Oregano: Chemical Analysis and Evaluation of Its Antimalarial, Antioxidant, and Cytotoxic Activities

Food packaging films based on ionically crosslinked konjac glucomannan incorporating zein-pectin nanoparticle-stabilized corn germ oil-oregano oil Pickering emulsion

This study addresses the limitations of konjac glucomannan (KGM) films in mechanical properties, hydrophobicity and antibacterial activities. For the first time, a zein-pectin nanoparticle-stabilized corn germ oil-oregano essential oil Pickering emulsion (ZPCEO) was incorporated into KGM, with the resulting film being further ionically crosslinked with Ca2+, Cu2+ or Fe3+. FTIR, SEM and EDS results showed that the metal ions were crosslinked with the hydroxyl and carbonyl groups of polysaccharides and uniformly distributed throughout the films (degree of crosslinking: Fe3+ > Cu2+ > Ca2+). Compared with pure KGM films, the ionic crosslinked ZPCEO/KGM (IL-ZPCEO/KGM) films have superior water resistance mechanical properties, and exhibit unique UV-blocking properties, antioxidant and antibacterial activities. The ZPCEO/KGM-Fe3+ film offered the best all-round properties, including the highest tensile strength, water resistance, UV-blocking capacity, and antimicrobial activity. Thus, ionic crosslinking of ZPCEO/KGM films can be applied to the preparation of food packaging for use in high humidity environments.

Emerging Insights into the Applicability of Essential Oils in the Management of Acne Vulgaris

The occurrence of pustules, comedones, nodules, and cysts defines acne vulgaris, a prevalent chronic inflammatory dermatological condition. In the past few decades, essential oils extracted from varied natural sources have acquired recognition due to their potential medicinal applications in acne therapy. However, there is not yet sufficient medical data to fully characterize this interaction. Multiple factors contribute to the development of acne vulgaris, including excessive sebaceous production, inflammatory processes, hyperkeratinization, and infection with Cutibacterium acnes. Essential oils, including oregano, lavender, lemon grass, myrtle, lemon, thyme, eucalyptus, rosemary, and tea tree, have been found to possess anti-inflammatory, antioxidant, and antimicrobial properties, which may target the multifactorial causes of acne. Analytical methods for determining antioxidant potential (i.e., total phenolic content, diphenyl-1-picrylhydrazyl free radical scavenging assay, reducing power assay, ferrous ion chelating activity, thiobarbituric acid reactive species assay, β-carotene bleaching assay, etc.) are essential for the evaluation of these essential oils, and their method optimization is crucial. Further studies could include the development of novel acne treatments incorporating essential oils and an assessment of their efficacy in large clinical trials. In addition, further research is necessary to ascertain the mechanisms of action of essential oils and their optimal doses and safety profiles for optimal implementation in the management of acne vulgaris.

Can Origanum be a hope for cancer treatment? A review on the potential of Origanum species in preventing and treating cancers

In this study, the potential of aromatic Origanum species belonging to Lamiaceae family to prevent and treat cancer was investigated. Since aromatic plants contain phytochemicals such as essential oils, phenolic acids, terpenoids, flavonoids, alkaloids, vitamins, enzymes and minerals with beneficial biological activities, they have become more interesting and important in medicine, pharmacy and industry. Publications/research between 1950 and 2022 were screened to investigate the effects of Origanum species on cancer, and the effects of their extracts and essential oils in cancer prevention and treatment. Essential phytochemicals found in plants provide efficacy in the prevention and treatment of many diseases. Besides, the essential oils found in these plant extracts are another reason that makes them important. Therefore, it is preferred in traditional medicine in the fight against many diseases as well as cancer. Essential oils of Origanum species mainly contain monoterpenes such as p-cymene, carvacrol, thymol and γ-terpinene. Since these compounds exhibit anticancer properties, Origanum species are becoming the plants of choice in the fight against cancer. In this context, Origanum majorana L. Origanum vulgare and Origanum munzurense are promising species, considering the composition of their extracts and essential oil.

Photodynamic Therapy, Probiotics, Acetic Acid, and Essential Oil in the Treatment of Chronic Wounds Infected with Pseudomonas aeruginosa

As a prevalent medical problem that burdens millions of patients across the world, chronic wounds pose a challenge to the healthcare system. These wounds, often existing as a comorbidity, are vulnerable to infections. Consequently, infections hinder the healing process and complicate clinical management and treatment. While antibiotic drugs remain a popular treatment for infected chronic wounds, the recent rise of antibiotic-resistant strains has hastened the need for alternative treatments. Future impacts of chronic wounds are likely to increase with aging populations and growing obesity rates. With the need for more effective novel treatments, promising research into various wound therapies has seen an increased demand. This review summarizes photodynamic therapy, probiotics, acetic acid, and essential oil studies as developing antibiotic-free treatments for chronic wounds infected with Pseudomonas aeruginosa. Clinicians may find this review informative by gaining a better understanding of the state of current research into various antibiotic-free treatments. Furthermore. this review provides clinical significance, as clinicians may seek to implement photodynamic therapy, probiotics, acetic acid, or essential oils into their own practice.

Essential oils of Origanum compactum Benth: Chemical characterization, in vitro, in silico, antioxidant, and antibacterial activities

This study was performed to investigate the phytochemical profile, and the, in vitro, and, in silico, antioxidant and antibacterial properties of the essential oil (EO) extracted from Origanum compactum. EO phytochemical screening was examined by gas chromatography coupled to mass spectrometry. The antioxidant potential, in vitro, was assessed using reducing power(FRAP), free 2,2 diphenylpicrylhydrazyl (DPPH) radical scavenging and total antioxidant capacity tests. Antibacterial properties against two Gram (−) and two Gram (+) bacteria were assessed using the minimal inhibitory concentration (MIC) and the disc diffusion methods. By use of molecular docking, antioxidant and antibacterial activities of oregano EO were also tested. Thymol (75.53%) was the major compound among the nine compounds identified in the EO of Origanum compactum, followed by carvacrol (18.26%). Oregano EO showed an important antioxidant capacity, as tested by FRAP and DPPH assays, with EC50 and IC50 values of 13.300 ± 0.200 and 0.690 ± 0.062 mg/mL, respectively. The same EO has a total antioxidant capacity of 173.900 ± 7.231 mg AAE/g EO. The antibacterial results showed significant activity of Origanum compactum EO against all tested bacteria, especially against S. aureus (MIC = 0.25 mg/mL) and B. subtilis (MIC = 0.06 mg/mL). In silico, carvacrol was the most active molecule against nicotinamide adenine dinucleotide phosphate oxidase (2CDU) and S. aureus nucleoside diphosphate kinase (3Q8U) with a glide score of −6.082, and −6.039 kcal/mol, respectively. Regarding the inhibition of E. coli beta-ketoacyl-[acyl carrier protein] synthase (1FJ4), piperitenone was the most active molecule with a glide score of −7.112 kcal/mol. In light of the results obtained, the EO of Origanum compactum Moroccan species can be used as promising natural food conservatives and an agent to fight antibiotic-resistant nosocomial microbes.

