Oregano Species Research Articles

Extraction of Origanum onites L. using an industrial-type microwave-assisted distillation (MWAD) system: Increasing energy saving and essential oil yield compared to conventional steam distillation

Oregano species are commonly utilized for different medical purposes as well as for other essential oil products. One of the oregano species, Origanum onites L. has a dense natural distribution in the Aegean and Mediterranean regions of Turkey and Greece and is cultivated mainly in Denizli province. Turkey meets 80 % of the world's oregano market. Since Origanum onites L., whose essential oils are of high quality, has a high economic value, assessing the quality and production of essential oils extracted using various methods is important. Microwave-assisted distillation (MWAD) processes are generally carried out under laboratory conditions using clevenger or small-scale specialized instruments made for research in the lab. Thus, designing industrial-scale distillation systems with microwave power is necessary. For this reason, an industrial-type MWAD system with 12 magnetrons (power output of 1 kW) was developed in this work, and both conventional steam distillation (SD) and MWAD of oregano plant were realized, as a novelty. This study experimentally investigated the effects of microwave power and applied time on both energy saving (%) and essential oil yield (%). System was designed to distill 9 kg of dried plants chopped at once and the results obtained were used to obtain reference data for MWAD systems that can be used in industrial systems. The obtained essential oil samples were subjected to GC-MS analysis for chemical analysis. A statistical analysis of the experimental data was performed via Design Expert software to elucidate the impact of microwave power and time on essential oil yield and energy savings. When the results were evaluated, the essential oil yield of oregano plant increased by 4–22 % with the MWAD system compared to SD. The highest increase in yield was achieved with the test (500 W + 40 min). Also, the distillation time with MWAD system was 50 % shorter than with SD system. The MWAD system consumed at least 25 % less energy. According to the GC-MS analysis results, carvacrol increased steadily depending on the time applied microwave power as well as oxygenated monoterpenes. The chemical composition of the essential oils obtained from the proposed MWAD system did not show any incompatible value according to the ISO-7925 standard. As a result, this proposed method can be safely used in industrial systems.

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.

Qualitative and quantitative food authentication of oregano using NGS and NMR with chemometrics

Culinary herbs and spices represent increasingly popular food products, especially in an environment of increased consciousness of food quality. Health-conscious consumers expect clean and reliable labels for food products. For spices this implies significant challenges considering complex and long supply chains, often with unknown sources or intermediates. A recent report by the EU Joint Research Centre identified oregano as one of the most vulnerable spices for adulterations. The analysis of herbs is complex, traditionally using visual inspection, and more recently genetic and chemical analysis. Here, metabarcoding by next generation sequencing (NGS) has been used to identify the nature of oregano products and possible adulterations. In parallel, metabolite extracts are generated and analysed on a 400 MHz Nuclear Magnetic Resonance (NMR) spectrometer. NMR metabolic profiles in conjunction with multivariate statistics was used to identify oregano species and to identify and quantify the level of adulteration with other plant products. • New analytical strategy for qualitative and quantitative authentication of oregano by combination of metabarcoding by NGS and metabolomics/chemometrics by NMR. • Unique biomarkers discovered in adulterants by NMR. • Metabolomic profiles obtained by NMR correlate well with oregano species and regional origin. • Quantification of the percentage of an adulterant with error rates of 3–7%. • Simultaneous quantification of two and more different adulterants in a specimen.

Antioxidant potential, cytokines regulation, and inflammation-related genes expression of phenolic extracts from Mexican oregano.

The Mexican population traditionally uses oregano infusions to treat oxidative and inflammation-related disorders. Therefore, this study was focused on the examination of the antioxidant capacity and potential against inflammation from three Mexican oregano species (Lippia graveolens [LG], Lippia palmeri [LP], and Hedeoma patens [HP]). The extracts from LG showed a superior total phenolic content. LG, LP, and HP exhibited a higher capacity to inhibit the radical DPPH (up to 90.33 ± 0.25%) and significantly lowered the release of MCP-1 and IL-6. At the same time, LG and HP increased the secretion of IL-10. Extracts from LG, LP, and HP did not significantly diminish the expression of il-1β or inos, although a slight decrease in inos expression was observed. Our findings support that phenolic extracts from L. graveolens, L. palmeri, and H. patens possess antioxidant and anti-inflammatory properties and might be potential therapeutic candidates against oxidative and inflammation-related diseases. PRACTICAL APPLICATIONS: Oregano species have traditionally been exploited as remedies against inflammatory-related diseases, namely headaches, asthma, bowel disorders, and rheumatism. This study explored the antioxidant potential of three Mexican oregano species (Lippia graveolens, Lippia palmeri, and Hedeoma patens) and their anti-inflammatory effects in a murine cell model. Phenolic extracts from oregano showed antioxidant capacity and exerted activity against inflammation by improving anti-inflammatory cytokines secretion or negatively regulating pro-inflammatory cytokines. The results of our study demonstrate that the phenolic extracts from these Mexican oregano species have the potential in treating inflammation-related diseases.

