Abstract
OBJECTIVES: To verify whether hesperetin (Hes) alleviates doxorubicin (DOX)-induced cardiotoxicity by reducing inflammation via regulating the AMPK/NLRP3 pathway. METHODS: C57/bl6 mice and H9c2 cells treated with DOX to mimic cardiotoxicity were randomly divided into Sham (or control) group, DOX group, DOX+Hes group, DOX+Hes+compound C (CC, an AMPK inhibitor) group. Cardiac function and myocardial pathologies of the mice were evaluated, and the changes in H9c2 cell morphology and viability were assessed. Lactate dehydrogenase (LDH) activity in mouse myocardial tissues and H9c2 cells was measured using ELISA, and H9c2 cell apoptosis was detected with TUNEL staining. In both H9c2 cells and the myocardial tissues of the mice, cellular expression levels of TNF-α, IL-6 and IL-1β mRNAs and cleaved caspase-3, Bcl2, Bax, IL-1β, IL-18, p-AMPK, AMPK, p-mTOR, mTOR, NLRP3, ASC and caspase-1 proteins were detected using RT-PCR and Western blotting. RESULTS: DOX treatment caused cell swelling, decreased cell viability and increased LDH activity in H9c2 cells, resulting also in significantly increased cell apoptosis and cleaved caspase-3 expression and decreased Bcl2/Bax ratio. The DOX-treated mice showed obvious myocardial fiber swelling and inflammatory infiltration, decreased cardiac function and significantly increased myocardial LDH activity. In H9c2 cells, DOX treatment significantly increased the mRNA expressions of TNF-α, IL-6 and IL-1β and protein expressions of IL-1β and IL-18, lowered the expressions of p-AMPK and p-mTOR, and increased the expressions of NLRP3, ASC and caspase-1. Hes treatment obviously reduced these toxic effects of DOX in H9c2 cells, but its protective effects were blocked by application of compound C. CONCLUSIONS: Hes reduces DOX-induced cardiotoxicity by inhibiting inflammation via regulating the AMPK/NLRP3 pathway.