Nature has been a source of medicinal agents for thousands of years and an impressive number of modern drugs have been derived from natural source. The reasons for this are complicated, but probably result from the ability of nature to produce a fantastic array of structurally complex and diversemolecules. (HeinrichMetal.,2010) Plants are potent biochemical factories and have been components of phytomedicine since times immemorial. The medicinal value of the plants lies in some chemical substances that produce a definite physiological actions on the human body , these substances are called phytochemicals ,which can be used for therapeutic purpose. Plants based medicinal constituents can be derived from any part of plant like bark, leaves, flowers, roots, fruits, and seeds. ( Srivastava P.K., 2014)
Various medicinal plants and their phytoextracts have shown numerous medicinal properties like antioxidant , antiinflammatory , anti-cancer , anti-microbial, anti-diabetes, anti- nociceptive action , etc .(Ullah N., et al.2011).
Medicinal plants play a key role in human health care . About 80% of the world population relies on the use of traditional medicine, which is predominantly based on plants , the reasons of this popularity are the safety, efficacy of medicinal plants and their cost effectiveness. (Arulselvan , et al .2013).
Many of medicinal plants are used as spices and food items. They also played an important role in many medicines like allopathic medicine, herbal medicine, alternative medicine, homoeopathy and aromatherapy. (DeviP.R., 2014)
Among different sources of natural products, plants have been a source of novel chemical substance, which serves as starting materials for a number of old and new pharmaceutical products.
Medicinal plants are the foundation of many drugs prescribed today in modern medicinal system . About 25% of modern pharmaceutical drugs have botanical origins, For example, the herb foxglove is the source for digitalis and the herb salicin is the source for aspirin. The breast-cancer-fighting drug taxol (tamoxifen) comes from the pacific yew tree, quinidine from Cinchona spp., vincristrine and vinblastine from Catharanthus roseus, atropine from Atropa belladonna and morphine and codeine from Papaver somniferum. (Sahoo N.et al,2010)
Research needs in the field of medicinal plants are huge, but are balanced by the potential health benefits and the enormous size of the market. Research into the quality, safety, biological activity , and clinical efficacy of the numerous plants in common usage is required.
Newly emerging scientific techniques and approaches have been used in the growing area of medicinal plant research , for the investigation of constituents and determination of biological activity of medicinal plants .
Evidence for the benificial effects of selected plants is generally based on experiments demonstrating a biological activity in a relevant in vitro bioassay or experiments using animal models. (Iris F. F. etal,2011)
Plants that demonstrated anticancer, antioxidant , anti-inflammatory, immunostimulatory,and antimicrobial properties have received research attention.
The presence of techniques like: chromatographic (TLC, GC, HPLC), spectroscopic (UV, IR, 1H- and 13C-NMR,MS) helped in the elucidation of the structures of active principles,which opened the way for synthesis and derivatization for compounds with higher efficacy and lower side effects(e.g.,Metformin,nabilone,oxycodon,verapamil,etc).
Recently, the linking of the folkloring use of plants and knowledge of specialist in herbal medicine to modern research activities provides a new approach, which makes the rate of discovery of drugs much more effective than with random collection.( Zuhair T.,2009).
Iraq was known as the valley of the two rivers ‘Mesopotamia’, occupies an excellent geographic position where it encompasses mountainous areas in the north, the temperature of which drops below zero; a desert areas around the middle and south part of the country of a very high temperatures and pelagic humidity impregnated areas. All those factors gave Iraq an important geographic position led to the creation of different environments that helped considerably the diversification of its flora.
The use of medicinal plants in Iraq goes back thousands of years, and the clay tablets of Sumerian and Babylonian civilization clarified the use of many different methods of treatment by medicinal plant. (Albayaty N., 2011)
Later on, this knowledge was translated and enriched by the Arab physicians during Abbasid period 500-1038 A.D. In many countries in the world, traditional medicine remains equally important to the formal health system. Among these countries are the Arab countries including Iraq.
(Al-Douri N.,2010 )
...(download the rest of the essay above)