Effect of Zuogui Jiangtang Tongmai Prescription on SCFAs/GPR43/GLP-1/GLP-1R Signaling Pathway in Rats with Diabetes Mellitus Complicated with Cerebral Infarction / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo explore the potential mechanism of Zuogui Jiangtang Tongmai prescription （ZJT） in the treatment of diabetes mellitus complicated with cerebral infarction （DM-CI） in rats based on the short-chain fatty acids （SCFAs）/G protein-coupled receptor 43 （GPR43）/glucagon-like peptide-1 （GLP-1）/GLP-1 receptor （GLP-1R） signaling pathway. MethodSixty SD rats were randomly divided into sham operation group， model group， low- and high-dose ZJT groups （12， 24 g·kg-1）， western medicine group （140 mg·kg-1 pioglitazone metformin tablets + 27 mg·kg-1 enteric-coated aspirin tablets）. Except for the sham operation group， all other groups were fed a high-sugar high-fat diet for 4 weeks and then subjected to intraperitoneal injection of 1% streptozotocin at 35 mg·kg-1 combined with middle cerebral artery occlusion （MCAO） to establish a DM-CI rat model. The corresponding interventions were performed with distilled water， low-dose ZJT， high-dose ZJT， pioglitazone metformin tablets， and enteric-coated aspirin tablets. After surgery， National Institutes of Health Stroke Scale （NIHSS） scoring and triphenyltetrazolium chloride （TTC） staining to measure the rat's cerebral infarct volume were carried out. Random blood glucose levels were measured， and hematoxylin-eosin （HE） staining was used to observe histopathological changes in rat brain tissues. Gas chromatography was employed to detect the content of SCFAs in the cecum contents. Enzyme-linked immunosorbent assay （ELISA） was adopted to measure serum GLP-1 level. Western blot was used to detect the protein expression of GPR43 in rat ileal tissues and GLP-1R in the ischemic brain tissues. ResultCompared with the sham operation group， the model group showed significantly increased NIHSS scores， random blood glucose levels， and cerebral infarct volumes （P<0.01）， and significantly decreased SCFAs content， GLP-1 levels， and GPR43 and GLP-1R protein expression （P<0.01）. Compared with the model group， the high-dose ZJT group and the western medicine group exhibited significantly reduced NIHSS scores， random blood glucose levels， and cerebral infarct volumes （P<0.05， P<0.01）， and significantly increased SCFAs content， GLP-1 levels， and GPR43 and GLP-1R protein expression （P<0.01）. ConclusionZJT can improve glucose metabolism disorder and reduce neurological damage in DM-CI rats， and its mechanism may be related to the increase in SCFAs content and the upregulation of the GPR43/GLP-1/GLP-1R signaling pathway.