Objective To explore the renoprotective effect of Huoxue Huayu Tongluo Formula（blood-quickening

stasistransforming and network vessels-freeing formula

HHTF）on diabetic renal damage and its possible mechanism.Methods Forty male healthy Sprague-Dawley rats of clean grade were randomized into the normal group（n=10）and model group（n= 30）.The diabetic rat models were established with a one-time intraperitoneal injection of 60mg/kg streptozotocin（STZ）in the model group.Twenty-eight successful model rats were randomized into control group and intervention group

with 14in each.The intervention group was gavaged with 1ml/100g HHTF which was composed of 0.96g/（kg·d）chuanxiong（Rhizoma Chuanxiong）

1.2g/（kg·d）Danshen（Radix et Rhizoma Salviae Miltiorrhizae）

0.8g/（kg·d）Dilong（Pheretima）

0.48 g/（kg·d）Shuizhi（Hirudo）and 0.48g/（kg·d）Quanxie（Scorpio）.The normal group and control group were gavaged with 1ml/100g purified water.After 16weeks

the levels of body weight（BW）

kidney index（KI）

fasting blood glucose（FBG）

HbA1cand urinary albumin（U-Alb）were detected and the morphological changes and thickness of glomerular basement membrane（GBM）in renal tissues were observed with light microscopy and electron microscopy.The expression of bone morphogenetic protein 7（BMP-7）was detected with Western blotting and the expression of BMP-7mRNA was detected with real-time polymerase chain reaction（PCR）.Results Comparing with the normal group

the BW and the expressions of BMP-7 and BMP-7mRNA in the control group were significantly decreased（P<0.05）

but the levels of KI

FBG

HbA1cand U-Alb and the thickness of GBM were significantly increased（P<0.05）.Comparing with the control group

the BW and the expressions of BMP-7and BMP-7mRNA in the intervention group were significantly increased（P<0.05）

but the levels of KI and U-Alb and the thickness of GBM were significantly decreased（P<0.05）.There was no significant difference between the intervention group and control group in the levels of FBG and HbA1c.Conclusion HHTF can reduce early diabetic renal damage and up-regulate the expression of BMP-7

which may be one of its mechanisms.