Anti-Trypanosomatidae Activity of Essential Oils and Their Main Components from Selected Medicinal Plants

Kinetoplastida is a group of flagellated protozoa characterized by the presence of a kinetoplast, a structure which is part of a large mitochondria and contains DNA. Parasites of this group include genera such as Leishmania, that cause disease in humans and animals, and Phytomonas, that are capable of infecting plants. Due to the lack of treatments, the low efficacy, or the high toxicity of the employed therapeutic agents there is a need to seek potential alternative treatments. In the present work, the antiparasitic activity on Leishmania infantum and Phytomonas davidi of 23 essential oils (EOs) from plants of the Lamiaceae and Asteraceae families, extracted by hydrodistillation (HD) at laboratory scale and steam distillation (SD) in a pilot plant, were evaluated. The chemical compositions of the EOs were determined by gas chromatography-mass spectrometry. Additionally, the cytotoxic activity on mammalian cells of the major components from the most active EOs was evaluated, and their anti-Phytomonas and anti-Leishmania effects analyzed. L. infantum was more sensitive to the EOs than P. davidi. The EOs with the best anti-kinetoplastid activity were S. montana, T. vulgaris, M. suaveolens, and L. luisieri. Steam distillation increased the linalyl acetate, β-caryophyllene, and trans-α-necrodyl acetate contents of the EOs, and decreased the amount of borneol and 1,8 cineol. The major active components of the EOs were tested, with thymol being the strongest anti-Phytomonas compound followed by carvacrol. Our study identified potential treatments against kinetoplastids.

Chemical Composition, Antioxidants, Antibacterial, and Insecticidal Activities of Origanum elongatum (Bonnet) Emberger & Maire Aerial Part Essential Oil from Morocco

The aim of this research is to profile the chemical composition of the essential oil (EO) extracted from the aerial parts of Origanum elongatum (O. elongatum) and to evaluate its antioxidant, antibacterial and insecticidal activities on Ceratitis capitata adults. Gas chromatography coupled with mass spectrometry (GC/MS) revealed a total of 27 constituents in EO of O. elongatum, which accounted for 99.08% of its constituents. Carvacrol (57.32%) was a main component, followed by p-cymene (14.70%) and γ-terpinene (9.84%). The antioxidant activity of O. elongatum EO was investigated using DPPH (1,1-diphenyl-2-picrylhydrazyl), FRAP (Ferric reducing antioxidant power), and TCA (the total antioxidant capacity) methods. This EO exhibited a remarkable antiradical and reducing power against DPPH (IC₅₀ = 2.855 ± 0.018μL/mL), FRAP (EC_0.5 = 0.124 ± 0.013µL/mL) and TCA (IC₅₀ = 14.099 ± 0.389 mg AAE/g of the EO). The antibacterial tests in vitro, using the disc and dilution methods, were carried out on nine pathogenic bacteria isolated from the hospital patients, such as Enterococcus faecalis, Serratia fonticola, Staphylococcus aureus, Acinétobacter baumannii, Klebsiella oxytoca, Klebsiella pneumoniae sensible, E.coli sensible, E.coli resistante, and Enterobacter aerogenes. The EO demonstrated a considerable antibacterial activity with minimum inhibitory concentrations (MIC) from 2 to 8 µL/mL against all strains except Staphylococcus aureus (MIC = 32 µL/mL). Regarding the insecticidal activity, the fumigation test indicated a high efficacy (100% mortality), and a lethal dose of LD₅₀  =  17 ± 0.53 μL/L air was found after 24 h of exposureTherefore, O. elongatum EO could be utilized as a natural antioxidant, antibiotic and biopesticides.

Oregano (Origanum vulgare) Consumption Reduces Oxidative Stress and Markers of Muscle Damage after Combat Readiness Tests in Soldiers

Military activities often involve high-intensity exercise that can disrupt antioxidant capacity. We investigated the effects of oregano supplementation on muscle damage, oxidative stress, and plasma antioxidant markers of soldiers performing the army combat readiness test (ACRT). Twenty-four healthy male soldiers (age: 24 ± 3 years, height: 167 ± 14 cm, mass: 66 ± 3 kg) were randomized into a placebo group (n = 12) or an oregano supplementation group (n = 12). The participants consumed a capsule containing 500 mg Origanum vulgare immediately after completing the ACRT. Blood sampling was taken before exercise, immediately after exercise, and 60 and 120 min after oregano consumption. Plasma levels of creatine kinase (CK), lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), total antioxidant capacity (TAC), and glutathione peroxidase (GPX) were measured at the four time points. The time × group interactions were found for CK (p < 0.0001, d = 3.64), LDH (p < 0.0001, d = 1.64), MDA (p < 0.0001, d = 9.94), SOD (p < 0.0001, d = 1.88), TAC (p < 0.0001, d = 5.68) and GPX (p < 0.0001, d = 2.38). In all variables, the difference between placebo and oregano groups were significant at 60 (p < 0.0001) and 120 (p < 0.0001) minutes after ACRT test. The main effect of time was also significant for all the variables (p < 0.0001). Our results suggest that oregano supplementation has the potential to reduce muscle damage and increase oxidative capacity following ACRT. Supplementation with oregano may serve as a dietary strategy to increase preparedness and promote recovery in military recruits.

Quality Control, Phytochemical Profile, and Antibacterial Effect of Origanum compactum Benth. Essential Oil from Morocco

Origanum compactum Benth (O. compactum) is widely used traditionally in Morocco to treat a broad range of illnesses, including infectious diseases. The aim of this study was to evaluate the phytochemical composition, quality control, and antibacterial activity of O. compactum leaf and flower essential oil. First, a quality control study on soil and irrigation water was performed to determine whether there was any risk of heavy metals endangering human health or causing stress to the plants studied. Laboratory examination of the environmental quality of the researched species revealed an almost absolute absence of metals that could endanger human health or any abiotic stressor. The essential oil was extracted by hydrodistillation. Chemical characterization was performed using gas chromatography-mass spectrometry (GC/MS). The yield of essential oil (EO) obtained by hydrodistillation of O. compactum leaves and flowers and moisture content were 4.27% and 12.20%, respectively. GC/MS identified 35 volatile compounds in the studied EO majorly composed of thymol (38.59%) followed by carvacrol (26.65%), o-cymene (14.33), and γ-terpinene (11.22%). The antibacterial activity of O. compactum leaf and flower essential oil was evaluated using the solid-state diffusion method against five Gram-negative bacterial strains and a Gram-positive strain. The results show that the essential oil of O. compactum leaves and flowers has a considerable inhibitory effect against E. coli with an MIC = 0.35 µg/mL, E. pseudocoloides (MIC = 0.35 µg/mL), E. vekanda (MIC = 0.35 µg/mL), K. pneumoniae (MIC = 0.7 µg/mL), P. aeruginosa (MIC = 0.35 µg/mL), and S. aureus (MIC = 0.35 µg/mL).

