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Oregano (Origanum vulgare) and Infection (general): evidence and sources
Antimicrobial (antibacterial and antifungal via carvacrol and thymol) - supports respiratory and gastrointestinal infections; a small clinical study found emulsified oregano oil cleared enteric parasites (incl. Blastocystis hominis) and improved gut symptoms
For educational purposes only, not medical advice. Always consult a qualified practitioner before using medicinal plants, especially alongside prescribed medication, during pregnancy, or for a serious condition.
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Oil of Mediterranean oregano Oreganum vulgare was orally administered to 14 adult patients whose stools tested positive for enteric parasites, Blastocystis hominis, Entamoeba hartmanni and Endolimax nana. After 6 weeks of supplementation with 600 mg emulsified oil of oregano daily, there was complete disappearance of Entamoeba hartmanni (four cases), Endolimax nana (one case), and Blastocystis hominis in eight cases. Also, Blastocystis hominis scores declined in three additional cases. Gastrointestinal symptoms improved in seven of the 11 patients who had tested positive for Blastocystis hominis.
Carvacrol (CV) is a phenolic monoterpenoid found in essential oils of oregano (Origanum vulgare), thyme (Thymus vulgaris), pepperwort (Lepidium flavum), wild bergamot (Citrus aurantium bergamia), and other plants. Carvacrol possesses a wide range of bioactivities putatively useful for clinical applications such antimicrobial, antioxidant, and anticancer activities. Carvacrol antimicrobial activity is higher than that of other volatile compounds present in essential oils due to the presence of the free hydroxyl group, hydrophobicity, and the phenol moiety. The present review illustrates the state-of-the-art studies on the antimicrobial, antioxidant, and anticancer properties of CV. It is particularly effective against food-borne pathogens, including Escherichia coli, Salmonella, and Bacillus cereus. Carvacrol has high antioxidant activity and has been successfully used, mainly associated with thymol, as dietary phytoadditive to improve animal antioxidant status. The anticancer properties of CV have been reported in preclinical models of breast, liver, and lung carcinomas, acting on proapoptotic processes. Besides the interesting properties of CV and the toxicological profile becoming definite, to date, human trials on CV are still lacking, and this largely impedes any conclusions of clinical relevance.
Origanum vulgare L. ( O. vulgare ) is an important medicinal herb of the family Lamiaceae. In the current study, we explained the critical evaluation of traditional uses, the phytochemistry and the antimicrobial properties of O. vulgare and its subspecies, with a focus on the mechanisms of actions of the most important phytochemicals from O. vulgare subspecies. The most important phytochemicals of O. vulgare are volatile (essential oil) and non-volatile phenolic compounds (phenolic acids & flavonoids). The constituents of the O. vulgare essential oil (EO) include high percentages of thymol and carvacrol with excellent antimicrobial activity alone or in combination with other antibiotics. Interesting results have been reported the remarkable antimicrobial activities of infusion or tea products of O. vulgare with a high amount of EO against multidrug-resistant bacterial and fungal microorganism (such as Escherichia coli, Staphylococcus aureus, Candida albicans and Pseudomonas aeruginosa ). The most important antibacterial mechanisms of O. vulgare are enzyme inhibition, efflux pump inhibition, ATP depletion, biofilm formation inhibition and cytoplasmic membrane damage. The antimicrobial activity of the hirtum subspecies has been confirmed in different in-vitro and in-vivo studies. The present review confirms the clinical and preclinical research showing the O. vulgare and its subspecies antimicrobial effects.
3 sources supporting Oregano for Infection (general). Includes scientific publications, books, monographs and traditional-use references.
Mechanistic basis
This use is associated with the plant's antifungal, antimicrobial actions. Further evidence for that pharmacology:
Malassezia sympodialis and Malassezia furfur are recognized as an important part of the human and animals healthy skin microbiota, but also as an opportunistic fungus due to their association with a broad spectrum of skin and systemic infections. Human skin infections associated with Malassezia spp. are often chronic, recurrent, and topical or oral azole treatments are challenging with not always successful outcomes. A wide inter and intraspecies antifungal susceptibility variability that may suggest a combination of wild-type strains and resistant mutants was reported. The essential oils are complex hydrophobic mixtures of different compounds extracted from plants by distillation and have demonstrated antimicrobial activity. In this study, toxicity in the larvae model and the ability of Origanum vulgare essential oil (OVEO) and carvacrol to inhibit virulence factors such as hydrophobicity, adherence, and biofilm formation of M. sympodialis and M. furfur was evaluated. We have demonstrated the antifungal activity of OVEO and carvacrol against both species. Carvacrol was more active and less toxic than OVEO at low concentrations (< 1 mg/ml). Malassezia sympodialis showed a significant decrease in adherence and its ability to form biofilms when OVEO or carvacrol is present. Both Malassezia species showed reduced hydrophobicity in the presence of carvacrol. Further studies will have to be carried out to understand how these substances act, but the inhibition of some virulence factors could represent a new target to overcome the problem of drug resistance.
