Baicalein ameliorates renal interstitial fibrosis by inducing myofibroblast apoptosis in vivo and in vitro.

ABSTRACT

OBJECTIVE: To investigate the anti-fibrotic effects of baicalein and its influence on myofibroblasts in vivo and in vitro. MATERIALS AND METHODS: An in vivo unilateral ureteric obstruction (UUO) mouse model and an in vitro transforming growth factor ß1 (TGF-ß1) activated normal rat kidney (NRK)-49F cell model were established. Baicalein treatment was then investigated in these models to assess its anti-fibrotic effects and potential mechanisms of action. RESULTS: Baicalein attenuated renal fibrosis by ameliorating kidney injury, reducing deposition of fibronectin and collagen type 1, and inducing apoptosis in myofibroblasts in the UUO mouse model. Baicalein also induced apoptosis of TGF-ß1-activated myofibroblasts in vitro in a dose-dependent manner. Furthermore, baicalein triggered a cascade of mitochondrion-associated apoptosis by upregulating cleaved-caspase-3, Bcl2-associated X protein (Bax), and cleaved-caspase-9 while downregulating the protein expression of B-cell lymphoma 2 (Bcl-2). Additionally, down-regulation of phosphorylated protein kinase B (pAkt) was found in the baicalein-induced pro-apoptotic components. CONCLUSIONS: The present findings show that baicalein can ameliorate tubulointerstitial fibrosis by inducing myofibroblast apoptosis through the mitochondrion-associated intrinsic pathway, which may be mediated by the inhibition of the phosphoinositide-3-kinase/Akt (PI3k/Akt) pathway.