In vitro investigation of antibacterial properties of Citrus medica essential oil against some human pathogenic bacteria

Abstract

<strong>Background & Aim:</strong> The medicinal plants are used in treatment of diseases caused by the human pathogenic bacteria due to their antimicrobial compounds. The aim of this study was to investigate antibacterial and antioxidant activity of <em>Citrus medica</em> essential oil on some human pathogenic bacteria.<br /> <strong>Experimental: </strong>The plant samples of <em>Citrus medica </em>were collected from North of Iran. Samples were transferred to the biotechnology laboratory, Bu Ali Sina University, Hamadan. The essential oil was extracted by Clevenger device. Antibacterial activity and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by agar well diffusion and by micro dilution broth methods, respectively. Antiradical activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl assay (DPPH).<br /> <strong>Results:</strong> The highest and lowest inhibitory activity of essential oil was observed on <em>Bacillus cereus</em> and <em>Escherichia coli</em>, respectively. Leaf essential oil showed the highest IC₅₀ value than the skin essential oil. The essential oil of <em>Citrus medica </em>skin <em>s</em>howed more inhibitory effect than the leaf essential oil. The MIC of leaf essential oil on<em> B. subtilis, B. cereus </em>and<em> E. aerogenes</em> and the MBC on <em>B. cereus </em>were found to be 3.12 mg ml^-1. The MIC of skin essential oil on <em>M. luteus</em> was 1.56 mg ml^-1 and the MBC on <em>M. luteus and S. aureus</em> was 3.12 mg ml^-1.<br /> <strong>Recommended applications/industries:</strong> The results confirmed the efficacy of <em>C. medica </em>essential oil as natural antimicrobial and suggested the possibility of employing it in drugs for the treatment of diseases caused by the test organisms.