Identification of Chemical Compounds, Antioxidant Activity, and Antimicrobial Effect of Elettaria cardamomum Essential Oil on a Number of Pathogenic Microorganisms in Vitro

Background and Objectives: Green cardamom with scientific name of Elettaria cardamomum belongs to Zingiberaceae family. The purpose of this study was to determine the chemical composition and antioxidant activity and antibacterial effects of Elettaria cardamomum essential oil on some pathogenic microorganisms in vitro.   Methods: In this experimental study, first, Elettaria cardamomum essential oil was extracted using hydrodistillation method by clevenger. Then, its chemical composition, were identified by gas chromatography and gas chromatography–mass spectrometry. Antioxidant activity of the essential oil, was evaluated based on the percentage of free radical inhibitory activity. The antimicrobial activity of Elettaria cardamomum essential oil was tested by disc diffusion, well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods. Data analysis was carried out using analysis of variance (ANOVA) test.    In this research, 23 compounds, were identified in Elettaria cardamomum essential oil. The major compound of the essential oil was Eucalyptol (31.51%) and the Antioxidant activity of Elettaria cardamomum essential oil, was obtained to be 43%±0.67. The MIC of Elettaria cardamomum essential oil ranged from 4 to 32mg/ml, depending on the type of bacteria (Gram positive or Gram negative).  The results of the disc diffusion and well diffusion tests showed that the maximum inhibition zone diameter (IZD) of Elettaria cardamomum essential oil was for the Streptococcus pyogenes and the minimum IZD was for Enterobacter aerogenes.   Conclusion: Based on the results of this research, the essential oil of Elettaria cardamomum has antioxidant activity and antimicrobial activity against several pathogenic strains. Therefore, further researches are required for clinical application of Elettaria cardamomum essential oil.