Anti-Inflammatory Activity of Capparis cartilaginea Decne. Essential Oil and Its Main Constituents via Modulation of the NLRP3 Inflammasome.

Capparis cartilaginea Decne. (C. cartilaginea) is traditionally used for the management of inflammatory conditions; however, the contribution of its volatile constituents to these effects remains poorly understood. This study evaluated the anti-inflammatory activity of the essential oil of C. cartilaginea and its major constituents, isopropyl isothiocyanate and 2-methylbutanenitrile, using an in vitro model of lipopolysaccharide (LPS)-induced inflammation in THP-1 human macrophages. The essential oil and its main constituents significantly reduced cytokine release and nitric oxide (NO) production compared with LPS-stimulated controls. These effects were associated with modulation of the NLRP3 inflammasome and inhibition of caspase-1 activation, partly mediated through MAPK-dependent pathways. In addition, treatment significantly inhibited NF-κB activation and phosphorylation. Overall, these findings demonstrate that the volatile fraction contributes to the anti-inflammatory activity of C. cartilaginea, providing mechanistic support for its traditional use.