Astragaloside IV Inhibits NLRP3 Inflammasome-Mediated Pyroptosis via Activation of Nrf-2/HO-1 Signaling Pathway and Protects against Doxorubicin-Induced Cardiac Dysfunction

Background: Doxorubicin (DOX) is an effective broad-spectrum antitumor drug, but its clinical application is limited due to the side effects of cardiac damage. Astragaloside IV (AS-IV) is a significant active component of Astragalus membranaceus that exerts cardioprotective effects through various pathways. However, whether AS-IV exerts protective effects against DOX-induced myocardial injury by regulating the pyroptosis is still unknown and is investigated in this study. Methods: The myocardial injury model was constructed by intraperitoneal injection of DOX, and AS-IV was administered via oral gavage to explore its specific protective mechanism. Cardiac function and cardiac injury indicators, including lactate dehydrogenase (LDH), cardiac troponin I (cTnI), creatine kinase isoenzyme (CK-MB), and brain natriuretic peptide (BNP), and histopathology of the cardiomyocytes were assessed 4 weeks post DOX challenge. Serum levels of IL-1β, IL-18, superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione (GSH) and the expression of pyroptosis and signaling proteins were also determined. Results: Cardiac dysfunction was observed after the DOX challenge, as evidenced by reduced ejection fraction, increased myocardial fibrosis, and increased BNP, LDH, cTnI, and CK-MB levels (p < 0.05, N = 3–10). AS-IV attenuated DOX-induced myocardial injury. The mitochondrial morphology and structure were also significantly damaged after DOX treatment, and these changes were restored after AS-IV treatment. DOX induced an increase in the serum levels of IL-1β, IL-18, SOD, MDA and GSH as well as an increase in the expression of pyroptosis-related proteins (p < 0.05, N = 3–6). Besides, AS-IV depressed myocardial inflammatory-related pyroptosis via activation of the expressions of nuclear factor E2-related factor 2 (Nrf-2) and heme oxygenase 1 (HO-1) (p < 0.05, N = 3). Conclusions: Our results showed that AS-IV had a significant protective effect against DOX-induced myocardial injury, which may be associated with the activation of Nrf-2/HO-1 to inhibit pyroptosis.