Role of antioxidant activity of essential oils in their acaricidal activities against Rhipicephalus annulatus

Essential oils of Origanum majorana and Satureja thymbra as well as carvacrol are natural products that are known to have potent antioxidant activities. The current study was designed to investigate the role of the antioxidant properties of these natural products in their acaricidal activities against Rhipicephalus annulatus larvae. The synergistic and/or antagonistic effects of the addition of vitamins E and C and hydrogen peroxide (H2O2) to these natural products were also evaluated. Larval packet tests were used to evaluate the acaricidal activities against the larvae of R. annulatus. The antioxidant effectiveness of these products was determined by a DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging assay. The addition of vitamin E at 100 mg/mL to O. majorana and S. thymbra decreased the concentrations required to achieve the death of half of the larvae (LC50) to 0.44 and 0.47%, respectively. The combination of O. majorana and S. thymbra attained the LC50 at 1.54% which was decreased to 0.69% after addition of vitamin E. Also, the addition of vitamin E to carvacrol reduced the LC50 to 0.27%. The total antioxidant activity of these natural products increased significantly in presence of vitamin E. The addition of H2O2 inhibited the acaricidal activity of all tested materials, especially at low concentrations. All treatments induced an increase in lipid peroxidation, whereas carvacrol-treated larvae revealed the lowest values for the superoxide dismutase. Glutathione peroxidase and catalase activity decreased in larvae treated with S. thymbra combined with vitamin E. In conclusion, the addition of vitamins E and C increased the acaricidal activities of the tested compounds, whereas the addition of H2O2 decreased these activities. The antioxidant activities of essential oils and their active components may play an important role in mediating their acaricidal activities.

Encapsulation of wild oregano, Plectranthus amboinicus (Lour.) Spreng, phenolic extract in baker's yeast for the postharvest control of anthracnose in papaya

BACKGROUND

Anthracnose caused by Colletotrichum gloeosporioides is considered as a major postharvest disease affecting many fruits. This plant disease is traditionally managed with synthetic fungicides, which are generally toxic and are linked to pathogen resistance. Recently, microencapsulated bioactives have been developed as potential alternative strategies to these methods, while utilizing natural fungicides and other phytochemicals. Wild oregano, Plectranthus amboinicus (Lour.) Spreng, contains potent antimicrobial phenolics, but these compounds are volatile and relatively unstable, which limits their efficacy during application. Herein, a baker's yeast microencapsulation system was applied to improve the stability of wild oregano phenolic extract (WOPE) and enhance its antifungal activity against anthracnose.

RESULTS

Encapsulation of WOPE in plasmolyzed yeast cells afforded a high encapsulation efficiency (93%) and yielded WOPE-loaded yeast microcapsules (WLYMs) with an average diameter of 2.65 μm. Storage stability studies showed WLYMs are stable for at least 4 months. A 24  -h in vitro release experiment showed that WLYMs had an initial burst release upon redispersion in water, followed by a controlled release to about 80% of the loaded WOPE. Upon application as a spray-type postharvest treatment for papaya, WLYMs exhibited a significantly improved mycelial inhibitory action against C. gloeosporioides and greatly reduced the anthracnose symptoms in papaya fruits.

CONCLUSION

This study presented a yeast microencapsulation system that can effectively stabilize WOPE and enhance its antifungal activity, making this microparticle formulation a promising environmentally safe postharvest treatment option to combat anthracnose symptoms in papaya fruits. © 2022 Society of Chemical Industry.

Cytotoxic Activity of Polyphenol Extracts from Three Oregano Species: Hedeoma patens, Lippia graveolens and Lippia palmeri, and Antiproliferative Potential of Lippia graveolens against Two Types of Breast Cancer Cell Lines (MDA-MB-231 and MCF-7)

Oregano infusions have traditionally been used to treat some diseases related to inflammation and cancer; also, some species have shown antiproliferative activity on cancer cell lines, for example, colon and liver, and this has been attributed to its phytochemical profile, mainly its phenolic compounds. This study aimed to evaluate the cytotoxicity and antiproliferative potential of the polyphenols-rich extracts (PRE) of the oregano species H. patens, L. graveolens, and L. palmeri on breast cancer cell lines. The PRE of the three oregano species were obtained from dried leaves. The extract was characterized by determining antioxidant activity, total phenols content, and identifying the profile of phenolic acids and flavonoids by chromatography UPLC-MS/MS. Furthermore, the cytotoxicity of the extracts was evaluated in vitro on a non-cancer cell line of fibroblast NIH3T3 and the antiproliferative potential on the breast cancer cell lines MDA-MB-231 and MCF-7. L. graveolens showed the highest antioxidant capacity and significantly inhibited the proliferation of MCF-7 and MDA-MB-231 cells at non-cytotoxic concentrations in normal cells, with a similar effect to that cisplatin in MDA-MB-231 cells. Therefore, the polyphenol-rich extract from L. graveolens showed the greatest potential to guide future research on the antiproliferative mechanism of action.

Determination of the Phenolic Profile, and Evaluation of Biological Activities of Hydroethanolic Extract from Aerial Parts of Origanum compactum from Morocco

Origanum compactum belonging to the family Lamiaceae is widely used in food and pharmaceutical fields due to its biologically active substances. We aimed to investigate the total phenol and flavonoid contents and the phenolic composition, and to evaluate the antioxidant and antibacterial properties of hydroethanolic extract from of Origanum compactum. Total phenol and flavonoid contents were evaluated using gallic acid and quercetin as standards, respectively, and the phenolic profile was characterized using high-performance liquid chromatography coupled to a photodiode array and electrospray ionization mass spectrometry (HPLC-PDA-ESI/MS). The antioxidant activity was determined by two methods: ferric reducing power (FRAP) assay and the phosphomolybdate method. The antibacterial effect was evaluated against four bacteria (Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Listeria monocytogenes) using the broth microdilution method. The findings show that the total phenolic and flavonoid contents were 107.789 ± 5.39 mg GAE/g dm and 14,977 ± 0.79 mg QE/g dm, respectively. A total of sixteen phenolic compounds belonging to phenolic acids and flavonoids were detected. Furthermore, the extract showed strong antioxidant activity, and displayed a bacteriostatic effect against Escherichia coli and Salmonella typhimuriumn, and a bactericidal effect against Staphylococcus aureus and Listeria monocytogenes. Therefore, this study reveals that Origanum compactum extracts display potential as antibacterial and natural antioxidant agents for fighting against pathogenic bacteria and preventing oxidative stress.

Nanoemulsion and Encapsulation Strategy of Hydrophobic Oregano Essential Oil Increased Human Prostate Cancer Cell Death via Apoptosis by Attenuating Lipid Metabolism

Origanum vulgare essential oil (EO) is traditionally well-known for its aromatic properties and biomedical applications, including anticancer. This was the first report where oregano essential oil-based nano emulsion (OENE) was synthesized for studying its effects on prostate cancer cell lines (PC3). At first, we have synthesized OENE and characterized using various spectroscopic analyses. The toxicity and inhibitory concentration (IC50) of OENE toward prostate cancer by MTT analysis were performed. The lipid biogenesis mediated, molecular target pathway analyses were performed using fluorescence cellular staining techniques, real-time RT-PCR, or western blotting analysis. OENE showed IC50 at 13.82 µg/mL and significantly induced distinct morphological changes, including cell shrinkage, cell density, and cell shape reduction. In addition, OENE could also significantly decreased lipid droplet accumulation which was confirmed by studying mRNA transcripts of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) (0.31-fold), fatty acid synthase (FASN) (0.18-fold), and sterol regulatory element-binding protein (SREPB1) (0.11-fold), respectively. Furthermore, there is a significant upregulation BAX (BCL2 associated X) and caspase 3 expressions. Nevertheless, OENE decreased the transcript level of BCL2 (B-cell lymphoma 2), thus resulting in apoptosis. Overall, our present work demonstrated that OENE could be a therapeutic target for the treatment of prostate cancer and warrants in vivo studies.

