area was observed through HE and TTC staining. Apoptosis and autophagy were assessed by TUNEL and Western blotting. The artemisinin-treated myocardial I/R rats demonstrated less severe myocardial I/R injury (smaller infarct size and lower CK-MB, LDH), significant inhibition of cardiac autophagy (decreased LC3II/I and increased p62), improved mitochondrial electron transport chain activity, concomitant with decreased activation of NLRP3 inflammasome (decreased NLRP3, ASC, cleaved caspase-1, IL-1β). In conclusion, our findings further confirmed that activation of the NLRP3 inflammasome pathway is involved in myocardial I/R injury, whereas artemisinin preconditioning could effectively protect against myocardial I/R injury through suppression of NLRP3 inflammasome activation. Therefore, the NLRP3 inflammasome might serve as a promising therapeutic target providing new mechanisms for understanding the effect of artemisinin during the evolution of myocardial infarction.
Keywords: Artemisinin; Autophagy; Cardiac function; Myocardial I/R injury; NLRP3 inflammasome.