Effect of Huanglian Wendantang on Classical Pathway of Skeletal Muscle Pyroptosis in IGT Rats / 中国实验方剂学杂志

ABSTRACT

Objective:To explore the effects of Huanglian Wendantang （HLWDT） on pyroptosis of skeletal muscle in rats with impaired glucose tolerance （IGT） and to explain the mechanism based on NOD-like receptor protein 3 （NLRP3）/cysteine aspartate-specific protease-1 （Caspase-1）/gasdermin D （GSDMD）/interleukin-1<italic>β </italic>（IL-1<italic>β</italic>）/IL-18 signaling pathway. Method:The SD male rats were fed with 45% high-fat diet for 20 weeks to induce the IGT model. After modeling， the rats were randomly divided into a blank group， a model group， a positive control group （metformin hydrochloride， 0.05 g·kg^-1d^-1）， and an HLWDT （7.8 g·kg^-1d^-1） group based on the body weight of rats. The blank group and the model group were fed with the same volume of distilled water. The dose for each group was set as 10 mL·kg^-1d^-1. After four weeks of continuous gavage， blood was collected and serum was separated. The skeletal muscles of rats were stored in liquid nitrogen. Subsequently， serum IL-1<italic>β</italic> and IL-18 were detected by the enzyme-linked immunosorbent assay （ELISA）. The mRNA and protein expression levels of NLRP3， Caspase-1， and GSDMD were detected by real-time quantitative PCR （Real-time PCR） and Western blot， respectively. The expression of GSDMD， IL-1<italic>β</italic>， and IL-18 proteins in skeletal muscle tissues was detected by immunofluorescence. Hematoxylin-eosin （HE） staining was used to observe the pathological changes of skeletal muscles. Result:Compared with the blank group， the model group showed increased IL-1<italic>β</italic> and IL-18 in serum， and NLRP3， Caspase-1， and GSDMD gene and protein expression in skeletal muscle tissues （<italic>P</italic><0.01）. Immunofluorescence assay showed that GSDMD， IL-18， and IL-1<italic>β </italic>protein expression in skeletal muscle tissues of the model group was significantly elevated （<italic>P</italic><0.01）. HE staining showed obvious pathological changes in skeletal muscles. Compared with the model group， the HLWDT group and the positive control group could decrease IL-1<italic>β</italic> and IL-18 in serum and NLRP3， Caspase-1， and GSDMD gene and protein expression in skeletal muscle tissues （<italic>P</italic><0.01）. In addition， immunofluorescence assay revealed that HLWDT could reduce protein expression levels of GSDMD， IL-1<italic>β</italic>， and IL-18 in skeletal muscles of IGT rats （<italic>P</italic><0.01）. The results of HE staining showed that HLWDT could improve the pathological changes of skeletal muscles in IGT rats<bold>.</bold> Conclusion:HLWDT can inhibit skeletal muscle pyroptosis of IGT rats， and the mechanism may be closely related to NLRP3/Caspase-1/GSDMD/IL-18/IL-1<italic>β</italic> signaling pathway.