Chemical Composition, Antioxidant Potential, and Standardized Antimicrobial Activity of Lavandula angustifolia Mill. Essential Oil: An In Vitro and In Silico Study

Lavandula angustifolia essential oil (LEO) was obtained by hydrodistillation of air-dried flowers collected in the Mostar region (Bosnia and Herzegovina). Its chemical composition was analyzed by gas chromatography-mass spectrometry, revealing a camphor content of 16.96%, substantially higher than the maximum value specified in the European Pharmacopoeia. Antimicrobial activity was evaluated using quantitative suspension tests according to EN 1276 and EN 1650 under simulated “dirty” conditions with organic load (bovine albumin, 3 g/L) and a 5 min contact time. High-concentration LEO (80% w/v) exhibited strong bactericidal activity against Escherichia coli ATCC 10536 and Staphylococcus aureus ATCC 6538, and yeasticidal activity against Candida albicans ATCC 10231 (>5 log10 CFU/mL reduction for bacteria, >4 log10 CFU/mL reduction for yeast), but was ineffective against Pseudomonas aeruginosa ATCC 15442 and Enterococcus hirae ATCC 10541. Lower concentrations (1.0% and 0.1% w/v) showed no bactericidal and yeasticidal activity, highlighting LEO’s efficacy limits. Antioxidant activity, assessed by DPPH radical scavenging, was dose- and time-dependent. Molecular docking provided insight into the interaction of major constituents with selected microbial and antioxidant-related targets. These findings highlight both the potential and limitations of LEO as a renewable bio-based resource for sustainable disinfectant formulations while emphasizing the importance of chemical composition and regulatory compliance.