Comparison of Chemical Composition, Physicochemical Parameters, and Antioxidant and Antibacterial Activity of the Essential Oil of Cultivated and Wild Mexican Oregano Poliomintha longiflora Gray

Abstract

Mexican oregano Poliomintha longiflora Gray located in the municipality of Higueras, Nuevo Leon, Mexico was collected during the autumn (September, OCO), winter (January, OCI) and summer (June, OCV) seasons, under cultivation conditions. It was also collected in wild conditions during the autumn (OSO). Essential oil (EO) was extracted from leaves and the color, refractive index and density were reported. The EO yield, antioxidant activity by ORAC assay, thymol and carvacrol concentration and antibacterial activity were statistically compared (p-value = 0.05). Among the various harvests, the highest EO yield, antioxidant activity, thymol and carvacrol content and antibacterial activity against Salmonella Typhi were observed in leaves harvested in autumn. In order to compare wild oregano with cultivated oregano, analyses were performed in the season with the highest essential oil yield and antioxidant activity, recorded in autumn. The main difference found was the ratio of thymol:carvacrol in wild oregano oil, which was 1:8.6, while in cultivated oregano, it was approximately 1:2, which was maintained in all three seasons. The EO on wild conditions showed the best antibacterial activity in Salmonella Typhi. On the other hand, wild and cultivated oregano showed similar antioxidant activity. One advantage of the use of cultivated oregano is that its supply is guaranteed, in contrast to that of wild oregano.

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

“…These results differ from those found in the wild and cultivated oregano analyzed in this study but are similar to those observed in oregano obtained under controlled conditions (greenhouse) ( Table 1 ). Similarly, other reports have indicated that cultivated oregano ( O. dictamnus ) in northern Mexico contains over 47% carvacrol and no thymol [ 33 ], indicating that wild oregano oil has significantly higher carvacrol levels compared with cultivated oregano in terms of thymol [ 16 ]. Sarrazin et al [ 53 ] reported that carvacrol was the main component in the composition of the EO of Lippia origanoides produced during both the rainy and dry seasons, with 43.5% and 41.4%, respectively, followed by thymol, with 10.7% and 10.6%, indicating a low difference between the analyzed seasons.…”

“…The results indicated that all analyzed oregano oils possess a high potential to neutralize free radicals ( Table 2 ). The AoA of essential oils from different species known as oregano has been reported by several authors [ 3 , 16 , 17 , 20 , 22 , 47 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 ]. Although the results obtained in this study for the AoA of the EOE are comparable to those described in other regions of the world, they also turn out to be significantly higher than the published results ( Table 3 ).…”

“…Additionally, it is widely used in traditional medicine for a variety of ailments, relying on the extraction of its essential oils (EO), which possess recognized AoA and antibacterial activity (AbA) [ 9 , 10 , 11 ]. In the scientific literature, numerous reports strongly associate the chemical composition of oregano essential oil (OEO) with the antioxidant, antibacterial, antifungal, antiparasitic, and antimicrobial properties in several oregano species, as well as with its commercial applications [ 1 , 3 , 5 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. Consequently, given the wide range of reported properties of OEO, it stands as one of the favorite candidates for the natural production of antioxidants and antimicrobials.…”

Post-Distillation By-Products of Aromatic Plants from Lamiaceae Family as Rich Sources of Antioxidants and Enzyme Inhibitors

“…Regarding the metal chelating potential of EOs, only the EO from basil was active with 1.34 mg EDTAE/g, but others showed no chelating ability. The spent extracts from the tested Lamiaceae species (especially basil and oregano) contained significant antioxidant properties [55][56][57]. Consequently, the byproducts of post-distillation can be considered rich sources of natural antioxidants with potential pharmaceutical and nutraceutical applications.…”

Characterization of Essential Oils from the Skin of <em>Citrus limetta</em> Risso, <em>Citrus limetta</em> Sp., <em>Citrus reticulata</em> and <em>Citrus sinensis</em> Grown in Northeastern Peru

“…On the other hand, the density of the essential oils was determined using the mass over volume formula [37,38].…”