Origanum Vulgare Essential Oil Research Articles

Fabrication and characterization of electrospun zein nanofibers incorporated with citronellol-rich Origanum vulgare essential oil

Fabrication and characterization of electrospun zein nanofibers incorporated with citronellol-rich Origanum vulgare essential oil

The impact of Origanum Vulgare essential oil supplementation on sperm motility and subpopulation alterations in bulls, dogs, and rabbits

Artificial insemination is a widely adopted method in livestock production for various reasons such as health security and genetic improvement. Although sperm motility is of paramount importance in this technique as it directly influences the sperm's ability to fertilize the oocyte. In previous research on human sperm, we observed that in vitro supplementation with Origanum Vulgare essential oil significantly improved sperm motility and antioxidant activities, all without negatively affecting the integrity of their DNA. Based on these promising results, we considered it crucial to explore the potential effects of supplementation with this essential oil on sperm of other species. In this study, we studied the effects of oregano essential oil supplementation on sperm motility of (bulls = 15) (dogs = 15) and (rabbits = 9) and the changes that in vitro incubation with this oil could induce on sub-motile sperm populations of different species. The results of the study showed that in vitro oregano essential oil supplementation had a significant impact on sperm motility in the three species studied. This improvement in sperm motility was accompanied by an increase in the proportion of subpopulations with high velocity and progressivity: an increase of (2.16%, 10% and 4.84%) for subpopulation 1, (6.50%, 5.5% and 3.17%) for subpopulation 4 in bulls, dogs and rabbits respectively. While the subpopulations representing low motile and non-progressive sperm have decreased. These results suggest that the use of oregano essential oil can be a beneficial approach to improve sperm motility in different species, which can have important implications for the success of artificial insemination.

Antioxidant and antimicrobial effect of sodium alginate nanoemulsion coating enriched with oregano essential oil (Origanum vulgare L.) and Trachyspermum ammi oil (Carum cupticum) on food pathogenic bacteria.

Today, microbial contamination in food is one of the major problems of the food industry and public health in general around the world. Foodborne illnesses, such as diarrheal diseases, kill many people around the world each year. The general objective of this study was to evaluate the antioxidant and antibacterial activity of sodium alginate nanoemulsion coating incorporated with oregano essential oil (Origanum vulgare L.) and Trachyspermum ammi oil (Carum cupticum) on Escherichia coli, and Listeria monocytogenes. To achieve this study, fresh chicken meat was used for this experiment. Listeria monocytogenes ATCC 19111 and Escherichia coli ATCC 35218 were obtained from the American Type Culture Collection (Manassas, VA, USA). After the preparation of the essential oil, the chemical composition of this essential oil was determined by using (GC-MS). The physicochemical properties of the nanoemulsion essential oil prepared were characterized and their antimicrobial activity was evaluated. The results showed that the GC-MS analysis of the volatile constituents of the Origanum vulgare essential oil compounds allowed the identification of 19 compounds representing 93.72% of the total oil. The major components detected in Origanum vulgare essential oil were pulegone (49.25%), eucalyptol (18.23%), and menthone (12.37%). About the Carum cupticum essential oil, 21 compounds representing 98.5% of the total oil were identified. The major components detected in Origanum vulgare essential oil were thymol (23.3%), p-cymene (17.5%), and γ-terpinene (16.8%). The best z-average (d.nm) is 483.4 nm (Carum cupticum essential oil + nano) followed by 470.1 nm (nanochitosan). The results of the antimicrobial test showed that the different preparations have a good inhibitory activity for the invitro growth of Escherichia coli and Listeria monocytogenes. According to the MIC and MBC results of this study, the nanoemulsion also presented a good bacteriostatic activity against the two pathogenic bacteria tested in this study.

