The Protective Effect Of Polygonatum Sibiricum Polysaccharides On Kidney Injury In Diabetic Rats

ObjectiveWe observed the protective effects of Polygonatum Sibiricum Polysaccharides (PSP) on kidney tissue in diabetic rats, and explored their possible mechanisms, to provide a new basis for treatment on diabetes.Methods50 rats randomly selected from 60 healthy Sprague-Dawley rats were injected STZ of 35mg/kg in the tail veins, fasting blood glucose was measured with Anzhun glucose monitor after 72h, fasting blood glucose of the diabetes model was ≥16.7 mmol/L, the model rats were randomly divided into diabetic model group, captopril 10 mg/kg group, PSP1000,500,250 mg/kg groups, each group had eight rats. The rest 10 were used as the blank control group, the blank control group were injected citrate buffer with the same amount. The treatment groups were given corresponding drug intragastrically for 12 weeks, and the remaining groups were given equal volumes of saline. After 12 weeks, Fasting blood glucose was measured; measuring weight and kidney weight to calculate index number of kidney hypertrophy; Bradford detects 24-hour urinary protein in rats; serum creatinine (SCR) and blood urea nitrogen (BUN) was examined with automatic biochemistry analyzer; HE and Masson staining observed morphological changes; the expression of protein ET-1, TGF-β1 and Col-Ⅳ were measured by immunohistochemistry and Western Blot method.Results1. The results of fasting blood glucose showed that compared with control group, fasting blood glucose of the diabetic model group was significantly higher (P<0.01); compared with diabetic model group, fasting blood glucose of PSP groups was reduced (P<0.01).2. The results of the levels of index number of kidney hypertrophy showed that compared with control group, index number of kidney hypertrophy was significantly higher in diabetic model group (P<0.01); compared with diabetic model group, index number of kidney hypertrophy was reduced (P<0.01); compared with captopril group, index number of kidney hypertrophy of PSP 250 mg/kg group was higher (P<0.05).3. The result of 24-hour urinary protein showed that compared with control group,24-hour urinary protein of diabetic model group was increased significantly (P<0.01); compared with diabetic model group,24-hour urinary protein of treatment groups reduced significantly (P<0.01); compared with captopril group,24-hour urinary protein of PSP 250 mg/kg group was higher (P<0.01).4. The result of SCR and BUN showed that compared with control group, SCR and BUN of diabetic model group was increased significantly (P<0.01); compared with diabetic model group, SCR and BUN of PSP groups reduced differently (P<0.05 or P<0.01); captopril group was lower than PSP groups (P<0.01).5. The structure of kidney was examined by light microscope of hematoxylin-eosin staining (HE). There aren’t pathological changes in control group; compared with control group, inflammatory cell infiltration, renal tubular edema and glomerular angiectasis hyperemia in diabetic model group. The pathological changes were improved in the treatment groups.6. Immunohistochemistry and Western Blot showed that compared with control group, the expression of ET-1, TGF-β1, Col-Ⅳ was increased significantly in diabetic model group (P<0.01); compared with diabetic model group, the expression of ET-1, TGF-β1, Col-Ⅳ was reduced differently in treatment groups (P<0.05 or P<0.01); compared with captopril group, the expression of ET-1, TGF-β1, Col-Ⅳ was reduced differently in PSP groups (P<0.05 or P<0.01).ConclusionsPSP can relieve the damage of kidney in diabetic rats, its mechanism may be associated with lowering blood glucose and inhibiting the expression of ET-1, TGF-β1 and Col-Ⅳ.