Hinokiflavone from Platycladi cacumen as a potent broad-spectrum inhibitor of gut microbial Loop-1 β-glucuronidases: Inhibition kinetics and molecular simulation.

Gut microbial Loop-1 β-glucuronidases (gmGUS) played an important role in irinotecan-induced gastrointestinal toxicity by regulating the level of its active metabolite SN38 through enterohepatic recirculation. gmGUS inhibition has emerged as a promising approach to relieve its dose-limiting intestinal toxicity and improve its medication efficacy. This study aims to investigate the inhibitory effects and mechanisms of Platycladi cacumen and its main constituent hinokiflavone against four different types of Loop-1 gmGUS (EeGUS, SaGUS, CpGUS and EcGUS).