Vol. 5(10), pp. 170-177, October, 2013 DOI: 10.5897/JPP2013.0285 ISSN 2141-2502 ©2013 Academic Journals http://www.academicjournals.org/JPP Journal of Pharmacognosy and Phytotherapy Review Medicinal importance of genus Origanum: A review Shayista Chishti1*, Zahoor A. Kaloo1 and Phalestine Sultan2 1 Department of Botany, University of Kashmir, Hazratbal, Srinagar, J&K, India. 2 Indian Institute of Integrative Medicine, Sanatnagar, Srinagar, J&K, India. Accepted 1 August, 2013 Genus Origanum is important medicinally as it has antimicrobial, antifungal, antioxidant, antibacterial, antithrombin, antimutagenic, angiogenic, antiparasetic and antihyperglycaemic activities. Phytochemical investigations of the species of this genus have resulted in the extraction of a number of important bioactive compounds. This emphasizes on the need of extensive study for reporting the additional information on the medicinal importance of other unattended species of genus Origanum. Key words: Lamiaceae, secondary metabolites, Origanum, carvacrol. INTRODUCTION Primary and secondary metabolites produced by plants, encompass a wide array of functions. Secondary metabolites have been subsequently exploited by humans for their beneficial role. At the same time, essential oils and their components are also being exploited for potential multipurpose functional use (Sawamura, 2000; Ormancy et al., 2001; Gianni et al., 2005). Thus, medicinal and aromatic plants are valued for their biological activities which can be justified from the fact that about 80% of the local population still depend on these plants for primary health care. The formation and accumulation of essential oil in plants has been reviewed by many workers (Guenther, 1972; Corteau, 1986; Fischer, 1991). The compounds from the plant based essential oil are useful as an alternative therapy, either directly or as models for new synthetic products (Houghton, 2000). Origanum is an important multipurpose medicinal plant which belongs to the family Lamiaceae, tribe Mentheae and comprises of 42 species and 18 hybrids widely distributed in Eurasia and North Africa (Ietswaart, 1980; Duman et al., 1988). It is native to the mountainous parts of Mediterranean region of Europe and Asia. Following Ietswaart (1980) classification, the genus Origanum has been divided into 10 sections. These include the following. *Corresponding author. E-mail: shayista29nov@rediffmail.com. Amaracus (Gleditsch) Bentham Amaracus (Gleditsch) Bentham consists of seven species, all restricted in the east Mediterranean region. The species are mainly characterized by their usually purple bracts, 1 or 2-lipped sepals without teeth, and saccate corollas: Origanum boissieri Ietswaart, Origanum calcaratum Jussieu, Origanum cordifolium (Montbret et Aucher ex Bentham) Vogel, Origanum dictamnus L., Origanum saccatum Davis, Origanum solymicum Davis and Origanum symes Carlstrom. Anatolicon Bentham Anatolicon Bentham comprises of eight species, presenting a very restricted distribution in Greece, Asia Minor, Lebanon and Libya. The plants have strongly bilabiate 5-toothed sepals: Origanum akhdarense Ietswaart et Boulos, Origanum cyrenaicum Beguinot et Vaccari, Origanum hypericifolium Schwarz et Davis, Origanum libanoticum Boissier, Origanum scabrum Boissier et Heldreich, Origanum sipyleum L., Origanum vetteri Briquet et Barbey and Origanum pampaninii (Brullo et Furnari) Ietswaart. Chishti et al. Brevifilamentum Ietswaart Brevifilamentum Ietswaart comprises of six species which are steno-endemics mainly in the eastern part of Turkey. These species are characterized by bilabiate sepals and strongly unequal length of stamens; upper two stamens are very short and enclosed in the corolla: Origanum acutidens (Handel-Mazzeti) Ietswaart, Origanum bargyli Mouterde, Origanum brevidens (Bornmuller) Dinsmore, Origanum haussknechtii Boissier, Origanum leptocladum Boissier and Origanum rotundifolium Boissier. Longitubus Ietswaart Longitubus Ietswaart consists of a single species found in a few places in the Amanus Mountains. It is mainly characterized by the slightly bilabiate calyx, the lips of the corolla are nearly at right angles to the tube and has the presence of very short staminal filaments: Origanum amanum Post. Chilocalyx (Briquet) Ietswaart Chilocalyx (Briquet) Ietswaart includes four species which are steno-endemics of South Anatolia or of the island of Crete. The plants are slightly bilabiate, conspicuously pilose in throat sepals: Origanum bigleri Davis, Origanum micranthum Vogel, Origanum microphyllum (Bentham) Vogel and Origanum minutiflorum Schwarz et Davis. Majorana (Miller) Bentham Majorana (Miller) Bentham consists of three species. The species are characterized by 1-lipped sepals and green bracts. Out of these Origanum syriacum is further subdivided into three geographically distinct varieties; these are recognised mainly from differences in their indumentum and leaf shape: Origanum majorana L., Origanum onites L., O. syriacum L. Var. syriacum, Var. bevanii (Holmes) Ietswaart and Var. sinaicum (Boissier) Ietswaart. Campanulaticalyx Ietswaart Campanulaticalyx Ietswaart consists of six local endemic species. The sepals of the plants have 5 sub equal teeth and are campanulate