Chemical Composition and Biological Activities of Essential Oils from Origanum vulgare Genotypes Belonging to the Carvacrol and Thymol Chemotypes

Abstract

The remarkable biological activities of oregano essential oils (EOs) have recently prompted a host of studies aimed at exploring their potential innovative applications in the food and pharmaceutical industries. The chemical composition and biological activities of EOs from two Origanum vulgare genotypes, widely cultivated in Sicily and not previously studied for their biological properties, were characterized. Plants of the two genotypes, belonging to the carvacrol (CAR) and thymol (THY) chemotypes and grown in different cultivation environments, were considered for this study. The chemical profiles, including the determination of enantiomeric distribution, of the EOs, obtained by hydrodistillation from dried leaves and flowers, were investigated by GC–MS. Biological activity was evaluated as antimicrobial properties against different pathogen indicator strains, while intestinal barrier integrity, reduction in pathogen adhesion and anti-inflammatory actions were assayed in the intestinal Caco-2 cell line. The chemical profile of the CAR genotype was less complex and characterized by higher levels of the most active compound, i.e., carvacrol, when compared to the THY genotype. The enantiomeric distribution of chiral constituents did not vary across genotypes, while being markedly different from that observed in Origanum vulgare genotypes from other geographical origins. In general, all EOs showed high antimicrobial activity, both in vitro and in a food matrix challenge test. Representative EOs from the two genotypes resulted not altering epithelial monolayer sealing only for concentrations lower than 0.02%, were able to reduce the adhesion of selected pathogens, but did not exert relevant anti-inflammatory effects. These results suggest their potential use as control agents against a wide spectrum of foodborne pathogens.

Effect of Different Soil Treatments on Production and Chemical Composition of Essential Oils Extracted from Foeniculum vulgare Mill., Origanum vulgare L. and Thymus vulgaris L.

“…Analyses show that the thyme EOs samples (TV03-TV11) contained 44 recognized compounds, with p-cymene (present from about 2% to 32%) and thymol (about 35-64%) as the main components, suggesting that the EOs belong to the thymol chemotype. The other components were present in a total amount of less than 15% [35]. As reported for the OV EOs, these data are in good agreement with the literature which indicates that the main chemical components of thyme EO are thymol (20-60%) and carvacrol (5-20%) as well as p-cymene, α-terpinene and linalool (data from eo.3d-qsar.com (accessed on 15 July 2023)).…”

Comparative Study of Bioactive Compounds and Biological Activities of Five Rose Hip Species Grown in Sicily

“…Concerning R. corymbifera, the 25 mg/mL concentration induced a TEER drop already after 2 h, further decreasing between 3 and 5 h, up to the end of the experiment (Figure 3b). This TEER decrease was associated with a biologically relevant phenol red Papp increase, as the corresponding values were about 1.6 × 10 −6 cm s −1 , indicating that the tight junctions were open (Table 4, value in bold), as already described [33]. Finally, concerning 10 and 20 mg/mL R. corymbifera, the TEER drop was delayed at 5 h treatment compared to 25 mg/mL but did not reach the 25 mg/mL values (Figure 3b).…”

“…Thus, in the present study, the impact of the five extracts on human intestinal Caco-2 cells has been investigated since the intestinal mucosa represents an important site of contact between ingested food and the organism. To evaluate if exposure to Rosa extracts containing phenolic compounds could perturb intestinal epithelial permeability, Transepithelial Electrical Resistance (TEER) and phenol red passage (apparent permeability, Papp) were measured in differentiated Caco-2 cells following apical treatment with several concentrations (ranging from 1 to 25 mg/mL) of the five extracts for up to 24 h. An amount of 2% ethanol, corresponding to the concentration contained in the higher dilution of tested extracts, did not affect cell permeability for up to 24 h, as already shown [33].…”

Synthesis and Phytocytogenotoxic Activity of N-Phenyl-2-phenoxyacetamides Derived from Thymol

“…mp 117.5−118.9 °C. NMR, δ H (400 MHz, CDCl 3 ): 1.30 (d, 6H, J = 6.9 Hz, 2xCH (6); 149 (100); 121 (13); 105 (13); 91 (14); 65 (2); 41 (4).…”

“…There are natural compounds that exhibit proven phytotoxic activity and can be utilized to obtain semisynthetic compounds. For instance, thymol (2-isopropyl-5-methylphenol) is a crystalline and colorless phenolic monoterpene that can be found in essential oils derived from several plants, including thyme (Thymus vulgaris), oregano (Origanum vulgare), 6 and rosemary pepper (Lippia sidoides). 7 This substance has demonstrated antimicrobial, 8 antifungal, 9 antioxidant, 10 and phytotoxic activities.…”