Chemical profiling and antibacterial activity of the essential oil of the Moroccan endemic medicinal plant Cladanthus scariosus: in vitro and in silico insights

Abstract

Cladanthus scariosus, an endemic medicinal plant from Morocco, is traditionally used for its therapeutic properties. However, its biological activities and mechanisms remain insufficiently explored. This study investigated the chemical composition of its essential oil (CsEO) using GC-MS analysis and evaluated its antibacterial activity through in vitro assays, complemented by in silico molecular docking studies. GC-MS analysis identified 40 compounds, with sabinene (15.93%), (E)-sabinene hydrate (9.24%), ψ-limonene (7.79%), isoborneol (7.07%), γ-cadinene (7.23%), and α-pinene (6.44%) as the major constituents, indicating a profile dominated by monoterpenes and sesquiterpenes. CsEO exhibited notable antibacterial activity against most of the tested strains, with minimum inhibitory concentration (MIC) values reaching 0.57 μL/mL against Escherichia coli K-12 MG1655 and Micrococcus luteus ATCC 10240. In contrast, no significant activity was observed against Salmonella typhi. Molecular docking analysis indicated that γ-cadinene displayed a slightly higher binding affinity compared to the other major constituents, although several compounds also exhibited favorable interactions with the target proteins. Collectively, these findings expand the current knowledge on C. scariosus essential oil by providing new insights into its chemical composition, antibacterial activity, and potential active constituents through a combined in vitro and in silico approach. They also highlight the potential valorization of this Moroccan endemic species as a natural source of bioactive compounds with promising economic value for applications in the pharmaceutical, cosmetic, food, and related industries.