Chemical composition and antibacterial activity of methanolic extract from Echinops robustus on typical food-borne pathogens

Abstract

This study was conducted to evaluate the chemical composition and antibacterial activity of methanolic extract from Echinops robustus on typical food-borne pathogens. Chemical composition of the extract analyzed by gas chromatography-mass spectrometry (GC-MS). The GC-MS analysis of the extract revealed 54 compounds in which Butanal (2.222%), 4-Heptanone (1.717%) and Palmitic acid (4.799%) were the major constituents. The agar disk diffusion method was used to study the antibacterial activity of Echinops robustus methanolic extract against 5 bacterial strains. The extract of Echinops robustus showed moderate antibacterial activity against two gram-positive and three gram negative microorganisms tested with higher sensitivity for gram positive ones (Clear zone= 10mm for Bacillus cereus and 12mm for Staphylococcus aureus). Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were quantified by micro-dilution method. The MIC was 25 mg/ml for Bacillus cereus and 58 mg/ml for Escherichia coli and the MBC values were 400 and >400 mg/ml respectively for the mentioned species. Overall, results presented here suggest that the methanolic extract of Echinops robustus possesses antibacterial properties, and is, therefore, a potential source of active ingredients for food and pharmaceutical industry.