Evaluation of the antibacterial, modulatory and anti-adherent properties of oregano (Origanum vulgare) essential oil against food pathogenic bacteria

There are over 250 types of foodborne diseases, the majority of which are infections caused by bacteria. Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus saprophyticus are considered contaminants of meat products. The use of natural products as antimicrobials to combat these diseases can be an effective and economical approach. This study proposes to assess the antibacterial, modulatory, and anti-adherent activity of the essential oil of Origanum vulgare against strains of Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus saprophyticus isolated from meat products. The assay was conducted in duplicate. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined using the broth microdilution technique. MIC represents the lowest concentration of the product capable of inhibiting the growth of the bacterial strain, whereas MBC represents the lowest concentration capable of inhibiting total growth. The study of association of the product with antimicrobials was undertaken by disk diffusion using ampicillin, gentamicin, ceftazidime, and ciprofloxacin, resulting in synergistic, antagonistic, or indifferent effects. Anti-adherent activity was determined in the presence of sucrose, as the lowest concentration of the agent in contact with sucrose that prevented adherence to the glass tube. Oregano oil exhibited strong inhibitory and bactericidal activity against Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus saprophyticus, with MIC values ranging from 32 to 512 μg mL-1 and MBC values ranging from 128 to 512 μg mL-1. Origanum vulgare oil showed varied interactions when associated with antimicrobials, with modulations for synergism (37.5%), indifference (50%), and antagonism (12.5%). Regarding anti-adherent activity, the test product effectively inhibited the adherence of P. aeruginosa bacterial strains in the presence of sucrose (1:8) but had no effect against K. pneumoniae or S. saprophyticus. Therefore, oregano oil proves to be an antibacterial and modulating agent against different bacteria isolated from meat products. Additionally, it displays anti-adherent properties against P. aeruginosa, making it a natural product that could serve as an interesting alternative in efforts to combat foodborne diseases.

Oregano (Origanum vulgare) Essential Oil and Its Constituents Prevent Rat Kidney Tissue Injury and Inflammation Induced by a High Dose of L-Arginine.

This study aimed to evaluate the protective action of oregano (Origanum vulgare) essential oil and its monoterpene constituents (thymol and carvacrol) in L-arginine-induced kidney damage by studying inflammatory and tissue damage parameters. The determination of biochemical markers that reflect kidney function, i.e., serum levels of urea and creatinine, tissue levels of neutrophil-gelatinase-associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1), as well as a panel of oxidative-stress-related and inflammatory biomarkers, was performed. Furthermore, histopathological and immunohistochemical analyses of kidneys obtained from different experimental groups were conducted. Pre-treatment with the investigated compounds prevented an L-arginine-induced increase in serum and tissue kidney damage markers and, additionally, decreased the levels of inflammation-related parameters (TNF-α and nitric oxide concentrations and myeloperoxidase activity). Micromorphological kidney tissue changes correlate with the alterations observed in the biochemical parameters, as well as the expression of CD95 in tubule cells and CD68 in inflammatory infiltrate cells. The present results revealed that oregano essential oil, thymol, and carvacrol exert nephroprotective activity, which could be, to a great extent, associated with their anti-inflammatory, antiradical scavenging, and antiapoptotic action and, above all, due to their ability to lessen the disturbances arising from acute pancreatic damage. Further in-depth studies are needed in order to provide more detailed explanations of the observed activities.

Potential Antibacterial Effects of Ethanol Extract and Essential Oil of Origanum vulgare on Klebsiella pneumonia and Staphylococcus aureus

