A Recent Insight Regarding the Phytochemistry and Bioactivity of Origanum vulgare L. Essential Oil

Comprehensive Bio-Screening of Phytochemistry and Biological Capacity of Oregano (Origanum vulgare) and Salvia triloba Extracts against Oral Cariogenic and Food-Origin Pathogenic Bacteria

This study utilized phytochemical screening to conduct the qualitative analysis of plant extracts, aiming to identify various classes of secondary metabolites. Moreover, the antibacterial activity of different types of Oregano vulgare and Salvia triloba extracts was determined. To achieve the aim of this study, aqueous, ethanolic, and enzymatic extracts were prepared and screened for phytochemical capacity and antioxidant activities. The determination of the antibacterial activity included phenotypic screening of antibiotic susceptibility pattern of oral and food pathogenic bacterial strains, determination of the minimum inhibitory concentration and minimum bactericidal concentration-via microdilution broth test and in vitro valuation of antibacterial efficacies-of the anti-biofilm properties of the studied herbal extractions. Results: Our study evaluated the phytochemical composition and the antioxidant, antibacterial, and anti-biofilm properties of O. vulgare and S. triloba extracts. The analyzed samples contained bioactive compounds, such as phenolics and flavonoids, contributing to the observed strong antioxidant effect. Furthermore, they exhibited notable activity against oral biofilm formation and demonstrated significant antibacterial efficacy against dental caries' microorganisms as well as food pathogens. Despite methodological variations, all extracts showed significant antioxidant capacity and promising antibacterial activity against various pathogens, including resistant strains, while also inhibiting biofilm formation. Although limited to two plant species and facing methodological constraints, this study lays the groundwork for future research, indicating the therapeutic potential of O. vulgare and S. triloba extracts. Further exploration is needed to report on underlying mechanisms and validate efficacy through clinical trials.

Essential oil of oregano (Origanum vulgare L.) reduces infection and proliferation of Toxoplasma gondii in BeWo cells with induction of autophagy and death of tachyzoites through a mechanism similar to necrosis

Toxoplasmosis poses a global health threat, ranging from asymptomatic cases to severe, potentially fatal manifestations, especially in immunocompromised individuals and congenital transmission. Prior research suggests that oregano essential oil (OEO) exhibits diverse biological effects, including antiparasitic activity against Toxoplasma gondii. Given concerns about current treatments, exploring new compounds is important. This study was to assess the toxicity of OEO on BeWo cells and T. gondii tachyzoites, as well as to evaluate its effectiveness in in vitro infection models and determine its direct action on free tachyzoites. OEO toxicity on BeWo cells and T. gondii tachyzoites was assessed by MTT and trypan blue methods, determining cytotoxic concentration (CC50), inhibitory concentration (IC50), and selectivity index (SI). Infection and proliferation indices were analyzed. Direct assessments of the parasite included reactive oxygen species (ROS) levels, mitochondrial membrane potential, necrosis, and apoptosis, as well as electron microscopy. Oregano oil exhibited low cytotoxicity on BeWo cells (CC50: 114.8 µg/mL ± 0.01) and reduced parasite viability (IC50 12.5 ± 0.06 µg/mL), demonstrating 9.18 times greater selectivity for parasites than BeWo cells. OEO treatment significantly decreased intracellular proliferation in infected cells by 84% after 24 h with 50 μg/mL. Mechanistic investigations revealed increased ROS levels, mitochondrial depolarization, and lipid droplet formation, linked to autophagy induction and plasma membrane permeabilization. These alterations, observed through electron microscopy, suggested a necrotic process confirmed by propidium iodide labeling. OEO treatment demonstrated anti-T. gondii action through cellular and metabolic change while maintaining low toxicity to trophoblastic cells.

Oregano Essential Oil in Livestock and Veterinary Medicine

With a growing global concern over food safety and animal welfare issues, the livestock and veterinary industries are undergoing unprecedented changes. These changes have not only brought challenges within each industry, but also brought unprecedented opportunities for development. In this context, the search for natural and safe products that can effectively replace traditional veterinary drugs has become an important research direction in the fields of animal husbandry and veterinary medicine. Oregano essential oil (OEO), as a natural extract, is gradually emerging in the fields of animal husbandry and veterinary medicine with its unique antibacterial, antioxidant, and multiple other biological activities. OEO not only has a wide antibacterial spectrum, effectively fighting against a variety of pathogenic microorganisms, but also, because of its natural properties, helps us to avoid traditional veterinary drugs that may bring drug residues or cause drug resistance problems. This indicates OEO has great application potential in animal disease treatment, animal growth promotion, and animal welfare improvement. At present, the application of OEO in the fields of animal husbandry and veterinary medicine has achieved preliminary results. Studies have shown that adding OEO to animal feed can significantly improve the growth performance and health status of animals and reduce the occurrence of disease. At the same time, pharmacokinetic studies in animals show that the absorption, distribution, metabolism, and excretion processes of OEO in animals shows good bioavailability. In summary, oregano essential oil (OEO), as a substitute for natural veterinary drugs with broad application prospects, is gradually becoming a research hotspot in the field of animal husbandry and veterinary medicine. In the future, we look forward to further tapping the potential of OEO through more research and practice and making greater contributions to the sustainable development of the livestock and veterinary industries.

Antioxidant, insecticidal, antifeedant, and repellent activities of oregano (Origanum vulgare)

This study aimed to assess the antioxidant capacity, the insecticidal, feeding deterrence, repellent effects against Tribolium confusum of the essential oil (EO) and the organic extracts (ME) of Origanum vulgare. The chemical composition of the EO revealed the presence thirty-nine components dominated by carvacrol (81%). With respect to the EO, the ME acted as a potent free radical scavenger with IC50 values of 0.127 and 0.058 mg/mL, respectively. The EO exhibited the most significant toxicity compared to the ME with a mortality of 62 and 20% at 0.08 µL/insect after 24h whereas the EO expressed the highest repellency compared to the ME with a PR of 70 and 38% after 24h. As for feeding deterrence, both samples influenced all nutritional indexes. The findings found in this work might help in the promotion of oregano as natural antioxidant, antifeedant, repellent and insecticide as an alternative to conventional harmful ones.

Lippia graveolens Essential Oil to Enhance the Effect of Imipenem against Axenic and Co-Cultures of Pseudomonas aeruginosa and Acinetobacter baumannii

This research focuses on assessing the synergistic effects of Mexican oregano (Lippia graveolens) essential oil or carvacrol when combined with the antibiotic imipenem, aiming to reduce the pathogenic viability and virulence of Acinetobacter baumannii and Pseudomonas aeruginosa. The study highlighted the synergistic effect of combining L. graveolens essential oil or carvacrol with imipenem, significantly reducing the required doses for inhibiting bacterial growth. The combination treatments drastically lowered the necessary imipenem doses, highlighting a potent enhancement in efficacy against A. baumannii and P. aeruginosa. For example, the minimum inhibitory concentrations (MIC) for the essential oil/imipenem combinations were notably low, at 0.03/0.000023 mg/mL for A. baumannii and 0.0073/0.000023 mg/mL for P. aeruginosa. Similarly, the combinations significantly inhibited biofilm formation at lower concentrations than when the components were used individually, demonstrating the strategic advantage of this approach in combating antibiotic resistance. For OXA-51, imipenem showed a relatively stable interaction during 30 ns of dynamic simulation of their interaction, indicating changes (<2 nm) in ligand positioning during this period. Carvacrol exhibited similar fluctuations to imipenem, suggesting its potential inhibition efficacy, while thymol showed significant variability, particularly at >10 ns, suggesting potential instability. With IMP-1, imipenem also displayed very stable interactions during 38 ns and demonstrated notable movement and positioning changes within the active site, indicating a more dynamic interaction. In contrast, carvacrol and thymol maintained their position within the active site only ~20 and ~15 ns, respectively. These results highlight the effectiveness of combining L. graveolens essential oil and carvacrol with imipenem in tackling the difficult-to-treat pathogens A. baumannii and P. aeruginosa.

