Preliminary study of the dose-proportion relation of Tibetan medicine Siwei Jianghuang Prescription on diabetic nephropathy rats induced by STZ / 中成药

ABSTRACT

AIM To investigate the dose-proportion relation of Tibetan medicine Siwei Jianghuang Prescription (SJP) for protective effects on diabetic nephropathy (DN),and the underlying mechanism.METHODS Diabetes mellitus rats induced by intraperitoneal injection of streptozotocin (STZ) (60 mg/kg) were randomly divided into model group,metformin support group,and eight SJP groups with dose-proportion variation (with reference to the uniform design method) for corresponding drug administration once a day,for four weeks.Measurement of fasting blood glucose (FBG) by a blood glucose meter,the concentrations of blood urea nitrogen (BUN),uric acid (UA),serum creatinine (SCr) and total protein (TP) by chemical methods,serum transforming growth factor-β1 (TGF-β1) and vascular endothelial growth factor (VEGF) by ELISA kits were conducted,the pathological morphology observation and glomerular basement membrane thickness detection by electron microscope were accomplished as well.Principal components analysis (PCA) and multivariate progressive regression analysis (MSRA) were employed to analyze the relationship between the dose-proportion to pharmacodynamics.RESULTS The resultant indexes revealed variant pharmacological improvement in each treatment group.MSRA results showed that the levels of BUN,renal index,FBG,glomerular basement membrane thickness,VEGF,Scr,and UA had correlative relations with a multiple linear or a multiple non-linear in all groups,which regression equation had a statistical significance (P ＜ 0.05);TGF-β1 level and total protein index with the dose-proportion had no linear or non-linear relation,which the regression equation statistical showed non-significance (P ＞ 0.05).In the global optimization comparison around the range of uniform design,the optimal dosage of the rats model was Curcumae Longae Rhizoma ∶ Berberidis dictyophyllae Cortex ∶ Phyllanthi Fructus ∶ Tribuli Fructus =1 ∶ 2 ∶ 1 ∶ 2.CONCLUSION Siwei Jianghuang Prescription shows better therapeutic effects on DN,which may be related to reducing the levels of BUN,renal index,FBG,glomerular basement membrane thickness,VEGF,Scr and UA.