Investigate the bactericidal efficacy of Carvacrol from oregano essential oil and extract compared with commercial disinfectant.

Author: Prakash Neupane

Neupane, Prakash, 2024 Investigate the bactericidal efficacy of Carvacrol from oregano essential oil and extract compared with commercial disinfectant., Flinders University, College of Medicine and Public Health

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Herbal extracts and oils are potential alternatives to chemical-based disinfectants due to concerns on antibiotic resistance and adverse consequences of synthetic antimicrobials on human health. A native Mediterranean spice herb, Oregano harbors bioactive compounds Carvacrol and Thymol which possessed outstanding bacteriostatic effect on broad community of microbes. A comparative analysis of Oregano plant-based extracts, their oil and commercial synthetic antimicrobial was focused on this research. Solvent extraction method for Oregano extracts synthesis and microdilution assay was performed to determine the minimum inhibitory concentration of derived product against Escherichia coli ATTC®15597 strain. Four products viz: ethanol extracts from freshly produced Oregano, Carvacrol rich essential oil of Oregano, Benzalkonium chloride and Sodium hypochlorite-based disinfectant were assessed for their efficacy as antimicrobial agent in invitro condition. Data analysis was performed using SPSS and MS-EXCEL to calibrate the bacterial growth curve based on optical density at 600nm. All the disinfectants killed bacteria at different concentration at different time and a significant bactericidal effect was observed between plant based and chemical based biocide. Oregano essential oil at 25% concentration, Bleach at 100%, 50%, 25% and 12.5% concentration, Pine-o-Cleen® at 25%, 12.5%, 6.3% and 3.2% dilution were highly effective to suppress bacterial growth for 24 hours. Oregano ethanol extracts depicted moderate antibacterial effect until 10-15 hours of exposure but fails for a complete growth inhibition. Oregano-based antimicrobials exhibited a promising substitute against conventional disinfectants and inherent challenges of antibiotic resistance offering reduced toxic effects on human health.

Keywords: Bactericidal Efficacy, Carvacrol, Oregano Essential Oil, Commercial Disinfectant

Subject: Biotechnology thesis

Thesis type: Masters
Completed: 2024
School: College of Medicine and Public Health
Supervisor: Associate Professor Harriet Whiley