Effects Of Puerarin Combined With Saxagliptin On Blood Glucose And Renal Fibrosis In Diabetic Rats, And On Mesangial Cell Proliferation Induced By High Glucose

Objective: To observe effects of puerarin combined with saxagliptin on blood glucose and MCs proliferation in high glucose, as well as to study the effect of combination on renal fibrosis and its mechanism.Methods:(1) Fifty male Wistar rats were used, of which 8 rats were randomly chosen as normal control group, and the remaining rats were used to establish the diabetic model. The rats that met the criterion for the model were randomly divided into diabetic control group, puerarin treatment group, saxagliptin treatment group, puerarin combined with saxagliptin treatment group and metformin combined with saxagliptin treatment group. The above-mentioned drugs were administered for 8 weeks. After that period, all rats were sacrificed. The weight, fasting plasma glucose, fasting insulin, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, serum creatinin and blood urea nitrogen were examined in all the rats. Myocardial pathological changes were observed through hematoxylin-eosin(HE) and Masson staining. The levels of tumor necrosis factor alpha(TNF-α) and macrophage migration inhibitory factor(MIF) in the renal were measured by ELISA. The m RNA and Protein expression of TNF-α, MIF and CD68 were examined by RT-PCR and Western blot.(2) Glomerular mesangial cells were incubated in vitro, then divided into 5 groups: normal sugar group(5.6 mmol/L), high sugar group(30 mmol/L), Puerarin + high sugar group, Saxagliptin + high sugar group and puerarin combined with saxagliptin + high sugar group. The correlations between effects and concentrations or time were investigated by cell culture using MTT. The apoptosis cycle of cells was detected by flow cytometry analysis. The m RNA expression of TNF-α, MIF and CD68 was examined by Q-PCR.Results:(1) Compared with normal group, the weight was decreased(P<0.01), the fasting insulin, total cholesterol, low-density lipoprotein cholesterol, serum creatinin and blood urea nitrogen were increased(P<0.01 or P<0.05), the high-density lipoprotein cholesterol were decreased(P<0.01); the levels of TNF-α and MIF were increased(P<0.01); the m RNA and protein expression of TNF-α, MIF and CD68 were increased(P<0.01) in the kidney tissues in model group. Compared with model group, the weight was increased, the fasting insulin, total cholesterol, low-density lipoprotein cholesterol, serum creatinin and blood urea nitrogen were decreased(P<0.01 or P<0.05), the high-density lipoprotein cholesterol were increased(P<0.05);the levels of MIF and TNF-α were decreased(P<0.05), the m RNA expression of TNF-α, MIF and CD68 was decreased(P<0.05) in puerarin combined with saxagliptin treatment group.(2) Compared with normal sugar group, the proliferation activity of glomerular mesangial cell induced by high sugar, the m RNA and protein expression of TNF-α, MIF and CD68 were increased(P<0.01). Compared with high sugar group, such proliferation was inhibited(P<0.01), and the m RNA expression of TNF-α, MIF and CD68 were reduced in puerarin combined with saxagliptin group.Conclusion:(1) Puerarin combined with saxagliptin lowers blood sugar and blood lipid, increases level of serum insulin, and the combination has stronger effects on those parameters.(2) The combination has synergistic effect on renal fibrosis, and its mechanism may be related to the down-regulation of m RNA and protein expression of TNF-α, MIF and CD68, and inhibiting proliferation of glomerular mesangial cell.