Klebsiella pneumonia (K. pneumonia) and Staphylococcus aureus (S. aureus) are pathogenic bacteria causing various infectious diseases in humans and animals. Currently, herbal ingredients are widely used as antibacterial agents to combat bacterial infections due to their lower side effects, compared to chemical drugs. One such plant with medicinal promise as an antibacterial agent is the oregano plant (Oregano vulgare). It contains substances, such as tannin, flavonoids, carvacrol, thymol, and saponin. Therefore, the current study was conducted to regularly compare the in vitro antibacterial potential of ethanol extract essential oil oregano (Oregano vulgare) on K. pneumonia and S. aureus. In this research, the diffusion method using discs was employed to observe the inhibition zones, while the dilution tube method was utilized to determine the minimum inhibitory concentration (MIC) of the ethanol extract and essential oil of oregano against the test bacteria. The bacterial treatment group received the test material at concentrations of 100%, 50%, 25%, and 12.5%. The obtained data were analyzed descriptively in terms of zone inhibition and MIC values. According to the disc diffusion test, the essential oil of oregano demonstrated greater efficacy as an antibacterial agent against K. pneumoniae at a concentration of 100%, resulting in an average inhibition zone of 18 mm. Conversely, for S. aureus, a concentration of 1.5% of the essential oil exhibited higher effectiveness, yielding an average inhibition zone of 30 mm. Based on the MIC values, the essential oil was more effective as an antibacterial for K. pneumonia at a concentration of 0.2% (2 mg/mL), while for S. aureus it was more effective at a concentration of 0.19% (1.9 mg/mL).

Assessing the In Vitro and In Vivo Effect of Supplementation with a Garlic (Allium sativum) and Oregano (Origanum vulgare) Essential Oil Mixture on Digestibility in West African Sheep.

This study assessed the impact of a mixture of garlic (Allium sativum) and oregano (Origanum vulgare) essential oils (EOGOs) on in vitro dry matter digestibility (IVDMD) and in vivo apparent nutrient digestibility. Different EOGO inclusion levels were evaluated to assess the dose response and potential effects of the mixture. Three EOGO inclusion levels (0.5, 0.75, and 1 mL/kg of incubated dry matter) were evaluated in vitro, while four treatments (0.5, 0.75, and 1 mL/day of EOGO and a control group) were tested in vivo on 12 West African sheep. A randomized controlled trial was conducted using a 4 × 4 design. Blood parameters (glucose, blood urea nitrogen, and β-hydroxybutyrate) were measured to observe the effect of EOGO on the metabolism. The results showed that the inclusion of EOGO significantly enhanced IVDMD at low levels (p < 0.052) compared with the highest levels in treatments containing 0.5 and 0.75 mL/kg of EOGO dry matter. A higher intake of dry matter (DM), crude protein (CP), and neutral detergent fiber (NDF) (p < 0.05) was observed in the in vivo diets with the inclusion of EOGO. In terms of in vivo apparent digestibility, significant differences were found among treatments in the digestibility coefficients of DM, CP, and NDF. EOGO inclusion increased the digestibility of DM. CP digestibility displayed a cubic effect (p < 0.038), with the lowest values of digestibility observed at 1 mL EOGO inclusion. Additionally, NDF digestibility showed a cubic effect (p < 0.012), with the highest value obtained at 0.75 mL of EOGO inclusion. The inclusion levels above 0.75 mL EOGO showed a cubic effect, which indicates that higher concentrations of EOGO may not be beneficial for the digestibility of CP and NDF. Although no significant difference was observed in total digestible nutrients, a linear trend was observed (p < 0.059). EOGO improved the intake of DM, CP, and NDF. EOGO supplementation improved the digestibility of DM and NDF, with optimal levels observed at 0.5 mL/day. No significant effects were observed in the blood parameters. These results suggest that EOGO has the potential as an additive in ruminal nutrition to improve food digestibility and serve as an alternative to antibiotic additives. The use of EOGO potentially improves fiber digestion and may reduce the use of antibiotics in livestock production. Garlic (A. sativum) and oregano (O. vulgare) essential oils effectively modulated fiber digestibility at 0.75 mL/day. Garlic (A. sativum) and oregano (O. vulgare) essential oils have the potential to improve digestibility at low inclusion levels and serve as an alternative to antibiotic additives. The effectiveness of essential oils is greater in a mixture and at lower doses.