even when bearing fruits: Origanum dayi Post, Origanum isthmicum Danin, Origanum ramonense Danin, Origanum petraeum Danin, Origanum punonense Danin and Origanum jordanicum Danin and Kunne. Elongatispica Ietswaart Elongatispica Ietswaart comprises of three steno- 171 endemic species of North Africa, which are characterized by loose and tenuous spikes and tubular calyces with 5 equal teeth: Origanum elongatum (Bunnet) Emberger et Maire, Origanum floribundum L. Munby and Origanum grosii Pau et Font Quer ex Ietswaart. Origanum Origanum is a monospecific section consisting of the species O. vulgare, widely distributed in North Africa and in temperate and arid zones of Eurasia (Baser et al., 2010). Introduced by humans, this species has also been encountered in North America (Ietswaart, 1980). The plants of O. vulgare have dense spikes, and tubular 5toothed calyces, never becoming turbinate in fruit: O. vulgare L. Six subspecies have been recognised within O. vulgare L. based on differences in indumentum, number of sessile glands on leaves, bracts and calyces, and in size and colour of bracts and flowers: subsp. vulgare, subsp. glandulosum (Desfontaines) Ietswaart, subsp. gracile (Koch) Ietswaart, subsp. hirtum (Link) Ietswaart, subsp. viridulum (Martrin-Donos) Nyman and subsp. virens (Hoffmannsegg and Link) Ietswaart. Prolaticorolla Ietswaart Prolaticorolla Ietswaart comprises of three species endemic to eastern or western parts of the Mediterranean. These species are characterized by dense spikes and tubular calyces becoming turbinate in fruiting: Origanum compactum Bentham, Origanum ehrenbergii Boissier and Origanum laevigatum Boissier. ORIGANUM SPECIES Origanum spp. have been used for thousands of years as spice and in ethnomedicine (Fleisher and Fleisher, 1988). It has antifungal, antimicrobial, insecticidal and antioxidant activities (Kokkini, 1997; Baydar et al., 2004; Kulisic et al., 2004; Bakkali et al., 2008). Antispasmodic, antitumoral, antifungal and analgesic activities of Origanum spp. have been reported (Elgayar et al., 2001; Puertas et al., 2002; Sokovic et al., 2002; Sari et al., 2006). Baser (2002) and Dundar et al. (2008) reported that Origanum has been used as expectorant, antiparasitic, antihaelminthic and for gastrointestinal complaints in Turkish folk medicine. Origanum spp. are also used as a carminative, diaphoretic, stimulant and tonic (Hummer et al., 1999). Silva et al. (2012) have suggested that carvacrol present in the essential oil of Origanum probably interferes in the release and/or synthesis of inflammatory mediators, such as the protanoids and thus favour the healing process for gastric ulcers. Further as a 172 J. Pharmacognosy Phytother. folk remedy, it is used against colic, cough, toothaches and irregular menstrual cycles (Force et al., 2000; Kintzios, 2002a). Origanum spp. are also used as powerful disinfectant, flavouring agent in perfumes and in scenting soaps (Guenther, 1949; Chiez, 1984; Kotb, 1985). As a culinary herb, it is used in flavouring food products and alcoholic beverages (Aligiannis et al., 2001; Bendahou et al., 2008; Sivropoulou et al., 1996). Oregano has a promising potential for preventing diabetes complications in the long term treatments and has an anti inflammatory efficacy as depicted by inhibiting soybean lipoxygenase (Koukoulitsa et al., 2006). The secondary metabolites of this plant have been well studied in terms of polyphenolic compounds and essential oils. Consequently, more than one hundred nonvolatile compounds have already been identified in this plant which includes flavonoids, depsides and origanosides (Nakatani et al., 1987; Lin et al., 2003; Koukoulitsa et al., 2006; Liang et al., 2010; Skaltsa et al., 2010). The species of this plant which have been subjected to chemical profiling as discussed subsequently. Origanum vulgare (L.) O. vulgare (L.) is a medicinal and perennial plant, locally known as Jungali Tulsi or Oregano or Himalayan marjoram. It is widely distributed in Mediterranean areas and Northern Africa (Ietswaaart, 1980; Kokkini, 1997). This is the only species of genus Origanum which is found in India. It is found in temperate Himalayas from Kashmir to Sikkim at an altitude of 1500 to 3600 m. It is particularly grown in Simla Hills, Giligit, Nilgris and in the Kashmir valley. Vokou et al. (1993), Kokkini et al. (1997), D’antuonu et al. (2000) and Skoula (2002) reported carvacrol and thymol as dominant components of its essential oil. Andreas et al. (2013) found carvacrol as dominant component in the essetial oil of O. vulgare ssp. hirtum. Lagouri et al. (1993), Aeschbach et al. (1994), and Yanishlieva et al. (1999) revealed that antioxidant effect of this plant is as a result of carvacrol and thymol. Mastelic et al. (2008) reported its antimicrobial and antioxidant properties and in addition revealed carvacrol's antiproliferative activity on tumor cells of Hela. Essential oil of this plant possesses a variety of biological activities, namely, antiradical (Cervato et al., 2000; Ahmad et al., 2010a, b; 2011a, b), antifungal (cleff et al., 2010; Farag et al., 1989; Curtis et al., 1996; Sahin et al., 2004), antihyperglycaemic (Lemhadri et al., 2004), antibacterial (Dorman and Deans, 2000; Govaris