Oregano as a potential source of antidiabetic agents.

Oregano is the name given to a great variety of herbs belonging mainly to the Lamiaceae and Verbenaceae botanical families. Oregano species are rich sources of phytochemicals such as phenolic compounds like rosmarinic acid, salvianolic acid, and luteolin, among others. A few articles have previously accessed some potential pharmacological bioactivities of oregano plants; however, none has focused on the antidiabetic studies. This review aims to summarize recent studies about the potential effect of phenolic compounds from oregano plant species. The reports were retrieved from electronic databases such as PubMed, Web of Science, National Center for Biotechnology Information (NCBI), and Scopus. In addition, articles related to the mentioned topics and published between 2004-2022 were selected. The results from this study show that the antidiabetic pharmacological reports of oregano phenolic compounds are mainly in vitro reports. Therefore, the diversity of oregano species yields a broad variety of phenolic constituents, where preclinical and clinical studies are strongly recommended.

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.

In vitro antiviral activity of Thymbra spicata L. extract on bovine respiratory viruses (BCoV, BPIV-3, BRSV, BVDV and BoHV-1)

Viral pathogens are the primary agents in bovine respiratory disease cases, and there is no direct effective antiviral drug application. Thymbra is a genus of oregano commonly found in Turkey. The primary component (34.9%) of the extract obtained from Thymbra spicata L. is the carvacrol which is used in traditional medicine. This study evaluates the potential antiviral activity and inactivation efficiency of T. spicata L. extract against bovine respiratory viruses, including BCoV, BPIV-3, BRSV, BVDV and BoHV-1. To evaluate its effect on viral replication, viral titres were taken from infected cells treated with non-cytotoxic T. spicata L. extract concentrations (0.75% and 1.5%, 1.32 and 2.64µg/ml of carvacrol as active ingredient, respectively) and compared to non-treated infected cells. The viruses were treated directly with 1.5% T. spicata L. extract, and the viral titres were evaluated at certain time points to determine the efficiency of direct inactivation. The number of infectious virions for BCoV, BPIV-3, BRSV, BVDV and BoHV-1 treated with 1.5% T. spicata L. extract were decreased by 99.44%, 100.0%, 94.38%, 99.97% and 99.87%, respectively.T. spicata L. extract strongly inhibits the replication of mentioned viruses in a dose-dependent manner in vitro. In addition, T. spicata L. extract shared direct inactivation efficiency on the mentioned viruses in a time-dependent manner. This study shows the antiviral efficiency of T. spicata L. on BRD-related viral agents for the first time. The oregano species T. spicata and its main component, carvacrol, may have a potential for antiviral activity in the alternative treatment of respiratory viral diseases in cattle. Given the similarity of replication strategies, obtained data suggest the possible efficiency of T. spicata L. on human respiratory viruses.

The biosynthesis of thymol, carvacrol, and thymohydroquinone in Lamiaceae proceeds via cytochrome P450s and a short-chain dehydrogenase

Thymol and carvacrol are phenolic monoterpenes found in thyme, oregano, and several other species of the Lamiaceae. Long valued for their smell and taste, these substances also have antibacterial and anti-spasmolytic properties. They are also suggested to be precursors of thymohydroquinone and thymoquinone, monoterpenes with anti-inflammatory, antioxidant, and antitumor activities. Thymol and carvacrol biosynthesis has been proposed to proceed by the cyclization of geranyl diphosphate to γ-terpinene, followed by a series of oxidations via p-cymene. Here, we show that γ-terpinene is oxidized by cytochrome P450 monooxygenases (P450s) of the CYP71D subfamily to produce unstable cyclohexadienol intermediates, which are then dehydrogenated by a short-chain dehydrogenase/reductase (SDR) to the corresponding ketones. The subsequent formation of the aromatic compounds occurs via keto-enol tautomerisms. Combining these enzymes with γ-terpinene in invitro assays or invivo in Nicotiana benthamiana yielded thymol and carvacrol as products. In the absence of the SDRs, only p-cymene was formed by rearrangement of the cyclohexadienol intermediates. The nature of these unstable intermediates was inferred from reactions with the γ-terpinene isomer limonene and by analogy to reactions catalyzed by related enzymes. We also identified and characterized two P450s of the CYP76S and CYP736A subfamilies that catalyze the hydroxylation of thymol and carvacrol to thymohydroquinone when heterologously expressed in yeast and N. benthamiana Our findings alter previous views of thymol and carvacrol formation, identify the enzymes involved in the biosynthesis of these phenolic monoterpenes and thymohydroquinone in the Lamiaceae, and provide targets for metabolic engineering of high-value terpenes in plants.

