Antioxidant and Antibacterial Activity of Mexican Oregano Essential Oil, Extracted from Plants Occurring Naturally in Semiarid Areas and Cultivated in the Field and Greenhouse in Northern Mexico

Abstract

In recent years, the determination of the antioxidant and antibacterial activity of essential oils in wild plants, such as Mexican oregano (Lippia graveolens Kunth), has become increasingly important. The objective was to compare the antioxidant and antibacterial activity of Mexican oregano essential oil obtained from plants occurring naturally in semiarid areas (Wild1 and Wild2), and those cultivated in the field (CField) and greenhouse (CGreenhouse) in northern Mexico. The Mexican oregano essential oil extraction was performed using the hydrodistillation method, the antioxidant activity was determined using the ABTS method, and the antibacterial activity was assessed through bioassays under the microwell method at nine different concentrations. The aim was to determine the diameter of the inhibition zone and, consequently, understand the sensitivity level for four bacterial species. The results revealed an antioxidant activity ranging from 90% to 94% at the sampling sites, with Wild1 standing out for having the highest average antioxidant activity values. Likewise, six out of the nine concentrations analyzed showed some degree of sensitivity for all the sampling sites. In this regard, the 25 µL mL−1 concentration showed the highest diameter of inhibition zone values, highlighting the Wild2 site, which showed an average diameter greater than 30 mm for the four bacteria tested. Only in the case of S. typhi did the CGreenhouse site surpass the Wild2, with an average diameter of the inhibition zone of 36.7 mm. These findings contribute to the search for new antioxidant and antibacterial options, addressing the challenges that humanity faces in the quest for opportunities to increase life expectancy.

Chemical Composition, and Antioxidant and Antimicrobial Activity of Oregano Essential Oil

“…The proportions of individual compounds are genetically determined and form the basis for the classification of oregano species and chemotypes [ 16 ]. It should be added that OEO composition can be modified by ontogenetic factors [ 17 ], environmental factors [ 18 ], and production conditions [ 5 , 19 ]. Carvacrol, β-caryophyllene, o-cymene, γ-terpinene, linalool and thymol are mentioned as primary components of OEO [ 3 , 5 ].…”

Plants from Arid and Semi-Arid Zones of Mexico Used to Treat Respiratory Diseases: A Review

“…Ellagic acid has been found to stimulate enzyme responses like SOD and CAT, thereby attenuating pulmonary emphysema by inhibiting ROS, reducing lipid peroxidation, and enhancing antioxidant activity [ 14 , 102 , 103 , 104 ]. Carvacrol disrupts bacterial cell membranes, increases membrane permeability, and decreases cytoplasmic pH, thereby affecting the respiratory system [ 104 , 105 , 106 , 107 ]. Besides, additional compounds are listed in Table 2 .…”