et al., 2001; Harpaz et al., 2003; Burt and Reinders, 2003; Burt, 2004), and antithrombin (Goun et al., 2002). Antioxidant (Lamaison et al., 1991; Lagoun and Boskou, 1996; Nakatani, 2000; Vichi et al., 2001; Stashenko et al., 2002) function of this species could become helpful agent in treatment of cancer, heart disease and high blood pressure. Cervato et al. (2000) reported that antioxidant activities of O. vulgare leaves can inhibit all places of lipid peroxidative processes. O. onites O. onites (L.) is distributed in Western and Southern Turkey. Baser et al. (2010) have reported that it grows naturally in Agean and Mediterranean regions of Turkey. It is a perennial species with woody stem and is commonly known as ‘Turkish oregano’. An essential oil reported from this plant contains carvacrol as a major component and has the potential to be utilized at reasonable concentrations to control tick infestations (Sevki et al., 2008). Diversified effects such as antispasmodic (Daferera et al., 2000, 2003), antibacterial (Burt, 2004), and antifungal (Ultee et al., 1997) have been attributed to this plant by modern pharmacological study. It is also used in flavouring Turkish delight candy (Facciola et al., 1998) and is also used in tea, salads and meat dishes (Small et al., 1997). Consumption of O. onites distillate has beneficial effects on lipid profiles, antioxidant status and endothelial functions in patients with mild hyperlipidaemia (Ozdemir et al., 2008). O. syriacum O. syriacum commonly known as 'Syrian marjoram' is an aromatic, herbaceous and perennial plant growing wild in the Sinai desert of Egypt (Tackholm, 1974). Biblical authorities consider this plant to be referred in the Bible as hyssop, particularly in the old Testament pages (Moldenke et al., 1952). It is a very popular culinary herb that has been used through ages in traditional medicine mainly in Lebanon and Arab world. It has antiseptic properties and has the ability to relieve stomach and intestinal pain. It is also used to treat heart problems, cough, toothaches (Gardner et al., 1989), cold, anxiety and wounds (Chandler et al., 2004). Kamela et al. (2001) and Baser et al. (2003) isolated thymol and carvacrol as a major constituent of its essential oil. Carvacrol is the signature chemical largely responsible for its sharp, pungent oregano flavor (Tucker et al., 1992). The volatile phenolic oil has been reported to be among the top 10 essential oils (Letchamo et al., 1995), showing antibacterial, antimycotic, antioxidative, natural food preservative and mammalian age delaying properties (Jackson and Hay, 1994; Letchamo et al., 1995). O. majorana (L.) O. majorana (L.) is an endemic medicinal plant of Cyprus and is commonly known as 'Sampsishia'. Johannes et al. (2002) reported sabinene linalyl acetate and Cis-sabinene Chishti et al. hydrate from the essential oil of this plant species. It is used against common cold, as spasmolytic and as an antirheumatic. Dried leaves and flowering tips of this species are used in formulation of vermouths and bitters. The essential oil is used for flavouring sauces, condiments and other products (de Vincenzi et al., 1997). In India, it is used as diuretic, antiasthmatic and an antiparlytic drug (Yadava and Khare, 1995). This was a common salad herb in the 16th century (Picton et al., 2000). It is also used in herbal vinegars and tea can be made from its leaves (Facciola et al., 1998). Furthermore, it has been used to treat cancer as well (Johnson et al., 2002; Leung et al., 2003). Stefanakis et al. (2013) have assayed the essential oil extracted from O. majorana L., O. onites L. and O. vulgare L. ssp. hirtum as potential antibacterial agents for disinfection of rotifers (Brachionus plicatilis). Abdel Massih et al. (2010) suggested that Marjoram extracts exhibit antiproliferative effect and have high antioxidant activity as well. 173 and Skaltsa (1986) and Harvala et al. (1987) reported that the leaves of this plant contain flavonoids and flavonoid glycosides some of which have spasmolytic activity. The essential oil has carvacrol, α- terpinene, pcymene, caryophyllene, borneol, terpin1-en-4-ol and carvacrol methyl ether as predominant compounds. Various studies, concerning O. dictamnus, have shown that their oils possess strong antimicrobial activity; this activity could be attributed to their high percentage of phenolic compounds and specifically, carvacrol, thymol, p-cymene and their precursor c-terpinene (Sivropoulou et al., 1996). The variety of non-polar components such us fatty acids, lipids, sterols and essential oil has been identified from O. dictamnus (Revinthi-Moraiti et al., 1985; Komaitis et al., 1988). Origanum dubium O. microphyllum is a medicinal plant species of genus Origanum, endemic to Cretan and commonly known as 'Cretan marjoram' (Karousou, 1995). Aligannis et al. (2001) and Gotsiou et al. (2002) isolated carvacrol, terpineol-4, linalool, sabinene, α-terpinene, ϒ-terpinene, cis-sabinene hydrate and trans-sabinene hydrate from the essential oil of this species. This small leaved oregano has a strong spicy flavor (Small et al., 1997). O. dubium an endemic Mediterranean shrub is widely spread in Cyprus, Greece and in Southern Turkey. It is commonly