ABSTRACT
OBJECTIVE To investigate the protective effect and potential mechanism of cornuside on diabetic nephropathy （DN） model mice. METHODS Male KK-Ay mice were fed with high-fat and high-sugar diet for two weeks to reproduce the DN model. The successfully modeled mice were randomly grouped into model group， aminoguanidine group （positive control，100 mg/kg） and cornuside group （100 mg/kg）， and male C57BL/6J mice were included as normal group， with 6 mice in each group. Administration groups were given relevant medicine intragastrically， and normal group and model group were given a constant volume of normal saline intragastrically， once a day， for 8 consecutive weeks. The levels of fasting blood glucose （FBG）， 24 h urinary protein， serum interleukin-12 （IL-12）， IL-10， blood urea nitrogen （BUN） and serum creatinine （Scr） were detected； the pathological injury， fibrotic change and glomerular microstructure of renal tissue were observed； the expressions of the receptor of advanced glycation end products （RAGE）， collagen type Ⅳ （COL-Ⅳ） and inducible nitric oxide synthase （iNOS） in renal cortex were detected in each group. RESULTS Compared with normal group， the renal cortex of mice in model group showed obvious inflammatory cell infiltration and fibrotic changes； the mesangial hyperplasia of glomerulus was serious and the basement membrane had a large number of irregular dark dense deposits； the levels of FBG and 24 h urinary protein， the serum levels of IL- 12， BUN and Scr， and the expression levels of RAGE， COL-Ⅳ and iNOS in the renal cortex were significantly increased， while the serum level of IL-10 was significantly decreased （P＜0.01）. Compared with the model group， the renal pathological injuries， fibrotic changes and glomerular microstructure of mice in administration groups were improved significantly， and the above quantitative indexes were generally improved （P＜0.05 or P＜0.01）. CONCLUSIONS Cornuside has a certain protective effect on DN model mice. It can inhibit the inflammatory response， reduce urinary protein excretion， and alleviate renal fibrosis， which may be related to the inhibition of the advanced glycation end products/RAGE signaling pathway.
ABSTRACT
Aim To investigate the effect that catalpol intervenes macrophage polarization mediated by mouse mesangial cells(MMCs) stimulated by advanced glycation end products(AGEs).Methods RAW264.7 macrophages and MMCs were co-cultured in vitro and divided into model group(100 mg·L-1 AGEs), control group(100 mg·L-1 BSA), catalpol(0.1, 1.0, 10.0 μmol·L-1) group, and aminoguanidine(1.0 μmol·L-1) group which was set as positive control.After being incubated with catalpol for 1 h, MMCs were stimulated by AGEs for 23 h.The proliferation-inhibition rate of MMCs was measured by MTT assay.MCP-1 in supernatant liquid of MMCs was detected by ELISA method.The expression of iNOS, CD16/32, TNF-α, COX-2, CD206 and Arg-1 was detected by Western blot.Simultaneously, the percentage of iNOS and CD206 was also measured by flow cytometry.Results AGEs could increase the level of MCP-1 secreted by MMCs.The expression of iNOS, TNF-α, CD16/32 and COX-2 protein of macrophage was up-regulated after MMCs stimulated by AGEs, while the expression of CD206 and Arg-1 was down-regulated.After being intervened by catalpol, these effects could be reversed.All the changes were concentration-related.Conclusions Catalpol can inhibit macrophages M1-type polarization process and promote M2-type polarization, which may be mediated through MCP-1 secreted by MMCs after AGEs stimulation.Catalpol can ameliorate inflammation and relieve diabetic kidney injury.