[Effects of ferulic acid on the expressions of nephrin and podocin in podocytes of diabetic rats].

OBJECTIVE: To investigate the effects of ferulic acid (FA) on the streptozocin (STZ) -induced kidney injury in diabetic rats and its possible mechanisms. METHODS: Diabetes was induced in male SD rats by an injection of STZ (40 mg/kg,i.v.). After 72 hours, blood glucose levels were detected and blood glucose levels exceeded 16.7 mmol/L were diagnosed as diabetic model rats. Diabetic model rats were randomly divided into model group and FA group, ten animal in each group. Another 10 healthy male SD rats were treated as control group. The rats in FA group were treated with FA (100 mg/kg, i.g.,qd) from the 5th week since the diabetic rats model was successfully established and lasted for 8 weeks. The levels of blood glucose, body weight, organ coefficient of kidney, blood urea nitrogen and creatinine were tested. HE staining was employed to observe the pathological changes of the renal tissue. Immunohistochemistry was employed to determine the protein of nephrin and podocin. RESULTS: Compared to control group, the levels of blood glucose, organ coefficient of kidney, blood urea nitrogen(BUN) and serum creatinine(sCr) were increased significantly. Renal cells from model group rats showed atrophied and disordered after HE staining and interstitial proliferation were also appeared in renal tissue of the model group. Meantime, the levels of nephrin and podocin protein were obviously decreased. These changes were significantly attenuated in the model group treated with FA. CONCLUSIONS: FA can evidently ameliorate renal damage in rats with diabetic nephropathy induced by STZ, which might be related to increase the level of nephrin and podocin protein.

[Protective effect of total flavonoids of epimedium on the kidney in experimental diabetic rats].

OBJECTIVE: To investigate the influence of total flavonoids of epimedium (TFE) on the streptozocin (STZ)-induced kidney injury in diabetic rats and discuss the possible mechanism. METHODS: Diabetes was produced by a single injection of streptozocin (40 mg/kg, iv) in male SD rats. The rats were randomly divided into three groups (n = 10): control group, model group and TFE group (100 mg/kg, ig). Animals were sacrificed 12 weeks later. The level of blood glucose, blood urea nitrogen (BUN) and creatinine (Cr) as well as the renal index were determined. Detect the specific biochemical of renal tissue: superoxide dismutase (SOD), malondialdehyde (MDA). Use masson staining to observe the morphology of the renal tissue. Immunohistochemistry was employed to determine the protein levels of transforming growth factor-beta1 (TGF-beta1). RESULTS: Compared to control group, the enhancement of blood glucose, renal index, BUN and Cr was found in model group, which was significantly attenuated by treatment with TFE. Meanwhile, elevated MDA level in renal tissue as well as decreased SOD activities in renal tissue were significantly remitted by TFE. Furthermore, TFE decreased the expression of TGF-beta1. CONCLUSION: TFE can evidently relieve renal damage in rats with diabetic nephropathy induced by STZ, which might be related to antioxidation and modulating the expression of TGF-beta1 protein.

[Study on the protective effect of ursolic acid on alloxan-induced diabetic renal injury and its underlying mechanisms].

OBJECTIVE: To investigate the effect of ursolic acid (UA) on the alloxan-induced kidney injury in diabetic mice and explored its possible mechanisms. METHODS: Diabetes mellitus was induced in male Kunming mice by an injection of alloxan (70 mg/kg, i.v.). After 72 hours, blood glucose levels were detected and mice with blood glucose levels over 13.9 mmol/L were considered as diabetic and selected for further experiment. Thirty mice were randomly divided into three groups: control, diabetic and diabetic + UA(35 mg/kg/d, i.g. continuously for 8 weeks). Blood glucose concentration, organ coefficient of kidney, blood urea nitrogen (BUN), creatinine (Cr) as well as renal tissue levels of superoxide dismutase (SOD), methane dicarboxylic aldehyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined. Pathology of the renal tissue was measured by hematoxylin-eosin staining. RESULTS: Compared to the control group, blood glucose, organ coefficient of kidney, BUN and Cr increased significantly. In addition, SOD activities was reduced markedly and levels of MDA and inflammatory factors (TNF-α, IL-6) increased significantly. Renal cells from model group rats showed atrophy and disordered after HE staining and infiltration of inflammatory cells also appeared in renal tissue of the model group. These changes were significantly attenuated in the diabetic group treated with UA. CONCLUSION: UA can significantly relieve renal damage in mice with diabetic nephropathy induced by alloxan, which might be related to decreased blood glucose level, antioxidation effect and inhibiting the production of inflammatory factors such as TNF-α and IL-6.