Protective effect of icariin on kidney in 5/6 nephrectomized rats and its mechanism.

The aim of this study was to investigate the renal protective effect of icariin in 5/6 nephrectomized rats and the molecular mechanisms involved. Forty male Sprague-Dawley rats were randomly divided into 5 groups: sham-operated group, 5/6 nephrectomy model group, icariin groups (20 and 40 mg/kg), and benazepril group. After 12-weeks treatment, 24-h urine and serum were collected, and urine protein, serum creatinine, and blood urea nitrogen were determined. The rats were then sacrificed and fresh kidney tissues were prepared to obtain single cell suspensions. Cell cycle distribution and cell apoptosis were determined by annexin V-FITC/propidium iodide (PI) double staining using a flow cytometer. mRNA expression of Bcl-2 and Bax was examined using quantitative real-time PCR. After 12-weeks treatment, urinary protein, serum creatinine, and blood urea nitrogen in the icariin-treated group were much lower than in the untreated group compared with 5/6 nephrectomy model. Icariin reduced the percentage of S phase cells, increased the percentage of G0/M phase cells, and inhibited apoptosis in the renal cells. mRNA expression of Bcl-2 and Bax was decreased. In conclusion, icariin has a renal protective effect in 5/6 nephrectomized rats, which may be related mainly to alterations in cell cycle distribution and expression of apoptotic genes.