Phytochemical Characterization and Biological Activities of Essential Oil from Satureja montana L., a Medicinal Plant Grown under the Influence of Fertilization and Planting Dates

The rising demand for safe plant compounds and herbal products that contribute positively to human health is in line with current market trends. Plants belonging to the Satureja genus, particularly the aromatic medicinal S. montana L. from the Lamiaceae family, are well suited to these trends as they serve as pharmaceutical raw materials. This research aimed to assess the influence of sowing date and fertilization doses, as well as their interaction, on the fresh weight, essential oil content, and composition of S. montana. Experimental cultivation involved varying nitrogen and phosphorus levels. The second cut had the highest fresh weight and oil production compared to the first cut. The highest total plant biomass was achieved with autumn sowing and fertilization at 55 kg N/ha and 37 kg P/ha, whereas Spring sowing exhibited higher essential oil production, with the maximum oil % with 74 kg P/ha and oil yield after applying 55 kg N/ha and 74 kg P/ha. The GC-MS analysis revealed that carvacrol was the predominant compound, with it being recommended to grow S. montana in Spring at doses of 55 kg N/ha and 74 kg P/ha for the superior oil yield. Additionally, S. montana essential oil demonstrated notable biological and antimicrobial activity, positioning it as a potential alternative to chemical food preservatives.

Therapeutic benefit of oregano oil in the acute idiosyncratic hepatotoxicity induced by carbon tetrachloride in rats: Adverse effects of high dose of oreganum

Toxicity caused by carbon tetrachloride (CCl4) can lead to serious liver injury. The aim of the study is to investigate the protective effects of oregano oil (Origanum minutiflorum extract oil) against CCl4-induced liver injury. Two doses of oregano oil were used in the experiment: a low dose (LD; 20 mg/kg) and a high dose (HD; 60 mg/kg) during 2 weeks. CCl4 caused severe liver damage, nucleolus destruction in hepatocytes and cytogenetic changes in the nucleus. Indirectly, CCl4 causes decreased protein synthesis and significantly high creatinine and urea values. Hematological disorders have been recorded, such as decreased RBC and hemoglobin concentration, increased WBC and deformability of the erythrocyte membrane. Both doses of oregano oil had protective effects. Improved protein synthesis and high globulins level, creatinine and urea were found in both groups. Cytogenetic changes in the nucleus of hepatocytes were reduced. A high dose of oregano oil had maximal protective effects for RBC, but a very weak effect on hemoglobin synthesis. Also, WBC and lymphocyte values were low. Origanum stimulates protein synthesis and recovery of hepatocytes after liver injury, reduces the deformability of the erythrocyte membrane. High doses of oregano oil decreased WBC and lymphocytes which may lead to a weakening of the immune response. However, high doses are more effective against severe platelet aggregation than low doses, suggesting an effective treatment against thrombocytosis.

Overview of Ethnobotanical-Pharmacological Studies Carried Out on Medicinal Plants from the Serra da Estrela Natural Park: Focus on Their Antidiabetic Potential

The Serra da Estrela Natural Park (NPSE) in Portugal stands out as a well-preserved region abundant in medicinal plants, particularly known for their pharmaceutical applications in diabetes prevention and treatment. This comprehensive review explores these plants' botanical diversity, traditional uses, pharmacological applications, and chemical composition. The NPSE boast a rich diversity with 138 medicinal plants across 55 families identified as traditionally and pharmacologically used against diabetes globally. Notably, the Asteraceae and Lamiaceae families are prevalent in antidiabetic applications. In vitro studies have revealed their significant inhibition of carbohydrate-metabolizing enzymes, and certain plant co-products regulate genes involved in carbohydrate metabolism and insulin secretion. In vivo trials have demonstrated antidiabetic effects, including glycaemia regulation, insulin secretion, antioxidant activity, and lipid profile modulation. Medicinal plants in NPSE exhibit various activities beyond antidiabetic, such as antioxidant, anti-inflammatory, antibacterial, anti-cancer, and more. Chemical analyses have identified over fifty compounds like phenolic acids, flavonoids, terpenoids, and polysaccharides responsible for their efficacy against diabetes. These findings underscore the potential of NPSE medicinal plants as antidiabetic candidates, urging further research to develop effective plant-based antidiabetic drugs, beverages, and supplements.

Effects of Supplementation with Oregano Essential Oil during Late Gestation and Lactation on Serum Metabolites, Antioxidant Capacity and Fecal Microbiota of Sows

A total of 20 healthy white × landrace sows were evenly and randomly divided into two groups, and fed basal diets unsupplemented or supplemented with 500 g/t Meriden-Stim® from day 100 of gestation until day 21 of lactation. Serum and fecal samples were collected from the sows on the final day for subsequent analysis. Compared to the control group, there were no significant differences in the sows' performances; however, an increase was observed in the piglets' weight at weaning (p = 0.08). Moreover, oregano essential oil (OEO) significantly reduced the levels of urea (UREA) (p < 0.01), total cholesterol (TC) (p < 0.05), low-density lipoprotein (LDL-C) (p < 0.05) and alanine aminotransferase (ALT) (p < 0.05) in serum. In terms of antioxidant indexes in serum, the catalase (CAT) and glutathione (GSH) levels showed significant increases (p < 0.05) while the malondialdehyde (MDA) level exhibited a decrease tendency (p = 0.09). 16S rRNA analysis identified the specific bacteria taxa in feces. OEO significantly decreased the relative abundance of Proteobacteria and Actinobacteria at the phylum level (p < 0.05). At the genus level, OEO significantly increased the relative abundance of Lactobacillus and Prevotellaceae UCG 003 and UCG 005, while decreasing that of Escherichia-Shigella (p < 0.05). Taken together, OEO supplementation in maternal diets during late gestation and lactation improved serum metabolites, antioxidant capacity and regulated the intestinal-flora balance of sows, thereby tending to increase the piglets' weight at weaning.

Cytotoxic Effect Induced by Sicilian Oregano Essential Oil in Human Breast Cancer Cells

Origanum vulgare L. is an aromatic plant that exerts antibacterial, antioxidant, anti-inflammatory, and antitumor activities, mainly due to its essential oil (EO) content. In this study, we investigated the possible mechanism underlying the in vitro antitumor activity of EO extracted by hydrodistillation of dried flowers and leaves of Origanum vulgare L. grown in Sicily (Italy) in MDA-MB-231 and MCF-7 breast cancer cell lines. Gas chromatography-mass spectrometry analysis of Oregano essential oil (OEO) composition highlighted the presence of twenty-six major phytocompounds, such as p-cymene, γ-terpinene, and thymoquinone p-acetanisole. OEO possesses strong antioxidant capacity, as demonstrated by the DPPH test. Our studies provided evidence that OEO reduces the viability of both MCF-7 and MDA-MB-231 cells. The cytotoxic effect of OEO on breast cancer cells was partially counteracted by the addition of z-VAD-fmk, a general caspase inhibitor. Caspases and mitochondrial dysfunction appeared to be involved in the OEO-induced death mechanism. Western blotting analysis showed that OEO-induced activation of pro-caspases-9 and -3 and fragmentation of PARP decreased the levels of Bcl-2 and Bcl-xL while increasing those of Bax and VDAC. In addition, fluorescence microscopy and cytofluorimetric analysis showed that OEO induces a loss of mitochondrial membrane potential in both cell lines. Furthermore, we tested the effects of p-cymene, γ-terpinene, thymoquinone, and p-acetanisole, which are the main components of OEO. Our findings highlighted that the effect of OEO on MDA-MB-231 and MCF-7 cells appears to be mainly due to the combination of different constituents of OEO, providing evidence of the potential use of OEO for breast cancer treatment.

Effects of Essential Oil and/or Encapsulated Butyrate on Fecal Microflora in Neonatal Holstein Calves

This study was conducted to investigate the effects of feeding oregano essential oil, butyrate, and its mixture on the intestinal microbial diversity of calves. A completely randomized experimental design was used. Sixty-four healthy neonatal Holstein female calves with birth weight ≥ 35 kg were randomly divided into one control and three treatments (16 calves per group). The control group was fed normally, and the treatment group was fed oregano essential oil, butyrate, and their mixture, respectively. The experiment lasted for 70 days, and the lactation period lasted for 56 days. On days 55 and 70, rectal fecal samples from five calves were collected from each group for 16S rRNA amplification and sequencing. The results showed as follows: (1) the three treatments had no significant effects on the intestinal microbial community diversity, community uniformity, and community pedigree diversity of calves (p > 0.05). (2) At the phylum level, Firmicutes, Bacteroidota, Spriochatetota, Actinobacteriota, Firmicutes, and Bacteroidota gates of the main bacteria were detected in feces. (3) At the genus level, the top ten species with relative abundance detected are: norank_ F_Muribaaculaceae, Ruminococcus, unclassified_ F_ Lachnospiraceae, UCG-005, Prevotelaceae_NK3B31_Group, Prevotella, Bacteroides, Rikenellaceae_RC9_Gut_Group, and Faecalibacterium, Alloprevotella. (4) LEfSe analysis results show that the species with significant differences in the control group were f__Lachnospiraceae, o__Lachnospirales, o__Coriobacteriales, and c__Coriobacteriia, g__Megasphaera; in the essential oil group were g__Lachnospiraceae_AC2044_group, o__Izemoplasmatales, g__norank_f__norank_o__Izemoplasmatales, and f__norank_o__Izemoplasmatales; in the sodium butyrate group were g__Lachnospiraceae_NK4A136_group, and g__Sharpea, g__Fournierella; in the mixed group were g__Flavonifractor, and g__UBA1819. (5) The functional prediction analysis of calf gut microbes, found on the KEGG pathway2, shows that essential oil significantly improved membrane transport, Sodium butyrate inhibits lipid metabolism and improves the body's resistance to disease. (p < 0.05). (6) The effects of each treatment on the intestinal microbial structure of calves did not last for 14 days after the treatment was stopped. In conclusion, the addition of oregano essential oil, butyrate, and its mixtures to milk fed to calves can modulate the microbial structure, and it is recommended that oregano essential oil and butyrate be used separately, as a mixture of the two can increase the rate of diarrhea in calves.

