Background: Marjoram belongs to the Lamiaceae family of plants is common in most parts of the world as a medicinal plant used. Objective: The aim of this study was to identify and compare the essential oil of two Origanum species to determine their composition is the most important. Methods: The aerial parts of two species of plants belong to Origanum genus, including Origanum vulgare L. and Origanum majorana L. in July 2013, in the beginning of flowering stage, were collected from the farm research of Medicinal Plants Institute. The aerial parts were dried in shadow condition in room and then after the essential oil content and its components were measured. The essential oils were extracted by clevenger apparatus and its constituents were determined by GC-MS. Results: The results indicated that amount of essential oil in O. vulgare was 0.13% (v/v), and its main components were trans-caryophyllene (21.46%), germacrene D (18.99%) and (E, E-α) farnesene (9.12%). While amount of essential oil in O. majorana was 1.09% (v/v), and its main components consisted of terpinolene-4-ol (23.11%), γ-terpinene (13.94%) and α-terpinene (8.11%). Conclusion: General differentiation between two species related to amount of component groups and their most important essential oil content. In O. vulgare, sesquiterpene hydrocarbons (69/18%) are the most amount of essential oil; while in O. majorana, monoterpene hydrocarbons (42/53%) are the major parts of essential oil.

Oregano (Origanum vulgare L.) is one of the most selled culinary and medicinal herb throughout the world. Flowering aerial parts and leaves of oregano have been used as a popular flavoring of food stuffs and as an antioxidant agent in cosmetics. Oregano contains a wide array of active components, including flavonoids, phenolic acids and glucosides, phenols and triterpenes.Several biological activities namely antibacterial, antifungal, antiviral, antidiabetic, antispasmodic, antimelanogenesis and antiproliferative have been demonstrated for oreganobased essential oils and extracts. Among the main bioactive constituents of these products, the phenols carvacrol and thymol, and the phenolic rosmarinic acid and origanoside proved to be strong antioxidant, anti-inflammatory and cardioprotective agents.

Introduction and purpose: Oregano (Origanum vulgare L. ) is an aromatic plant belonging to the Lamiaceae family. The aerial parts of this medicinal herb, including leaves, flowers, stems, and fruits, are used to e xtract essential oils. The current narrative review aimed to discuss and investigate the repellent efficacy of oregano essential oil in public health pests managemen t. Methods: In the current study, the search was conducted on PubMed, Web of Science, Science Direct, Scopus, and Google Scholar databases using the following keywords: "Oregano essential oil", "Public health pests", and "Repellency". Accordingly, seven articles were extracted and studied, and their results were extracted. Results: The chemical compositions of the Oregano essential oil varies according to its place of growth and its varieties. However, carvacrol and thymol have been introduced as the most important compounds of this plant's essential oil. Oregano essential oil has repellent efficacy against public health pests, including bed bugs, head lice, and brown-banded cockroach, and also against vectors of infectious diseases, such as Aedes albopictus, Culex pipiens, and Amblyomma americanum. Conclusion: Plant essential oils, such as oregano, have fewer harmful side effects on humans and the environment and are convenient and cost-effective to be prepared. So, they can be considered relatively proper alternatives for synthetic chemicals to control public health pests.

To study the effect of different levels of drought stress on growth, yield and some physiological and phytochemical characteristics of oregano (Origanum vulgare L. ssp. gracile), a pot experiment, in a randomized complete design with four treatments and five replications, was conducted. Drought stress treatments were 100% (non-stress), 80%, 60% and 40% of field capacity. The results showed that drought stress had significant effect on growth parameters, dry herb yield, leaf relative water content (RWC), total phenol and flavonoid content, antioxidant activity, a, b and total chlorophyll content, essential oil content and yield. There was no significant difference between drought stress treatments for carotenoids. As the soil water content decreased, plant height, stem diameter, number and length of axillary shoots, dry herb yield, RWC, a, b and total chlorophyll content and essential oil yield decreased, but total phenol and flavonoid content, antioxidant activity and essential oil content increased. Despite the decrease in dry herb yield, the difference between 80%, 60% and 40% treatments was not significant. The highest essential oil content (1. 54 ml/100 g DW) was observed in 60% of field capacity and the highest amounts of total phenol (5. 21 mg gallic acid/g FW), total flavonoid (0. 5 mg quercetin/g FW) and antioxidant activity (77. 36%) were obtained in 40% of field capacity. The highest percentage of essential oil (54. 1 mg / g dry matter) was observed in 60% of treatment capacity and the highest amount of total phenol (0. 51 mg gallic acid per gram of fresh material), total flavonoid (0. 5 mg Gram quercetin in grams of fresh milk) and antioxidant activity (37. 36%) in 40% of treatment capacity.

