Diabetic nephropathy (DN) is a major complication of diabetes and becomes the chief cause of end-stage renal disease. Our study was undertaken to investigate the ameliorative effect and underlying mechanism of Xueshuantong for Injection (XST) on DN in streptozotocin (STZ)-induced rats. Effect of XST treatment (XST, 50 mg/kg/day, i.p.) lasting 60 days after STZ-induced (60 mg/kg, i.p.) diabetes was investigated. Blood sugar levels and body weight were recorded every week of the experiment. At the 28th and 56th days after injection urine glucose and 24 h urine protein excretion were determined. Apoptosis related factors such as cleaved caspase-3, Bcl-2, Bax and inflammation related factors, including tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), IL-1β, inducible nitric oxide synthase (iNOS) and intercellular adhesion molecule-1 (ICAM-1) were detected by PCR or western blot. The expression levels of fibronectin, Collagen Ⅰ, α-smooth muscle actin (α-SMA) and proliferating cell nuclear antigen (PCNA), TGF-β-Smad2/3 signaling pathway, and receptor for advanced glycation end products (RAGE) was investigated. Our results showed that XST treatment did not affect levels of body weight, blood glucose and urine glucose levels. Our analysis revealed that XST inhibited cell apoptosis and suppressed the properties of RAGE in the kidney. XST treatment could also significantly suppress the overexpression of pro-inflammatory mediators in kidney and prevent renal fibrosis by blocking the TGF-β/Smad2/3 signaling pathway. In conclusion, our findings suggested that XST could provide protection against DN through reduction of RAGE accumulation, decreasing inflammation, inhibition of renal fibrosis, and blocking the TGF-β/Smad2/3 signaling pathway.
Keywords: diabetic nephropathy; panax notoginseng saponins; TGF-β/Smad2/3 signaling pathway; Xueshuantong.