A review of the bioactive properties of Mongolian plants, with a focus on their potential as natural food preservatives

Consumers have recently preferred food that is easy to make and of excellent quality, as well as food that is safe, natural, and minimally processed, but has a longer shelf life. Food deteriorates over time as a result of microbiological, chemical, or physical changes. Phytochemicals derived from medicinal and food plants have long been recognized for their biological activity to protect plants. These bioactivities are designed to increase the shelf life of food while inhibiting the growth of microorganisms. The use of natural plant food preservatives containing bioactive compounds as health-promoting agents is particularly intriguing. Furthermore, due to their effectiveness against food spoilage and foodborne pathogens, natural plant-origin antimicrobial compounds have been investigated as alternatives to synthetic antimicrobial compounds for preserving food quality. This review focused on the plant composition and properties that can be utilized as a natural food preservative, as well as the possibilities of using Mongolian medicinal plants.

Chemical Composition, Antibacterial and Antibiofilm Actions of Oregano (Origanum vulgare subsp. hirtum) Essential Oil against Salmonella Typhimurium and Listeria monocytogenes

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.

Stability Profile and Clinical Evaluation of an Innovative Hydrogel Containing Polymeric Micelles as Drug Delivery Systems with Oregano Essential Oil against Fibroepithelial Polyps

Skin tags, also known as fibroepithelial polyps (FPs) or acrochordons, are soft, pigmented excrescences, with a prevalence of 50-60% in the population, occurring especially in the fourth decade of life. To date, FPs have been efficiently eliminated using minimum invasive methods such as surgical removal, cauterization, laser irradiation, and cryosurgery. Over-the-counter treatments are also of interest for patients due to their non-invasive character, but their clinical efficiency has not been clearly demonstrated. This study was designed in order to evaluate the efficacy of a modern-pharmaceutical-formulation-type poloxamer-based binary hydrogel, having Origanum vulgare L. essential oil (OEO-PbH) as an active ingredient in the management of FPs. The formulation has been shown to possess good qualities in terms of stability and sterility. Non-invasive measurements revealed changes in some physiological skin parameters. An increase in transepidermal water loss (TEWL) and erythema index was noted, while skin surface water content (SWC) decreased during eight weeks of treatment. The macroscopic evaluation revealed that the FPs dried and shrunk after topical treatment with OEO-PbH. Clinically, patients presented a lowering of the number of lesions on the treated area of 20-30% after one month of treatment and around 50% after the second month. Histopathological examination suggests that topical treatment with OEO-PbH may induce histological changes in the epidermis, dermis, and fibrovascular cores of FPs, including a loss of thickness, reduced size and number of blood vessels, and low cellularity. These changes may contribute to the observed reduction in size of FPs after treatment with OEO-PbH.

Cutaneous Polymeric-Micelles-Based Hydrogel Containing Origanum vulgare L. Essential Oil: In Vitro Release and Permeation, Angiogenesis, and Safety Profile In Ovo

Origanum vulgare var. vulgare essential oil (OEO) is known as a natural product with multiple beneficial effects with application in dermatology. Oregano essential oil represents a potential natural therapeutic alternative for fibroepithelial polyps (FPs), commonly known as skin tags. Innovative formulations have been developed to improve the bioavailability and stability of essential oils. In this study, we aimed to evaluate the morphology of a polymeric-micelles-based hydrogel (OEO-PbH), the release and permeation profile of oregano essential oil, as well as to assess in vivo the potential effects on the degree of biocompatibility and the impact on angiogenesis in ovo, using a chick chorioallantoic membrane (CAM). Scanning electron microscopy (SEM) analysis indicated a regular aspect after the encapsulation process, while in vitro release studies showed a sustained release of the essential oil. None of the tested samples induced any irritation on the CAM and the limitation of the angiogenic process was noted. OEO-PbH, with a sustained release of OEO, potentially enhances the anti-angiogenic effect while being well tolerated and non-irritative by the vascularized CAM, especially on the blood vessels (BVs) in the presence of leptin treatment. This is the first evidence of in vivo antiangiogenic effects of a polymeric-micelle-loaded oregano essential oil, with further mechanistic insights for OEO-PbH formulation, involving leptin as a possible target. The findings suggest that the OEO-containing polymeric micelle hydrogel represents a potential future approach in the pathology of cutaneous FP and other angiogenesis-related conditions.

Synergistic Antileishmanial Effect of Oregano Essential Oil and Silver Nanoparticles: Mechanisms of Action on Leishmania amazonensis

American tegumentary leishmaniasis, a zoonotic disease caused by the Leishmania genus, poses significant challenges in treatment, including administration difficulty, low efficacy, and parasite resistance. Novel compounds or associations offer alternative therapies, and natural products such as oregano essential oil (OEO), extracted from Origanum vulgare, have been extensively researched due to biological effects, including antibacterial, antifungal, and antiparasitic properties. Silver nanoparticles (AgNp), a nanomaterial with compelling antimicrobial and antiparasitic activity, have been shown to exhibit potent leishmanicidal properties. We evaluated the in vitro effect of OEO and AgNp-Bio association on L. amazonensis and the death mechanisms of the parasite involved. Our results demonstrated a synergistic antileishmanial effect of OEO + AgNp on promastigote forms and L. amazonensis-infected macrophages, which induced morphological and ultrastructural changes in promastigotes. Subsequently, we investigated the mechanisms underlying parasite death and showed an increase in NO, ROS, mitochondrial depolarization, accumulation of lipid-storage bodies, autophagic vacuoles, phosphatidylserine exposure, and damage to the plasma membrane. Moreover, the association resulted in a reduction in the percentage of infected cells and the number of amastigotes per macrophage. In conclusion, our findings establish that OEO + AgNp elicits a late apoptosis-like mechanism to combat promastigote forms and promotes ROS and NO production in infected macrophages to target intracellular amastigote forms.

A GC-MS and LC-HRMS perspective on the chemotaxonomic investigation of the natural hybrid Origanum × lirium and its parents, O. vulgare subsp. hirtum and O. scabrum

INTRODUCTION

The genus Origanum L. (Lamiaceae) is widespread in the Mediterranean region. However, approximately 75% of the species are only encountered in the eastern part. Out of these, a total of nine species (11 taxa) and three natural hybrids occur in Greece. Nevertheless, so far, there is no consensus regarding their precise botanical classification in the literature. In fact, the taxon Origanum × lirium has been proposed both as a separate species as well as natural hybrid between Origanum vulgare subsp. hirtum and Origanum scabrum.

OBJECTIVES

In this scope, the aim of the current study is to shed light on the matter through the investigation of the chemical composition of both the essential oils and the polar extracts of the mentioned taxa, collected from different geographical regions of Greece.

RESULTS

As it was demonstrated by both gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-high-resolution mass spectrometry (LC-HRMS) data, and highlighted by our comparative analysis, it can be stipulated that Origanum × lirium shares its chemotype to a large extent with its parent species concerning both volatile and polar constituents. Additionally, geographical origin conditions stood out as a key factor influencing their chemical composition.

CONCLUSION

Altogether, the present work provides useful information on the chemical composition of the taxa under investigation, while our findings support the opinion that Origanum × lirium should be considered not as a separate species, but rather as a hybrid on the way to becoming a species.