Albadr N, Nafidi HA, Ouahmane L, Mohamed F. Chemical Composition and Antifungal, Insecticidal and Repellent Activity of Essential Oils From Origanum compactum Benth. Used in the Mediterranean Diet

Essential oils (EO) of Origanum compactum Benth. (O. compactum) are well known for their biological and pharmacological activities. This study aimed to assess the chemical composition, antifungal, insecticidal and repellent activities of EO of O. compactum used in the Mediterranean diet. Phytochemical screening was conducted using gas chromatography-mass spectrometry (GC/MS). Antifungal activity was tested by the disc diffusion method followed by a minimal inhibitory concentration (MIC) assay against Candida albicans (C. albicans), Aspergillus flavus (A. flavus), Aspergillus niger (A. nige), and Fusarium oxysporum (F. oxysporum). Repellent potential and toxicity of EO by contact and inhalation were tested against Callosobruchus maculatus (C. maculatus). The yield of essential oil obtained by hydrodistillation of O. compactum was 4.41 ± 0.35%, mainly composed of Carvacrol (38%) and Thymol (31.46%). Regarding antifungal activity, the results revealed a wide antifungal spectrum of the studied EO against the tested strains, which reached 100% growth inhibition, especially against A. niger and C. albicans even at the lowest MIC values (3.125 μg/mL). Concerning insecticidal activity, the EO caused total mortality of C. maculatus adults at a dose of 20 μL/L air with LC₅₀ value of 5.3 μL/L air. A significant reduction in the number of eggs and emergence was proportionally recorded with increasing doses up to 100% at 20 μL/L air. For repellent activity, the studied EO showed a moderate repellent activity with an average percentage of 39.16%. The outcome of this work revealed that O. Compactum EO could be a sustainable and environmentally friendly alternative bioinsecticide and bio-fungicide to replace the chemically synthesized forms.

Health beneficial and pharmacological properties of p-cymene

p-cymene also known as p-cymol or p-isopropyltoluene is an alkyl-substituted aromatic compound naturally occurring in essential oils (EOs) of various aromatic plants, including the genus of Artemisia, Protium, Origanum, and Thymus. It is related to the family of terpenes, especially monocyclic monoterpenes. p-cymene is also present in several food-based plants such as carrots, orange juice, grapefruit, tangerine, raspberries and several spices. Numerous studies have demonstrated the pharmacological properties of the monoterpenes p-cymene, including antioxidant, anti-inflammatory, antiparasitic, antidiabetic, antiviral, antitumor, antibacterial, and antifungal activities. The p-cymene has also been reported to act as an analgesic, antinociceptive, immunomodulatory, vasorelaxant and neuroprotective agent. Its anticancer effects are related to some mechanisms such as the inhibition of apoptosis and cell cycle arrest. In this review, we critically highlighted the in vitro and in vivo pharmacological properties of the p-cymene molecule, providing insight into its mechanisms of action and potential applications in drug discovery. In light of this finding, in-depth in vivo studies are strongly required to validate the safety and beneficial effects of the p-cymene molecule in human healthcare and industrial applications as a potential source of drug discovery.

Exploring the powerful phytoarsenal of white grape marc against bacteria and parasites causing significant diseases

Natural extracts containing high polyphenolic concentration possess antibacterial, anti-parasitic and fungicidal activities. The present research characterises two extracts based on white grape marc, a winemaking by-product, describing their physicochemical features and antimicrobial capacities. The main components of these extracts are phenolic acids, flavan-3-ols and their gallates and flavonols and their glycosides. As a result of this complex composition, the extracts showed pronounced bioactivities with potential uses in agricultural, pharmaceutical and cosmetic industries. Polyphenol compounds were extracted by using hydro-organic solvent mixtures from the by-product of Albariño white wines (Galicia, NW Spain) production. The in vitro antimicrobial activity of these extracts was evaluated on Gram-positive and Gram-negative bacteria and Apicomplexan and Oomycota parasites. Microbial species investigated are causing agents of several human and animal diseases, such as foodborne illnesses (Bacillus cereus, Escherichia coli, Salmonella enterica, and Toxoplasma gondii), skin infections and/or mastitis (Staphylococcus aureus and Streptococcus uberis), malaria (Plasmodium falciparum) and plant infections as "chestnut ink" or "root rot" (Phytophthora cinnamomi). Both extracts showed activity against all the tested species, being nontoxic for the host. So, they could be used for the development of biocides to control a wide range of pathogenic agents and contribute to the enhancement of winemaking industry by-products.

Composition's effect of Origanum Syriacum essential oils in the antimicrobial activities for the treatment of denture stomatitis

This research has several purposes: First to assess the bacterial and fungal minimum inhibitory concentration of Origanum Syriacum essential oil. Second to quantify its bactericidal and fungicidal minimal concentration against S. aureus, S. mutans, and C. albicans found in denture stomatitis. The third purpose is to look at the influence of three different soils (Annaya, Bhanin and Michrif) on the essential oils composition. Three essential oils were extracted by hydro-distillation from three different Origanum Syriacum plant origins. Bioassays were conducted using a broth microdilution methods. Gas Chromatography analysis was used to calculate the abundance of most components in each essential oil. Post hoc tests assessed antimicrobial effects between ecotypes while Pearson's test correlated the different components and their antimicrobial efficiency (α < 0.05). All tested essential oils were efficient against all microorganisms. Origanum Syriacum essential oils derived from Annaya and Bhanin soils showed a superior antimicrobial activity compared to the Michrif one. The most abundant component and most efficient among all essential oils constituents was carvacrol. It can be concluded that Origanum Syriacum essential oils have an antimicrobial activity, which depends on the ecotype, its origin and its composition. They might be used to start a clinical trial for the treatment of denture stomatitis.

GC-MS Characterization of Antibacterial, Antioxidant, and Antitrypanosomal Activity of Syzygium aromaticum Essential Oil and Eugenol

Syzygium aromaticum has a diversity of biological activities due to the chemical compounds found in its plant products such as total phenolic compounds and flavonoids. The present work describes the chemical analysis and antimicrobial, antioxidant, and antitrypanosomal activity of the essential oil of S. aromaticum. Eugenol (53.23%) as the major compound was verified by gas chromatography-mass spectrometry. S. aromaticum essential oil was more effective against S. aureus (MIC 50 μg/mL) than eugenol (MIC 250 μg/mL). Eugenol presented higher antioxidant activity than S. aromaticum essential oil, with an EC₅₀ of 12.66 and 78.98 µg/mL, respectively. S. aromaticum essential oil and eugenol exhibited Trypanosoma cruzi inhibitory activity, with IC₅₀ of 28.68 ± 1.073 and 31.97 ± 1.061 μg/mL against epimastigotes and IC₅₀ of 64.51 ± 1.658 and 45.73 ± 1.252 μg/mL against intracellular amastigotes, respectively. Both compounds presented low cytotoxicity, with S. aromaticum essential oil displaying 15.5-fold greater selectivity for the parasite than the cells. Nitrite levels in T. cruzi-stimulated cells were reduced by essential oil (47.01%; p = 0.002) and eugenol (48.05%; p = 0.003) treatment. The trypanocidal activity of S. aromaticum essential oil showed that it is reasonable to use it in future research in the search for new therapeutic alternatives for trypanosomiasis.

