PHYSICOCHEMICAL PROPERTIES, GC-MS ANALYSIS, AND ANTIBACTERIAL ASSAY OF Citrus limon PEELS ESSENTIAL OIL AGAINST ANTIBIOTIC RESISTANT Escherichia Coli.

Essential oils (EOs) produced naturally by plants have been used as antimicrobial agents despite the majority of compounds have not been studied. The study was conducted to assess the effect of EOs found in Citrus limon peels against antibiotic resistance of E. coli by quantifying the specific gravity, refractive index, and GC-MS. The result of GC-MS presented that D-limonene, α-citral, and β-citral are the major constituents of C. limon EO, presenting 56.85; 13.24; and 10.40% of the oil content, respectively. Tests on the essential oil of C. limon confirm its potential antibacterial activity. This assertion was supported by the MIC and MBC values obtained at 250 µg/mL and 500 µg/mL, respectively. Meanwhile, tetracycline showed identical MIC and MBC at 125 µg/mL. The interaction between essential oil and tetracycline was evaluated using a checkerboard assay. Moreover, C. limon peels essential oil had a synergistic to decrease biofilm formation in bacterial tested. In addition, the combination of C. limon peels essential oil and tetracycline illustrated potential activities to lysis the cells and inhibit the efflux pumps of E. coli. The result suggests the combination of C. limon peels essential oil and tetracycline could be used to eradicate antibiotic-resistant E. coli. [ABSTRACT FROM AUTHOR]