called ‘Rigani’. An infusion of its leaves, flowering stems and flowers is used as a digestive aid while its essential oil when applied externally acts as an antirheumatic (Arnold et al., 1993). Carvacrol is the major component of its essential oil. The essential oil shows antimicrobial activity and their potential antioxidant activity was investigated and found to be significant in scavenging O2 (Karioti et al., 2006). Further, O. dubium shows inhibition of soybean lipoxygenase LOX and has high inhibitory activity (Karioti et al., 2006). O. hypericifolium O. sipyleum (L.) O. hypericifolium is an endemic species of Turkey. It is used as a condiment, for flavouring meat and as herbal tea for treatment of common cold and stomach complaints (Baser et al., 1994). The essential oil of pre flowering stage extracted from this plant species is carvacrol rich. O. sipyleum (L.) commonly called 'Showy Pink Oregano' is a polymorphic species of eastern Mediterranean area and is native to Western Anatolia, Turkey. It is used as a spice and against cough. It is also beneficial for the treatment of various respiratory and gastrointestinal disorders. The essential oil of this species is rich in αterpinene and monoterpenes (Baser et al., 1992). O. microphyllum O. dictamnus O. dictamnus commonly known as 'Dittany of Crete' is native to the Island of Crete, Greece. It is used in traditional medicine in Greece and all over Europe (Christos et al., 2010). It possesses numerous medicinal uses like antibacterial (Aureli et al., 1992; Biondi et al., 1993; Vokou et al., 1993) and antifungal (Arras and Picci, 1984; Collin et al., 1989; Paster et al., 1993). It is also used in cooking as well. As a culinary and medicinal herb, it is used as a tonic and digestive aid (Simon et al., 1984; Bown et al., 2001) for treating kidney and liver problems, obesity and headaches (Skoula et al., 1997). Its flowers and bracts are used to make tea and the plant when combined with garlic, thyme, salt and pepper is used in a Saxon fish sauce (Jones et al., 1973). Harvala O. compactum O. compactum is found in Morocco, South-West Spain and North Africa (Tutin et al., 1972). It is commonly called ‘Compact Oregano'. It produces one of the most powerful antimicrobial essential oil. It has antibacterial (Bouhdid, 2009), antioxidant (Bouhdid, 2008) and antifungal (Bouchra, 2003) properties. It demonstrates cytotoxic activity by oxidative stress as seen by mitochondrial damage (Bakkali, 2005). It has carvacrol, p-cymene and ϒ-terpinene as major components of its essential oil. O. floribundum O. floribundum is recorded in Algerian site. It is used to 174 J. Pharmacognosy Phytother. stimulate the appetite of cattle, sheep and horses. Furthermore, it is also used against diarrhoea and other digestive disorders (Houmani et al., 2002). Carvacrol, linalool, p-cymene and ϒ-terpinene were isolated by Baser et al. (2000) from the essential oil of this species. O. acutidens O. acutidens is an endemic, herbaceous, and perennial plant growing mainly in calcareous and non calcareous rocks, slopes, and screes in the Central Anatolia region of Turkey (Davis, 1982). The major components of O. acutidens oil are carvacrol, p-cymene, borneol, γterpinene, β-caryophyllene and linalool. Sokmen et al. (2004) has suggested that its essential oil has antagonistic activity against food-borne pathogenic bacteria and hence could be used in the food and pharmaceutical industries, and as an alternative to common synthetic antimicrobial products. Conclusion The synthesis of medicinally important phytochemicals by the species of genus Origanum has been established beyond doubt. The plant species are being used both in allopathic and traditional system of medicine as a remedial measure for number of ailments. Since, only limited species are being subjected to phytochemical investigation, there is a need to broaden this study for further phytochemical and pharmacological studies for the rest of the species as well, which may prove of vital importance and could lead to new therapeutic products. Furthermore, since the plant extracts of the genus Origanum and its essential oils are used as dietary supplements or for medicinal purposes, it has become crucial to screen them for ensuring authenticity and product quality as toxic adulterants may prove to be life threatening. REFERENCES DISCUSSION The aim of the present review is to present comprehendsive information about the medicinal importance of genus Origanum. Although, there are 42 species of genus Origanum, only about less than 50% species have been subjected to chemical profiling. Other species have not been broadly subjected to chemical characterization and biological studies as evident from perusal of the literature. Current studies have shown that the essential oil, as well as their active principles possess several pharmacological properties like antimutagenic, angiogenic, antiparasitic, antiplatelet, antielastase, antihepatotoxic ones (Baser, 2008). The species studied by various workers indicate that the genus Origanum is a potent source for isolation of a variety of bioactive molecules like terpenes, phenols, flavonoids, etc. Thereby, this genus has important biological activities and acts