Improving effects of Hedysarum polysaccharide on renal injury in db/db mice with diabetic nephropathy
Objective To study the effect of Hedysarum polysaccharides(HPS)on the expression of transforming growth factor-β,(TGF-β1),smad homologue 3 recombinant protein(smad3)and smad7 in renal tissue of db/db mice with diabetic nephropathy(DN).Methods According to their body weight,6-week-old male db/db mice were randomly divided into 5 groups:model group(0.9%NaCl 0.2 mL·d-1),positive control group(22.75 mg·kg-1·d-1 irbesartan)and experimental-H,-M,-L groups(200,100,50 mg kg-1·d-1 HPS),with 10 mice in each group;another 10 SPF grade male C57BL/6 mice of the same week were selected as normal group(0.9%NaCl 0.2mL·d-1).The mice in the 6 groups were given intragastric administration once a day for 12 weeks.The blood glucose concentration of mice was measured before treatment and at the 4th,8th and 12th week after treatment.The expression levels of TGF-β1,smad3 and smad7 were detected by Western blotting.Results After treatment,the blood glucose levels of the model group was significantly higher than those of the normal group(all P<0.01);compared with the model group,the levels of blood glucose in the experimental-H,-M groups decreased significantly,and the differences were statistically significant(P<0.05,P<0.01).The relative expression levels of TGF-β,protein in normal group,model group,positive control group and experimental-H,-M groups were 0.71±0.16,1.66±0.18,1.00±0.17,0.88±0.15 and 1.23±0.15;the relative expression levels of smad3 protein were 0.89±0.32,2.26±0.35,1.24±0.31,1.05±0.30 and 1.67±0.35;the relative expression levels of smad7 protein were 1.66±0.03,0.60±0.03,1.10±0.07,1.48±0.08 and 0.97±0.09;there were statistically significant differences between the experimental-H,-M groups and the model group(P<0.05,P<0.01).Conclusion Hedysarum polysaccharides can improve renal fibrosis and delay the development of diabetic nephropathy by regulating the level of blood glucose,inhibiting TGF-β1,smad3 and increasing the expression of smad7.