Influence of Agronomic Practice on Total Phenols, Carotenoids, Chlorophylls Content, and Biological Activities in Dry Herbs Water Macerates

Oregano (Origanum vulgare L.) and thyme (Thymus vulgaris L.) have long been known for their organoleptic properties. Both plants are widely used in cuisine worldwide in fresh and dried form and as a pharmaceutical raw material. The study aimed to assess if the type of cultivation influenced chosen chemical parameters (total polyphenols by Folin-Ciocalteu method; carotenoids and chlorophyll content by Lichtenthaler method), antimicrobial activity (with chosen reference microbial strains) and shaped cytotoxicity (with L929 mouse fibroblasts cell line) in water macerates of dry oregano and thyme. Polyphenols content and antimicrobial activity were higher in water macerates obtained from conventional cultivation (independently from herb species), unlike the pigments in a higher amount in macerates from organic herbs cultivation. Among all tested macerates stronger antimicrobial properties (effective in inhibiting the growth of Pseudomonas aeruginosa, Bacillus cereus and Salmonella enteritidis) and higher cytotoxicity (abilities to diminish the growth of L929 fibroblasts cytotoxicity) characterized the conventionally cultivated thyme macerate.

Anticancer medicinal plants used by Moroccan people: Ethnobotanical, preclinical, phytochemical and clinical evidence

ETHNOPHARMACOLOGICAL RELEVANCE

Cancer is a major health problem worldwide. Drugs' side effects and high cost of treatment remain the main limitations of conventional therapy. Nowadays, developing new therapeutic strategies is necessary. Therefore, medicinal plants can be used to promote novel, safe, and potent anticancer drugs through their natural compounds.

AIM OF THE STUDY

This review aims to provide scientific evidence related to the anticancer activities of medicinal plants used by Moroccan people as well as approving their efficiency as an alternative cancer therapy.

METHODS

An ethnopharmacological review approach was conducted by analyzing Moroccan published ethnobotanical surveys from 1991 to 2019 and consulting peer-reviewed articles worldwide to investigate the pharmacological, phytochemical, and clinical effects related to the anticancer activities. Plants with anticancer proprieties were classified into four groups: (a) plants only cited as anticancer, (b) plants pharmacologically investigated, (c) plants with bioactive compounds tested as anticancer, and (d) plants clinically investigated.

RESULTS

A total of 103 plant species belonging to 47 botanical families used by Moroccans to treat cancer have been recorded. Aristolochia fontanesii Boiss. & Reut, Marrubium vulgare L., and Allium sativum L. are the most referred species in Morocco. Medicinal plants used for cancer treatment were classified into four groups: 48 species were used traditionally as anticancer (group a), 41 species pharmacologically investigated for their anticancer activities (group b), 32 plants with bioactive compounds tested against cancer (group c), and eight plants were clinically investigated for their anticancer effects (group d). Out of 82 plants' extracts pharmacologically tested (from plants of group b), only 24 ones show a significant cytotoxic effect. A total of seventy-seven compounds are isolated from plants of group (c). However, only six ones were clinically evaluated, and most of them exhibit a beneficial effect on cancerous patients with few side effects.

CONCLUSION

Medicinal plants can be a promising candidate for alternative cancer therapy. Nevertheless, it is critical to increasing the clinical trials to confirm their beneficial effect on patients with cancer. Overall, this review can serve as a database for further studies.

Distribution of inhaled volatile β-caryophyllene and dynamic changes of liver metabolites in mice

β-caryophyllene (BCP), an essential oil component of many herbs and spices, has various biological activities as a functional food factor. A distinct feature of BCP is its volatile double-ring sesquiterpene structure. Orally administered BCP is reportedly detected in its intact form in mice serum; however, the distribution of inhaled volatile BCP throughout the body remains unknown. This study aimed to estimate the distribution properties of inhaled volatile BCP and to investigate its effects on metabolism. After mice were exposed to volatile BCP, it was detected in the lung, olfactory bulb, brain, serum, heart, liver, kidney, epididymal fat, and brown adipose tissue. BCP was further detected in the brain, liver, and brown adipose tissue 24 h after exposure. Metabolites related to glutathione metabolism were significantly altered in the liver. These results suggest that inhaled volatile BCP is widely distributed in murine tissues and affects the dynamics of metabolites in the liver.

Aniba rosaeodora (Var. amazonica Ducke) Essential Oil: Chemical Composition, Antibacterial, Antioxidant and Antitrypanosomal Activity

Aniba rosaeodora is one of the most widely used plants in the perfumery industry, being used as medicinal plant in the Brazilian Amazon. This work aimed to evaluate the chemical composition of A. rosaeodora essential oil and its biological activities. A. rosaeodora essential oil presented linalool (93.60%) as its major compound. The A. rosaeodora essential oil and linalool showed activity against all the bacteria strains tested, standard strains and marine environment bacteria, with the lower minimum inhibitory concentration being observed for S. aureus. An efficient antioxidant activity of A. rosaeodora essential oil and linalool (EC₅₀: 15.46 and 6.78 µg/mL, respectively) was evidenced by the inhibition of the 2,2-azinobis- (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical. The antitrypanosomal activity of A. rosaeodora essential oil and linalool was observed at high concentrations against epimatigote forms (inhibitory concentration for 50% of parasites (IC₅₀): 150.5 ± 1.08 and 198.6 ± 1.12 µg/mL, respectively), and even higher against intracellular amastigotes of T. cruzi (IC₅₀: 911.6 ± 1.15 and 249.6 ± 1.18 µg/mL, respectively). Both A. rosaeodora essential oil and linalool did not exhibit a cytotoxic effect in BALB/c peritoneal macrophages, and both reduced nitrite levels in unstimulated cells revealing a potential effect in NO production. These data revealed the pharmacological potential of A. rosaeodora essential oil and linalool, encouraging further studies.

Extraction Techniques and Analytical Methods for Characterization of Active Compounds in Origanum Species

Phytochemical research based on ethnopharmacology is gaining interest in industries such as functional food, nutraceuticals, cosmetics and pharmaceutical industries. Plants and plant extracts are a rich source of bioactive secondary metabolites. These compounds are often involved in plant protection against biotic or abiotic stresses. The exploitation of available technologies should be oriented and intensified to extend and enhance the continued usefulness of the plants as renewable sources of chemicals, especially medicinal compounds. This current contribution is focused on extraction and analytical techniques for their isolation from the oregano species, their characterization and their potential antioxidative, as well as their antimicrobial, antifungal and anticarcinogenic properties. The work is structured rendering to the different steps involved in the research; starting with extraction and sample preparation, followed by discussing the analytical techniques employed for the isolation and identification of compound/s responsible for the biological activity and methods and techniques for biological activity assessment.