against different types of diseases and is being used for culinary and economic uses. Furthermore it is also used as a feed additive, in honeybee breeding and in treatment of gastrointestinal ailments (Baser, 2008). The recent scientific data and the rich historical evidence of its medicinal uses could support further research as well as its use as a safe herbal medicinal product. The antimicrobial activity can promote the use of the aforementioned natural products as potent preservative and conservation agents, not only in the food industry after testing the toxic and irritating effects on humans, but also in cosmetics and medical preparations. The present literature study further reveals that the biological properties of the investigated genus are not due only to their essential oils and their main compounds such as cavacrol and thymol, but also to the other polar constituents acting synergistically or possessing different biological activities. Abdel-Massih RM, Fares R, Bazzi S, El-Chami N, Baydoun E (2010). The apoptotic and antiproliferative activity of Origanum majorana extracts on human leukemic cell line. Leuk. Res. 34:1052-1056. Aeschbach R, Loliger J, Scott C, Murcia A, Butler J, Halliwell B, Aruoma OI (1994). Antitoxidant actions of thymol, Carvacrol, 6– gingerol, zingerone and hydroxytyrosol. Food Chem. Toxicol. 32: 31-36. Ahmad N, Fazal H, Abbasi BH (2011 a). In vitro larvicidal and antioxidative enzyme activities in Ginkgo biloba, Stevia rebaundiana and Parthenium hysterophororus. Asian pacific J. Trop. Med. 4(3):169-175. Ahmad N, Fazal H, Abbasi BH (2011 b). Free radical scavenging (DPPH) potential in nine Mentha species. Toxicology and Industrial Health, Doi 10. 1177/0748233711407238. Ahmad N, Fazal H, Abbasi BH, Farooq S (2010 b). Efficient free radical scavenging activity of Ginkgo biloba, Stevia rebaundiana and Parthenium hysterophorous leaves through DPPH (2, 2– diphenyl – 1– picrylhydrozyl). Int. J. Phytomed. 2:231-239. Ahmad N, Hina F, Bilal HA, Muhammad R, Tariq M, Nighat F (2010a). Efficient regeneration and antioxidant potential in regenerated tissues of Piper nigrum L. Plant, Cell, Tissue and Organ culture, 102:129134. Aligiannis N, Kalpoutzakis E, Mitaku S, Chinou IB (2001). Composition and Antimicrobial Activity of The essential Oils of Two Origanum species. J. Agr. Food Chem. 49:4168-4170. Andreas JK, Dimitra EKS (2013). Field studies of nitrogen application on Greek Oregano(Origanum vulgare ssp.hirtum(link)Ietswaart) essential oil during two cultivation seasons. Ind. Crops Prod. 46:246252. Arnold N, Bellomaria B, Valentini G, Arnold HJ ( 1993). Comparative study of the essential oils from three species of Origanum growing wild in the eastern Mediterranean region. J. Essent. Oil Res. 5(1 ):7177. Arras G, Picci V (1984). Attivita fungistatica di alcuni olii essenziali nei contronti dei principali agenti di alterazioni post-racolta dei frutti di agrumi. Rivista della Ortofrutticoltura Italiana 68:361-366. Aureli P, Costantini A, Zolea S (1992). Antimicrobial activity of some essential oils against Listeria monocytogenes. J. Food Prot. 55(5):344–348. Bakkali F (2005). Cytotoxicity and gene induction by some essential oils in the yeast Saccharomyces cerevisae. Mutat. Res. 585(1-2):1-13. Bakkali F, Averbbeck S, Averbeck D, Idaomar M (2008). Biological effects of essential oils – A review. Food Chem.Toxicol. 46:446-475. Baser KHC (2002). The Turkish Origanum species. Oregano, the Genera Origanum and Lippia, Ed., Kintzios SE, London and New York, Taylor and Francis, PP:109-126. Chishti et al. Baser KHC (2008). Biological and Pharmacological Activities of Carvacrol and Carvacrol Bearing Essential Oils. Curr. Pharm. Design 14:3106-3120. Başer KHC, Buchbauer G (2010). Handbook of Essential Oils: Science, Technology and Applications, CRC Pres, Boca Raton, London, New York. Baser KHC, Kurkcuoglu M, Demirci B, Ozek T (2003). The Essential oil of Origanum syriacum L .Var. sinaicum (Bioss.) Ietswaart. Flavour Frag. J. 18:98-99. Baser KHC, Ozek T, Kurkcuoglu M, Tumen G (1994). The essential oil of Origanum vulgare Subsp. hirtum of Turkish origin. J. Essent. Oil Res. 6:31-36 Baser KHC, Tumen G (1992). Composition of the Essential Oil of Origanum sipyleum of Turkish Origin. J. Essent. Oil Res. 4:139-142. Baydar H, Osman S, Ozkan G, Karadoa T (2004). Antibacterial activity and composition of essential oils from Origanum, Thymbra and Satureja species with commercial importance in Turkey. Food Control, 15:169-172. Bendahou A, Muselli A, Grigmon-Dubois M, Benyoucef M, Desjobert JM, Bernardini AF, Costa J (2008). Antimicrobial activity and Chemical composition of Origanum glandulosum Desf. Essential Oil and Extract Obtained by Microwave extraction :Comparison with Hydrodistillation. Food Chem.106:132-139. Biondi D, Cianci P, Geraci C, Ruberto G, Piatteli M (1993). Antimicrobial activity and Chemical Composition of essential oils from Sicilian aromatic plants. Flavour Frag. J. 8:331-337. Bouchra C(2003). Chemical composition and antifungal activity of essential oils of seven Moroccan Labiatae against Botrytis cinera Pers: Fr. J. Ethnopharmacol. 89(1):165-169. Bouhdid S (2008). Antibacterial and antioxidant activities of Origanum compactum essential oil. Afr. J. Biotech. 