Objective Xanthine oxidase is a highly versatile enzyme that is widely distributed among different species. The hydroxylation of purines is catalysed by xanthine oxidase and especially the conversion of xanthine to uric acid. Xanthine oxidase inhibitors are much useful, since they possess lesser side effects compared to uricosuric and anti-inflammatory agents. The present study deals with in silico and in vitro xanthine oxidase inhibitory analysis of commercially available terpenoids (bisabolol, β-caryophyllene, limonene, and α- terpinene). Methods Molecular docking studies were performed using AutoDock 4.2 and in vitro xanthine oxidase inhibitory activity was carried out using xanthine as the substrate. In addition, enzyme kinetics was performed using Lineweaver Burkplot analysis. Allopurinol, a known xanthine oxidase inhibitor was used as the standard. Results The results revealed that bisabolol exhibited a lowest binding energy value of about -7.33 kcal/mol. All other compounds showed binding energy values ranging between -7.33 to -5.87 kcal/mol which was less than the standard (-4.78 kcal/mol). In the xanthine oxidase assay, IC₅₀ value of bisabolol was found to be 34.70 µg/ml, whereas that of allopurinol was 8.48 µg/ml. All the remaining compounds exhibited IC₅₀ values ranging between 34.70 to 68.45 µg/ml.  In the enzyme kinetic studies, bisabolol, β-caryophyllene showed non competitive and Limonene, α- terpinene and allopurinol showed competitive type of enzyme inhibition. Conclusion It can be concluded that terpenoids could be a promising remedy for the treatment of gout and related inflammatory disorders. Further in vivo studies are required to develop potential compounds with lesser side effects.

No abstract

No abstract

No abstract

In an attempt to develop potent anti gout agents, coumarin derivatives and polyphenolic compounds were selected for present study. The docking energy of 2-benzyl coumarin was found to be -7.50 kcal/mol which was less than that of the standard allopurinol (-4.47 kcal/mol). All the selected compounds were found to exhibit lower binding energy (-7.50 to -4.68 kcal/mol) than allopurinol. Docking results confirm that selected compounds showed greater inhibition of xanthine oxidase due to their active binding sites. In xanthine oxidase assay, IC50 value of 2-benzyl coumarin was found to be 26 ± 1.16 µg/ mL, whereas that of allopurinol was 24 ± 0.28 µg/mL. All the compounds exhibited IC50 values ranging between 26 ± 1.16 to 58 ± 0.74 µg/mL. In enzyme kinetic studies, coumarin derivatives showed competitive and polyphenolic compounds showed non competitive type of enzyme inhibition. It can be concluded that coumarin derivatives could be a remedy for the treatment of gout and related inflammatory disorders. Article Info