Abstract: OBJECTIVE: To determine the effect of Wenyang Huazhuo Fang(WHF), a Traditional Chinese Medicine decoction, on renal function in a rat model of doxorubicin-induced nephropathy, and to elucidate the underlying mechanism.METHODS: Sprague-Dawley rats were randomly divided into six groups: control, doxorubicin-nephropathy, and prednisone-treated(6.45 mg·kg-1·d-1) doxorubicin nephropathy groups, as well as high-(7.26 g·kg-1·d-), medium-(2.42 g·kg-1·d-),and low-dose(0.81 g·kg-1·d-) WHF-treated doxorubicin-nephropathy groups. The nephropathy rat model was established by two tail vein injections of doxorubicin, followed by prednisone or WHF treatment for 8 weeks. Body weights were monitored and urinary protein was measured every 2 weeks.After the end of the treatment period, the rats were euthanized. Serum biochemical indicators were determined and renal morphological alterations were assessed using histological staining. The expression of transient receptor potential cation channel subfamily C member 6(TRPC6), stromal interaction molecule 1(STIM1), and calcium release-activated calcium channel protein 1(Orai1)was detected using western blotting, and their m RNA levels were examined using quantitative real-time reverse transcription-polymerase chain reaction.RESULTS: WHF treatment was found to significantly ameliorate weight loss, proteinuria, hypoalbuminemia, and dyslipidemia in doxorubicin-nephropathy rats. The protein and m RNA levels of TRPC6, STIM1, and Orai1 were partially, but significantly suppressed by prednisone or WHF treatment.CONCLUSION: Treatment with WHF significantly ameliorates renal injury in a rat model of doxorubicin-induced nephropathy, which could be at least partially related to repression of the TRPC6 pathway.

Key words: Nephropathy, Doxorubicin, TRPC6 cation channel, Stim1 protein,rat, Orai1 protein,rat, Wenyang Huazhuo Fang