Investigation of Chemical Constituents, Anti‐oxidant, Anti‐inflammatory, and Anti‐cancer Effects of the Essential Oil Isolated From <i>Nosema cochinchinensis</i> Leaves

Nosema cochinchinensis (NCO), a medicinal herb belonging to the Lamiaceae family, is traditionally used to alleviate hepatitis, sore eyes, and pyrexia. Nevertheless, the chemical composition and biological activity of its essential oil (NCO) remain insufficiently explored. In this study, gas chromatography-mass spectrometry analysis identified 64 compounds, predominantly sesquiterpenes and their derivatives, comprising 99.8% of NCO's chemical profile. Furthermore, the mild antioxidant activity of NCO was confirmed via 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl assays (SC₅₀: 274.27 ± 51.13 and >500 µg/mL, respectively). The binding affinities of four major compounds of NCO with five key proteins involved in inflammation (iNOS) and cancer progression, including TopoIIa (Topoisomerase IIa), TopoIIb, ATP-binding domain Topo IIa (ATP-TopoIIa), and mutant p53, were evaluated via molecular docking studies. The data revealed a strong binding affinity toward mutant p53 and ATP-TopoIIa, whereas interactions with iNOS, TopoIIa, and TopoIIb were restrained. Additionally, NCO exhibited a moderate anti-inflammatory effect by suppressing NO release (half-maximal inhibitory concentration IC₅₀: 60.18 ± 4.29 µg/mL). The potent anti-cancer effects against lung and liver cancer cells (IC₅₀: 12.15 ± 1.52 and 8.27 ± 0.99 µg/mL, respectively) have been reported for the first time. These findings underscore the potential application of NCO in managing oxidative stress, inflammation, and particularly cancer.