Aim: To investigate the inhibitory effect of tea polyphenols (TP) on the transforming growth factor-beta1 (TGF-beta1) expression in rat model of cyclosporine A (CsA)-induced chronic nephrotoxicity.
Methods: The rat model of CsA-induced chronic nephrotoxicity was used, 4 groups of rats were respectively treated with vehicle (0.1 mL/kg/d sc), TP (80 mg/kg/d ig), CsA (15 mg/kg/d sc) and TP plus CsA (CsA 15 mg/kg/d sc+TP 80 mg/kg/d, ig). At the end of day 28 of treatment, serum and urine are analyzed for creatinine clearance, kidney tissue for pathologic analysis. The TGF-beta1 mRNA and its protein expression were detected by RT-PCR, immunohistochemistry, and Western blot.
Results: CsA-treated rats had increased renal expression of TGF-beta1 mRNA and its protein, compared with the vehicle- or TP-treated controls. The renal function and interstitial fibrosis were ameliorated and renal expression of TGF-beta1 mRNA and its protein was decreased in animals treated with CsA plus TP, compared with animals treated with CsA alone (P<0.05).
Conclusion: TP significantly inhibits renal expression of TGF-beta1 in rat model of cyclosporine-induced chronic nephrotoxicity, suggesting that the decreased renal expression of TGF-beta1 exerted by TP is one of mechanisms to protect renal function and tissue structure.