Effect of Dendrobii Caulis Mixture on Cell Inflammatory Response and Apoptosis in Diabetic Rats with Nonalcoholic Fatty Liver Disease Based on NF-κB/NLRP3/IL-1β Signaling Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo investigate the effect of Dendrobii Caulis mixture on cell inflammatory response and apoptosis in diabetic rat with non-alcoholic fatty liver disease（NAFLD） and its possible mechanism. MethodForty male SD rats were randomly divided into blank group and model group of type 2 diabetes mellitus（T2DM） with NAFLD according to body weight. The model was established by high-sugar and high-fat diet combined with intraperitoneal injection of streptozotocin（STZ）， which was randomly divided into the model group， Dendrobii Caulis mixture group（16.67 g·kg-1·d-1） and metformin group（100 mg·kg-1·d-1） according to blood glucose and body weight， and 10 rats in each group. Rats in each group were administered by continuous gavage for 4 weeks， the blank and model groups were given saline by gavage at 10 mL·kg-1·d-1. Fasting blood glucose（FBG）， serum insulin（INS）， glycosylated serum protein（GSP）， triglyceride（TG）， total cholesterol（TC）， high density lipoprotein（HDL-C）， low density lipoprotein（LDL-C）， alanine aminotransferase（ALT） and aspartate aminotransferase（AST） were detected in each group of rats. The liver tissues of rats in each group were stained with hematoxylin-eosin（HE） to observe the pathological changes， and the positive expressions of nuclear transcription factor（NF）-κB， NOD-like receptor heat protein structural domain-related protein 3（NLRP3）， interleukin（IL）-1β and tumor necrosis factor（TNF）-α were observed by immunohistochemistry. Western blot and fluorescence quantitative polymerase chain reaction（Real-time PCR） were used to detect the protein and mRNA expression of B-cell lymphoma-2（Bcl-2）， Bcl-2 associated X protein（Bax）， Caspase-3 and NF-κB p65， NLRP3， IL-1β， TNF-α in liver tissue of rats in each group. ResultCompared with the blank group， FBG， GSP， TC， TG， LDL-C， AST and ALT levels were increased， INS and HDL-C levels were decreased， Bax， Caspase-3， NLRP3， IL-1β， TNF-α protein and mRNA expression were increased in model group， the ratio of p-NF-κB/NF-κB protein increased， the expression of Bcl-2 protein and mRNA decreased， and the positive immunohistochemical expression of NF-κB， NLRP3， IL-1β and TNF-α increased， and the differences were statistically significant（P<0.01）. The morphological structure of the liver was disrupted， and obvious fat vacuoles were seen. Compared with the model group， FBG， GSP， TC， TG， LDL-C， AST and ALT levels of Dendrobii Caulis mixture group and metformin group were decreased， INS and HDL-C levels were increased， and protein and mRNA expressions of Bax， Caspase-3， NLRP3， IL-1β and TNF-α were decreased， the protein ratio of p-NF-κB/NF-κB decreased， the expression of Bcl-2 protein and mRNA increased， and the positive immunohistochemical expressions of NF-κB， NLRP3， IL-1β and TNF-α decreased， and the differences were statistically significant（P<0.01）. The liver morphology and structure were relatively complete， and the fat vacuoles were reduced. ConclusionDendrobii Caulis mixture can inhibit cell apoptosis， reduce inflammatory response and alleviate liver injury in rats with T2DM and NAFLD， the mechanism may be related to inhibiting the activation of NF-κB pathway， blocking the activation of NLRP3 inflammatory vesicles， reducing IL-1β secretion， attenuating Caspase-3 activity and reducing the ratio of Bcl-2/Bax.