Unravelling the Chemotaxonomic Identity of "White" and "Black" Oregano (Origanum vulgare) in Northern Greece

The two types of oregano used by the inhabitants of the villages of Μount Belles (GR1260001), the "white" oregano with white flowers and "black" oregano with purple flowers, were studied. The two oregano types were collected from five localities along an altitudinal gradient from 217 m up to 1299 m. "White" oregano, was found in the three lowland regions (up to 752 m) where the Pannonian-Balkanic turkey oak-sessile oak forest habitat (code 91M0) dominates. The "black" oregano was collected from the two higher altitudes, at 1177 m and 1299 m, where the Asperulo-Fagetum beech forest habitat (9130) occurs. Measurements of the density and size of peltate glandular hairs (sessile glands) on calyces, bracts, and leaves suggest that "white" oregano is distinguished by its conspicuous - apparently larger - glands. These differences were reflected in the total essential oil content, with the "white" oregano being much richer (up to 4.3 mL/100 g dry weight) than the "black" (up to 0.6%). Striking differences have also been found in the volatile fraction of their essential oil composition. The "white" oregano oils were characterized by the high content of carvacrol (up to 92.6% of identified peaks, by Headspace GC-MS). On the other hand, the two "black" oregano oils have a different aromatic profile, first reported from Greece, with main components including the sesquiterpenes β-caryophyllene, D-germacrene, δ-cadinene and β-bisabolene. The results so far indicate that "white" and "black" oregano, Origanum vulgare subsp. hirtum and subsp. vulgare respectively, can be clearly distinguished either by their morphological (glandular) differences or by chemical (essential oil) composition.

Essential Oils Distilled from Colombian Aromatic Plants and Their Constituents as Penetration Enhancers for Transdermal Drug Delivery

The study aimed to determine the enhanced effects of essential oils (EOs) and plant-derived molecules (PDMs) as penetration enhancers (PEs) for transdermal drug delivery (TDD) of caffeine. A 1% w/w solution of eight EOs and seven PDMs was included in the 1% caffeine carbopol hydrogel. Franz diffusion cell experiments were performed using mice with full-thickness skin. At various times over 24 h, 300 μL of the receptor were withdrawn and replaced with fresh medium. Caffeine was analyzed spectrophotometrically at 272 nm. The skin irritation effects of the hydrogels applied once a day for 21 days were investigated in mice. The steady-state flux (J_SS) of the caffeine hydrogel was 30 ± 19.6 µg cm^-2 h^-1. An increase in caffeine J_SS was induced by Lippia origanoides > Turnera diffusa > eugenol > carvacrol > limonene, with values of 150 ± 14.1, 130 ± 47.6, 101 ± 21.7, 90 ± 18.4, and 86 ± 21.0 µg cm^-2 h^-1, respectively. The Kp of caffeine was 2.8 ± 0.26 cm h^-1, almost 2-4 times lower than that induced by Lippia origanoides > Turnera diffusa > limonene > eugenol > carvacrol, with Kp values of 11 ± 1.7, 8.8 ± 4.2, 6.8 ± 1.7, 6.3 ± 1.2, and 5.15 ± 1.0 cm h^-1, respectively. No irritating effects were observed. Lippia origanoides, Turnera diffusa, eugenol, carvacrol, and limonene improved caffeine's skin permeation. These compounds may be as effective as the PE in TDD systems.

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

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.

Impact of heat priming on heat shock responses in Origanum vulgare: Enhanced foliage photosynthetic tolerance and biphasic emissions of volatiles

Climate change enhances the frequency of heatwaves that negatively affect photosynthesis and can alter constitutive volatile emissions and elicit emissions of stress volatiles, but how pre-exposure to mildly warmer temperatures affects plant physiological responses to subsequent severe heat episodes remains unclear, especially for aromatic plants with high and complex volatile defenses. We studied the impact of heat shock (45 °C/5 min) applied alone and after exposure to moderate heat stress (35 °C/1 h, priming) on foliage photosynthesis and volatile emissions in the aromatic plant Origanum vulgare through 72 h recovery period. Heat stress decreased photosynthesis rates and stomatal conductance, whereas the reductions in photosynthesis were primarily due to non-stomatal factors. In non-primed plants, heat shock-induced reductions in photosynthetic activity were the greatest, but photosynthetic activity completely recovered by the end of the experiment. In primed plants, a certain inhibition of photosynthetic activity remained, suggesting a sustained priming effect. Heat shock enhanced the emissions of volatiles including lipoxygenase pathway volatiles, long-chained fatty acid-derived compounds, mono- and sesquiterpenes, geranylgeranyl diphosphate pathway volatiles, and benzenoids, whereas different heat treatments resulted in unique emission blends. In non-primed plants, stress-elicited emissions recovered at 72 h. In primed plants, volatile emissions were multiphasic, the first phase, between 0.5 and 10 h, reflected the primary stress response, whereas the secondary rise, between 24 and 72 h, indicated activations of different defense metabolic pathways. Our results demonstrate that exposure to mild heat leads to a sustained physiological stress memory that enhances plant resistance to subsequent severe heat stress episodes.

Exploring Iberian Peninsula Lamiaceae as Potential Therapeutic Approaches in Wound Healing

Skin tissue has a crucial role in protecting the human body from external harmful agents, preventing wounds that frequently demand proper healing approaches. The ethnobotanical knowledge of specific regions with further investigation on their medicinal plants has been paramount to create new and effective therapeutical agents, including for dermatological purposes. This review attempts, for the first time, to investigate the traditional applications of Lamiaceae medicinal plants that are already used by local communities in the Iberian Peninsula in wound healing. Henceforward, Iberian ethnobotanical surveys were reviewed, and the information about the traditional wound healing practices of Lamiaceae was comprehensively summarized. Afterwards, the scientific validation of each Lamiaceae species was exhaustively checked. From this, eight out of twenty-nine Lamiaceae medicinal plants were highlighted by their wound-related pharmacological evidence and are in-depth presented in this review. We suggest that future studies should focus on the isolation and identification of the active molecules of these Lamiaceae, followed by robust clinical trials that may confirm the security and effectiveness of such natural-based approaches. This will in turn pave the way for more reliable wound healing treatments.

Phytochemical Composition and Insight into Antibacterial Potential of Origanum vulgare Essential Oil from Saudi Arabia Using In Vitro and In Silico Approaches

In Saudi Arabia, Origanum vulgare is widely disseminated. In the present work, we used GC-MS analysis to identify the components of Origanum vulgare essential oil. The disc diffusion assay was used to assess the essential oil’s in vitro antibacterial efficacy against Gram-positive and Gram-negative Staphylococcus aureus and Escherichia coli. The antimicrobial efficacy against many microbial proteins, including tyrosyl-tRNA synthetase (TyrRS), DNA gyrase, and dihydrofolate reductase (DHFR), was further evaluated using molecular docking. Eighteen compounds were identified using GC-MS analysis, which constituted 99.81% of the total essential oil content. Terpinen-4-ol (34.3%), Beta-Terpineol (16.96%), 3-Epimoretenol (11.84%), and Alpha-Terpineol (3.86%) were the main substances identified. According to the antibacterial investigation, the inhibition zone against Staphylococcus aureus was 8 mm and 6 mm against Escherichia coli. High affinities were found between 3-Epimoretenol and tyrosyl-tRNA synthetase (TyrRS) and dihydrofolate reductase (DHFR) compared to positive controls (Clorobiocin, SCHEMBL2181345); the affinity values were −8.3 Kcal/mol and −9.2, respectively. The results of the present study indicate that Origanum vulgare essential oil can be used as a nutraceutical to treat infectious diseases.

Mediterranean Diet: The Role of Phenolic Compounds from Aromatic Plant Foods

Today's global food system aggravates climate change while failing in meeting SDG2 and more. Yet, some sustainable food cultures, such as the Mediterranean Diet (MD), are simultaneously safe, healthy, and rooted in biodiversity. Their wide range of fruits, herbs, and vegetables convey many bioactive compounds, often associated with colour, texture, and aroma. Phenolic compounds are largely responsible for such features of MD's foods. These plant secondary metabolites all share in vitro bioactivities (e.g., antioxidants), and some are evidenced in vivo (e.g., plant sterols lower cholesterol levels in blood). The present work examines the role of polyphenols in the MD, with respect to human and planetary health. Since the commercial interest in polyphenols is increasing, a strategy for the sustainable exploitation of Mediterranean plants is essential in preserving species at risk while valuing local cultivars (e.g., through the geographical indication mechanism). Finally, the linkage of food habits with cultural landscapes, a cornerstone of the MD, should enable awareness-raising about seasonality, endemism, and other natural constraints to ensure the sustainable exploitation of Mediterranean plants.