The Impact of Herbal Infusion Consumption on Oxidative Stress and Cancer: The Good, the Bad, the Misunderstood

The release of reactive oxygen species (ROS) and oxidative stress is associated with the development of many ailments, including cardiovascular diseases, diabetes and cancer. The causal link between oxidative stress and cancer is well established and antioxidants are suggested as a protective mechanism against cancer development. Recently, an increase in the consumption of antioxidant supplements was observed globally. The main sources of these antioxidants include fruits, vegetables, and beverage. Herbal infusions are highly popular beverages consumed daily for different reasons. Studies showed the potent antioxidant effects of plants used in the preparation of some herbal infusions. Such herbal infusions represent an important source of antioxidants and can be used as a dietary protection against cancer. However, uncontrolled consumption of herbal infusions may cause toxicity and reduced antioxidant activity. In this review, eleven widely consumed herbal infusions were evaluated for their antioxidant capacities, anticancer potential and possible toxicity. These herbal infusions are highly popular and consumed as daily drinks in different countries. Studies discussed in this review will provide a solid ground for researchers to have better understanding of the use of herbal infusions to reduce oxidative stress and as protective supplements against cancer development.

Origanum compactum Benth., from traditional use to biotechnological applications

Origanum compactum Benth., is a Moroccan medicinal plant known by its local name as Zaatar. In Morocco, it has various traditional applications such as the use to treat diabetes, metabolic disorders, digestive, and respiratory problems. In this review, we critically highlighted current investigations on the ethnopharmacological studies, the phytochemistry, pharmacological investigations, biotechnological applications, and future perspective of O. compactum. A bibliometric electronic search in worldwide accepted scientific databases such as ScienceDirect, PubMed, SpringerLink, Web of Science, Scopus, Wiley Online, and Google Scholar was carried out to gather on O. compactum. Chemical analysis using GC-MS and/or HPLC allowed the identification of several bioactive compounds such as terpenoids and phenolic acids. Furthermore, O. compactum extracts and essential oils have been tested for various biological activities such as antibacterial, antioxidant, antiparasitic, antifungal, and anticancer effects. Moreover, an alignment between traditional use and biological effects was demonstrated, in particular for the antimicrobial activity. These properties are related to O. compactum bioactive components, especially the volatile compounds such as thymol and carvacrol. The pharmacological mechanisms involve several cellular and molecular targeted actions. Moreover, the biological potential of this species had led some laboratories to apply the biotechnological tools for its regeneration. PRACTICAL APPLICATIONS: Origanum compactum is applied as traditional drug against different illnesses and for food preservation. Scientific investigations proved the application of O. compactum essential oils in food industries as antioxidants and antimicrobials. These volatile compounds could be applied also in pharmaceutical industries, in particular as antibacterial, antifungal, and antileishmanial drugs. Moreover, further investigations concerning toxicological evidences and pharmacokinetic as well as pharmacodynamic mechanistic targets and clinical trials could develop anticancer, antimalaria and anti-inflammatory, and antidiabetic drugs. Finally, the results of the findings of these purposes encourage other research groups to carry out further investigations on the pharmacological properties of O. compactum.

New Bioactive Esters and Phosphonates Semisynthesized From (±)-Vasicinone: An Alkaloid Isolated FromPeganum harmala

A series of N-tosyl α-amino acids 2a-e, prepared using a tosyl chloride protecting group, was condensed with (±)-vasicinone 1, isolated from the seeds of the plant Peganum harmala, to generate the corresponding esters 3a-e and 3b′-e′. (±)-Vasicinone 1 was also reacted with chloroacetic acid chloride to afford a new chlorinated ester 4 which was refluxed with trialkyl phosphites to give 2 new phosphonates 5a,b. All synthesized compounds were characterized with the help of spectroscopic means, including NMR (1H,13C, and31P) and ES-HRMS, and then screened for their in vitro anti-acetylcholinesterase (AChE), anti-5-lipoxygenase (5-LOX), and cytotoxic activities (MCF-7, OVCAR-3, and HCT-116 cell lines). Most synthesized derivatives exhibited a cytotoxic activity against 3 cell lines used. The phosphonate derivative 5b was found to be the most active one (IC50= 63.7 ± 1.4 µM) against AChE enzyme. Only 2 diastereoisomers 3e and 3e′ exhibited activity against 5-LOX enzyme with IC50values of 63.1 ± 4.2 and 79.2 ± 8.3 µM, respectively.

Genetic diversity analysis of some Egyptian Origanum and Thymus species using AFLP markers

BACKGROUND

In the present investigation, two genera of family Labiatae (genus Origanum and genus Thymus including their available species in Egypt) were analyzed genetically on DNA level using amplified fragment length polymorphism (AFLP) markers. Four selective primer combinations (E-AGC/M-CAA, E-AGC/M-CAC, E-AGG/M-CTC, and E-ACC/M-CAT) were used to detect genetic variations (polymorphisms) within and between the studied plant species of each genus and with their cultivated relatives.

RESULTS

A total of 193 amplified fragments were obtained overall primer combinations with a disparity in the number of bands for each primer combination. The primer combination E-AGG/M-CTC exhibited a large number of amplicons (67) compared to the other primers with polymorphism percentage 69%. The polymorphism information content (PIC) was calculated for the four primer combinations showing a very high values ranging between 0.98 and 0.99. On the other hand, Thymus species (Thymus vulgaris, Thymus capitatus L., and Thymus decassatus Benth.) exhibited a total number of 171 amplicons for all primer combinations with an average of 42 bands. The primer combination E-AGG/M-CTC produced the largest number of bands (62 bands) with polymorphism percentage 35%, even though the primer combination AGC/M-CAA was more efficient to give high polymorphisms within Thymus species where it resulted in a total of 35 bands with polymorphism percentage 63%. The PIC values were calculated ranging from 0.96 to 0.99.

CONCLUSION

One can conclude that AFLP technique was informative and efficient technique to give a good coverage of Origanum and Thymus genomes. Furthermore, it was helpful to elucidate the genetic variations and phylogenetic relationships within the studied species as a basis for further studies on these genera and related species.

Antiprotozoal Activity of Turkish Origanum onites Essential Oil and Its Components

Essential oil of Origanum species is well known for antimicrobial activity, but only a few have been evaluated in narrow spectrum antiprotozoal assays. Herein, we assessed the antiprotozoal potential of Turkish Origanum onites L. oil and its major constituents against a panel of parasitic protozoa. The essential oil was obtained by hydrodistillation from the dried herbal parts of O. onites and analyzed by Gas Chromatography-Flame Ionization Detector (GC-FID) and Gas Chromatography coupled with Mass Spectrometry (GC-MS). The in vitro activity of the oil and its major components were evaluated against Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani, and Plasmodium falciparum. The main component of the oil was identified as carvacrol (70.6%), followed by linalool (9.7%), p-cymene (7%), γ-terpinene (2.1%), and thymol (1.8%). The oil showed significant in vitro activity against T. b. rhodesiense (IC₅₀ 180 ng/mL), and moderate antileishmanial and antiplasmodial effects, without toxicity to mammalian cells. Carvacrol, thymol, and 10 additional abundant oil constituents were tested against the same panel; carvacrol and thymol retained the oil’s in vitro antiparasitic potency. In the T. b. brucei mouse model, thymol, but not carvacrol, extended the mean survival of animals. This study indicates the potential of the essential oil of O. onites and its constituents in the treatment of protozoal infections.

Essential Oil and Ethanol Extract of Oregano (Origanum vulgare L.) from Armenian Flora as a Natural Source of Terpenes, Flavonoids and other Phytochemicals with Antiradical, Antioxidant, Metal Chelating, Tyrosinase Inhibitory and Antibacterial Activity

Background:

Origanum vulgare is used in Armenian cuisine as well as in folk medicine. The aim of this investigation was to determine the peculiarities of the chemical composition of Armenian flora’s oregano essential oil (EO) and ethanol extract (EE) and to characterize mainly antioxidant and antibacterial properties in vitro.

