The Role Of Baicalin Bai Against Glomerulosclerosis By Regulating CTGF

ObjectiveTo study the effect of Baicalin Bai on rat glomerular mesangial cell (GMC) proliferation induced by high glucose(HG) and the effect of Baicalin Bai on renal connective tissue growth factor(CTGF) of diabetic nephropathy(DN) rats.Methods1.Rat GMCs were co-cultured with low glucose(5.5mmol/L, LG), high glucose (25mmol/L, HG), HG+Losartan(40μmol/L), HG+Baicalin Bai high dose (80μmol/L) and HG+Baicalin Bai low dose(40μmol/L) for 24h,48h and 72h respectively. Cell proliferation of each group was assessed by MTT.2. SPF male SD 50 rats with the weight 230-250g were randomly divided into normal control group 10 rats and DN model group 40 rats. All subject rats after fasted 24 hours, were weighed and measured blood glucose that was drawn from tail by needles. The normal group was single injected 0.1mol/L citric acid-sodium citrate buffer 0.5ml/rat into the abdomen.DN model group was single injected 2% STZ 55mg/kg into the abdomen. One week later, the rats whose random blood glucose more than 16.7mmol/L were diagnosed as DM. Six weeks later, if blood glucose more than 16.7mmol/L, urine glucose more than 3+, and urine volume more than 1.5 times the original urine volume were diagnosed as DN. According to blood glucose, weight, urine volume, and urine glucose, DN model rats were divided into four groups:model group 8 rats, Losartan group 7 rats, Baicalin Bai high dose group 8 rats, and Baicalin Bai low dose group 8 rats. Rats in the normal group were not gavaged; rats in model group were gavaged water lml/rat/day; rats in Losartan group weregavaged Losartan solution 5.2mg /kg/day; rats in Baicalin Bai high dose group were gavaged Baicalin Bai high dose solution 60mg/kg/day; rats in Baicalin Bai low dose group were gavaged Baicalin Bai low dose solution 40mg/kg/day. Their food was controlled: 25g/rat/day, but they were free to drink. After 6 weeks of treatment, all rats were killed and were weighed body and kidney. One side of kidney was fixed in 10% formalin solution for pathologic examination. The other side of kidney was fixed in 4% paraformaldehyde solution for detecting CTGF and FN in renal by immunohistochemical. Results1. Average inhibition rate:The GMC average inhibiton rate of Baicalin Bai high dose group and Baicalin Bai low dose group were higher than HG group but lower than Losartan group in 24h,48h and 72h,while there was significant difference compared to the model group(P<0.05). The average of inhibiton rate of Baicalin Bai high dose group, Baicalin Bai low dose group grew time by time. The average of inhibiton rate of Baicalin Bai high dose group was higher than Baicalin Bai low dose group each time.2. Renal Index:Model group, Losartan group, model group, Baicalin Bai high dose group, Baicalin Bai low dose group increased renal index and there were significant difference compared to the normal group (P<0.05). Baicalin Bai high dose group, Baicalin Bai low dose group were similar with model group and there were no significant difference compared to the model group(P>0.05).3.Kidney Pathological Observation:Baicalin Bai high dose group, Baicalin Bai low dose group and Losartan group glomerular hypertrophy was alleviated, compared to the model group, while there was a decrease in the area of PAS dye positive substance in those treatment groups.The change of glomerular hype-rtrophy and PAS dye positive substance, Baicalin Bai high dose group was similar with Losartan group, while Baicalin Bai low dose group was worse than Losartan group.4. Renal FN:The FN expression of Baicalin Bai high dose group, Baicalin Bai low dose group in glomerular were lower decresded than model group, while higher than Losartan group.5. Renal CTGF:The CTGF expression of Baicalin Bai high dose group, Baicalin Bai low dose group in tubule were lower decresded than model group, while higher than Losartan group.ConclusionBaicalin Bai can inhibit GMC proliferation in a time-dependent manner. Baicalin Bai has protective effect on kidney structure, the mechanism of which is probably related to its reduce the expression of CTGF on renal in Diabetic Nephropathy Rats.