Fu Fang Zhen Zhu Tiao Zhi Capsules Protect against Myocardial Ischemia by Inhibiting Cardiomyocyte Pyroptosis

Fu Fang Zhen Zhu Tiao Zhi (FTZ) is a traditional Chinese herbal prescription widely used to treat dyslipidemia, metabolic diseases, and diabetic coronary disorders. Cardiomyocyte death and loss of regenerative ability cause cardiac dysfunction and heart failure. FTZ can effectively treat diabetic cardiomyopathy and macrovascular diseases; however, the mechanism behind the phenomenon is still unclear. Here, we determined the mechanism of action of FTZ in treating myocardial infarction.

Male C57BL/6 mice were treated with 2.4 or 1.2 g/kg FTZ, or administered saline by oral gavage daily for four weeks, and a 24-hour ligation was administered to the artery. Echocardiography was used to evaluate cardiac function. Hematoxylin and eosin and Evans blue/triphenyltetrazolium chloride staining were carried out by staining the cardiac tissue, used to evaluate cardiac function and infarct size. Using western blotting and reverse transcriptase-polymerase chain reaction, we determined the relative levels of NOD-like receptor protein (NLRP) 3, ASC, cleaved caspase-l (C-Caspase-1), GSDMD, and GSDMD-N. TUNEL, immunohistochemical, and immunofluorescence staining were used to determine cell death and NLRP3 expression. An enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of interleukin (IL)-1β and IL-18.

FTZ reduced ischemia-induced cardiomyocyte cell death in vivo and H₂O₂-induced cell death in vitro by maintaining cardiac architecture and restoring cardiac function. FTZ decreased the NLRP3 expression and inhibited pyroptosis-correlated genes, including NLRP3, ASC, GSDMD, C-Caspase-1, and GSDMD-N. NLRP3 overexpression impaired the efficacy of FTZ by inducing pyroptosis.

FTZ could preserve cardiac function resulting from ischemic insult by inhibiting pyroptosis, which was partially reversed by NLRP3 overexpression, indicating that NLRP3 could be a potential target of FTZ in treating myocardial infarction.