In Vitro Evaluation of Antibacterial Effects of Aqueous and Alcoholic Extracts of Echinops dichorus L. on Escherichia coli

The use of antibiotics as major drugs in infectious diseases has always been associated with two problems of side effects and drug resistance. The compounds found in various plants have been used as a treatment method since the past until today because medicinal plants possess side effects compared to other drugs. Given that different species of Echinops dichorus L. plant have indicated good antimicrobial effects, in this study antimicrobial effects of ethanol and aqueous extracts of Echinops dichorus L. plant have been investigated by disk diffusion method and determining the minimum inhibitory concentration (MIC) on the 24-hr culture of Escherichia coli (E. coli) standard strain. Echinops dichorus L. plant was dried after collection and its ethanol and aqueous extracts of were prepared by maceration method. Afterward, the concentrated and dried samples were stored in clean containers under standard conditions for further tests. The antibacterial effect of different concentrations of the extracts was determined by agar diffusion and compared with penicillin, gentamicin, and tetracycline antibiotics. Ethanol and aqueous extracts possessed a MIC of 31.25 µg/ml (diameter of the bacterial growth inhibition (halo): 12 mm) and 125 µg/ml (diameter of the bacterial growth inhibition (halo): 10 mm), respectively, as anti-microbial effect against E. coli.