7(10):1563-1570. Bouhdid S (2009). Investigation of functional and morphological changes in Pseudomonas aeruginosa and Staphylococcus aureus cells induced by Origanum compactum essential oil. J. Appl. Microbiol.106(5):1558-1568. Bown D (2001). The Herb Society of America new encyclopedia of herbs & their uses. New York: DK. Burt S (2004). Essential oils :their antibacterial properties and potential applications in foods – a review. In Int. J. Food Microbiol. 94:223-253. Burt SA, Reinders RD (2003). Antibacterial activity of selected plant essential oils against Escherichia coli 0157: H7. Letters in Applied Microbiology. 36:162-167. Cervato G, Carabelli M, Gervasio S, Cittera A, Cazzola R, Cestaro B (2000). Antioxidant properties of Oregano (Origanum vulgare) Leaf extracts. J. Food Biochem. 24:453-465. Chandler-Ezell K (2004). Folklore of oregano. The herbarist. 70:16-24. (HSA Library). Chiez R, (1984). The Macdonald Encyclopedia of Medicinal Plants. Macdonald Co. Ltd, London, pp. 212-297. Christos CL, Konstantia G, Skaltsa E, Chinou L (2010). Dittany of Crete: A botanical and ethnopharmacological review.. J. Εthnopharmacol. 131:229-241. Cleff M, Meinerz AR, Xavier M, Schuch LF, Carlos M (2010). In vitro activity of Origanum vulgare essential oil against Candida species. Braz. J. Microbiol. 41:116-123. Collin ME, Ducos de Lahitte J, Larribau E, Boue T (1989). Activite des huiles essentielles de Labiees sur Ascosphaera apis et traitement d’un rucher. Apidologie 20:221-228. Corteau R (1986). Biochemistry of monoterpenes and sesquiterpenes of the essential oils. Herbs, spices and medicinal plant : Recent advances in Botany, Horticulture and Pharmacology. Oryx press, Phoenix, AZ, 1:81-135. Curtis OF, Shetty K (1996). Growth medium effects of Vitrification, total phenolics, chlorophyll and water content of in vitro propagated Oregano cloves. Acta Horticulturae, 426:489-497. D’antuono LF, Galleti GC, Bocchini P (2000). Variability of essential oil content and composition of Origanum vulgare L. populations from a North Mediterranean Area (Liguria region, Northern Italy). Annals of Bot. 86:471–478. Daferera DJ, Basil N, Ziogas N, Polissiou MG (2003). The effectiveness of plant essential oils on Botrytis cinerea, Fusarium sp. and Clavibacter michiganensis subsp. michiganensis. Crop Prot. 22: 39-44. 175 Daferera DJ, Ziogas BN, Polissiou MG (2000). GC – MS analysis of essential oils from some Greek aromatic plants and their fungitoxicity and Pencillium digitatum. J. Agric. Food Chem. 48:2576–2581. Davis PH (1982). Flora of Turkey and East Eagen Islands. Edinburgh at the university press 7:309. de Vincenzi M, Mancini E (1997). Monographs on botanical flavouring substances used in foods. Part VI. Fitoterapia 68(1):49-61. Dorman HJD, Deans SG (20000. Antimocrobial agents from plants: Antibacterial activity of plant volatile oils. J. Appl. Microbiol. 88(2):308–316. Duman H, Baser KHC, Aytec Z (1998). Two new species and a new hybrid from Anatolia. Turk. J. Bot. 22:51–55. Dundar E, Olgun EG, Isiksoya S, Kukcuoglu M, Baser KHC, Bal C (2008). The effects of Intra-rectal and Intra-peritoneal Application of Origanum onites L. essential oil on 2, 4, 6 -Trinitrobenzene sulfonic Acid induced colitis in the Rat. Exp. Toxicol. Pathol. 59:399–408. Elgayyar M, Draughon FA, Golden DA, Mount JR (2001). Antimicrobial Activity of Essential Oils from Plants against Selected Pathogenic and Saprophytic Microorganisms. J. Food Protect. 64: 1019–1024. Facciola S (1998). Cornucopia II: a source book of edible plants. Vista: Kampong Publications(HSA Library). Farag RS, Daw ZY, Abo-Raya SH (1989). Influence of some spice essential oils on Aspergilus parasiticus growth and production of aflatoxins in a synthetic medium. J. Food Sci. 54:74–76. Fischer NH (1991). Methods in Plant Biochemistry, (Eds, B. C. Charlwood and D. V. Banthrope). Academic Press, London, 7:187. Fleisher A, Fleisher Z (1988). Identification of Biblical Hyssop and origin of the traditional use of Oregano-group herbs in the Mediterranean region. Econ. Bot. 42:232–241. Force M, Sparks WS, Ronzio RA (2000). Inhibition of enteric parasites by emulsified oil of Oregano. In vivo Phytother. Res. 14(3):213-214. Gardner J (1989). Holy land herbs revisited. The herbarist. 55:69-73. (HSA Library). Gianni S, Maietti S, Muzzoli M, Scaglianti M, Manfredini S, Radice M, Bruni R (2005). Comparative evaluation of 11 essential oils of different origin as functional antioxidants, antiradicals and antimicrobials in foods. Food Chem. 91:621–632. Gotsiou P, Naxakis G, Skoula M (2002). Diversity in the composition of monoterpenoids of Origanum microphyllum (Labiatae). Biochem.sytem. ecol. 30:865–879. Goun E, Cunnigham G, Krasnykch S, Miles H (2002). Antithrombin activity of some constituents from Origanum vulgare. Fitoterapia 73:692-694. Guenther E ( 1949). The Essential Oils, Van Nostraand Co, New York. vol.3:535. Guenther E (1972). The Essential Oil. The production of essential oils: methods of distillation, effleurage, maceration, and extraction with volatile solvents. History – Origin in plants, production analysis. In Guenther, E (Ed). Krieger Pub. Co., Malobar, FL,1:85–188. Harpaz S, Glatman L, Drabkin V, Gelman A (2003). Effects of herbal