EVALUATION OF CHEMICAL COMPOSITION AND ANTIBACTERIAL ACTIVITY OF METHANOLIC EXTRACTS FROM NINE MEDICINAL PLANTS AGAINST STANDARD BACTERIAL STRAINS IN VITRO

This research aims to identify the antibacterial properties of medicinal plants, which are crucial in traditional medicine due to their natural origin and high safety. Nine medicinal plants from East Azerbaijan Province were gathered for experimental-laboratory investigation, with essential oils extracted and gas chromatography-mass spectrometry analysis used to identify active components. Additionally, methanolic extracts were prepared at different concentrations using the Soxhlet method, and their effects on bacteria were evaluated through the agar well diffusion method, as well as MIC and MBC tests. At 400 mg mL-1, all plant extracts in this investigation exhibited the strongest antibacterial activity. When it came to Gram-positive bacteria like Staphylococcus aureus and Bacillus cereus, the antibacterial activity of all plant extracts was noticeably greater than that of Gram-negative bacteria like Pseudomonas aeruginosa and Escherichia coli. The extracts of Glycyrrhiza glabra, Mentha piperita L., Rosa damascena, and Peganum harmala showed the strongest effects against Gram-positive bacteria, according to an evaluation of MIC and MBC values. The findings show that all plant methanolic extracts exhibit strong antibacterial properties against Gram-positive bacteria and may be viable therapeutic options. Furthermore, the essential oils of the plants under study included 209 different chemicals. Keywords: medicinal plants; antibacterial activity; pathogenic bacteria; Gram-positive bacteria; Gram-negative bacteria.