The Mediterranean diet has long been known to provide a variety of health benefits such as cardiovascular protection, cancer prevention, and lowering gastrointestinal inflammation. Oregano ( Origanum vulgare ) is an herb prominent in the Mediterranean diet, and has been shown to possess several bioactive properties including anti-oxidant, anti-microbial, anti-inflammatory, and analgesic properties. The anti-oxidant and anti-microbial properties of oregano also make it a strong candidate as a natural food preservative. Because of the recent public concern with synthetic food preservatives, natural alternatives are increasingly being evaluated for effective food preservation. Oregano extract (OE) and essential oil (OEO) are two such agents that have shown promise as natural food preservatives. Additionally, oregano is being evaluated for its positive effect on gastrointestinal health, suggesting an additional benefit of food preservation with oregano. This review will describe in vitro studies related to the anti-microbial and anti-oxidant properties of oregano along with food preservation studies with oregano in various model food matrices. The major phytochemical content reported for OE and OEO will also be outlined to highlight the importance of characterizing the extract that is used, since the extraction process can have a significant effect on the phytochemicals therein. Finally, in vivo studies that investigate the gastrointestinal health benefits of oregano, specifically against inflammation, will be addressed to show the impact of oregano on gastrointestinal health.
Oregano essential oil (OEO), as a natural antimicrobial, has gained increased interest from food researchers and manufacturers. However, a few studies have investigated its possible antibacterial effects against Staphylococcus aureus using the proteomic tool. The present study aimed to explore the antibacterial effect and mechanism of a carvacrol-rich OEO extracted from Origanum vulgare "Hot & Spicy" on the inactivation of S. aureus . The gas chromatography-mass spectrometry analysis of the OEO allowed the detection of 27 compounds; the major constituent was carvacrol (84.38% of total compounds). The average diameter of the inhibitory zone (DIZ) value was 29.10 mm, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of OEO against S. aureus were 0.125 and 0.25 mg/mL, respectively. The growth curve assay indicated that the OEO prolonged the lag phase of S. aureus . The decrease in cell viability, changes in the integrity of cell membrane, and abnormal cell morphology further reflected the cell damage of S. aureus caused by the OEO. In addition, a label-free proteomic analysis was applied to analyze the regulatory networks of S. aureus in response to 1/2 MIC OEO-treatment stress. Of the 56 differentially expressed proteins (DEPs) identified, 26 were significantly upregulated and 30 downregulated. The Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis indicated that the DEPs were mainly involved in pathways of ribosomes; valine, leucine, and isoleucine biosynthesis; and phenylalanine, tyrosine, and tryptophan biosynthesis, which suggested that the growth inhibition of S. aureus might be due to the disordered effect of the OEO on protein synthesis and amino acid metabolism. These findings deepened our understanding regarding S. aureus survival and metabolism responses to the OEO treatment and suggested that the carvacrol-rich OEO could be used in food production environments to effectively control S. aureus.
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.
Essential oils (EOs) are plant mixtures that are known to present strong bioactivities, including a wide antimicrobial action. Biofilms are microbial sessile structures that represent the default mode of growth of microorganisms in most environments. This study focused on the antimicrobial action of the EO extracted from one of the most representative oregano species, that is, Origanum vulgare (subsp. hirtum ), against two important foodborne pathogens, Salmonella enterica (serovar Typhimurium) and Listeria monocytogenes . For this, the minimum inhibitory concentrations of the EO against the planktonic and biofilm growth of each bacterium were determined (MICs, MBICs), together with the minimum bactericidal and biofilm eradication concentrations (MBCs, MBECs). The EO was also analyzed for its chemical composition by gas chromatography-mass spectrometry analysis (GC-MS). The influence of EO exposure on the expression of some important virulence genes ( hly , inlA , inlB and prfA ) was also studied in L. monocytogenes . Results revealed a strong antibacterial and antibiofilm action with MICs and MBICs ranging from 0.03% to 0.06% ( v / v ) and from 0.06% to 0.13% ( v / v ), respectively. The application of the EO at 6.25% ( v / v ) for 15 min resulted in the total eradication of the biofilm cells of both pathogens. The EO was mainly composed of thymol, p -cymene, γ -terpinene and carvacrol. The 3 h exposure of L. monocytogenes planktonic cells to the EO at its MBIC (0.06% v / v ) resulted in the significant downregulation of all the studied genes ( p < 0.05). To sum, the results obtained advocate for the further exploitation of the antimicrobial action of oregano EO in food and health applications.