Methods:

EO of plant aerial parts was extracted by the hydro-distillation method, and the composition was analyzed by gas-chromatography (GC). EE was prepared using ethanol as a solvent. Antioxidant, antibacterial and other biological activity of EO and EE was determined using appropriate methods.

Results:

The terpenes were found to be the greatest part of oregano EO (β-caryophyllene epoxide - 13.3 %; β- caryophyllene -8.2 %; ο-cymene - 5.2 %). The flavonoid content of EE was 3.9±0.7 mg g-1 catechin equivalents. Antiradical activities of EO and EE expressed with half-maximum inhibitory concentrations were 1057 µg mL-1 and 19.97 µg mL-1. The antioxidant index in the case of using extract (1000 µg mL-1) was 77.3±1.5 %. The metal chelating activity of EE was 74.5±0.2 %. The tyrosinase inhibitory activities of EO, EE and arbutin were 26.5±0.3 %, 6.5±0.2 % and 50±0.1 %, respectively. Both EO and EE of oregano were able to suppress the growth of testmicroorganisms including clinical pathogen isolates, but have moderate antimicrobial activity. EO antibacterial activity against ampicillin-resistant Escherichia coli was similar to the activity against non-resistant strain. EE was not active against ampicillin-resistant E. coli in contrast to non-resistant one.

Conclusion:

The results indicate high antioxidant and moderate antibacterial as well as high antiradical, metal chelating, tyrosinase inhibitory activity of oregano EO and EE, which can be used as a natural source of terpenes, flavonoids and other phytochemicals in medicine, pharmaceutics, cosmetics and food industry. EO has antibacterial activity also against ampicillin-resistant E. coli.

Characterisation and screening of antimicrobial essential oil components against clinically important antibiotic-resistant bacteria using thin layer chromatography-direct bioautography hyphenated with GC-MS, LC-MS and NMR

INTRODUCTION

The antimicrobial activity of many essential oils (EOs) is well established, indicating that EOs may be a source of compounds for antimicrobial drug development. Thin layer chromatography-direct bioautography (TLC-DB) can quickly identify antimicrobial components in complex mixtures and can be applied to the screening of EOs for lead compounds.

OBJECTIVES

This study aimed to identify antimicrobial components of oregano, rosewood and cumin EOs against antibiotic-sensitive and -resistant bacteria using TLC-DB and a multi-faceted approach of GC-MS, LC-MS and NMR techniques to characterise bioactive compounds. The study also aimed to quantify the antimicrobial activity of bioactive compounds in order to evaluate their potential for the development of therapies against antibiotic-resistant bacteria.

MATERIALS AND METHODS

EOs were eluted on TLC plates and sprayed with a suspension of Staphylococcus aureus, Enterococcus faecium, Escherichia coli or Pseudomonas aeruginosa (antibiotic-sensitive and -resistant isolates). Zones of inhibition, visualised with iodonitrotetrazolium chloride, were subject to GC-MS, LC-MS and NMR to characterise the bioactive compounds.

RESULTS

Seven compounds were identified from the three EOs using GC-MS, while LC-MS and NMR failed to detect the presence of any further non-volatile or heat labile compounds. Carvacrol was most antimicrobial compound identified, with minimum inhibitory concentrations ranging 0.99-31.62 mM.

CONCLUSION

The identified antimicrobial compounds present in oregano, rosewood and cumin EOs including carvacrol may be candidates for the development of novel antimicrobial therapies against antibiotic-resistant bacteria.

The synergistic effect of hydroalcoholic extracts of Origanum vulgare, Hypericum perforatum and their active components carvacrol and hypericin against Staphylococcus aureus

AIM

This study was designed to evaluate the synergistic activities of hydroalcoholic extracts of medicinal plants Origanum vulgare and Hypericum perforatum and their active components, carvacrol and hypericin against Staphylococcus aureus.

METHODS

The synergistic effects of the plants, as well as carvacrol and hypericin, were examined using a checkered method against S. aureus (ATCC 12600).

RESULTS

A fractional inhibitory concentration of 0.5 was obtained for combination of O. vulgare and H. perforatum and 0.49 for combination of the active ingredients carvacrol and hypericin, both of which indicated a synergistic effect.

CONCLUSION

This preliminary evaluation demonstrated a synergistic property of O. vulgare and H. perforatum extracts in treating S. aureus infection. This study indicates that combination of the plants, as well as combination of carvacrol and hypericin, might be used as a new antibacterial strategy against S. aureus.

Anti-dermatophytes Activity of Origanum compactum Essential Oil at Three Developmental Stages

The main aim of this study is to determine the chemical compounds of Origanum compactum essential oils (OCEO) at three phenological stages (vegetative, flowering, and post-flowering) and to evaluate their antifungal activity against three dermatophytes fungal strains: Trichophyton violaceum, Trichophyton tonsurans, and Trichophyton mentagrophytes using direct contact method. The main compounds of OCEO are carvacrol, thymol, p-cymene, and γ-terpinene. Oregano EOs showed important antifungal activities with some variability between EOs and fungal testing. At a concentration of 0.75% (v/v), the best inhibition values showed with OCEO at vegetative stage against Trichophyton mentagrophytes (95.17%), Trichophyton tonsurans (92.47%), and Trichophyton violaceum (91.41%). The OCEO at vegetative stage also showed the best IC50 (concentration of an inhibitor where the response is reduced by half) values of 52.86, 0.56, and 0.57% (v/v) against Trichophyton mentagrophytes, Trichophyton tonsurans, and Trichophyton violaceum, respectively. The findings reveal that OCEO is a good source of anti-dermatophytes agents.

Bactericidal Property of Oregano Oil Against Multidrug-Resistant Clinical Isolates

Development of non-antibiotic alternatives to treat infections caused by multidrug-resistant (MDR) microbes represents one of the top priorities in healthcare and community settings, especially in the care of combat trauma-associated wound infections. Here, we investigate efficacy of oregano oil against pathogenic bacteria including MDR isolates from the combat casualties in vitro and in a mouse burn model. Oregano oil showed a significant anti-bacterial activity against 11 MDR clinical isolates including four Acinetobacter baumannii, three Pseudomonas aeruginosa, and four methicillin-resistant Staphylococcus aureus (MRSA) obtained from combat casualties and two luminescent strains of PA01 and MRSA USA300, with a MIC ranging from 0.08 mg/ml to 0.64 mg/ml. Oregano oil also effectively eradicated biofilms formed by each of the 13 pathogens above at similar MICs. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) revealed that oregano oil damaged bacterial cells and altered the morphology of their biofilms. While efficiently inactivating bacteria, there was no evidence of resistance development after up to 20 consecutive passages of representative bacterial strains in the presence of sublethal doses of oregano oil. In vivo study using the third-degree burn wounds infected with PA01 or USA300 demonstrated that oregano oil, topically applied 24 h after bacterial inoculation, sufficiently reduced the bacterial load in the wounds by 3 log₁₀ in 1 h, as measured by drastic reduction of bacterial bioluminescence. This bactericidal activity of oregano oil concurred with no significant side effect on the skin histologically or genotoxicity after three topical applications of oregano oil at 10 mg/ml for three consecutive days. The investigation suggests potentials of oregano oil as an alternative to antibiotics for the treatment of wound-associated infections regardless of antibiotic susceptibility.

