The protective effect of catalpol on vascular lesions of T2DM rats and the involvement of the oxLDL/LDL and NF-κB signaling pathway

LUO Chuanchao; WANG Jiaxing; ZHU Qinwei

doi:10.3969/j.issn.1002-7386.2023.24.005

Abstract：Objective To investigate the protective effect of catalpol on vascular lesions of type 2 diabetes mellitus(T2DM)rats and the involvement of the oxidized low density lipoprotein(oxLDL)/low density lipoprotein(LDL)and nuclear transcription factor-κB(NF-κB)signaling pathway.Methods A rat T2DM model was created by feeding a high-sugar and high-fat diet and intraperitoneal injection of streptozotocin(STZ).The rats were randomly grouped into blank control group,model group,metformin group(134 mg·kg-1·d-1),catalpol group(10 mg·kg-1·d-1),with 10 in each group.Rats in the model group and blank control group were given the same volume of normal saline for 4 weeks.Serum total cholesterol(TC),triacylglycerol(TG),fasting blood glucose(FBG),low-density lipoprotein(LDL)and high-density lipoprotein(HDL)were measured by automatic biochemical analyzer.The contents of human macrophage chemoattractant protein-1(MCP-1)and oxLDL were determined by enzyme-linked immunosorbent assay(ELISA).The real-time reverse transcription polymerase chain reaction(RT-PCR)and Western blot applied to detect the mRNA and protein expressions of lectin-like oxidized low-density lipoprotein receptor-1(LOX-1),NF-κB p65 and MCP-1 in rat aortic wall,respectively.The structure of rat aortic endothelial cells was observed by transmission electron microscopy(TEM).Results The morphology of aortic endothelial cells in the blank control group was normal,which,in the model group,were obviously swollen,with continuous interruption and vacuoles.Some endothelial cells in the model group were obviously exfoliated,with folded and deformed nuclei,moderately swollen mitochondria and endoplasmic reticulum,swollen,disordered or dissolved cristae,and presence of lipid droplets and glycogen granules.The morphology and structure of endothelial cells in metformin group and catalpol group were slightly swollen,and the structure of mitochondria and endoplasmic reticulum was normal,with slightly deformed nucleus,some slightly shed endothelial cells,and significantly milder degree of injury.Compared with those of the control group,serum FBG,TC,TG,and LDL levels,contents of MCP-1 and oxLDL,and mRNA and protein expressions of LOX-1,NF-κB p65,and MCP-1 in the aortic wall were significantly higher in the model group(P<0.05),which,in the metformin group and catalpol group were significantly lower than those of model group(P<0.05).Conclusion Catalpol may alleviate the vascular lesion of T2DM rats through the oxLDL/LDL and NF-κB signaling pathway.