Protective effect of Icariin on the early stage of experimental diabetic nephropathy induced by streptozotocin via modulating transforming growth factor β1 and type IV collagen expression in rats.
BACKGROUND
Icariin is a major constituent of flavonoid isolated from the plant Herba epimedii, which is used as a traditional Chinese medicine to nourish the kidney and reinforce yang. Therefore, the pharmacological studied of its diabetic nephropathy effect was undertaken to validate its traditional use.


METHODS
Diabetes was induced in male Sprague-Dawley rats by an injection of streptozotocin (40 mg/kg i.v.). Sustained blood glucose levels (>16.7 mmol/l) were considered as diabetic and selected for experimentation. Thirty rats were randomly divided into three groups: control, diabetic, diabetic+Icariin (80 mg/kg, i.g.) administered 8 weeks from 5th to 12th week. Experiment was carried out at the beginning of 13th week. All rats were anaesthetized and then were killed to remove kidneys. Blood glucose, serum creatinine (Cr), blood urea nitrogen (BUN), the activity of superoxide dismutase (SOD), malondialdehyde (MDA) and hydroxyproline (Hyp) in the kidney tissue were measured. Glomerular morphology was observed by light microscopy. Immunohistochemistry and Western blot were employed to determine the proteins levels of TGF-β(1) and type IV collagen.


RESULTS
The enhancement of Cr and BUN was found in model group, which was significantly attenuated by treatment with Icariin. Meanwhile, elevated MDA and Hyp levels in renal tissue as well as decreased SOD activities in renal tissue were significantly remitted by Icariin. The renal pathological changes in Icariin treatment group were ameliorated. Furthermore, the Icariin decreased the expression of TGF-β(1) and collagen IV protein.


CONCLUSIONS
Icariin can evidently relieve renal damage in rats with diabetic nephropathy induced by STZ, which might be related to modulating the expression of collagen IV and TGF-β(1) protein.
Department of Pharmacology, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, Zhejiang, China. qiminyou@163.com
Min-You
MY
Qi
Kai-Chen
Hao-Ran
HR
Liu
Yan-hui
YH
Su
Su-Qing
SQ
Yu
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001806:Blood Urea Nitrogen; D024141:Collagen Type IV / Q000378:metabolism; D003404:Creatinine / Q000097:blood; D003921:Diabetes Mellitus, Experimental / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D003928:Diabetic Nephropathies / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use*; D005419:Flavonoids / Q000627:therapeutic use*; D006909:Hydroxyproline / Q000378:metabolism; D007668:Kidney / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D020011:Protective Agents / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin; D013482:Superoxide Dismutase / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000378:metabolism
D001786:Blood Glucose; D024141:Collagen Type IV; D004365:Drugs, Chinese Herbal; D005419:Flavonoids; D020011:Protective Agents; C508962:Tgfb1 protein, rat; D053773:Transforming Growth Factor beta1; D008315:Malondialdehyde; D013311:Streptozocin; D003404:Creatinine; D013482:Superoxide Dismutase; D006909:Hydroxyproline; C056599:icariin