Molecular docking and anti-inflammatory effect of the essential oil isolated from Chuc leaf (Citrus hystrix) cultivated in VIET NAM.

Citrus hystrix, a member of the genus Citrus, is a widely recognized plant in VIET NAM with diverse applications in herbal medicine, gastronomy, and cosmetics. However, the anti-inflammatory effect of the essential oil extracted from C. hystrix leaves has not been investigated yet. GC/MS analysis identified 40 chemical constituents in the leaf essential oil (EOL) from C. hystrix, accounting for 97.42 % of the total peak area. The predominant compounds included citronellol (22.28 %), citronellal (17.75 %), linalool (9.53 %), and nerolidol (8.69 %). Molecular docking studies revealed strong binding affinities between these compounds and two key inflammatory mediators, cyclooxygenase-2 and inducible nitric oxide synthase, with binding energies ranging from -5.4 to -7.2 kcal/mol. These findings suggest a moderate anti-inflammatory potential of the EOL. This was further supported by an in vitro cell-based approach, in which EOL demonstrated a moderate inhibitory effect on nitric oxide production at a concentration of 20 μg/mL, resulting in a reduction of 26.79 ± 1.77 %. Furthermore, EOL weakly inhibited heat-induced protein denaturation with an IC50 value of approximately 311.40 ± 30.04 μg/mL. To the best of our knowledge, this is the first report to investigate the anti-inflammatory activity of C. hystrix leaf essential oil, providing a foundation for future research into its therapeutic applications for managing inflammatory conditions.