NMR-based metabolomics for frauds detection and quality control of oregano samples

In this work 1H NMR metabolomics has been employed for quality control of oregano samples. NMR data and morphological analysis (MA) were combined by PCA, obtaining a model able to individuate non-marketable samples, and to distinguish between the two marketable oregano species (Origanum vulgare and O. onites) on the basis of their metabolomic profile. Through this approach distinctive biomarkers of the two species were found, namely apigenin and p-cymene for O. onites, and salvianolic acid B for O. vulgare. Furthermore, the percentage of the samples’ impurity (evaluated by MA) and the metabolomic profiles were correlated by OPLS models, which showed that, in addition to the species-specific biomarkers, thymol and rosmarinic acid (common to both marketable species) strongly correlate to oregano degree of purity. Cistus was one of the most frequent contaminants, thus, a further OPLS model, able to detect the degree of cistus contamination in oregano samples, was also built.

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.

Economic Importance and Usage Fields of Oregano Species Growing In Turkey

Türkiye coğrafi konumu, iklim ve bitki çeşitliliği, tarımsal potansiyeli, geniş yüzölçümü sayesinde tıbbi ve aromatik bitkiler ticaretinde önde gelen ülkelerden biridir. Kekik ilk çağlardan itibaren ilaç, gıda, içecek, tekstil, boya, parfümeri ve kozmetik gibi farklı alanlarda kullanılmaktadır. Antimikrobiyal özellikleri nedeniyle organik hayvancılıkta yem rasyonlarına antelmintik (solucan düşürücü) ve antibiyotik amaçlı ilave edilebilmektedir. Kekik bitkisi ülkemizden ihracatı yapılan önemli türler arasındadır. Bu derlemede kekik türlerinin kullanım alanları, sınıflandırılması ve orijini, uçucu yağı ve bileşenleri, ekonomik önemi ve kalite kriterleri ile ilgili bilgiler verilmiştir.

THE POTENTIAL APPLICATION OF Origanum dubium Boiss. ESSENTIAL OIL AS A SEED PROTECTANT AGAINST BEAN AND TOMATO SEED-BORNE BACTERIAL PATHOGENS

Origanum dubium is a valuable wild oregano species of the natural flora of Antalya, Turkey. In this study, we extracted essential oil (EO) by hydro-distillation of the aerial parts of selected O. dubium chemotype with highest EO content, and analyzed by gas chromatography/mass spectrometry. Carvacrol was the pri- mary component (85.9%) among 24 different compounds in the EO. The volatile test showed minimum inhibitory effect of the EO against Xanthomonas axonopodis pv. vesicatoria, Clavibacter michiganen- sis subsp. michiganensis, Xanthomonas axonopodis pv. phaseoli, Xanthomonas axonopodis pv. phaseoli var. fuscans, and Pseudomonas syringae pv. tomato, at 309, 303, 318, 254, and 901 µL/mL, respectively. A 1-hour treatment of bean and tomato seeds in the volatile phase of the EO effectively sterilized the seeds from bacterial pathogens without inhibiting their germination. To the best of our knowledge, this is the first study on the potential for the use of O. dubium EO as a seed protectant against bean and tomato seed-borne bacterial pathogens.

Cellular antioxidant activity and in vitro inhibition of α-glucosidase, α-amylase and pancreatic lipase of oregano polyphenols under simulated gastrointestinal digestion

Different oregano species have been traditionally used as infusions in folk medicine. Oregano medicinal properties, such as antioxidant and anti-inflammatory, have been partially attributed to its polyphenolic content. However, information regarding bioaccessibility of oregano polyphenols is limited. Cell-based antioxidant activity, and in vitro hypoglycemic, and hypolipidemic properties of polyphenolic extracts from three species of oregano species, namely, Hedeoma patens (HP), Lippia graveolens (LG) and Lippia palmeri (LP), subjected to simulated gastrointestinal digestion were evaluated. LC-TOF-MS analysis of HP, LG and LP allowed the identification of 9 flavonoids and 6 hydroxycinnamic acid derivatives with nutraceutical significance. Oregano polyphenolic extracts and digests from HP, LG, and LP exhibited cellular antioxidant capacity, hypoglycemic and hypolipidemic properties. Altogether, our results suggest that HP, LG and LP polyphenols exhibit potential for use as hypoglycemic, hypolipidemic, and antioxidant agents.

