Essay: Production of medicinal and aromatic plants

The production of more and clean medicinal and aromatic plants to satisfy the needs of the over increasing population of the world is become is a great target. Egypt has a rich history in the production and trade of medicinal and aromatic plants. The Egyptian government recommended the increase of the production of the medicinal and aromatic plants in order to face the extending demands of local markets and exportation. It is of interest to increase the production of medicinal and aromatic plants to avoid chemical therapy side effects on human health, as it has a major role in the treatment of human and animal diseases. Chemical fertilizers and pesticides used in agriculture for increasing yield and controlling pests can contaminate the water, air, food, decrease soil fertility, inhibit growth of soil microorganisms and effect on human health (Sharifuddinn and Zaharah, 1987; Li et al., 1999; Abdel-ghany, 2007 and Hamed, 2011).
Most widely used is the genus Origanum (family Lamiaceae) (from the Greek words oros– mountain and hill and ganos– ornament). Oregano is the most valued spice and the common name for a general aroma and flavor primarily derived from more than 60 plants species used worldwide as a seasoning. Origanum spp. (Lamiaceae) includes more than 70 species, subspecies, varieties, and hybrids, and most of the species are shrubs (Kintzios, 2002; Wiersema and Leon, 1999).
One of the most important commercially grown species is Origanum vulgare ssp. hirtum, which is endemic to the Mediterranean area (Skoula and Harborne, 2002).
Oregano is found in many areas and is a perennial shrub native to the dry, rocky calcareous soils in the mountainous area of southern Europe and Southwest Asia. It is also cultivated because of its uses as an herb and its therapeutic properties, which have been known since ancient times (Bariceric and Bartal, 2002).
In addition, the significance of herbs such as oregano has increased in recent years, especially with the interest in growing alternative crops and in nutraceutical and functional foods. Sixty percent of all are recorded to grow in Turkey, indicating this country as the gene center of Origanum (Kintzios, 2002).
The origanum species are sub shrubs or perennial herbs with several stems, ascending or erect, sub sessile or petiolate leaves and flowers in verticillasters aggregated in dense or loose spikes which are arranged in a paniculate or corymbiform inflorescence. Origanum plants are widely used all over the world as a very popular spice, under the vernacular name   (oregano). They are of great economic importance which is not only related to their use as a spice (Kokkini and Padulosi, 1997).
The work of  Letswaart (1980), currenly accepted as the taxonomic reference for the genus Origanum, distinguishes six subspecies of O. vulgare on the basis of morphological characters: gracile (Kock) letswaart, glandulosum (Desfontaines) letswaart, hirtum (Link) letswaart, vulgare L., virens (Hoffmannsegg et Link) letswaart and viride (boissier) Hayek.
The subspecies hirtum has been more thoroughly investigated with respect to essential oil composition, since it includes high-quality, essential oil- rich, commercial types (Kokkini and Padulosi, 1997 and Putievesky et al., 1997).
Origanum is known widely in the world of herbs and spices for its volatile oils. Oregano is the commercial name of those species that are rich in the phenolic monoterpenoids, mainly carvacrol, occasionally thymol, while marjoram is the commercial name of those that are rich in bicyclic monoterpenoids cis- and trans-sabinene hydrate (Kintzios, 2002).
As a medicinal plant, Oregano (Origanum spp.) has been used for thousands of years as spice and in ethno medicine (Fleisher and Fleisher, 1988).
As a culinary herb, it is used in flavoring food products and alcoholic beverages (Aligiannis et al., 2001; Bendahou et al., 2008 and Sivropoulou et al., 1996).
Further as a folk remedy, it is used against colic, cough, toothaches and irregular menstrual cycles (Force et al., 2000 and Kintzios, 2002a).  Origanum spp. are also used as powerful disinfectant, flavoring agent in perfumes and in scenting soaps (Guenther, 1949; Chiez, 1984 and Kotb, 1985).
Vokou et al. (1993), Kokkini et al. (1997), D’antuonu et al.  (2000) and Skoula (2002) reported that carvacrol and thymol as dominant components of its essential oil. Andreas et al.  (2013) found that carvacrol as dominant component in the essential 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 and 2011a, b), antifungal (Cleff et al., 2010; Farag et al.,  1989; Curtis et al., 1996 and Sahin et al., 2004), antihyperglycaemic  (Lemhadri et al., 2004), antibacterial (Dorman and Deans, 2000; Harpaz et al., 2003; Burt and Reinders, 2003 and Burt,  2004),  and antithrombin (Goun et al., 2002). Antioxidant function of this species could become helpful agent in treatment of cancer, heart disease and high blood pressure (Lamaison et al., 1991; Lagouri and Boskou, 1996; Nakatani, 2000; Vichi et al., 2001 and Stashenko et al., 2002). Cervato et al. (2000) reported that antioxidant activities of O. vulgare leaves can inhibit all places of lipid peroxidative processes. Oregano  has  a  promising  potential  for  preventing diabetes  complications  in  the  long  term  treatments  and has an antiinflammatory efficacy as depicted by inhibiting soybean  lipoxygenase (Koukoulitsa et al., 2006). 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 and Skaltsa et al., 2010).
The essential oil of Origanum vulgare ssp. vulgare great potential of antimicrobial activity against all 10 bacteria, and 15 fungi and yeast species tested. The result may suggest that the essential oil O. vulgare ssp. vulgare possesses compounds with antimicrobial properties as well as antioxidant activity, and therefore can be used as a natural preservative ingredient in food and/or pharmaceutical industry (Sahin et al., 2004). Origanum vulgare ssp. hirtum was showed antioxidant activity (Milos et al., 2000). Origanum vulgare ethanolic extract and essential oil revealed antibacterial properties and antioxidant activity (Bárbara Teixeira et al., 2013).