CP-25 ameliorates methotrexate induced nephrotoxicity via improving renal apoptosis and methotrexate excretion.

Paeoniflorin-6'-O-benzene sulfonate (CP-25) is a derivative of Paeoniflorin. We investigate beneficial effect of CP-25 on methotrexate (MTX) induced nephrotoxicity in rats. Plasma blood urea nitrogen (Bun), plasma creatinine (CREA), urine CREA and protein in the rats were quantitatively measured. Renal tissues were pathologically observed, and apoptosis was detected. Apoptosis related proteins and organic anion transporter-3 (OAT3) expression were determined by western blotting analysis. MTX induced nephrotoxicity and hematotoxicity in rats with abnormal levels of serum Bun, serum CERA, 24 h urine protein excretion, white blood cells, platelets, plateletcrit and abnormal renal pathological appearance. Either pre-treatment or treatment of CP-25 restored normal levels of hematological and renal function parameters, and improved histopathology in rats treated with MTX. CP-25 prevented MTX induced apoptosis of renal tubular cells, and the effect was further confirmed by its regulatory effects on abnormal expression of Bax, cleaved-caspase-3, cleaved-caspase-8, Cyt-c, Bcl-2. The other important finding is co-administration of CP-25 with MTX significantly increased MTX renal excretion in the damaged rats, and the effect is supposed to be linked with its regulation on abnormal renal OAT3 expression. Taken together, CP-25 shows well protective activity against MTX induced nephrotoxicity, and this effect is via its anti-apoptosis and detoxification properties.