essential oils used to extend the shelf life of fresh water-reared Asian sea fish (Lates calcarifer). J. Food Prot. 66:410–417. Harvala C, Skaltsa H (1986). Contribution a l’etude chimique d’Origanum dictamnus L. 1 recommunication. Plantes Méd. Phytothér. Tome 20(4):300–304. Hervala C, Menounos P, Argyriadou N (1987). Essential oil from Origanum dictamnus. Planta Med. 53(1):107-109. Houghton PJ (2000). Use of small scale bioassays in the discovery of novel drugs from natural sources. Phytother. Res. 14:419-423. Houmani Z, Samir A, George N, Melponin S (2002). The essential oil composition of Algerian Zaatar: Origanum spp. and Thymus spp. J. Herbs Spices Med. Plants 9(4):275-280. Hummer KA, Caraon CF, Rilet TV (1999). Antimicrobial activity of essential oils and other plant extract. J. Appl. Microbiol. 86:985–990. Ietswaart JH (1980). A taxonomic revision of the genus Origanum (Labiatae), Leiden Botanical series, Leiden University Press, The Hague, Leiden. Vol. 4 Jackson SAL, Hay RKM (1994). Characteristics of varieties of thyme (Thymus vulgaris L.) for use in the UK: oil content, composition and related characters. Ann. Hort. Sci. 69:275–281. Johannes N, Christina B, Freidrisch P, Jan L, Chlodwig FM (2002). Distribution of cis sabinene hydrate acetate chemotype in accessions 176 J. Pharmacognosy Phytother. of marjoram (Origanum marjorana L.). Euphytica 127:69 –74 CA 2003, 138, 103585. Jones DB 1973). The great dittany of Crete-then and now. The herbarist. 39:13-18(HSA Library). Kamela MS, Assafa MH, Hasaneana HA, Ohtanib K, Kasaib R, Yamasakib K (2001). Monoterpene glucosides from Origanum syriacum. Phytochemistry 58:1149-1152. Karioti A, Vrahimi-Hadjilouca T, Droushiotis D, Rancic A, HadjipavlouLitina DS (2006). Analysis of the Essential Oil of Origanum dubium Growing Wild in Cyprus. Investigation of its Antioxidant Capacity and Antimicrobial Activity. Planta Med. 72(14):1330-1334. Karousou R (1995). Taxonomic studies on the Cretan Labiatae: Distribution, morphology and essential oils. Ph.D Thesis, Univ. of Thessaloniki, Thessaloniki (in Greek,English summary). Kintzios SE (2002a). Profile of the multifaceted prince of the herbs. In: Kintzios SE (Ed.) Oregano : The Genera Origanum and Lippia. Medicinal and Aromatic plants Industrial Profiles 25. Taylor and Francis/ CRC Press USA, PP 236–242. Kokkini S (1997). Taxonomy, diversity and distribution of Origanum species. In: Padulosi S, (ed.) Oregano, 14. Proceedings of IPGRI International workshop. Italy, Rome, pp. 2–12. Komaitis ME, Revinthi-Moraiti K, Evangelatos G (1988). The lipid composition of fresh Origanum dictamnus leaves. Food Chem. 27(1):25-32. Kotb F (1985). Medicinal plants in Libya, 632, Arab Encyclopedia House. Koukoulitsa C, Zika C, Hadjipavlou–Litina D, Demopoulos VJ, Skaltsa H (2006). Inhibitory effect of polar oregano extracts on aldose reductase and soybean lipoxygenase in vitro. Phytother. Res. 20:605–606. Kulisic T, Radoni A, Katalinic V, Milos M (2004). Use of different methods for testing antioxidative activity of Oregano essential oil. Food chem. 85:633–640. Lagouri V, Blekas G, Tsimidou M, Kokkini S, Boskou D (1993). Composition and antioxidant activity of essential oils from Oregano plants grown wild in Greece. Z. Lenbenson. Unters. Forsch. 197:20– 23. Lagouri V, Boskou D (1996). Nutrient antioxidants in Oregano. Int. J. Food Sci. Nutr. 47:493–497. Lamaison JL, Ptitjean-Freytet C, Carnat A (1991). Lamiaceae medicinal antioxidant properties, rosmaranic acid as potential source. Pharm. Acta. Helv. 66:185–188 CA 1991, 115, 787152. Lemhadri A, Zeggwagh NA, Maghrani M, Jouad H, Eddouk M (2004). Antihyperglycaemic activity of aqueous extract of Oreganum vulgare growing wild in Tafilate region. J. Ethnopharmocol, 92(2 – 3): 251– 256. Letchamo W, Xu H, Gosselin A (1995). Variations in photosynthesis and essential oil in thyme. J. Plant Physiol. 147:29–37. Leung AY, Steven F (2003). Encyclopedia of common natural ingredients used in food,drugs and cosmetics. Hoboken, NJ: WileyInterscience. (HSA Library). Liang CH, Chou TH, Ding HY (2010). Inhibition of melanogensis by a novel origanoside from Origanum vulgare. J. Dermatol. Sci. 57:170−177. Lin YL, Wang CN, Shiao YJ, Liu TY, Wang WY (2003). Benzolignanoid and polyphenols from Origanum vulgare. J. Chin.Chem. Soc. 50:1079−1083. Mastelic J, Jerkovic I, Blazevic I, Poljak-Blazi M, Borovic S, IvancicBace I, Smrecki V, Zarkovic N, Brcic-Kostic K, Vikic–Topic D, Muller N (2008). Comparative study on the antioxidant and biological activities of carvacrol, thymol and eugenol derivatives. J. Agric. Food Chem. 56:3989–3996. Moldenke HN, Alma LM 1952). Plants of the bible. New York: Dover.Publications, Inc. (HSA Library). Nakatani N (2000). Phenolic antioxidants from herbs and spices. Biofactors, 3:141–146. Nakatani N, Kikuzaki H (1987). A new antioxidative glucoside isolated from oregano (Origanum vulgare L.). Agric. Biol. Chem. 51:2727−2732. Ormancy X, Sisalli S, Couliere P (2001). Formulation of essential oils in functional perfumery. Perfumes, Cosmetiques, Actualities, 157:30– 40. Ozdemir B, Ekbul A, Topal NB, Sarandol E, Sag S, Başer KHC, Cordan J, Gullulu S, Tuncel E, Baran I, Aydinlar A (2008). Effects of Origanum onites on endothelial function and serum