Protective effect of Huang Gan formula in 5/6 nephrectomized rats by depressing the Wnt/β-catenin signaling pathway

Huang Gan formula (HGF) is a new traditional Chinese herbal medicine created according to the basic theory of traditional Chinese medicine. The aim of this study is to evaluate the effects of HGF on chronic kidney disease and determine the mechanisms of action. The extract of HGF was prepared, and qualitative and quantitative determination of phytochemical was performed with quadrupole time-of-flight mass spectrometer and high-performance liquid chromatography. Sprague-Dawley rats (n=72) were submitted to 5/6 nephrectomy (Nx), and then respectively treated with uremic clearance granule, losartan, HGF low dose, HGF middle dose, and HGF high dose once per day for 12 weeks. The sham group of operated rats (n=22) was treated with normal saline or HGF middle dose as a background control group. Blood and urine biochemical parameters, renal tissue morphology, and mRNA and proteins of Wnt/β-catenin signaling pathways were investigated. The results showed that the quality of the extraction process could be controlled, and a total of eight major compounds were identified and quantified. HGF could decrease the level of serum creatinine, blood urea nitrogen, and urine protein and increase the renal index and creatinine clearance rate in a dose-dependent manner. HGF also remarkably reduced the glomerulosclerosis and tubulointerstitial fibrosis by blocking the Wnt/β-catenin signaling pathway through inhibiting the Wnt1, β-catenin, transcription factor 4, and fibronectin 1 expressions, simultaneously measured through mRNA and protein levels in the remnant kidney. These results suggest that extraction of HGF could improve remnant renal function and possibly ameliorate glomerulosclerosis and tubulointerstitial fibrosis by depressing the Wnt/β-catenin signaling pathway.