ObjectiveRenal fibrosis is the common pathological foundation of many chronic kidney diseases (CKDs). The aim of this study was to investigate whether Hydroxysafflor yellow A (HSYA) can preserve renal function by inhibiting the progression of renal fibrosis and the potential mechanisms.MethodsRenal fibrosis was induced by unilateral ureteral obstruction (UUO) performed on 7-week-old C57BL/6 mice. HSYA (10, 50 and 100 mg/kg) were intragastrically administered. Sham group and model group were administered with the same volume of vehicle. Serum and kidney samples were collected 14 days after the UUO surgery. Serum biochemical indicators were measured by automatic biochemical analyzer. Histological changes were evaluated by HE and Masson staining. In vitro, the anti-fibrotic effect of HSYA was tested on human recombinant transforming growth factor-β1 (TGF-β1) stimulated HK-2 cells. The protein levels of α-SMA, collagen-I and fibronectin in kidney tissue andHK-2 cells were measured by immunohistochemistry and immunofluorescence. The protein levels of apoptosis-relative and TGF-β1/Smad3 signaling were detected by western blot.ResultsHSYA slowed the development of renal fibrosis both in vivo and in vitro. In UUO rats, renal function index suggested that HSYA treatment decreased the level of serum creatinine (Scr) and blood urea nitrogen (BUN) rose by UUO (P<0.05). HE staining and Masson staining demonstrated that kidney interstitial fibrosis, tubular atrophy, and inflammatory cell infiltration were notably attenuated in the high-dose HSYA group compared with the model group. The expressions of α-SMA, collagen-I and fibronectin were decreased in the UUO kidney and HK-2 cells of the HSYA-treatment group. Moreover, HSYA reduced the apoptotic rate of HK-2 cells stimulated by TGF-β1. Further study revealed that HSYA regulated the TGF-β1/Smads signaling pathway both in kidney tissue and HK-2 cells.ConclusionsThese results suggested that HSYA had a protective effect against fibrosis in renal cells, at least partly, through inhibiting TGF-β1/smad3-mediated Epithelial–mesenchymal transition signaling pathway.

Islet β cell mass reduction induced by glucose fluctuation is crucial for the development and progression of T2DM. Chikusetsu saponin IVa (CHS) had protective effects against DM and related injuries. Here we aimed to investigate the role of CHS in β cell injuries and its possible mechanism involved. Isolated rat islets, βTC3 cells and T2DM mice were used in this study. The results showed that CHS restored the secretion activity, promoted β cell survival by increasing β cell proliferation and decreasing apoptosis which induced by intermittent high glucose (IHG). In vivo, CHS protected β cell apoptosis to normalize blood glucose and improve insulin sensitivity in DM mice. Further studies showed that CHS activated Wnt3a signaling, inhibited HBP1, promoted β-catenin nuclear translocation, enhanced expressions of TCF7L2, GIPR and GLP-1R, inhibited p53, p27 and p21. The protective effect of CHS was remarkably suppressed by siRNAs against TCF7L2 or XAV-939 (a Wnt/β-catenin antagonist) in vitro and in β-catenin -/mice. In conclusion, we identified a novel role of CHS in protecting β cell survival and regeneration by mechanisms involving the activation of Wnt3a/β-catenin/TCF7L2 signaling. Our results indicated the potential value of CHS as a possible intervention drug for T2DM.

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