Oregano (Origanum vulgare L.), a native plant from Iran, belongs to Lamiaceae family. This species is traditionally utilized as sedative, diuretic, sweater and antiseptic, It is also used to treat of gastrointestinal diseases and constipation. Origanum species are widely used in spice industry. In this study, the essential oil of the aerial parts of a subspecies from this plant namely Origanum vulgare ssp. vulgare was isolated through hydro-distillation following its collection from South region of Chalus in its flowering as well as in seed stages. The extracted essential oils were analyzed through GC and GC/MS systems. Nienteen compounds were identified in the extracted essential oil in the flowering stage which constituted about 99% of the total oil. The latter sample was found to be rich in linalyl acetate (27.2%), g-terpinene (16.5%), 3-octanone (10.9%), b-pinene (8.4%) and carvacrol (6.4%). The 22 identified compounds made up 98.6% of the essential oil in seed stage, carvacrol (23.2%), a-pinene (15.8%), b-pinene (10.7%) and trans-caryophyllene (5.3%) constituted the main compounds. According to the GC/MS results, the monoterpenes were characterized as the most predominant essential oil fraction in either stage. The percentages of the other components of the oils were 16.8 and 5.7 for the plant at flowering and at its seed stages, respectively.

To investigate the effects of different salinity levels on the essential oil content, and some morphological and physiological characteristics of two oregano subspecies (Origanum vulgare subsp. gracile (K. Koch) letsw. and O. vulgare subsp. hirtum (Link) letsw. ), a factorial greenhouse experiment was conducted in a completely randomized design with four treatments and three replications. The salinity stress treatment was applied using sodium chloride in Hoagland nutrient solution at four levels of control (no stress), and mild (salinity 30 mM), moderate (salinity 60 mM), and severe (salinity 90 mM) stresses. According to the results, under salinity stress the growth indices, total carotenoids, and chlorophyll index decreased, but the activity of antioxidant enzymes and concentration of malondialdehyde and hydrogen peroxide increased in both subspecies. The wet and dry weight, carotenoids, hydrogen peroxide, and guaiacol peroxidase activity were obtained higher in subsp. hirtum than subsp. gracile. The percentage and essential oil composition were also affected by salinity. With increasing the salinity levels, the essential oil percentage was significantly increased compared to the control and its highest amount (0. 8%) was observed under mild stress. Thirty five compounds were identified in both oregano subspecies essential oil. Carvacrol (30-72%: subsp. hirtum crarvacrol more than the other subsp. ), γ,-terpinene, carvacrol methyl ether, and p-cymene were the main components of both subspecies. The results of this study demonstrated the superiority of subsp. hirtum to the other oregano subspecies in terms of the tolerance to salinity stress and also quantitative and qualitative yields.

Oregano (Origanum vulgare L. ) is a perennial herbaceous plant belonging to the fam. lamiaceae that is used as a spice for flavoring foods and also for medicinal purposes as carminative, diaphoretic, expectorant, sedative, stomachic, diuretic, antitussive, and antirheumatic. To evaluate the effects of salinity stress on some growth and physiological parameters, essential oil content, and nutrients absorption in two oregano subspecies, a factorial pot experiment was conducted in a completely randomized design with three replications. The experimental factors included two subspecies of oregano (ssp. vulgare and ssp. gracile) and salinity stress at four levels (0, 25, 50, and 100 mM of NaCl). The results showed that the salinity stress had a significant effect on the measured parameters. With increasing the salinity level, the growth characteristics (plant height, stem diameter, number of leaves, and dry matter yield), leaf relative water content (RWC), chlorophyll index (SPAD), percentage and essential oil yield, N, P, and K content and K/Na ratio in leaves and roots decreased, while Na and Cl content in leaves and roots of both subspecies increased. The two subspecies response to the different levels of salinity stress was different. The higher Na accumulation in the roots and higher K/Na ratio in the leaves compared to the roots indicated the ability of oregano subspecies to limit the transfer and accumulation of Na+ ions in their shoots. Overall, the findings of this study showed that the ssp. vulgare had higher tolerance to the salinity stress than ssp. gracile due to the less accumulation of Na and Cl ions, higher K/Na ratio, and lower reduction in chlorophyll index and dry matter yield.