Picroside II prevents inflammation injury in mice with diabetic nephropathy via TLR4/NF-κB pathway

The purpose of this study was to investigate the therapeutic effects of picroside II on diabetic nephropathy and reveal the involved underlying signal pathway. Male Sprague–Dawley (SD) mice were used to construct an animal model of streptozotocin (STZ)-induced diabetic nephropathy. Body weight and fasting blood glucose values were recorded. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of proteinuria, blood urea nitrogen (BUN), serum creatinine (Scr), interleukin (IL)-1β, IL-6, monocyte chemoattractant protein-1 (MCP-1) and necrosis factor alpha (TNF-α). Protein expression was determined using Western blotting test. Hema-toxylin and eosin (H&E) staining was used to examine the morphological changes in kidney tissues. Treatment with picroside II (10 and 20 mg/kg) increased the STZ-induced reduction in body weight of diabetic mice. It also reversed the elevation of fasting blood glucose in STZ-induced diabetic mice. The levels of proteinuria, BUN and Scr were significantly increased in STZ-induced diabetic mice and these increments were prevented by picroside II. The serum levels of MCP-1, IL-1β, IL-6 and TNF-α were reduced, and the morphological damage was lessened by Picroside II in mice with diabetic nephropathy. Besides, picroside II prevented the activation of TLR4/NF-κB pathway. This study proved that picroside II inhibited inflammatory response and prevented kidney injury in mice with diabetic nephropathy through modulation of TLR4/NF-κB pathway, indicating beneficial effect of picroside II on diabetic nephropathy.