Assessment of bioactive compounds, antibacterial potential and acute toxicity of a volatile Origanum compactum extract, an endemic plant of northern Morocco

Abstract

The search for a natural alternative against the resistance of bacterial strains pathogenic to antibiotics remains a necessity to prevent human diseases. In this work the identification of the chemical composition of essential oil by GC/ MS revealed the presence of three major compounds; Carvacrol (72.97%), r-Cymene (14.5%), and g- Terpinene (6.01%). The evaluation of the antibacterial activity of the essential oil of Origanum compactum and two synthetic antibiotics (Piperacillin (PRL), Ampicillin (AMP)) was carried out by diffusion techniques on agar and micro-Dilution on agar medium for the determination of the minimum inhibitory concentration , against strains of clinical origin; Escherichia coli, salmonella sp, Klebsiella pneumoniae, Pseudomonas Aeruginosa, streptococcus sp, Staphylococcus aureus. The toxicity assessment was conducted in accordance with OECD Protocol 423 (Organization for Economic Cooperation and Development). The results showed a strong antibacterial effect of the volatile extract compared to the two antibiotics used. The essential oil is classified in category 5 GHS (harmonized classification system) with LD50 greater than 5000 mg/kg. These results suggest the use of this natural product in the treatment and prevention of infectious diseases caused by pathogenic bacteria.