Bridging in silico and in vitro perspectives to unravel molecular mechanisms underlying the inhibition of ß-glucuronidase by coumarins from Hibiscus trionum.

ABSTRACT

Unraveling the intricacies of ß-glucuronidase inhibition is pivotal for developing effective strategies in applications specific to gastrointestinal health and drug metabolism. Our study investigated the efficacy of some Hibiscus trionum phytochemicals as ß-glucuronidase inhibitors. The results showed that cleomiscosin A and mansonone H emerged as the most potent inhibitors, with IC50 values of 3.97 ± 0.35 µM and 10.32 ± 1.85 µM, respectively. Mechanistic analysis of ß-glucuronidase inhibition indicated that cleomiscosin A and the reference drug EGCG displayed a mixed inhibition mode against ß-glucuronidase, while mansonone H exhibited noncompetitive inhibition against ß-glucuronidase. Docking studies revealed that cleomiscosin A and mansonone H exhibited the lowest binding affinities, occupying the same site as EGCG, and engaged significant key residues in their binding mechanisms. Using a 30 ns molecular dynamics (MD) simulation, we explored the interaction dynamics of isolated compounds with ß-glucuronidase. Analysis of various MD parameters showed that cleomiscosin A and mansonone H exhibited consistent trajectories and significant energy stabilization with ß-glucuronidase. These computational insights complemented experimental findings, underscoring the potential of cleomiscosin A and mansonone H as ß-glucuronidase inhibitors.