Polygonatum polysaccharide attenuates inflammation through inhibiting NLRP3 inflammasome in diabetic cardiomyopathy rats

Polygonatum polysaccharide (PP) has good myocardial protection. This study aims to find whether PP can relieve inflammation and play a protective role in diabetic cardiomyopathy (DCM). Intraperitoneal injection of streptozotocin was used to induce DCM in rats, which were then separated into four groups: model group, PP-200 group (200 mg/kg PP), PP-400 group (400 mg/kg PP), and Met group (120 mg/kg metformin). Both control (NC) and model groups of rats were administered normal saline. According to the kit instructions mentioned on the kit, the levels of blood glucose, glycosylated hemoglobin, insulin (INS), and myocardial enzymes (creatinine kinase, B-type natriuretic peptide, and cardiac troponin I) were measured after 8 weeks. Cardiac function was detected by echocardiography. Hematoxylin and eosin (HE) and Masson staining were used to observe pathological changes. Myocardial RNA and protein levels of NLR family pyrin domain containing 3 (NLRP3), caspase-1, and Gasdermin D (GSDMD) were quantified through reverse transcription-polymerase chain reaction and Western blotting analysis. The in vivo findings showed that PP could reduce blood glucose, glycosylated hemoglobin, and INS levels, enhance heart functioning, restore histological alterations and myocardial enzymes, and relieve myocardial fibrosis. Furthermore, PP suppressed the expressions of NLRP3, caspase-1, and GSDMD. PP could reduce inflammation in DCM rats by suppressing NLRP3 inflammasome.