Targeting lipid metabolism with natural products: A novel strategy for gastrointestinal cancer therapy

Gastrointestinal cancer (GIC), including gastric cancer and colorectal cancer, is a common malignant tumor originating from gastrointestinal epithelial cells. Although the pathogenesis of GIC remains unclear, aberrant lipid metabolism has emerged as a hallmark of cancer. Several enzymes, proteins, and transcription factors are involved in lipid metabolism reprogramming in GIC, and their abnormal expression can promote lipid synthesis and accumulation of lipid droplets through numerous mechanisms, thereby affecting the growth, proliferation, and metastasis of GIC cells. Studies show that some natural compounds, including flavonoids, alkaloids, and saponins, can inhibit the de novo synthesis of lipids in GIC, reduce the level of lipid accumulation, and subsequently, inhibit the occurrence and development of GIC by regulating Sterol regulatory element-binding protein 1 (SREBP-1), adenosine monophosphate-activated protein kinase (AMPK), 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), phosphatidylinositol-3-kinase/Akt and the mammalian target of rapamycin PI3K/Akt/mTOR, amongst other targets and pathways. Therefore, targeting tumor lipid metabolism is the focus of anti-gastrointestinal tumor therapy. Although most natural products require further high-quality studies to firmly establish their clinical efficacy, we review the potential of natural products in the treatment of GIC and summarize the application prospect of lipid metabolism as a new target for the treatment of GIC, hoping to provide a reference for drug development for gastrointestinal tumors.

Essential Oils from Origanum vulgare subsp. virens (Hoffmanns. & Link) Ietsw. Grown in Portugal: Chemical Diversity and Relevance of Chemical Descriptors

Origanum vulgare L. is a well-known aromatic and medicinal plant, whose essential oil (EO) has recognised flavouring and medicinal properties. In this study, Origanum vulgare subsp. virens (Hoffmanns. & Link) Ietsw. EOs, isolated from accessions grown in experimental fields, were evaluated. The plant material was grown from rooted cuttings or nutlets (fruits), originally collected in 20 regions in mainland Portugal and harvesting for EO isolation was performed in two years. EOs were isolated by hydrodistillation and analysed by gas chromatography and gas chromatography-mass spectrometry, for EO quantification and identification, respectively. EO yields ranged from <0.05-3.3% for rooted cuttings, with oregano samples obtained in Portalegre and Alandroal, respectively. Ninety-one compounds were identified, mainly grouped in oxygen-containing monoterpenes and monoterpene hydrocarbons. EO agglomerative cluster analysis evidenced two main clusters, with the first subdivided into four subclusters. From the obtained data, the putative O. vulgare subsp. virens chemotypes are carvacrol, thymol and linalool, with γ-terpinene, p-cymene, cis- and trans-β-ocimene also contributing as these EOs chemical descriptors. The comparison between the present data and a survey of the existing literature on Portuguese O. vulgare reinforces the major variability of this species' EOs and emphasises the importance of avoiding wild collections to obtain a defined chemical type of crop production of market relevance.

Evaluation of the antimicrobial effect of the Origanum vulgare L essential oil on strains of Klebsiella pneumoniae

Bacteria may be the initial cause of certain pathologies as well as a secondary agent responsible for the development of complications such as pressure ulcer infections. Pressure ulcers are a persistent health problem, especially in immunocompromised patients, and associated with infection by opportunistic microorganisms with antimicrobial resistance, such as Klebsiella pneumoniae, highlight the need for the development of new antimicrobial approaches. Thus, the aim of this study was to evaluate the antibacterial and anti-adherent activity of Origanum vulgare L. (oregano) essential oil against Klebsiella pneumoniae strains, as well as the effect of its association with synthetic antimicrobials. To this end, the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) analyses were performed on microdilution plates. The assay of the Minimum Inhibitory Adherence Concentration (MIAC), with test tubes. As well as, the association study through the infusion disc method containing ampicillin (AMP), gentamicin (GEN), ciprofloxacin (CIP) and ceftriaxone (CEF). Therefore, it was possible to obtain that the essential oil of oregano presents antimicrobial and bactericidal activity, with MIC ranging between 128μg/mL and 256 μg/mL and MBC between 256 μg/mL and 512 μg/mL, on the tested K. pneumoniae strains. When used in association with ampicillin and gentamicin, oregano essential oil showed synergistic effect for some strains. Therefore, it is observed that the tested essential oil can act as a promising antibacterial in the treatment of diseases caused by K. pneumoniae.

Effect of Agrimonia eupatoria L. and Origanum vulgare L. Leaf, Flower, Stem, and Root Extracts on the Survival of Pseudomonas aeruginosa

Pseudomonas aeruginosa is one of the most antibiotic multi-resistant bacteria, causing chronic pulmonary disease and leading to respiratory failure and even mortality. Thus, there has been an ever-increasing search for novel and preferably natural antimicrobial compounds. Agrimonia eupatoria L. and Origanum vulgare L. shoots are commonly used as teas or alcoholic tinctures for their human health-promoting and antibacterial properties. Here, we explored the antimicrobial effects of all plant parts, i.e., leaf, flower, stem, and root extracts, prepared in water or in 60% ethanol, against P. aeruginosa. The impact of these extracts on bacterial survival was determined using a luminescent strain of P. aeruginosa, which emits light when alive. In addition, the antimicrobial effects were compared with the antioxidant properties and content of phenolic compounds of plant extracts. Ethanolic extracts of O. vulgare roots and flowers showed the highest antimicrobial activity, followed by A. eupatoria roots. In particular, chlorogenic acid, the ethanolic extract of O. vulgare roots contained high levels of protocatechuic acid, hesperidin, shikimic acid, rutin, quercetin, and morin. The synergistic effects of these phenolic compounds and flavonoids may play a key role in the antibacterial activity of teas and tinctures.

Optimizing the Distillation of Greek Oregano-Do Process Parameters Affect Bioactive Aroma Constituents and In Vitro Antioxidant Activity?

The aim of the present work was to optimize the conditions of the distillation process at a pilot scale to maximize the yield of specific bioactive compounds of the essential oil of oregano cultivated in Greece, and subsequently to study the in vitro antioxidant activity of these oils. Steam distillation was conducted at an industrial distillery and a Face-Centered Composite (FCC) experimental design was applied by utilizing three distillation factors: time, steam pressure and temperature. Essential oil composition was determined by static headspace gas chromatography-mass spectrometry (HS-GC/MS). To obtain a comprehensive profile of the essential oils, instrumental parameters were optimized, including sample preparation, incubation conditions, sampling process, injection parameters, column thermal gradient and MS conditions. With the applied GC-MS method, more than 20 volatile compounds were identified in the headspace of the oregano essential oils and their relative percentages were recorded. Carvacrol was the most prominent constituent under all distillation conditions applied. Data processing revealed time as the main factor which most affected the yield. The Desired Space (DSc) was determined by conducting a three-dimensional response surface analysis of the independent and dependent variables, choosing yields of thymol and carvacrol as optimization criteria. The in vitro antioxidant activity of the essential oils of all samples was measured in terms of the interaction with the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) after 20 and 60 min. The most prominent essential oils at different distillation conditions were also tested as inhibitors of lipid peroxidation. Higher % values of carvacrol and thymol were correlated to higher antioxidant activity. Evaluating the impact of the distillation conditions on the in vitro results, it seems that lower pressure, less time and higher temperature are crucial for enhanced antioxidant activities.

