Identification of Escherichia coli β-glucuronidase inhibitors from Polygonum cuspidatum Siebold & Zucc

Abstract Gut bacterial β-glucuronidase (GUS) can reactivate xenobiotics that exert enterohepatic circulation- triggered gastrointestinal tract toxicity. GUS inhibitors can alleviate drug-induced enteropathy and improve treatment outcomes. We evaluated the inhibitory effect of Polygonum cuspidatum Siebold & Zucc. and its major constituents against Escherichia coli GUS (EcGUS), and characterized the inhibitory mechanism of each of the components. Trans-resveratrol 4'-O-β-D-glucopyranoside (HZ-1) and (-)-epicatechin gallate (HZ-2) isolated from P. cuspidatum were identified as the key components and potent inhibitors. These two components displayed strong to moderate inhibitory effects on EcGUS, with Ki values of 9.95 and 1.95 μM, respectively. Results from molecular docking indicated that HZ-1 and HZ-2 could interact with the key residues Asp163, Ser360, Ile 363, Glu413, Glu504, and Lys 568 of EcGUS via hydrogen bonding. Our findings demonstrate the inhibitory effect of P. cuspidatum and its two components on EcGUS, which supported the further evaluation and development of P. cuspidatum and its two active components as novel candidates for alleviating drug-induced damage in the mammalian gut.

Advanced Role of Hippo Signaling in Endometrial Fibrosis: Implications for Intrauterine Adhesion / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>Intrauterine adhesion (IUA) is a major health problem that causes infertility, menstrual irregularities, and recurrent pregnancy losses in women. Unfortunately, treatments for IUA are limited, and there are currently no effective strategies for preventing IUA recurrence. In this review, we introduced the role of Hippo signaling in the normal endometrium and IUA and described the mechanisms by which the Hippo pathway integrates with the Wnt and transforming growth factor-β (TGF-β) signaling pathways to form an intricate network governing the development of fibrosis.</p><p><b>DATA SOURCES</b>Original research articles in English that were published until July 2017 were collected from the PubMed database.</p><p><b>STUDY SELECTION</b>Literature search was conducted using the search terms "endometrial fibrosis OR fibrosis AND or OR intrauterine adhesion OR Asherman syndrome OR IUA," "Hippo AND or OR Hippo/TAZ," "TGF-β," and "Wnt." Related original research articles were included in the comprehensive analysis.</p><p><b>RESULTS</b>Endometrial fibrosis is recognized as a key pathological event in the development of IUA, which is characterized by epithelial/fibroblast-myofibroblast transition. Myofibroblasts play crucial roles in the pathogenesis of fibrous scarring, and myofibroblast differentiation can be triggered by multiple signaling pathways. Hippo signaling is a critical regulator of the epithelial/fibroblast-myofibroblast transition and α-smooth muscle actin, which exhibits a specific spatiotemporal expression in the endometrium.</p><p><b>CONCLUSIONS</b>Hippo signaling plays a critical role in fibrous diseases and participates in cross talks with Wnt and TGF-β signaling. Our findings not only contributed to knowledge on the pathogenesis of endometrial fibrosis, but can also serve as a useful resource for developing specific molecular inhibitors for IUA treatment and prevention.</p>