[Protective effects of Curcumin analogue L6H4 on kidney from type 2 diabetic rats]

To investigate the protective effect of curcumin analogue L6H4 on the kidney from the type 2 diabetic rats.

Twenty-four SPF male SD rats were randomly divided into 3 groups(n=8):normal control group(NC),diabetes mellitus group(DM) and DM+L6H4-treatment group(DT). After rats were fed with high-fat diet for 4 weeks, both the DM and DT groups were injected with streptozotocin intraperitoneally to induce type 2 diabetes mellitus models. The rats in DT group were given L6H4 by gavage at the dose of 0.2 mg/kg·d for 8 weeks. After the treatment, the 24 h urinary protein, fasting blood glucose (FBG), triglyceride (TG), serum creatinine(Scr),blood urea nitrogen (BUN) and uric acid (UA) were detected biochemically. The pathological changes of the kidneys were observed under light and transmission electron microscopes. The expressions of TGF-β1, FN and Col IV were detected by immunohistochemistry.

The levels of the 24 h urinary protein, FBG, TG, Scr and BUN were elevated significantly in diabetic group(P<0.01). The glomerular volume of DM group rats became irregularly enlarged, diffused mesangial matrix accumulated, with basal membrane proliferous hypertrophy and fusion phenomenon of foot process, the expressions of TGF-β1,FN and Col-IV were elevated significantly (P<0.05). After treated with L6H4, the levels of the 24 h urinary protein, FBG, TG, Scr and BUN were decreased in DT group compared to DM group (P<0.01), the morphological changes of kidney were ameliorated. The expression levels of TGF-β1, FN and Col-IV were downregulated (P<0.05).

L6H4 exerts the protective effect on kidneys of type 2 diabetic rats by reducing expression of TGF-β1, inhibiting secretion of Col-IV and FN, relieving the deposition of the extracellular matrix.