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

There is currently no use for the vast quantities of post-distillation by-products, such as spent plant materials and residual waters, produced by the essential oil (EO) industry of aromatic herbs. In this study, the EOs of three Lamiaceae species (thyme, oregano, and basil) and their total, spent, and residual water extracts were phytochemically characterized and biologically assessed. The collected information was put through a series of analyses, including principal component analysis, heatmap analysis, and Pearson correlation analysis. Concerning the EOs, 58 volatile compounds were present in thyme (e.g., p-cymene, thymol), 44 compounds in oregano (e.g., thymol, carvacrol), and 67 compounds in basil (e.g., eucalyptol, linalool, estragole, (E)-methyl cinnamate). The LC-HRMS/MS analysis of the total, spent, and residual water extracts showed the presence of 31 compounds in thyme (e.g., quercetin-O-hexoside, pebrellin, eriodictyol), 31 compounds in oregano (e.g., rosmarinic acid, apigenin, kaempferol, salvianolic acids I, B, and E), and 25 compounds in basil (e.g., fertaric acid, cichoric acid, caftaric acid, salvianolic acid A). The EOs of the three Lamiaceae species showed the highest metal-reducing properties (up to 1792.32 mg TE/g in the CUPRAC assay), whereas the spent extracts of oregano and basil displayed very high radical-scavenging properties (up to 266.59 mg TE/g in DPPH assay). All extracts exhibited anti-acetylcholinesterase (up to 3.29 mg GALAE/g), anti-tyrosinase (up to 70.00 mg KAE/g), anti-amylase (up to 0.66 mmol ACAE/g), and anti-glucosidase (up to 1.22 mmol ACAE/g) effects. Thus, the present research demonstrated that both the raw extracts (EOs and total extracts) and the post-distillation by-products (spent material and residual water extracts) are rich in bioactive metabolites with antioxidant and enzyme inhibitory properties.

Essential Oils in the Treatment of Various Types of Acne-A Review

Acne is a chronic, common disease that poses a significant therapeutic, psychological and social problem. The etiopathogenesis of this disease is not fully understood. Drugs used in general and external therapy should have anti-seborrhoeic, anticomadogenic, bactericidal, bacteriostatic, and anti-inflammatory properties. Acne treatment is often associated with the long-term use of antibiotics, contributing to the global antibiotic resistance crisis. In order to solve this problem, attention has been paid to essential oils and their terpene components with potent antimicrobial, anti-inflammatory, and antioxidant properties. Research shows that certain essential oils effectively reduce inflammatory acne lesions through mechanisms related to the sebaceous glands, colonization of Cutibacterium acnes, and reactive oxygen species (ROS). An example is tea tree oil (TTO), a more commonly used topical agent for treating acne. TTO has antimicrobial and anti-inflammatory activity. The paper presents the latest scientific information on the activity and potential use of specific essential oils in treating acne. Evidence of antibacterial, anti-inflammatory, and antioxidant activity of several essential oils and their main components was presented, indicating the possibility of using them in the treatment of acne.

"In vivo" and "in vitro" antimicrobial activity of Origanum vulgare essential oil and its two phenolic compounds on clinical isolates of Candida spp

A limited therapeutic arsenal is currently available against Candida infections that show high resistance to antifungal agents. For this reason, there is a great need to prioritize testing therapeutic agents for the treatment of candidiasis. The use of essential oils and their phytoconstituents has been emphasized as a new therapeutic approach. The cell surface hydrophobicity (CSH), polysaccharide content, antimicrobial activity of essential oil from Origanum vulgare L. (OVEO), and its two phenolic compounds carvacrol and thymol were evaluated in four different Candida spp. (Candida albicans and emerging non-albicans Candida (NAC) species, such as C. glabrata, C. tropicalis, and C. krusei). The results showed the differences between Candida species; for example, C. tropicalis revealed higher resistance than other strains to different natural molecule treatments. The ultrastructural variabilities in the biomembranes and cell walls of these Candida spp. might explain the different biological effects observed after OVEO, carvacrol and thymol treatments. Therefore, to study the biological effects of these natural compounds on Candida strains, the samples were observed by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Moreover, the release of cellular materials and their "in vivo" antimicrobial activity on infected G. mellonella larvae were evaluated. The novelty of this study is the demonstration that exists a close correlation between both structural architecture of cell walls and biomembranes' organization with cell fungal responses to essential oils treatments. Overall, these results suggest practical limits to the predictability.

Phytochemical Characterization and Biological Evaluation of Origanum vulgare L. Essential Oil Formulated as Polymeric Micelles Drug Delivery Systems

This study presents phytochemical characterization and biological evaluation of Origanum vulgare L. essential oil (OEO) formulated as polymeric micelles drug delivery systems as a possible non-invasive approach for the management of skin tags. GC-MS analysis of Romanian OEO revealed the identification and quantification of 43 volatile compounds (thymol and carvacrol being the main ones). The antioxidant activity was shown by four consecrated methods: CUPRAC, ABTS, ORAC and DPPH. OEO was incorporated by micellar solubilization into a binary hydrogel based on a Pluronic F 127/L 31 block-copolymers mixture. The pH, consistency, spreadability, particle size, polydispersity index and zeta potential of the OEO-loaded poloxamer-based binary hydrogel (OEO-PbH) were investigated. OEO-PbH was skin compatible in terms of pH and exhibited adequate spreadability and consistency. The minimal inhibitory concentrations of the tested OEO were similar to those obtained for the formulation, lower (2.5 µg/mL) for yeast and higher (40-80 µg/mL) for Gram-negative bacilli. As keratinocytes are among main components of skin tags, an in vitro evaluation was conducted in order to see the effect of the formulation against HaCaT human keratinocytes. OEO-PbH decreased HaCaT cells migration and proliferation and elicited a cytotoxic and pro-apoptotic effect in a dose- and time-dependent manner. No harmful effect on the viability of dendritic cells (DCs) was detected following the incubation with different concentrations (0-200 µg/mL) of the 5% formulation. Treatment in inflammatory DCs (+LPS) indicated a decrease in cytokine production of IL-6, TNF-α and IL-23 but no significant effect on IL-10 in any of the tested concentrations.

Antibiotic properties of Satureja montana L. hydrolate in bacteria and fungus of clinical interest and its impact in non-target environmental microorganisms

The aim of this study was to analyse the microbicidal and microbiostatic activity of S. montana hydrolate L., the water-soluble fraction of the hydro-distillation process used to obtain the essential oil, on 14 Gram-positive and Gram-negative bacteria and a fungus of clinical interest. To consider whether this hydrolate is a more environmentally friendly alternative to traditional antibiotics, its effect on non-target microorganisms in the aquatic and terrestrial environment was analysed using natural soil and river microorganism communities, characterized through 16S rRNA gene sequencing. Results showed that S. montana hydrolate was especially effective (25% v/v concentration) against Pasteurella aerogenes, Streptococcus agalactiae and Acinetobacter baumannii (priority 1, WHO). It was also a microbicide for a further 7 bacterial strains and the fungus Candida albicans (50% v/v concentration). The river and soil communities exposed to the hydrolate showed a decrease in their growth, as well as a decrease in their ability to metabolize polymers and carbohydrates (soil microorganisms) and polymers, carboxylic and ketone acids (river microorganisms). Hydrolates could be an alternative to conventional antibiotics, but their impact on the environment must be taken into account.

Endophytic Bacteria Associated with Origanum heracleoticum L. (Lamiaceae) Seeds

Seed-associated microbiota are believed to play a crucial role in seed germination, seedling establishment, and plant growth and fitness stimulation, due to the vertical transmission of a core microbiota from seeds to the next generations. It might be hypothesized that medicinal and aromatic plants could use the seeds as vectors to vertically transfer beneficial endophytes, providing plants with metabolic pathways that could influence phytochemicals production. Here, we investigated the localization, the structure and the composition of the bacterial endophytic population that resides in Origanum heracleoticum L. seeds. Endocellular bacteria, surrounded by a wall, were localized close to the aleurone layer when using light and transmission electron microscopy. From surface-sterilized seeds, cultivable endophytes were isolated and characterized through RAPD analysis and 16S RNA gene sequencing, which revealed the existence of a high degree of biodiversity at the strain level and the predominance of the genus Pseudomonas. Most of the isolates grew in the presence of six selected antibiotics and were able to inhibit the growth of clinical and environmental strains that belong to the Burkholderia cepacia complex. The endophytes production of antimicrobial compounds could suggest their involvement in plant secondary metabolites production and might pave the way to endophytes exploitation in the pharmaceutical field.

