Research Progress in Inhibitors against Bacterial β-Glucuronidase in Gastrointestinal Tract

β-glucuronidases (GUS) are an important class of hydrolase produced by intestinal flora and catalyze the hydrolysis of glucuronides of many drugs and endogenous hormones into corresponding aglycones. Many studies have clearly demonstrated that bacterial GUS could significantly modulate the pharmacokinetic properties of drugs and their in vivo efficacy. Notably, the glucuronides of several therapeutic drugs (such as CPT-11 and indomethacin) could be readily hydrolyzed by bacterial GUS into corresponding aglycones with strong toxicity. The overproduction of aglycone in intestine may lead to severe gastrointestinal reactions. Thus, bacterial GUS has been recognized as a key target for alleviating drug-induced gastrointestinal reactions, and the development of safe and potent inhibitors against bacterial GUS are very important for the amelioration of drug-induced life-threatening diarrhea in clinical setting. This paper reviewed the structure and function of bacterial GUS, the methods for screening inhibitors against bacterial GUS, as well as the recent advances in the development of bacterial GUS inhibitors.