Mechanistic insights into how cichoriin inhibits P2Y14R to suppress MSU-induced gouty inflammation

Background: Gout is a prevalent, chronic inflammatory joint diseases, and its global prevalence and incidence are continue to rise. Currently, the adverse side effects of anti-gout drugs underscore the urgent need for safer and more effective anti-gout agents.

Objective: Cichoriin is a kind of coumarin, which exhibits diversity of biological activities. The current investigation aimed to explore the mechanism of the inhibition of MSU-induced gouty inflammation by cichoriin.

Methods: The enzyme inhibitory assay of P2Y₁₄R, cell viability detection, ELISA, immunofluorescence staining, and flow cytometry were used to explore the molecular mechanism of cichoriin in the inhibition of MSU-induced gouty inflammation. The molecular level details of inhibitory effects of chchoriin against P2Y₁₄R were obtained by molecular dynamics simulation.

Results: The in vitro experiments revealed that cichoriin could inhibit the activity of P2Y₁₄R, up-regulate the expressions of NLRP3, Caspase-1, GSDMD and ASC, increase IL-1β and IL-18 levels, and decrease the percentage of Caspase-1/PI double-positive cells. The computational calculations revealed that cichoriin and P2Y₁₄R could form a stable and rigid complex. Free energy landscape exhibited that cichoriin stabilized the global conformations of P2Y₁₄R to the minimum global energy. MM-PBSA provided evidence for cichoriin's stability inside the binding pocket of P2Y₁₄R with a binding free energy of -35.13 kcal/mol. The decomposition of binding energy showed the pivotal Amino acids residues responsible for the stability of cichoriin's interaction with P2Y₁₄R by forming hydrogen bonds and hydrophobic interactions.

Conclusions: This work highlighted the potential roles of cichoriin in attenuating MSU-induced gouty inflammation.