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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. [ABSTRACT FROM AUTHOR]

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.

The present study shows the chemical profile and the in vitro properties (antioxidant and inhibition of nitric oxide production) of the Origanum heracleoticum L. (Lamiaceae). The ethanolic extract of the aerial parts is characterized by terpenes and fatty acids. The extract, with high total phenol and flavonoid content, showed a significant radical-scavenging activity (IC50 value of 12.8 μμg/mL) using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test and an interesting antioxidant activity with the ββ-carotene bleaching test (IC50 values of 12.9 and 14.1 μμg/mL at 30 and 60 min of incubation, respectively). The test for the inhibition of NO production, performed using the murine monocytic macrophage RAW 264.7 cell line, showed that the extract had significant activity with an IC50 value of 108.5 μμg/mL. The cytotoxic effect of O. heracleoticum extract in presence of lipopolysaccharide (LPS) (1 μμg/mL) was evaluated but found to be negligible. [ABSTRACT FROM AUTHOR]

In this study, Origanum heracleoticum was examined as potential source of phenolic antioxidants. The components of the plant were extracted in a Soxhlet apparatus sequentially with solvents of increasing polarity, specifically with petroleum ether ( P), diethyl ether ( D) and ethanol ( E); the ethanol extract was further fractionated to obtain a diethyl ether (ED) and an ethyl acetate (EEAc) fraction. The activity of the extracts to scavenge 2′2′-diphenyl-1-picrylhydrazyl followed the order ED > E> D > EEAc >> P. Moreover, the antioxidant activity in refined cottonseed oil at a concentration of 500 ppm was monitored through peroxide value measurements and revealed that ED resulted in the highest decrease in the rate of peroxide formation followed by D. Specific flavonoids and rosmarinic acid were detected as the main components of D, ED through HPLC–DAD and HPLC–MS/MS analyses. [ABSTRACT FROM AUTHOR]