Antibacterial Potential of Chitosan Scaffolds Incorporated with Oregano and Thyme Essential Oils against Escherichia coli

The aim of this study was to evaluate the antibacterial potential of chitosan-based scaffolds associated with the essential oils of Origanum vulgare L. and Thymus vulgaris L. against a strain of Escherichia coli. The antibacterial potential was assessed by reading the inhibition halos formed around the chitosan-based scaffolds incorporated with thyme EO, oregano EO and thyme and oregano EO against the Escherichia coli strain, using the Mueller Hinton agar diffusion methodology per well. To do this, Mueller Hinton Agar was used as the culture medium in Petri dishes, and holes 6 mm in diameter were formed using a mold to create the wells. The plates were inoculated with the microorganism using a swab, then incubated in a bacteriological oven at 37 °C for 24 hours. Scaffolds, in the form of disks, were aseptically deposited in the wells of the inoculated media, which were incubated at 37 °C for 24 hours. After incubation, the plates were observed for homogeneity of bacterial growth and the diameter of the inhibitory halo was measured using a millimeter ruler in cases where inhibition of bacterial growth was verified. The tests were carried out in duplicate and the results correspond to the average values. The association of chitosan with Origanum vulgare L. and Thymus vulgaris L. EOs was found to have antibacterial activity against the Escherichia coli strain. For the scaffolds incorporated with Origanum vulgare L. EO, Thymus vulgaris L. EO and associated Origanum vulgare L. and Thymus vulgaris L. EOs, 16 mm inhibition halos were formed against the Escherichia coli strain. The association of chitosan with the EOs of Origanum vulgare L. and Thymus vulgaris L. has antibacterial activity, acting as a bactericide against the Escherichia coli strain tested.

Investigation on 5-Isopropyl-2-Methylphenol via Quantum Chemicals, Pharmacokinetics, Molecular Docking and Cytotoxicity Evaluation Against Breast Cancer

The 5-isopropyl-2-methylphenol (5IP2MP) molecule, a monoterpenoid phenol mostly existing in the essential oil of Origanum vulgare L., was used as a potent breast cancer inhibitor in this present investigation. First, the structural and spectroscopic properties of the 5-isopropyl-2-methylphenol (5IP2MP) molecule were assessed via density functional theory (DFT) calculation. The structural optimization was performed through the DFT/B3LYP method with the 6-311++G (d,p) basis set, and the structural geometry was calculated. From the optimized structure of 5-isopropyl-2-methylphenol, vibrational frequencies were allotted and related with analytically calculated vibrational frequencies, the UV–Visible spectrum was theoretically simulated, and absorbance was experimentally confirmed. The 5-isopropyl-2-methylphenol’s reactive potential was further investigated through a molecular electrostatic potential surface. Exploiting the HOMO-LUMO energies and energy gap, the molecular reactivity and stability of the 5-isopropyl-2-methylphenol molecule were assessed. Mulliken and natural population analysis revealed the charge distribution over the atoms of 5-isopropyl-2-methylphenol. The bioactivity of the 5IP2MP was confirmed through natural bond orbital analysis. Thermodynamic evaluation has been utilized to acquire values of 5-isopropyl-2-methylphenol’s thermodynamic parameters that reveals the thermal stability of the title molecule. To determine the bonding domains and weakest interactions in 5IP2MP, topological investigations have been carried out based on electron localization function, localized orbital locator and reduced density gradient. Through the DPPH assay, the antioxidant potential was confirmed. The physicochemical and pharmacokinetic studies confirm the drug-likeness properties of 5-isopropyl-2-methylphenol. The anti-cancer potential of 5-isopropyl-2-methylphenol in contradiction to breast cancer proteins was confirmed through molecular docking analysis, which showed the highest binding affinity was detected against NAMPT with –7.9 kcal/mol. The previously chosen title chemical might be promoted as a possible pharmacological candidate for the development of new breast cancer prevention medications. The in vitro cytotoxicity studies exhibited the IC50 value of 67.96 [Formula: see text]g/ml with T-47D cells for a time period of 24 h. Overall, this study showed that the 5IP2MP molecule possesses better structural stability, reactivity and excellent anticancer activity in both in silico and in vitro studies.

