Preventive effect of imperatorin against doxorubicin-induced cardiotoxicity through suppression of NLRP3 inflammasome activation

Cardiotoxicity is one of the major obstacles to anthracycline chemotherapy. Anthracycline cardiotoxicity is closely associated with inflammation. Imperatorin (IMP), a furocoumarin ingredient extracted from Angelica dahurica, might have potential activity in preventing anthracycline cardiotoxicity due to its anti-cancer, anti-inflammatory, anti-oxidant, cardioprotective properties. This study aims to reveal the effect of IMP on doxorubicin (DOX)-induced cardiotoxicity and its underlying mechanism. We established a rat model of DOX-induced cardiotoxicity by intraperitoneal injection with DOX (1.25 mg/kg twice weekly for 6 weeks), and found that both IMP (25 mg/kg and 12.5 mg/kg) and dexrazoxane 12.5 mg/kg relieved DOX-induced reductions in heart weight, change in cardiac histopathology, and elevated serum levels of LDH, AST and CK-MB. Moreover, DOX upregulated mRNA levels of NLRP3, CASP1, GSDMD, ASC, IL-1 beta and IL-18, elevated protein expressions of NLRP3, ASC, GSDMD-FL, GSDMD-N, pro-caspase-1, caspase-1 p20, pro-IL-1 beta and IL-1 beta in heart tissues, as well as increased serum levels of pro-inflammatory cytokines including IL-1 beta and IL-18, however both of IMP and dexrazoxane suppressed these alterations. In addition, we carried out neonatal rat cardiomyocytes experiments to confirm the results of the in vivo study. Consistently, pretreatment with IMP 25 mu g/mL relieved DOX (1 mu g/mL)-induced cardiomyocytes injury, including decreased cell viability and reduced supernatant LDH. IMP inhibited DOX-induced activation of NLRP3 inflammasome in cardiomyocytes. In conclusion, IMP had a protective effect against DOX-induced cardiotoxicity via repressing the activation of NLRP3 inflammasome. These findings suggest that IMP may be a promising alternative or adjunctive drug for the prevention of anthracycline cardiotoxicity.