Divergence in tissue-specific expression patterns of genes associated with the terpeniod biosynthesis in two oregano species Origanum vulgare L., and Origanum majorana

Oregano (Origanum vulgare) and marjoram (O. majorana) are two discrete (in terms of sensory characteristics) species within the genus Origanum (Lamiaceae). Their aroma, flavor, and pharmaceutical value are a result of their essential oils, which comprise mainly of monoterpenes and sesquiterpenes. Marjoram is rich in bicyclic monoterpene cis-sabinene hydrate derived from the biosynthetic “sabinyl” pathway while the phenolic monoterpene carvacrol, arising from the “cymyl” pathway, is the distinctive feature of oregano. To investigate differences between the terpene biosynthetic pathways of both species, we identified key enzymes of terpene biosynthesis from the two species of genus Origanum. The heterologous expression of these enzymes showed that each formed multiple mono- or sesquiterpene products and, in combination, were responsible for the direct production of almost all terpenes found in Origanum essential oils. The correlation between essential oil composition and relative terpene synthase transcript concentrations in O. vulgare and O. majorana demonstrated that monoterpene synthase activity is predominantly regulated at the level of transcription and that the phenolic monoterpene alcohol thymol is derived from α-terpinene, the product of a single monoterpene synthase. The combination of heterologously expressed terpene synthases for in vitro assays resulted in blends of mono- and sesquiterpene products that strongly resembled those found in vivo, indicating that terpene synthase expression levels directly control the composition of the essential oils. These results will facilitate the metabolic engineering, directed breeding of Origanum cultivars with higher quantities of essential oils, and improved oil compositions.

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.

The Influence of Different Oregano Species on the Antioxidant Activity Determined Using HPLC Postcolumn DPPH Method and Anticancer Activity of Carvacrol and Rosmarinic Acid.

The aim of this study was to evaluate concentration-dependent antioxidant and anticancer activities of CA and RA in ethanol extracts of three different Oregano species (Origanum onites L., Origanum vulgare L., and Origanum vulgare ssp. hirtum). The study revealed the highest RA antioxidant activity in O. vulgare ssp. hirtum (9550 ± 95 mmol/g) and the lowest in O. vulgare L. (2605 ± 52 mmol/g) (p < 0.05). The highest CA amount was present in O. onites L., which was 1.8 and 4.7 times higher (p < 0.05) than in O. vulgare ssp. hirtum and O. vulgare L., respectively. The anticancer activity was evaluated on human glioblastoma (U87) and triple-negative breast cancer (MDA-MB231) cell lines in vitro. RA anticancer activity was negligible. CA and the extracts were about 1.5–2 times more active against MDA-MB231 cell line (p < 0.05) compared to U87 cell line. The anticancer activities of three tested extracts were similar against U87 cell line (p > 0.05) but they had different activities against MDA-MB231 cell line.

Agronomic and chemical performance of selected Origanum dubium Boiss.clones for industrial use

Origanum dubium Boiss. is an economically important wild oregano species that is intensely collected from the natural flora of Antalya, Turkey. This herb is used mainly to produce an essential oil due to its high yield and high carvacrol content. The aim of this study was to improve the biomass yield and essential oil and carvacrol content of O. dubium for industrial use. In preliminary studies, a basic population was established using seeds collected from wild plants and then trials of A and B clones were run. Dry biomass yield per A clone plant and essential oil content varied at 5.05-40.86 g and 5%-14%, respectively. Carvacrol was the main constituent in all samples and varied from 72.26% to 88.21%. Dry biomass yield per B clone plant was 21.64-95.52 g, dry leaf yield per plant was 14.80-48.77 g, essential oil content was 6%-9%, and carvacrol rate was 80.99%-88.46%. After evaluating the B clones, 10 clones were selected and they were planted in a plot with a randomized block design and three replications in Antalya in 2014. In this trial, clone 7 produced the highest biomass yields per plot (2874.33 g fresh and 1185.00 g dry) and the highest fresh (2379.67 g) and dry (795.33 g) leaf yields per plot. Essential oil content varied from 7.97% to 11.16%. Clone 137 had the best essential oil content (11.16%), followed by clone 7 (10.76%) and clone 119 (10.59%). Clone 7 appeared to be superior to the others in terms of agronomic features, followed by clone 119. Essential oil and carvacrol rates were 10.76% and 85.02% in clone 7 and 10.59% and 91.04% in clone 119, respectively. Consequently, clones 7 and 119 appeared to be superior to the others.