Thymol inhibits oral squamous cell carcinoma growth via mitochondria-mediated apoptosis

BACKGROUND

Thymol is a transient receptor potential ankyrin subtype 1 channel, (TRPA1) agonist found in thyme and oregano. Thymol has antioxidant, anti-inflammatory, and antimicrobial properties; thus, thymol is added to many commercially available products including Listerine mouthwash. Thymol is also cytotoxic to HL-60 (acute promyelocytic leukemia) cells in vitro. Therefore, we evaluated the effects of thymol against oral squamous cell carcinoma (OSCC) and its anticancer mechanism-of-action.

METHODS

The antiproliferative effects of thymol in OSCC Cal27 cells were determined by MTS assays. Antitumor effects were evaluated in Cal27- and HeLa-derived mouse xenografts. Calcium imaging, mitochondrial transmembrane potential (ΔΨm) studies, and Western blot analysis of cleaved PARP (c-PARP) evaluated thymol's mechanism-of-action.

RESULTS

Thymol had significant, long-lasting antiproliferative effects in vitro. In vivo, thymol displayed significant antitumor effects in Cal27-derived tumors. Thymol's anticancer effects were confirmed in HeLa-derived xenografts demonstrating that thymol effects are not tumor-type specific. Calcium imaging verified calcium influx in Cal27 cells that were reversed with the TRPA1 antagonist, HC030031. However, no calcium influx was seen in HeLa cells indicating that TRP channels do not regulate thymol cytotoxicity. This was confirmed using cell viability assays in which pre-treatment with HC030031 had no effect on thymol cytotoxicity. Instead, ΔΨm studies revealed that thymol induces significant ΔΨm depolarization and apoptosis.

CONCLUSION

Our findings provide the first evidence of thymol's novel antitumor effects against OSCC in vivo, which do not rely on TRPA1 activity. Instead, we show that thymol induces mitochondrial dysfunction and apoptosis and may be efficacious against multiple cancers.

Chemical analysis of aqueous extracts of Origanum majorana and Foeniculum vulgare and their efficacy on Blastocystis spp. cysts

BACKGROUND

Origanum majorana (O. majorana) and Foeniculum vulgare (F. vulgare) are traditionally used herbs in Egypt for treatment of several diseases including parasitic diseases. The Purpose was to determine the efficacy of O. majorana and F. vulgare aqueous extracts (AEs) on Blastocystis spp. in vitro, and to reveal their phenolic, flavonoids components and antioxidant activities through chemical analysis.

METHODS

The Efficacy of both plant AEs on human Peripheral Blood Mononuclear Cells (PBMCs) viability was assessed using MTT assay. Isolated Blastocystis spp. cysts from patients' diarrhea samples were incubated with different concentrations of O. majorana and F. vulgare AEs for different incubation periods (24, 48 and 72 h) in comparison with nitazoxanide (NTZ) as a drug control. The total contents of phenolic and flavonoid compounds in the AEs and their ability to reduce DPPH were assessed. High performance liquid chromatography (HPLC) analysis for quantitative and qualitative determination of the phenolic and flavonoid contents was performed.

RESULTS

O. majorana AE at a dose of 400 µg /ml showed efficacy rates of 96% and 100% against Blastocystis parasite after 48 and 72 h, respectively, which nearly equivalent to NTZ at a dose of 500 µg/ml. F. vulgare at a dose of 250 µg/ml showed less efficacy rate of 56.4% after 48 h and increased to 70.7% after 72 h. Both extracts contain high phenolic and flavonoid compounds that possess antioxidant and free radical scavenging activities.

CONCLUSION

O. majorana and F. vulgare AEs showed dose and time dependent anti-Blastocystis activity.

Flavonoids and Phenolic Acids from Oregano: Occurrence, Biological Activity and Health Benefits

Several herb species classified as oregano have been widely used in folk medicine to alleviate inflammation-related diseases, respiratory and digestive disorders, headaches, rheumatism, diabetes and others. These potential health benefits are partially attributed to the phytochemical compounds in oregano such as flavonoids (FL) and phenolic acids (PA). Flavonoids and phenolic acids are among the most abundant and most studied phytochemicals in oregano species. Epidemiological, in vitro and in vivo experiments have related long-term consumption of dietary FL and PA with a decreased risk of incidence of chronic diseases. The aim of this manuscript is to summarize the latest studies on the identification and distribution of flavonoids and phenolic compounds from oregano species and their potential antioxidant, anti-inflammatory and anti-cancer health benefits.

In-vitro antimicrobial activity and identification of bioactive components using GC-MS of commercially available essential oils in Saudi Arabia

This study was designed to evaluate antimicrobial activity and chemical composition of four different plant essential oils i.e. Ginger oil (GiO), Black seed oil (BSO), Oregano oil (OO) and Rose oil (RO) against different bacterial and fungal strains. Anti-microbial activities of selected essential oils were determined by the microbiological technique using Agar well diffusion assay. After in vitro study, most of the essential oils showed antimicrobial activity against all the selected pathogens. Among all the tested oils, GiO showed strong antimicrobial activity. GiO showed highest antimicrobial activity against Shigella (119.79%), Enteococcus hirae (110.61%) and Escherichia coli (106.02%), when compared with the tetracycline (50 µg/mL) activity. However, Antifungal activity of GiO was found to be present against Candida albicans and Aspergilluas flavus, when compared with clotrimazole (50 µg/mL) activity. Among all the selected bacteria, BSO showed maximum antimicrobial activity against the E. coli followed by Citrobacter freundii. Moreover, BSO had highest zone of inhibition against the C. ablicans (33.58%). OO indicated that, Shigella had the highest sensitivity (12.6 ± 0.58, 131.25%), followed by E. hirae (19.1 ± 0.61, 96.46%) and Salmonella typhi (15.2 ± 0.27, 83.06%) when compared with tetracycline activity. OO showed poor sensitivity against all the selected fungal strains. Furthermore, Gas Chromatography analysis revealed that, Gingerol (10.86%) was the chief chemical constituents found in GiO followed by α-Sesquiphellandrene (6.29%), Zingiberene (5.88%). While, BSO, OO and RO had higher percentage of p-Cymene (6.90%), Carvacrol (15.87%) and Citronellol (8.07%) respectively. The results exhibited that the essential oils used for this study was the richest source for antimicrobial activity which indicates the presence of broad spectrum antimicrobial compounds in these essential oils. Hence, essential oils and their components can be recommended for therapeutic purposes as source of an alternative medicine.

Antioxidant Activity of Spices and Their Impact on Human Health: A Review

Antioxidants are substances that prevent oxidation of other compounds or neutralize free radicals. Spices and herbs are rich sources of antioxidants. They have been used in food and beverages to enhance flavor, aroma and color. Due to their excellent antioxidant activity, spices and herbs have also been used to treat some diseases. In this review article, the chemical composition and antioxidant activity of spices and culinary herbs are presented. The content of flavonoids and total polyphenols in different spices and herbs are summarized. The applications of spices and their impacts on human health are briefly described. The extraction and analytical methods for determination of antioxidant capacity are concisely reviewed.