Efficacy and Potential Mechanism of Essential Oils of Three Labiatae Plants against the Pathogenic Fungi of Root Rot Disease in Atractylodes chinensis

Atractylodes chinensis has a high medicinal value and is widely cultivated. However, root rot disease seriously affects the yield and quality of A. chinensis. To develop green and safe pesticides, the inhibitory effect of essential oils (EOs) of three Labiatae plants on the pathogenic fungi that causes root rot disease in Atractylodes chinensis was investigated. The results showed that the Origanum vulgare EO and Thymus mongolicus EO exhibited strong inhibitory effects on Fusarium oxysporum, Fusarium solani, and Fusarium redolens, with 100% inhibition rate. The low MIC values of EOs and their main components against the three pathogenic fungi indicated that all of them showed strong fungicidal effects. The MIC values of O. vulgare EO against F. oxysporum, F. solani, and F. redolens were 2.60 mg/mL, 3.13 mg/mL, and 1.56 mg/mL, respectively. Analyses using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that the O. vulgare EO severely damaged the cell wall and cell membrane of mycelial cells. The O. vulgare EO increased cell permeability, leading to a large leakage of cell contents (DNA and proteins). In addition, O. vulgare EO inhibited F. oxysporum by inducing ROS production and reducing the amount of intracellular GSH, leading to a large accumulation of ROS. This study showed that plant EOs have excellent fungicidal activity and can be used as novel natural and environmentally friendly pesticides for the control of root rot in A. chinensis.

Optimizing Salmonella Enteritidis inactivation in Salmon (Salmo salar) by the combined treatment of UV-LED and of Origanum vulgare essential oil nanoemulsion

The combination of oregano essential oil (OVEO) and its nanoemulsion (nOVEO) with UVC-LED treatment was optimized for maximum S. Enteritidis inactivation while mitigating lipid oxidation and color changes using a response surface methodology. Individually nOVEO was two-fold more efficient in S. Enteritidis inactivation than OVEO. The combination of UVC-LED with nOVEO led to higher pathogen inactivation and lower oxidation compared to OVEO, which seemed to have a saturation point. The optimum levels of each combined treatment (UVC-LED + OVEO = 4,974 mJ/cm2 + 12.25 mg/mL and UVC-LED + nOVEO = 1,752 mJ/cm2 + 8.50 mg/mL) inactivate more than 1 log CFU with low oxidation (0.11 mg malondialdehyde/kg). However, only the use of nOVEO resulted in low color changes (ΔE = 3.6), besides required milder conditions. Therefore, the combination of nOVEO with UVC-LED proved to be a feasible non-thermal hurdle approach to control S. Enteritidis in salmon while retaining its quality.

Active chitosan/gelatin‐based films and coatings containing eugenol and oregano essential oil for fresh cheese preservation

AbstractThe use of active substance‐containing biodegradable and edible coatings has become a potentially viable alternative for food preservation, especially to retard oxidative processes and the growth of pathogenic and spoilage microorganisms on the surface of the foodstuffs. In this context, the objective of this research was to develop and characterize gelatin (GL)/chitosan (CH)‐based active, biodegradable, and edible films and coatings containing eugenol (EU) and oregano (Origanum vulgare) essential oil (OEO) in different OEO:EU ratios, and obtained via casting for application in fresh cheese. More soluble, wetter, yellower, and opaque films than the control film system were obtained as a consequence of a higher OEO:EU ratio. Although, the water vapor barrier properties in OEO‐containing films were markedly enhanced with respect to control film system. All the films displayed a slight phase separation, but this was more noticeable when increasing the OEO:EU ratio. This could explain the higher moisture content and water solubility values as the OEO:EU ratio increased. The films containing EU and OEO showed antimicrobial activity against Staphylococcus aureus and Escherichia coli. The best film systems were selected and tested as coatings for the preservation of fresh cheese. In particular, the coating F4 (0.5% wt/wt of OEO + 0.5% wt/wt of EU) displayed the best conservation capacity of fresh cheese during 14 days of storage at 4°C. This predominantly through the reduction of the colony‐forming units of S. aureus, total coliforms, and mesophilic aerobic.Practical applicationsThe addition of EU and OEO in CH/GL‐based coatings presented a synergistic effect in terms of their antimicrobial activity. These food packaging materials would be an alternative for the preservation of foods susceptible to contamination by pathogenic and/or spoilage microorganisms during storage. Besides, the addition of OEO improved particularly the barrier properties of active, biodegradable, and edible films, which allows their use as a protection mechanism for high‐moisture and medium‐moisture foods, such as fresh cheese. Overall, assessed coatings could increase the shelf life of fresh cheese in terms of food safety, but not its quality in terms of maintaining its freshness.

