Scutellarin mitigates LPS-ATP-induced cardiomyocyte pyroptosis through the inhibition of the NLRP3/caspase-1/GSDMD signalling pathway

Scutellarin has a good myocardial protective effect. However, the underlying mechanism of scutellarin on cardiomyocyte pyroptosis remains unclear. In this study, we elucidated the mechanism of scutellarin to protect the injured myocardium. The molecular docking technique was used to predict the targets of scutellarin in protecting against myocardial injury. H9c2 cell pyroptosis was induced by lipopolysaccharide (LPS) and adenosine triphosphate (ATP). Then, the activities of CK and LDH were measured through a colourimetric assay. The level of cTnI was quantified by ELISA. mRNA expressions of NLRP3, cysteine-dependent aspartate-specific protease-1 (caspase-1), gasdermin D (GSDMD), interleukin-1β (IL-1β), and interleukin-18 (IL-18) were analyzed using RT-qPCR. Protein expressions of NLRP3, caspase-1, and GSDMD were detected by the immunofluorescence technique. Protein expression of NLRP3 was analysed by using Western blotting. Scutellarin had a good binding affinity with NLRP3, caspase-1, and GSDMD. Compared with LSP and ATP-treated cells, concentrations of 25, 50, and 100 µmol L⁻¹ scutellarin reduced CK and LDH activities and the level of cTnI, decreased the mRNA expression of NLRP3, caspase-1, and GSDMD. In the mechanism study, scutellarin decreased mRNA expressions of NLRP3, caspase-1, GSDMD, IL-1β, and IL-18, and reduced the fluorescence expressions of NLRP3, caspase-1, and GSDMD. Scutellarin reduced the protein expression of NLRP3. Scutellarin inhibits myocardial cell pyroptosis induced by LPS and ATP, and the mechanism is related to the NLRP3/caspase-1/GSDMD signalling pathway.