The Study On Protective Effect And Related Mechanism Of Panax Notoginseng Saponins On Kidney Injury In Diabetic Nephropathy Mice

ObjectiveTo explore whether Panax notoginseng saponins can improve the degree of kidney damage in diabetic mice induced by streptozotocin through the Nrf2/HO-1signaling pathway,thereby protecting the kidney function of diabetic nephropathy mice.MethodsGrouping:Fifty male C57BL/6 mice were randomly divided into normal control group,model group,and panax notoginseng saponins low,medium and high dose(50,100,200 mg·kg^-1)administration groups.Modeling:The mice in the normal control group were injected with normal saline,and the mice in other groups were injected intraperitoneally with 50 mg·kg^-1 streptozotocin for 5 consecutive days to establish a diabetic mouse model.Fasting blood glucose（FBG）≥16.7 mmol·L^-1 is regarded as successful.The establishment of a diabetes model can induce kidney damage.On the second day of the establishment of the model,mice in the administration group were given the above-mentioned corresponding doses by gavage,and mice in the normal group and model group were gavage with normal saline for 8 weeks.Testing indicators:The weight and fasting blood glucose level of the mice were measured with a weight scale and blood glucose meter every week;the mice were sacrificed after gavage for 8 weeks,blood was taken from the abdominal aorta,and the blood creatinine and urea nitrogen;HE staining was used to observe the pathological changes in the kidneys of each group of mice;the glycogen staining was used to observe the changes of glomerular basement membrane in each group of mice;ELISA method was used to detect the contents of glutathione,superoxide dismutase,malondialdehyde and serum interleukin-1β,interleukins-6,tumor necrosis factor-αcontent;Western blot method was used to determine the expression of Nrf2,heme oxygenase 1,benzoquinone oxidoreductase 1and NF-κB p65 protein in the kidney tissues of each group of mice.Results（1）Changes in fasting blood glucose and body weight of DN mice:After successful modeling,compared with the normal group,the mice in the model group are in poor spirits,their coats are getting grayer and darker,and the symptoms of polydipsia,food and urine appear symptoms,weight were loss（P<0.01）,blood sugar increased（P<0.01）.Compared with the model group,the body weight of the mice in the medium dose group increased in the 6th and 8th weeks（P<0.05）,and the weight of the mice in the high dose group increased in the 4th,6th and 8th weeks（P<0.05）;the blood glucose of the mice in each administration group did not change significantly.（2）Changes of serum creatinine and urea nitrogen in DN mice:Compared with the normal group,the Scr and BUN of the mice in the model group were increased（P<0.01）;compared with the model group,the Scr and BUN of the mice in the middle and high-dose groups were decrease（P<0.05）.（3）Pathological changes in kidney tissues of DN mice:HE staining and PAS staining of kidney tissues of mice in each group showed that the size and shape of the glomerulus in the normal group were normal,the renal tubules were arranged regularly and the structure was clear;the mice in the model group had severe kidney damage.The glomerulus volume was larger than normal and the shape was irregular,and the renal tubule arrangement was disordered;compared with the model group,the kidney damage of the mice in each administration group was alleviated.With the increase of the dose,the shape of the glomerulus tends to be normal,and the renal tubules were arranged regularly.（4）Changes in oxidative stress indicators,superoxide dismutase（SOD）,glutathione（GSH）,and malondialdehyde（MDA）in kidney tissues of DN mice:Compared with the normal group,the SOD and GSH contents of the model group decreased（P<0.01）,the content of MDA increased（P<0.01）;compared with the model group,the SOD content of the middle and high-dose mice in the PNS administration group increased（P<0.01）,and the GSH content increased in a dose-dependent manner high（P<0.01）,the content of MDA decreased in a dose-dependent manner（P<0.01）.（5）Changes in inflammatory factors IL-6,IL-1β,and TNF-αlevels in kidney tissues of DN mice:Compared with the normal group,the TNF-α,IL-6,and IL-1βlevels in the model group increased（P<0.01）;Compared with the model group,the levels of IL-6 and TNF-αin the PNS administration group and the high-dose group decreased（P<0.05）,and the content of IL-1βin the high-dose group decreased（P<0.05）.（6）Protein expression of Nrf2/HO-1 antioxidant pathway and NF-кB p65inflammatory factor in kidney tissue of DN mice:Compared with the normal group,the expression of Nrf2 in the model group increased,and the expression of HO-1 and NQO1 also increased,but there was no statistical significance;Compared with the model group,medium and high doses of PNS can increase the expression of Nrf2（P<0.05）;the expression of antioxidant proteins HO-1 and NQO1 in the medium and high dose groups were also up-regulated,and the difference was statistically significant（P<0.05）.Compared with the normal group,the expression level of NF-кB p65 protein in the model group was increased（P<0.05）.Compared with the model group,the expression of NF-кB p65 in the medium and high dose groups of PNS could decrease the expression of NF-кB p65（P<0.05）.ConclusionsPanax notoginseng saponins have a protective effect on STZ-induced diabetic nephropathy in mice,and the mechanism may be realized by activating the Nrf2/HO-1 signal pathway.