Comparative Investigation of Antibacterial Properties of the Yarrow Plant Hydroalcoholic Extract and Phenol on a Group of Intestinal Bacteria in Vitro

Abstract

Background and purpose: Yarrow is a member of the Asteraceae family, utilized extensively in the field of medical sciences. Among the medicinal plants, one may encounter few specimens like the aforementioned plant, which enjoys widespread distribution across various regions of the globe and boasts a diverse array of uses that contribute to its renown. The aim of the present study was the synthesis of Yarrow extract evaluation of its antibacterial effects on a group of intestinal bacteria and comparing its antibacterial properties with phenol. Materials and methods: In this experimental study, Yarrow plant extract was extracted with the hydroalcoholic method. The aerial parts of Achillea ageratum plant with herbarium number 1753 were prepared from the slopes of Ardabil mountains and after determining the identity, the extract of this plant was extracted by hydroalcoholic method. In this method, after preparing the plant and drying the aerial parts of the plant, 10 g of it was crushed in a sterile mortar, then it was poured into an Erlenmeyer flask, and 50 mL of 100% ethanol was added to it. After 24 hours of mixing in a magnetic stirrer using a Buchner funnel with Whatman filter paper and a vacuum pump, the remaining components of the plant were separated. Then, a certain amount of distilled water (20 ml) was added to the desired solution and placed again in the magnetic stirrer whose temperature was set at 80 degrees Celsius, so that the alcohol was completely removed from the reactor. The Antibacterial effect of yarrow extract was performed by disc diffusion method and micro broth dilution on standard species of Enterobacteriaceae families including the standard bacterial strains of Klebsiella pneumoniae (ATCC:10031), Escherichia coli (ATCC:23591), Shigella dysentery (ATCC:25922) and Enterobacter aerogenes (ATCC:13048). All experiments were performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: In the present study, the growth rate of bacteria decreased by increasing the concentration of yarrow extract. The MIC of Yarrow plant extract for Klebsiella pneumonia and Enterobacter aerogenes was obtained in %6.25 and for Shigella dysentery and Escherichia coli was obtained in %12.5 and %25, respectively. Also, the MBC of extract for Shigella dysentery, Klebsiella pneumonia, and Enterobacter aerogenes bacteria was obtained in 25%, and for Escherichia coli it was obtained in 50%. The results of MIC and MBC show that the most sensitive bacteria to yarrow extract among the studied bacteria is Enterobacter aerogenes and the most resistant is Escherichia coli. The diameter of the inhibition zone for Shigella dysentery, Escherichia coli, Klebsiella pneumoniae, and Enterobacter aerogenes bacteria was obtained at 19, 18, 20, and 23 mm, respectively. In this experiment, Enterobacter aerogenes bacteria were the most sensitive and Escherichia coli was the most resistant among the investigated bacteria. Comparative investigation of the antibacterial properties of yarrow extract with phenol, showed that yarrow extract had a lower killing effect than phenol at 5, 10, and 15-minute contact time. In this test, the most resistant bacteria are Shigella dysentery and the most sensitive bacteria are Escherichia coli and Enterobacter aerogenes. The reason that the type of resistant and sensitive bacteria was slightly different in the method of comparing the antibacterial effect of yarrow extract with phenol with the results of MIC, MBC, and non-growth halo diameter is related to the reduction of contact time of the extract with bacteria. Conclusion: The results of the present research show that the hydroalcoholic extract of the yarrow plant is very effective in the removal of gram-negative intestinal bacteria. Also, the hydroalcoholic extract of the yarrow plant is more effective in removing gram-negative bacteria than phenol

Keywords

• yarrow
• antibacterial effect
• hydroalcoholic extract
• enterobacteriaceae
• phenol