biochemical markers in hyperlipidaemic patients. J. Int. Med. Res. 36(6):1326-34. Paster N, Menasherov M, Shaaya E, Juven B, Ravid U (1993). The use of essential oils applied as fumigants to control mycotoxigenic fungi attacking stored grain. Hassadeh 74(1):25-27. Picton M. 2000). The book of magical herbs: herbal history, mystery, & folklore. London: Barron's. Puertas MM, Hille BS, Stashenko E, Winterhalter P (2002). In vitro Radical Scavenging Activity of Essential Oils from Columbian Plants and Fractions from Oregano (origanum vulagre L.) Essential oil. Flavor Frag. J. 17:380–384. Revinthi-Moraiti K, Komaitis ME, Evangelatos G, Kapoulas V (1985). Identification and quantitative determination of the lipids of dried Origanum dictamnus leaves. Food chem. 16:15-24. Sahin F, Gulluce M, Daferera D, Sokmen A, Sokmen M, Polissiou M, Agar G, Ozer H (2004). Biological activities of the essential oils and methanol extracts of Origanum vulgare ssp. vulgare in the eastern Anatolia region of Turkey. Food Contr.15:549–557. Sari M, Biondi DM, Kaabeche M, Mandalari G, Darrigo M, Bisignano G, Saija A, Daquino C, Ruberto G (2006). Chemical Composition, Antimicrobial and AntioxidantActivities of the Essential Oil of Several Populations of Algerian Origanum glandulosum Desf. Flavour Frag. J. 21:890–898. Sawamura M (2000). Aroma and functional properties of Japenese yuzu (Citrus junos Tanaka). Essen. Oil Aroma Res. 1(1):14–19. Sevki C, Girisgin O, Kurkcuoglu M, Malyer H, Girisgin AO, Kinmer N, Baser KH (2008). Acaricidal efficacy of Origanum onites L. essential oil against Rhipicephalus turanicus (Ixodidae). Parasitol. Res. 103(2):259-261. Silva FV, Guimaraes AG, Silva ER, Sousa-Neto BP, Machado FD, Quintans-Júnior LJ, Arcanjo DD, Oliveira FA, Oliveira RC (2012). Anti-inflammatory and anti-ulcer activities of carvacrol, a monoterpene present in the essential oil of oregano. J. Med. Food. 15(11):984-991. Simon JE, Alena FC, Lyle EC (1984). Herbs: an indexed bibliography 1971-1980 - the scientific literature on selected herbs, and aromatic and medicinal plants of the temperatezone. Archon Books. (HSA Library). Sivropoulou A, Papanikolaou E, Nikolaou C, Kokkini S, Lanaras T, Arsenakis M, (1996). Antimicrobial and Cytotoxic Activities of Origanum Essential Oil. J. Agric. Food Chem. 44:1202– 1205. Skaltsa H, Chatzopoulou A, Karioti A, Gousiadou C, Vivancos VL, Kyriazopoulos P, Golegou S (2010). Depsides and other polar constituents from Origanum dictamnus L. and their in vitro antimicrobial activity in clinical strains. J. Agric. Food Chem. 58:6064−6068. Skoula M, Harborne JB, (2002). Taxonomy and Chemistry. In :Kintzios SE (ed) Oregano: The genera Origanum and Lippia. Medicinal and aromatic plants -industrial profiles, vol. 25. Taylor and Francis CRC Press, USA Pp 67– 108. Skoula M, Sotiris K (1997). Origanum dictamnus L. and Origanum vulgare L.subsp. hirtum (Link) Ietswaart: traditional uses and production in Greece. In Oregano:proceedings of the IPGRI international workshop on oregano 8-12May1996, CIHEAM, Valenzano(Bari), Italy. Edited by S. Padulosi. Rome: Int. Plant Genetic Resources Institute. Small E (1997). Culinary herbs. Ottawa: NRC Research Press. (HSA Library). Sokmen M, Serkedjieva J, Daferera D, Gulluce M, Polissiou M, Tepe B, Akpulat HA, Sahin F, Sokmen A (2004). The in vitro antioxidant, antimicrobial and antiviral activities of the essential oil and various extracts from herbal parts and callus cultures of Origanum acutidens. J. Agric. Food Chem. 52:3309-3312. Sokovic M, Tzakou O, Pitarokili D, Couladis M (2002). Antifungal Activities of selected Aromatic Plants Growing Wild in Greece. Nahrung / Food 46:317- 320. Stashenko EE, Puertas MA, Martinez JR (2002). SPME determination of volatile aldehydes for evaluation of in vitro antioxidant activity. Analyt. Bioanalyt. Chem. 373:70-74. Stefanakis MK, Anastasopoulos E, Katerinopoulos HE, Makridis P Chishti et al. (2013). Use of essential oils extracted from three Origanum species for disinfection of cultured rotifers (Brachionus plicatilis) Aquacult. Res. doi:10.1111/are.12137. Tackholm V (1974). Students Flora of Egypt, 2nd edn.,562.Cooperative Printing Co., Beirut. Tucker AO (1992). Will the real oregano please stand up? The herb companion. (HSA Library) 4(3):20-22. Tutin TG, Heywood VH, Burges NA, Moore DM, Valintine DH, Walters SM, Webb DA (1972). Flora Europaea. University Press, Cambridge. 3:171-172. Ultee A, Kets E, Smid EJ (1997). Mechanism of action of Carvacrol on the food borne pathogen Bacillus cerlus. Appl. Environ. Microbiol. 65:4606–4610. Vichi S, Zitterl-Eglseer K, Jugl M, Franz C (2001). Determination of the presence of antioxidants deriving from sage and Oregano extracts added to animal fat by means of assessment of the radical scavenging capacity by photo chemiluminescence analysis. Nabrung 45(2):101-104. 177 Vokou D, Kokkini S, Bessiere JM (1993). Geographic variation of Greek oregano (Origanum vulgare ssp.hirtum) essential oils. Biochem. System. Ecol. 21:287–295. Yadava RN, Khare MK (1995). A triterpenoid from Majorana hortensis. Fitoterapia 66(2):185. Yanishlieva NV, Marinova EM, Gordon MH (1999). Antioxidant activity and mechanism of action of thymol and carvacrol in two lipid systems. Food chem. 64:59-66.