Alpha-Phellandrene and Alpha-Phellandrene-Rich Essential Oils: A Systematic Review of Biological Activities, Pharmaceutical and Food Applications

Alpha-phellandrene is a very common cyclic monoterpene found in several EOs, which shows extensive biological activities. Therefore, the main focus of the present systematic review was to provide a comprehensive and critical analysis of the state of the art regarding its biological activities and pharmaceutical and food applications. In addition, the study identified essential oils rich in alpha-phellandrene and summarized their main biological activities as a preliminary screening to encourage subsequent studies on their single components. With this review, we selected and critically analyzed 99 papers, using the following bibliographic databases: PubMed, SciELO, Wiley and WOS, on 8 July 2022. Data were independently extracted by four authors of this work, selecting those studies which reported the keyword "alpha-phellandrene" in the title and/or the abstract, and avoiding those in which there was not a clear correlation between the molecule and its biological activities and/or a specific concentration from its source. Duplication data were removed in the final article. Many essential oils have significant amounts of alpha-phellandrene, and the species Anethum graveolens and Foeniculum vulgare are frequently cited. Some studies on the above-mentioned species show high alpha-phellandrene amounts up to 82.1%. There were 12 studies on alpha-phellandrene as a pure molecule showed promising biological functions, including antitumoral, antinociceptive, larvicidal and insecticidal activities. There were 87 research works on EOs rich in alpha-phellandrene, which were summarized with a focus on additional data concerning potential biological activities. We believe this data is a useful starting point to start new research on the pure molecule, and, in particular, to distinguish between the synergistic effects of the different components of the OEs and those due to alpha-phellandrene itself. Toxicological data are still lacking, requiring further investigation on the threshold values to distinguish the boundary between beneficial and toxic effects, i.e., mutagenic, carcinogenic and allergenic. All these findings offer inspiration for potential applications of alpha-phellandrene as a new biopesticide, antimicrobial and antitumoral agent. In particular, we believe our work is of interest as a starting point for further studies on the food application of alpha-phellandrene.

Ethanolic extract of Origanum syriacum L. leaves exhibits potent anti-breast cancer potential and robust antioxidant properties

Background: Breast cancer (BC) is the second most common cancer overall. In women, BC is the most prevalent cancer and the leading cause of cancer-related mortality. Triple-negative BC (TNBC) is the most aggressive BC, being resistant to hormonal and targeted therapies. Hypothesis/Purpose: The medicinal plant Origanum syriacum L. is a shrubby plant rich in bioactive compounds and widely used in traditional medicine to treat various diseases. However, its therapeutic potential against BC remains poorly investigated. In the present study, we screened the phytochemical content of an ethanolic extract of O. syriacum (OSEE) and investigated its anticancer effects and possible underlying mechanisms of action against the aggressive and highly metastatic human TNBC cell line MDA-MB-231. Methods: MTT, trans-well migration, and scratch assays were used to assess cell viability, invasion, or migration, respectively. Antioxidant potential was evaluated in vitro using the DPPH radical-scavenging assay and levels of reactive oxygen species (ROS) were assessed in cells in culture using DHE staining. Aggregation assays were used to determine cell-cell adhesion. Flow cytometry was used to analyze cell cycle progression. Protein levels of markers of apoptosis (BCL-2, pro-Caspase3, p53), proliferation (p21, Ki67), cell migration, invasion, or adhesion (FAK, E-cadherin), angiogenesis (iNOS), and cell signaling (STAT3, p38) were determined by immunoblotting. A chorioallantoic Membrane (CAM) assay evaluated in ovo angiogenesis. Results: We demonstrated that OSEE had potent radical scavenging activity in vitro and induced the generation of ROS in MDA-MB-231 cells, especially at higher OSEE concentrations. Non-cytotoxic concentrations of OSEE attenuated cell proliferation and induced G₀/G₁ cell cycle arrest, which was associated with phosphorylation of p38 MAPK, an increase in the levels of tumor suppressor protein p21, and a decrease of proliferation marker protein Ki67. Additionally, only higher concentrations of OSEE were able to attenuate inhibition of proliferation induced by the ROS scavenger N-acetyl cysteine (NAC), indicating that the anti-proliferative effects of OSEE could be ROS-dependent. OSEE stimulated apoptosis and its effector Caspase-3 in MDA-MB-231 cells, in correlation with activation of the STAT3/p53 pathway. Furthermore, the extract reduced the migration and invasive properties of MDA-MB-231 cells through the deactivation of focal adhesion kinase (FAK). OSEE also reduced the production of inducible nitric oxide synthase (iNOS) and inhibited in ovo angiogenesis. Conclusion: Our findings reveal that OSEE is a rich source of phytochemicals and has robust anti-breast cancer properties that significantly attenuate the malignant phenotype of MD-MB-231 cells, suggesting that O. syriacum may not only act as a rich source of potential TNBC therapeutics but may also provide new avenues for the design of novel TNBC drugs.

Investigation of Chemical Compounds and Evaluation of Toxicity, Antibacterial, and Anti-Inflammatory Activities of Three Selected Essential Oils and Their Mixtures with Moroccan Thyme Honey

Throughout history, honey has been used to treat various diseases. The present work examined and assessed the in vivo anti-inflammatory potential of Moroccan thyme honey and its association with essential oils from three selected plants: Origanum vulgare L.; Mentha spicata L.; Eucalyptus globulus L. The chemical composition of the essential oils was studied, and preliminary toxicity, in vitro anti-inflammatory, and antibacterial tests were conducted. Then the anti-inflammatory effect was determined by applying carrageenan and an experimental trauma-induced paw edema test in rats. The essential oils were rich in phytochemicals and showed significant antibacterial activity against four selected ATCC bacterial strains. The results revealed the significant anti-inflammatory potential of honey and mixtures with essential oils and indicated higher efficiency of mixtures compared to honey alone. It can be concluded that the mixtures of honey and essential oils have advantageous anti-inflammatory effects and may be used for treating different types of inflammation in humans after certain clinical trials.

Comparison of Origanum Essential Oil Chemical Compounds and Their Antibacterial Activity against Cronobacter sakazakii

Origanum vulgare L. (oregano) is an aromatic plant with wide applications in the food and pharmaceutical industries. Cronobacter sakazakii, which has a high detection rate in powdered infant formula, adversely impacts susceptible individuals. Oregano essential oil (OEO) is a natural antibacterial agent that can be used to fight bacterial contamination. Here, OEO chemical compounds from eight oregano varieties were analyzed by gas chromatography–mass spectrometry and their antibacterial properties were assessed. The eight OEOs were clustered into two groups and were more diverse in group 2 than in group 1. Six compounds, including p-cymene, 3-thujene, γ-terpinene, thymol, carvacrol, and caryophyllene, were shared by eight OEOs. Among the eight oregano varieties, OEOs from O. vulgare sc2 had the strongest antibacterial activity against C. sakazaki, with the inhibition zone of 18.22mm. OEOs from O. vulgare jx, O. ‘Nvying’, O. vulgare ‘Ehuang’, and O. vulgare ssp. virens were also potent. Moreover, the antibacterial activity of OEOs was positively correlated with the relative content of thymol. As the main OEO antibacterial compound, thymol affected the normal growth and metabolism of C. sakazakii cells by destroying the bacterial membrane and decreasing the intracellular ATP concentration. Thus, in light of the antibacterial activity detected in the OEOs from the eight oregano varieties, this study provides a theoretical foundation for oregano cultivar management and development.

Effects of Origanum vulgare and Scutellaria baicalensis on the Physiological Activity and Biochemical Parameters of the Blood in Rats on a High-Fat Diet

The pharmacological effects of medicinal plants play a primary role in the mild correction of body weight in humans and animals, reducing the accumulation of fat in their bodies during a state of obesity. Origanum vulgare L. and Scutellaria baicalensis Georgi are widely used as food additives and medicinal plants, but their comprehensive physiological evaluation in model animals in a state of obesity has not been carried out. In a 30-day laboratory experiment on male rats which had developed obesity through a hypercaloric diet, the effects of adding the dry crushed grass O. vulgare or dry crushed roots of S. baicalensis to their feed was evaluated. During the experiment, the rats fed with O. vulgare increased in body weight to only 105.5% of their initial weight, while the body weight of the control group increased to 111.5%, and that of animals fed on S. baicalensis increased to 124.0% of their initial body weight. The average daily increase in the rats’ body weight when O. vulgare was added to their diet decreased to 205 mg/day, and when S. baicalensis was added, on the contrary, it increased to 1417 mg/day, compared to 700 mg/day among the control group. Under the influence of O. vulgare, the lipid metabolism of the rats normalized: the atherogenic index decreased to 33.7%, compared with the values of the control group, due to an increase in the concentration of high-density lipoproteins from cholesterol. The concentration of triglycerides decreased, and the concentration of glucose decreased. The roots of S. baicalensis being added into the diet of rats increased the activity of alkaline phosphatase and decreased the concentration of urea. The atherogenic index also decreased (by up to 35.5% in the control group) and the concentration of high-density lipoprotein cholesterol increased, while the concentrations of triglycerides and glucose decreased. The physical activity of the rats showed a slight tendency to decrease when both O. vulgare and S. baicalensis were added to their diet. Both plant species contributed to a decrease in the emotional status of animals, which was most pronounced when the O. vulgare grass was added to the feed. The results of the study demonstrate the potential of the use of O. vulgare and S. baicalensis as herbal supplementations for the correction of hyperlipidemia and type-2 diabetes mellitus in overweight patients.