Oxidative Protection of Sunflower Oil Used in Industrial Process at High Temperature by Volatile Components from Origanum vulgare and Humulus lupulus Essential Oils

Oxidative Protection of Sunflower Oil Used in Industrial Process at High Temperature by Volatile Components from Origanum vulgare and Humulus lupulus Essential Oils

Application of Chromatographic and Microbiological Analyses to Identify and Assess the Durability of Antimicrobial Properties of Innovative Materials for the Footwear Industry─Leather Modified with Origanum vulgare Oil

A modification of the leather finishing technology in which the essential oil of Origanum vulgare is applied during the process of fatliquoring imparts antimicrobial activity to leather. This paper presents the characteristics of cowhide lining leather enriched with oregano oil (3%wt) in terms of durability of the antimicrobial activity conferred to it. Analyses carried out using gas chromatography–mass spectrometry have shown that carvacrol, the main component of oregano oil which is responsible for antiseptic action, constitutes more than 65% of the mixture of organic compounds detected in the vapor phase over samples of leather enriched with the oil even after 72 months of application. The results of an investigation into the kinetics of volatile compounds emission from leather samples treated with oil provided a proof that carvacrol emission decreased over time in an exponential way but did not fade out. This correlates with the results of microbiological analyses conducted using the agar plate diffusion method. The zones of growth inhibition obtained for the strains of microorganisms with sizes of 13 mm (Staphylococcus aureus), 1–3 mm (Candida albicans), and 2 mm (Staphylococcus epidermidis, Scopulariopsis brevicaulis) confirmed that the leather treated with oil still showed good activity against Gram-positive bacteria and fungi after 72 months of storage. The long-lasting antimicrobial properties of leather enriched with a natural biocide─oregano essential oil make it possible to be used in the production of special footwear intended for people with problems of the skin of the feet and toenails caused by pathogenic bacteria and fungi.

Essential Oil of Origanum vulgare as a Green Corrosion Inhibitor for Carbon Steel in Acidic Medium

In this study, Oregano (Origanum vulgare) leaf essential oil was studied as an environmental-friendly anticorrosion agent for carbon steel in aggressive hydrochloric acid. The corrosion inhibition of O. vulgare was characterized by surface morphology, electrochemical, weight loss, theoretical and computational methods. It was found that the highest inhibition performance of O. vulgare was 85.64% at 2 g/l in 1 M HCl. The results of Langmuir isotherm and adsorption thermodynamics investigation demonstrated that the O. vulgare inhibitor adsorbed on the metal surface by the formation of rigid covalent bonds. The adsorption and inhibition centers of the selected inhibitor were studied by the computational methods, resulting in that the hydroxyl functional groups and benzoyl rings are mainly responsible for the high inhibition efficiency.

Improvement of Physicochemical and Antibacterial Properties of Nanoemulsified Origanum vulgare Essential Oil Through Optimization of Ultrasound Processing Variables

Improvement of Physicochemical and Antibacterial Properties of Nanoemulsified Origanum vulgare Essential Oil Through Optimization of Ultrasound Processing Variables

Modulatory effect of Origanum vulgare essential oil and carvacrol on Malassezia spp. virulence factors.

