Effect of Alpina oxyphylla extract on streptozotocin-induced kidney injure via regulating TGF-β1 and MyD88

BACKGROUND: Abnormal renal metabolism is closely related to the development of chronic kidney disease. It is well known that renal inflammation plays an important role in the occurrence and development of tubulointerstitial damage in the renal tubules. The purpose of the experiment was to observe the bioactivity of Alpina oxyphylla extract (AOE) on renal injury in diabetic nephropathy (DN) rats induced by streptozotocin (STZ). METHODS: Thirty male Wistar rats were randomly divided into five group (n = 6): (1) intact control (non-diabetic, ND); (2) intact diabetic (STZ), (3) diabetic rats treated with gliclazide 5 mg/kg (STZ-gli), (4) diabetic rats treated with AOE 400 mg/kg (AOE 400), (5) diabetic rats treated with AOE 800 mg/kg (AOE 800). The diabetic nephropathy rat model was established by single intraperitoneal injected 50 mg/kg STZ. Fasting blood glucose (FBG) and body weight was observed at 1、3、6 weeks. After 6 weeks, the renal function parameters of five groups and 24 h urinary protein were detected. Expression of transforming growth factor-beta1 (TGF-β1) and myeloid differentiation factor 88 (MyD88) were assessed by Western Blot. RESULTS: The STZ group showed hyperglycemia, proteinuria, renal function damage, and the levels of 24 h urinary protein, fasting blood glucose (FBG), blood urea nitrogen (BUN), serum creatinine (Scr), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and interleukin-6 (IL-6) in the STZ group increased significantly compared with the ND group. The expression of TGF-β1 in STZ group was increase (p < 0.01), and the expression of MyD88 was significantly lower than in ND group (p < 0.05). The treatment of DN rats with AOE attenuated DN-associated in the serum biochemical index and the expression of TGF-β1. CONCLUSIONS: AOE can effectively protect kidney tissues of diabetic nephropathy, and probably through regulating level of TGF-β1/MyD88.