Antiproteinuric Effects of Green Tea Extract on Tacrolimus-Induced Nephrotoxicity in Mice.

INTRODUCTION: It has been reported that proteinuria is an early predictive marker in detection of tacrolimus (TAC) nephrotoxicity. The aim of this study was to investigate the antiproteinuric effects of green tea extract (GTE) on TAC-induced acute nephrotoxicity in mice. METHODS: The mice (n = 20) were divided into 4 groups (n = 5 per group); control group mice were intraperitoneally (IP) injected with 0.9% saline, TAC group mice were IP injected with TAC 1 mg/kg, and inducible nitric oxide synthase (iNOS) inhibitor group mice were given in addition NG-nitro-L-arginine-methyl ester 12 mmol/L by subcutaneous injection. TAC-GTE group mice were given TAC by IP injection and GTE 100 mg/kg by subcutaneous injection. RESULTS: The 24-hour urine protein amounts were significantly increased in TAC group mice (36.1 ± 9.9 mg/d) compared with control group mice (13.3 ± 5.4 mg/d) and significantly decreased in TAC-GTE group mice (19.1 ± 6.9 mg/d, P < .01) compared with TAC group mice. The nitric oxide (NO) production by TAC was significantly suppressed by GTE and iNOS inhibitor injection. Renal tissue malondialdehyde (MDA) level was significantly increased in the TAC group compared with the control group and was significantly decreased in the TAC-GTE group compared with that of the TAC group. The antioxidant enzyme activities of superoxide dismutase and catalase were significantly suppressed in the TAC group compared with the control group and were restored in the GTE injection group. CONCLUSIONS: GTE treatment has beneficial antiproteinuric effects on TAC-induced acute renal injury in mice.