Medicinal Plants (PPC101) Lecture Notes PDF

Medicinal Plants (PPC101) Reda F. A. Abdelhameed, PhD gu.edu.eg Sumerians and Akkadians (3rd millennium BC) Code of Hammurabi in medicine Egyptians (Ebers papyrus, 1550 BC) Hippocrates “The Father of Medicine” Theophrastus's most important works: De historia plant...

Medicinal Plants (PPC101) Reda F. A. Abdelhameed, PhD gu.edu.eg Sumerians and Akkadians (3rd millennium BC) Code of Hammurabi in medicine Egyptians (Ebers papyrus, 1550 BC) Hippocrates “The Father of Medicine” Theophrastus's most important works: De historia plantarum (On the history of plants) and De causis plantarum (On the reasons for plant growth (Father of Botany)  Dioscorides (40-80 AD) “De Materia Medica” (600 medicinal plants)  The Islamic era Ibn Altabari (770−850) Ibn Sina (980-1037) “‫” فردوس الحكمه‬ “‫”القانون في الطب‬  ‫‪The Islamic era‬‬ ‫)‪Ibn Albitar (1148-1197‬‬ ‫”الجامع لمفردات األدوية واألغذية“‬  The 18 th century crude drugs were still being used as powders, simple extracts, or tinctures (concentrated alcoholic herbal extracts) Johann Adam (1759-1809) Carolus Linnaeus: work on medicinal plants and their properties Founder of Modern (Lehrbuch der Materia Medica). In this book Taxonomy the term "pharmacognosy" is originally coined  In 1803, a new era in the history of medicine (The era of pure compounds) In the 19th century, the chemical structures of many of the isolated compounds were determined In the 20th century, the discovery of important drugs. microorganisms have become a very important source of drugs  Important definitions Pharmacognosy: means the knowledge of drugs, it concerned with the study of the structural , chemical and sensory characters of crude drugs. It also includes their cultivation, collection, preservation, preparation for the market and their evaluation. Origin of the word “Pharmacognosy”: Two Greek words Pharmakon (drug) and gnosis (knowledge) Crude drug: it is the collected and usually dried or fresh plant or animal product of medicinal use without any further processing. Active constituents: compounds responsible for the therapeutic effects.  II. Value of natural products Compounds from natural sources play four significant roles in modern medicine: 1. They provide a number of extremely useful drugs that are difficult, if not impossible, to produce commercially by synthetic means 2. Natural sources also supply basic compounds that may be modified slightly to render them more effective or less toxic 3. Their utility as prototypes or models for synthetic drugs possessing physiologic activities similar to the originals 4. Some natural products contain compounds that demonstrate little or no activity themselves but which can be modified by chemical or biological methods to produce potent drugs not easily obtained by other methods Baccatin III → Taxol  Taxonomy It is the science of naming organisms and their correct integration into the existing system of nomenclature The names of species are given in binomial form: the first part of the name indicates the wider taxonomic group, the genus; the second part of the name is the species.  Nomenclature of Drugs There are two origins for each drug : the biological ( natural or botanical) origin and the geographical one. The biological origin of a drug : is the plant or animal yielding it The binomial system of naming plants: consists two names the first is ( Genus) and the second is the ( species)  Papaver somniferum L. Species: somniferum, here meaning ‘sleep- producing’ Genus: Papaver (a group of species, in this case poppies, which are closely related) Family: Papaveraceae (a group of genera sharing certain traits) L.: indicates the botanist who provided the first scientific description of the species and who assigned the botanical name The specific name is usually chosen to indicate : 1) some striking characteristics of the plant; for example: Glycyrrhiza glabra ( glabrous =smooth ; refers to the smooth fruits of this plant) Atropa belladonna (bella=beautiful ,donna = lady; the juice of the berry placed in the eyes causes dilatation of the pupils thus giving a striking look) 2) A characteristic colour of the plant; for example: Piper nigrum (nigrum = black; refers to the color of the fruits ) Digitalis purpurea ( purpurea=purple; refers to the colour of the flowers) 3) An aromatic plant or certain aroma e.g. Myristica fragrans ( having a fragrant nice aroma) 4) A geographical source e.g. Cannabis indica ( growing in India ) 5) A pharmaceutical activity or an active constituent e.g. Papaver somniferum (inducing sleep) Quillaia saponaria ( containing saponins) 6) A general meaning or a special indication e.g. Allium sativum (sativum = caltivated)  The generic name may also allude to certain characters of the plant For example: Glycyrrhiza glabra ( Glycyrrhiza is from glucose =sweet, riza= root.) Atropa belladonna (Atropa is from Atropos was the oldest of the Three Fates and was known as "the Inflexible One." It was Atropos who chose the manner of death and ended the life of mortals by cutting their threads, alluding to the poisonous characters of the drugs) The geographical and the commercial origins (sources) of the drugs The geographical source or habitat of the plant: is the region in which the plant or animal yielding the drug grows Cannabis (India , Italy) The commercial origin of the drug refers to the place of the drug production or transport, e.g. Alexandrian senna is first exported from Alexandria  Cultivation of medicinal plants Plants growing in their native land are said to be indigenous to this land. When plants grow in a foreign land or in a locality other than their natural home, they are said to be naturalized (cultivated). Gentian Cinnamon Senna  Cultivation 1. Wild plants are found in unlimited areas. 2. Difficulty in collection and transportion. 3. Continuous extensive collection may lead to extinction or a serious deficiency of the plant. 4. Adulteration: due to ignorance of collectors who may collect. 5. The collected amount of wild plants may be insufficient for the market needs and may lead to monopoly. advantages of Cultivation  Advantages of Cultivation 1. Control the purity of the drug 2. Concentration of a large number in small area so facilitate collection 3. Improvement of the drug by controlling certain factors in cultivation as: ▪ Treatment of seeds before sowing to ensure germination e.g. soaking Hyoscyamus seeds in diluted sulphuric acid fastens germination. ▪ The use of fertilizers by providing the essential elements for plant nutrition such as N, K and P. ▪ Controlling insects infestation. 4. Cultivation assures a regular and constant supply. 5. Cultivation of drugs in proximity to the factory for the manufacture of galenicals for making fresh green extracts. 6. Cultivation helps study of the constituents of plants grown under controlled conditions.  Disadvantages of cultivation 1. Cultivation may modify the morphological as well as the anatomical characters of the wild plant so that the identification of the plant becomes difficult. 2. The high cost of production except when carried on large scale. tropical climate Heavy rainful Hot weather