Current State of Knowledge Regarding WHO Critical Priority Pathogens: Mechanisms of Resistance and Proposed Solutions through Candidates Such as Essential Oils

The rise of multidrug-resistant (MDR) pathogens has become a global health threat and an economic burden in providing adequate and effective treatment for many infections. This large-scale concern has emerged mainly due to mishandling of antibiotics (ABs) and has resulted in the rapid expansion of antimicrobial resistance (AMR). Nowadays, there is an urgent need for more potent, non-toxic and effective antimicrobial agents against MDR strains. In this regard, clinicians, pharmacists, microbiologists and the entire scientific community are encouraged to find alternative solutions in treating infectious diseases cause by these strains. In its "10 global issues to track in 2021", the World Health Organization (WHO) has made fighting drug resistance a priority. It has also issued a list of bacteria that are in urgent need for new ABs. Despite all available resources, researchers are unable to keep the pace of finding novel ABs in the face of emerging MDR strains. Traditional methods are increasingly becoming ineffective, so new approaches need to be considered. In this regard, the general tendency of turning towards natural alternatives has reinforced the interest in essential oils (EOs) as potent antimicrobial agents. Our present article aims to first review the main pathogens classified by WHO as critical in terms of current AMR. The next objective is to summarize the most important and up-to-date aspects of resistance mechanisms to classical antibiotic therapy and to compare them with the latest findings regarding the efficacy of alternative essential oil therapy.

An Up-To-Date Review Regarding Cutaneous Benefits of Origanum vulgare L. Essential Oil

Due to the plethora of pharmacological activities reported in the literature, Origanum vulgare L. is a valuable aromatic plant for the medicine of the XXI century. Recent studies highlight that Origanum vulgare L. essential oil (OvEo) has gained attention in the dermatological field due to the cosmeceutical potential correlated with the presence of thymol and carvacrol. As a result of the fulminant expansion of bacterial resistance to antibiotics and the aggressiveness of skin infections, OvEo was extensively studied for its antimicrobial activity against Staphyloccocus spp. and Pseudomonas aeruginosa. Moreover, researchers have also assessed the anti-inflammatory activity of OvEo, suggesting its tissue remodeling and wound healing potential. Whereas OvEo comprises important biological activities that are used in a wide range of pathologies, recently, essential oils have shown great potential in the development of new therapeutic alternatives for skin disorders, such as acne, wounds or aging. Furthermore, substantial efforts have been committed to the development of modern formulations, such as microemulsions and nanoemulsions, in order to create the possibility for topical application. The review brings to the fore the most recent findings in the dermatological field regarding potential plant-based therapies involving OvEo, emphasizing the modern pharmaceutical formulation approaches and the cutaneous benefits in skin disorders.

Potential Applications of Essential Oils for Environmental Sanitization and Antimicrobial Treatment of Intensive Livestock Infections

The extensive use of antibiotics has contributed to the current antibiotic resistance crisis. Livestock infections of Salmonella spp, Clostridium spp. and E. coli antimicrobial-resistant bacteria represent a public threat to human and animal health. To reduce the incidence of these zoonoses, essential oils (EOs) could be effective antibiotic alternatives. This study aims at identifying EOs safe for use, effective both in complementary therapy and in the environmental sanitization of intensive farming. Natural products were chemo-characterized by gas chromatography. Three S. Typhimurium, three C. perfringens and four E. coli strains isolated from poultry and swine farms were used to assess the antimicrobial properties of nine EOs and a modified GR-OLI (mGR-OLI). The toxicity of the most effective ones (Cinnamomum zeylanicum, Cz; Origanum vulgare, Ov) was also evaluated on porcine spermatozoa and Galleria mellonella larvae. Cz, Ov and mGR-OLI showed the strongest antimicrobial activity; their volatile components were also able to significantly inhibit the growth of tested strains. In vitro, Ov toxicity was slightly lower than Cz, while it showed no toxicity on G. mellonella larvae. In conclusion, the study confirms the importance of evaluating natural products to consolidate the idea of safe EO applications in reducing and preventing intensive livestock infections.

Spicy and Aromatic Plants for Meat and Meat Analogues Applications

Aromatic and spicy plants are an important factor that contributes not only to improving the taste of meat, meat products, and meat analogues, but also to increasing the nutritional value of the products to which they are added. The aim of this paper is to present the latest information on the bioactive antioxidant and antimicrobial properties of the most commonly used herbs and spices (parsley, dill, basil, oregano, sage, coriander, rosemary, marjoram, tarragon, bay, thyme, and mint) used in the meat and meat analogues industry, or proposed to be used for meat analogues.

Pro-Angiogenic Effects of Essential Oil from Perilla frutescens and Its Main Component (Perillaldehyde) on Zebrafish Embryos and Human Umbilical Vein Endothelial Cells

Purpose

Perilla frutescens (L.) Britt., a traditional edible-medicinal herb in China, has been used to treat cardiovascular and cerebrovascular (cardio-cerebrovascular) diseases for thousands of years. However, knowledge of the mechanisms underlying the effects of essential oil from P. frutescens (EOPF) in the treatment of cardio-cerebrovascular diseases is lacking. The promotion of angiogenesis is beneficial in the treatment of ischemic cardio-cerebrovascular diseases. The current study investigated the pro-angiogenic role of EOPF and its main component perillaldehyde in sunitinib-injured transgenic Tg (flk1:EGFP) zebrafish embryos and human umbilical vein endothelial cells (HUVECs) for the first time.

Materials and Methods

The pro-angiogenic effects of EOPF and perillaldehyde were observed in vivo using transgenic Tg (flk1:EGFP) zebrafish embryos and in vitro using HUVECs. Cell viability, proliferation, migration, tube formation, and protein levels were detected by MTT, EdU staining, wound healing, transwell chamber, and Western blot assays, respectively.

Results

EOPF and perillaldehyde exerted a significant stimulatory effect on the formation of zebrafish intersegmental vessels (ISVs). Moreover, EOPF and perillaldehyde promoted proliferation, migration, and tube formation in sunitinib-treated HUVECs. Additionally, our findings uncovered that the pro-angiogenic effects of EOPF and perillaldehyde were mediated by increases in the expression ratios of p-ERK1/2 to ERK1/2 and Bcl-2 to Bax.

Conclusion

The present study is the first report to provide clear evidence that EOPF and perillaldehyde promote angiogenesis by stimulating repair of sunitinib-injured ISVs in zebrafish embryos and promoting proliferation, migration, and tube formation in sunitinib-injured HUVECs. The underlying mechanisms are related to increased p-ERK1/2 to ERK1/2 and Bcl-2 to Bax expression ratios. EOPF and perillaldehyde may be used in the treatment of cardio-cerebrovascular diseases, which is consistent with the traditional application of P. frutescens.

Origanum vulgare ssp. hirtum (Lamiaceae) Essential Oil Prevents Behavioral and Oxidative Stress Changes in the Scopolamine Zebrafish Model

Origanum vulgare ssp. hirtum has been used as medicinal herbs promoting antioxidant, anti-inflammatory, antimicrobial, and neuroprotective activities. We investigated the protective effects and the mechanism of O. vulgare ssp. hirtum essential oil (OEO) on cognitive impairment and brain oxidative stress in a scopolamine (Sco)-induced zebrafish (Danio rerio) model of cognitive impairment. Our results show that exposure to Sco (100 µM) leads to anxiety, spatial memory, and response to novelty dysfunctions, whereas the administration of OEO (25, 150, and 300 µL/L, once daily for 13 days) reduced anxiety-like behavior and improved cognitive ability, which was confirmed by behavioral tests, such as the novel tank-diving test (NTT), Y-maze test, and novel object recognition test (NOR) in zebrafish. Additionally, Sco-induced brain oxidative stress and increasing of acetylcholinesterase (AChE) activity were attenuated by the administration of OEO. The gas chromatography-mass spectrometry (GC-MS) analyses were used to elucidate the OEO composition, comprising thymol (38.82%), p-cymene (20.28%), and γ-terpinene (19.58%) as the main identified components. These findings suggest the ability of OEO to revert the Sco-induced cognitive deficits by restoring the cholinergic system activity and brain antioxidant status. Thus, OEO could be used as perspective sources of bioactive compounds, displaying valuable biological activities, with potential pharmaceutical applications.