Sustainable natural bio-antimicrobial: Composition, bacteriostatic activity, and antibacterial strategy of Cinnamomum camphora essential oil

In the post-pandemic era, there is increasing focus on safeguarding public health and environmental hygiene due to concerns over microorganisms. Commonly used disinfectants, alcohol, and antibiotic antimicrobials, though effective, are often non-biodegradable, leading to environmental pollution. Moreover, the emergence of antibiotic resistance in bacteria reduces the long-term efficacy of these products. Consequently, there is growing interest in developing environmentally safe, broad-spectrum, and durable antimicrobial agents.Cinnamomum camphora, a natural traditional Chinese herbal medicine, has been utilized for its promising antibacterial and anti-inflammatory properties in the management of skin inflammation.However, the precise antibacterial mechanism of camphor has not been thoroughly investigated. This study sought to determine the composition, antibacterial activity, and mode of action of hydrodistillation-extracted camphor essential oil (EOC) against Gram-positive（ Escherichia coli ） and Gram-negative bacteria（ Staphylococcus aureus ).The EOC demonstrated strong volatility, with the main components analyzed by GC-MS being camphor (25.94 %), eucalyptol (15.09 %), safrole (8.63 %), linalool (7.84 %), and α-pinitol (4.42 %). Additionally, it was found that the minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) of EOC against S. aureus and E. coli were 25 mg/mL and 6.25 mg/mL, respectively.Furthermore,the cell membrane damage test revealed that EOC induced lipid disorder, increased cell membrane permeability, and led to the loss of specific membrane activity, resulting in an elevation of the cell’s zeta potential. The oxidative stress test demonstrated that EOC interfered with the bacteria's ability tometabolize, which led to the buildup of reactive oxygen species and eventual bacterial damage. Finally, electron microscope study of the bacteria's shape and ultrastructure demonstrated that EOC significantly damaged the cell membrane, which resulted in bacterial mortality.These findings offer valuable insights for the development and utilization of camphor wood and the potential use of EOC as a sustainable natural bio-antimicrobial agent. • Extraction of antimicrobial active substances from camphor wood processing waste by steam distillation. • Studied the composition of EOC and demonstrated the high antimicrobial activity of camphor essential oil. • Exploration and discovery of the antibacterial mechanism of EOC against E.coli and S.aureus.