Essential Oil Composition and Antibacterial Activity of Origanum vulgare subsp. glandulosum Desf. at Different Phenological Stages

Abstract

Variation in the quantity and quality of the essential oil (EO) of wild population of Origanum vulgare at different phenological stages, including vegetative, late vegetative, and flowering set, is reported. The oils of air-dried samples were obtained by hydrodistillation. The yield of oils (w/w%) at different stages were in the order of late vegetative (2.0%), early vegetative (1.7%), and flowering (0.6%) set. The oils were analyzed by gas chromatography (GC) and GC-mass spectrometry (GC-MS). In total, 36, 33, and 16 components were identified and quantified in vegetative, late vegetative, and flowering set, representing 94.47%, 95.91%, and 99.62% of the oil, respectively. Carvacrol was the major compound in all samples. The ranges of major constituents were as follows: carvacrol (61.08-83.37%), p-cymene (3.02-9.87%), and γ-terpinene (4.13-6.34%). Antibacterial activity of the oils was tested against three Gram-positive and two Gram-negative bacteria by the disc diffusion method and determining their diameter of inhibition and the minimum inhibitory concentration (MIC) values. The inhibition zones and MIC values for bacterial strains, which were sensitive to the EO of O. vulgare subsp. glandulosum, were in the range of 9-36 mm and 125-600 μg/mL, respectively. The oils of various phenological stages showed high activity against all tested bacteria, of which Bacillus subtilis was the most sensitive and resistant strain, respectively. Thus, they represent an inexpensive source of natural antibacterial substances that exhibited potential for use in pathogenic systems.

Antimicrobial Properties of Plant Essential Oils against Human Pathogens and Their Mode of Action: An Updated Review

“…The oil obtained from Laurus nobilis and Lavandula intermedia showed inhibitory potential against Mycobacterium smegmatis and E. coli [37]. The bacterial strains ( Shigella sonnei, Sarcina lutea, and Micrococcus flavus ) were inhibited by the essential oil of Origanum vulgare [54]. The zone of inhibition and MIC values of O. vulgare oil were in the range of 9–36 mm and 125–600  μ g/mL, respectively.…”

Spectroscopic examination and release of microencapsulated oregano essential oil

“…By substituting the values of the above parameters into equation (2) [20,21] were also obtained using the dialysis method and therefore comparisons of the present with the previous data can be made. due to their accepted safe status [1][2][3][4]. Essential oils derived from aromatic plants and, oregano EO in particular fall into a group of antimicrobials that has attracted major attention as shown by the numerous reports in the literature [26][27].…”

“…Oregano essential oil (EO) has been receiving attention because of its antimicrobial activity against both Gram negative and Gram positive bacteria and to its colicidal and colistatic properties due to the presence of carvacrol and thymol in its composition [3][4][5]. Since oregano EO contains volatile and easily oxidized active ingredients protection from environmental factors is important for retaining its activity in the marketed product.…”

Effect of harvest year on production, chemical composition and antioxidant activities of essential oil of oregano (Origanum vulgare subsp glandulosum (Desf.) Ietswaart) growing in North Africa

“…Wide variations in the chemical composition of essential oils of Origanum glandulosum have been reported with relation to the geographic origin (Ruberto et al, 2002;Mechergui et al, 2010), the mode of the extraction (Bendahou et al, 2007;Bendahou et al, 2008;Bejaoui et al, 2013a) or plant different phenological stages (Bejaoui et al, 2013b).…”