Clone Selection for High Quality Types of Oregano (Origanum dubium Boiss.)

Origanum dubium Boiss. is one of the economically important wild oregano species and it is intensely collected from the natural flora of Antalya in Turkey. Carvacrol chemotype of Origanum dubium is used mainly for essential oil production due to its high essential oil content. In this study, chemical diversity of Origanum dubium was investigated in order to develop new cultivars with improved essential oil yield and carvacrol content using clone selection method under cultivated condition. Essential oils obtained by hydrodistillation of the aerial parts of Origanum dubium were analysed by GC-MS and 24 different components were identified. In these genotypes, carvacrol was the major component and followed by p-cymene, γ–terpinene, myrcene and α-thujene. Among the selected genotypes, essential oil yields were varied between 5.0% to 14.0%; carvacrol rates were varied between 73.76% to 88.21%; and p-cymene rates were varied between 3.16% to 9.10%.

Protective role of terpenes and polyphenols from three species of Oregano (Lippia graveolens, Lippia palmeri and Hedeoma patens) on the suppression of lipopolysaccharide-induced inflammation in RAW 264.7 macrophage cells

Ethnopharmacological relevanceMexican oregano infusions have been traditionally used in México for the treatment of inflammation-related diseases, such as respiratory and digestive disorders, headaches and rheumatism, among others. Nevertheless, there is limited information regarding the phenolic compounds, terpenes and composition as well as biological activity of Mexican oregano. Aim of the studyTo determine the phenolic and terpene composition and to evaluate the anti-inflammatory potential of three species of Mexican oregano (Lippia graveolens (LG), Lippia palmeri (LP) and Hedeoma patens (HP)) in order to provide a scientific basis for their use. Materials and methodsWe obtained methanol and chloroform extracts from dried oregano leaves of each species. We used LC-DAD-ESI-MS/MS and GC-MS to determine the phenolic and terpene profiles of the leaves, respectively. We evaluated anti-inflammatory potential by measuring the effect of Mexican oregano extracts on some pro-inflammatory mediators, such as nitric oxide (NO) and reactive oxygen species (ROS) using lipopolysaccharide(LPS)-stimulated RAW 264.7 macrophage cells and evaluating cyclooxygenase activity (COX-1, COX-2). ResultsNine phenolic compounds (phenolic acids and flavonoids) and 22 terpenes (monoterpenes and sesquiterpenes) were detected in LG, LP and HP. We studied extracts from LG, LP and HP, and fractions from LG and LP in order to know their effect on some pro-inflammatory mediators. The phenolic and terpene extracts from LG, LP and HP exhibited significant inhibitory effect on ROS and NO production and mitochondrial activity in LPS-induced inflammation in RAW 264.7 macrophage cells. Nitric oxide production was also diminished by the terpene LG fraction LGF2 and the LP fractions LPF1, LPF2 and LPF3, confirming that both monoterpenes and sesquiterpenes are active compounds of oregano. Furthermore, the total extracts of LG, LP and HP exhibited non-selective inhibitions against the activity of the cyclooxygenases COX-1 and COX-2. ConclusionsOur results suggest that Lippia graveolens, Lippia palmeri and Hedeoma patens extracts have the potential to treat inflammatory diseases; their activity is mediated by polyphenols and terpenes. These findings support the claim for their traditional use in the treatment of inflammation-related diseases.

Multiplex HRM analysis as a tool for rapid molecular authentication of nine herbal teas

Herbal infusions, commonly referred to as herbal teas are among the most widely consumed hot beverages. Herbal tea authenticity is an issue of food safety. Reliable test methods, which could identify the botanical origin of herbal tea products, are required in order to protect the consumer from fraud and authenticate genuine products considering also the potential medical use of the herbs. Herein, we present a method that enables the simultaneous and reliable identification of 9 herbal species of sage, Greek sage, chamomile, mountain-tea, oregano, Cretan oregano, yarrow, lemon balm and rosemary. A high resolution melting (HRM) assay, targeting a fragment of the internal transcribed spacer 2 (ITS2) gene, was developed in order to authenticate the botanical origin of the herbal teas and their mixtures. Species-specific primers were designed and combined in a multiplex PCR resulting in fragments of different length and therefore different melting behavior for each species. The method was developed using dried tissue from each of the nine species. The multiplex HRM assay proposed in this work can be applied as routine tests for the verification of botanical origin in herbal teas and can be extended to authenticate all types of herbal foodstuffs.