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 (< 1mg/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.

Evaluation of the inhibition of strains of Candida Albicans by the essential oil of &lt;em&gt;origanum vulgare&lt;/em&gt;

Candida albicans is a yeast normally found in the human microbiota, but it is considered opportunistic, causing a pathology called candidiasis. The essential oil of oregano (Origanum vulgare) has thymol and carvacrol in its composition, compounds with proven antimicrobial and antifungal action. Thus, the present study evaluated the Minimum Inhibitory Concentration (MIC) of essential oil of oregano on the strain ATCC 90028 of Candida albicans through macro and microdilution techniques, where it showed antifungal activity in vitro. Fungal suspensions were treated with different concentrations of essential oil (100, 50, 25, 12.5, 6.25, 3.125 and 1.56 uL/mL) where it was possible to identify the MIC's of 6.250 uL/mL and 12.5 uL /mL in the macrodilution and microdilution techniques, respectively. Thus, it is concluded that the essential oil of Origanum vulgare has a promising antifungal action, especially on Candida albicans, and, therefore, potential therapeutic action.

Piperonyl butoxide synergizes the larvicidal activity of Origanum vulgare essential oil and its major constituents against the larvae of Aedes albopictus and Culex pipiens quinquefasciatus

Piperonyl butoxide synergizes the larvicidal activity of Origanum vulgare essential oil and its major constituents against the larvae of Aedes albopictus and Culex pipiens quinquefasciatus

Antibacterial activity of oregano essential oils against Streptococcus mutans in vitro and analysis of active components

BackgroundStreptococcus mutans (S. mutans) is considered the most relevant bacteria during the transition of the non-pathogenic commensal oral microbial community to plaque biofilms that promote the development of dental caries. Oregano (Origanum vulgare L.), is a universally natural flavoring and its essential oil has been demonstrated to have good antibacterial effects. However, the specific antibacterial mechanism of oregano essential oil (OEO) against S. mutans is still not completely understood.MethodsIn this work, the composition of two different OEOs was determined by GC‒MS. Disk-diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined to assess their antimicrobial effect on S. mutans. The inhibition of acid production, hydrophobicity, biofilm formation and real-time PCR for gtfB/C/D, spaP, gbpB, vicR, relA and brpA mRNA expression by S. mutans were assessed to preliminarily investigate the mechanisms of action. Molecular docking was performed to simulate the interactions with the virulence proteins and active constituents. MTT test using immortalized human keratinocytes cells was also performed to investigate cytotoxicity.ResultsCompared with the positive drug Penicillin /streptomycin 100X (DIZ: 34.13 ± 0.85 mm, MIC: 0.78125 μL/mL, MBC: 6.25 μL/mL), the essential oils of Origanum vulgare L. (DIZ: 80 mm, MIC: 0.625μL/mL, MBC:2.5μL/mL) and Origanum heracleoticum L. (DIZ: 39.67 ± 0.81 mm, MIC: 0.625μL/mL, MBC: 1.25μL/mL) could also exhibit similar effects to inhibit the acid production and reduce the hydrophobicity and biofilm formation of S. mutans at 1/2-1MIC concentration. And gene expression of gtfB/C/D, spaP, gbpB, vicR and relA were found to be downregulated. Due to the composition of essential oils from different sources being highly variable, through effective network pharmacology analysis, we found that OEOs contained many effective compounds, like carvacrol and its biosynthetic precursors γ-terpinene and p-cymene, which may directly target several virulence proteins of S. mutans. Besides, no toxic effect was instigated by OEOs at 0.1 μL/mL in the immortalized human keratinocytes cells.ConclusionThe integrated analysis in the present study suggested that OEO might be a potential antibacterial agent for the prevention of dental caries.