Effect of luteolin on xanthine oxidase: inhibition kinetics and interaction mechanism merging with docking simulation

Food Chem. 2013 Dec 15;141(4):3766-73. doi: 10.1016/j.foodchem.2013.06.092. Epub 2013 Jun 28.


Xanthine oxidase (XO) catalyses hypoxanthine and xanthine to uric acid in human metabolism. Overproduction of uric acid will lead to hyperuricemia and finally cause gout and other diseases. Luteolin is one of the major components of celery and green peppers, its inhibitory activity on XO and their interaction mechanism were evaluated by multispectroscopic methods, coupled with molecular simulation. It was found that luteolin reversibly inhibited XO in a competitive manner with inhibition constant (Ki) value of (2.38±0.05)×10(-6) mol l(-1). Luteolin could bind to XO at a single binding site and the binding was driven mainly by hydrophobic interactions. Analysis of synchronous fluorescence and circular dichroism spectra demonstrated that the microenvironment and secondary structure of XO were altered upon interaction with luteolin. The molecular docking results revealed luteolin actually interacted with the primary amino acid residues located within the active site pocket of XO.

Keywords: Circular dichroism; Fluorescence quenching; Inhibition kinetics; Luteolin; Molecular simulation; Xanthine oxidase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apium / chemistry*
  • Binding Sites
  • Capsicum / chemistry*
  • Enzyme Inhibitors / chemistry*
  • Humans
  • Kinetics
  • Luteolin / chemistry*
  • Molecular Docking Simulation
  • Plant Extracts / chemistry*
  • Protein Binding
  • Xanthine Oxidase / antagonists & inhibitors
  • Xanthine Oxidase / chemistry*


  • Enzyme Inhibitors
  • Plant Extracts
  • Xanthine Oxidase
  • Luteolin