GC-MS profiling of Arabian balsam tree (Commiphora gileadensis) Cell sap and antibacterial, anti-virulence, and anti-biofilm potential of its major constituents

Commiphora gileadensis L. (CG) is traditionally utilized in Arabian and African folk medicine for its antimicrobial and wound-healing properties. Its resinous exudates and essential oils are rich in volatile compounds, but the anti-virulence potential of its cell sap (CG-CS) remains underexplored. This research aimed to profile the volatile constituents of CG-CS using GC-MS and assess its antibacterial, anti-biofilm, and anti-virulence activities against various Gram-positive and Gram-negative pathogens. A total of 107 volatiles were detected in CG-CS, belonging to monoterpene hydrocarbons (39.77%), alcohols (22.39%), and sesquiterpene hydrocarbons (18.09%). Key compounds such as sabinene, myrcene, α-pinene, p-cymene-8-ol, and spathulenol exhibited significant antibacterial activity, with MICs as low as 64 µg/mL, compared to ampicillin and kanamycin . CG-CS and its major constituents disrupted bacterial membranes and inhibited efflux pump function. At sub-inhibitory concentrations, they significantly reduced violacein production, biofilm formation, and secretion of virulence factors, i.e., proteases and hemolysins in S. aureus, P. aeruginosa, K. pneumoniae , and A. baumannii . Notably, CG-CS exhibited superior efficacy, suggesting promising complementary antibacterial activities of the complex volatile oil mixture. In conclusion , CG-CS and its major components demonstrated potential antibacterial and anti-virulence activities, primarily through membrane disruption and interference with QS-regulated pathways, especially for both hydrocarbon and alcohol monoterpenes. The obtained results support the traditional use of C. gileadensis as an antibacterial and warrant the development of a pharmaceutical formulation for further in vivo studies.