Chapter 1 Pharmacognosy Pharmacognosy is the study of the science of naturally derived drugs, and poisons. It is related to the stucly of the physical, chemical, and biological properties of drugs produced from natural sources such as plants, microbes, and animals. Modern pharmacognosy is related to the study of natural products from various sources including plants, bacteria, fungi, and marine organisms. Plants are the source of many active ingredients used for medicinal purposes. Examples include salicylic acid and caffeine, indole alkaloids from Vinca rosea, morphine, atropine, and Aloe gel, These natural compounds provide a great basis for the discovery of new drugs, Itis believed that people find plant-derived medicines that exist in nature and are not synthetic, About 25% of prescription medicines in the USA are believed to have an active ingredient from a natural source. In developing countries, it is estimated that about 80% of their populations rely on traditional medicines made from plants and herbs. To study a plant drug, following points are considered: 1, Biological Source: The biological source of a drug is mentioned in the Latin language which also includes the family to which it belongs. After the Latin name, the name of archer botanist responsible for the classification is mentioned in abbreviated The plant family to which the drug belongs determines certain of its characters. : The principal areas of collection and routes of transport are considered under the w Habit this head. Plant Habit: The general structure of the plant and morphology of crude plant drugs are studied. Cultivation, Collection and Preparation for the market: These factors require particular attention when they affect the appearance or quality of the product. Morphology and Sensory Characters: A knowledge of details of macroscopical structure is important. Cells and tissues are examined of powdered drugs. Histology: Microscopical characters such as cell structure and arrangement, starches, epidermal trichomes, calcium oxalate crystals and fibres are studied under this head. i Commercial Varieties, Substitutes and Adulteration: With a knowledge of the diagnostic characters of official drugs, a critical examination of commercial may be made to determine their quality, and substances known to be potential substitutes or adulteration. = xa a Textbook of Pharmacognosy 8, Chemical Constituents: The pharmacologically active constitue ihe more potent components, constituents affecting, the aoe identity and class of such compounds are considered of prep the purity and quality of drugs are determined 9, Evaluation of Drug: T! 10. Uses: Various medicinal uses and toxic effects are studied. Percentage aration, the Tre) mola PHARMACOGNOSY ‘The term ‘pharmacognosy’ was used for the firs time by the Austrian physician S gil and by Anotheus Seydler in 1815 (Greek: Pharmakon = drug; a, Physician Schmidt inawork titled Analecta Pharmacognostica y = knowledge) During the 19th century and the beginning of the 20th century, pharmacognos eng the branch of medicine or commodity sciences which deals aide ees used 10 de, or unprepared form. Crude drugs are the dried, unprepared material of cat animal or microbes origin, used for medicine. Pa , the subject had developed mainly on the botanical At the beginning of the 20th century, side. It is related with the description and identification of drugs both in their whole form and in powder state. It has been ‘developed for quality control purposes, pharmacopoeial protocols and related health regulatory frameworks. At the same time, development in P her areas of research has widely expanded the subject. PRESENT STATUS -e for the discovery of future medicines. Japan and Pharmacognosy is still a relevant scienc the United States of America (USA) are very active in the field. Researchers are encouraged to develop natural products as medicines. Since the beginning of this century, more than half of the world’s tropical forest area has been destroyed. Experts estimate that only 5-10% ofall plants in the world have been systematically investigated for their pharmacological activity. The future developments of pharmacognosy and the herbal drug industry are dep upon reliable procedures for the identification of ‘marker compounds of the plant extracts. The standardization and quality control of these extracts are important procedures. Pharmacognosy gives a sound knowledge of the vegetable drugs under botany and animal drugs. It also includes plant taxonomy, and plant breeding, plant pathology, plant one can improve the cultivation methods for both genetics and with this knowledge, medicinal and aromatic plants. Pharmacognosy is used by pharmaceutical industries to scr characterize and produce new drugs for the treatment of human diseases. Often, naturally occurring drugs cannot oe mass-produced, so they must be studied in order to develop, with synthetic procedures: ‘According to the Botanical Survey of India, India is home fo mG than 8,000 species of medicinal plants. The country has a rich history of traditional healing systems, °5 ‘Ayurveda, Unani, and Homeopathy medicinal systems. a ‘All plants produce chemical compounds as part of their normal metabolic activite® ‘These phytochemicals are divided into: 1. Primary metabolites such as sugars and fats, which are found in all plants: and 2. Secondary metabolites—compounds which are found in a range of plan'* serving more specific functions. endentFor example, some secondary metabolites are toxins used by plants for their otection and others are pheromones used to attract insects for pollination. It is these secondary metabolites and pigments that can have therapeutic actions in humans and which can be refined to produce drugs. Examples are inulin from the roots of dahlias, morphine and codeine from the opium poppy, quinine from the cinchona bark, tetrahydrocannabinol (THC) and cannabidiol constituents from the cannabis, and digoxin from the foxglove. Plants synthesize a variety of phytochemicals. Polyphenols (phenolics) such as anthocyanins, isoflavones, phytoestrogens and tannins give tea its astringency. Glycosides are molecules in which a sugar is bound to a non-carbohydrate moiety. Terpenes are a large and diverse class of organic compounds, produced by a variety of plants, which are often strong smelling and thus may have a protective function. The carotenoids produce shades of red, yellow and orange in pumpkin, maize, and tomatoes. An antimalarial drug, artemisinin, is isolated from Artemisia annua herb, a herb known in Chinese medicine to treat fever. The extracts of this plant showed antimalarial activity. SCOPE OF PHARMACOGNOSY The scope of pharmacognosy includes the study of the physical, chemical, biochemical and biological properties of drugs, drug substances, or potential drugs or drug substances of natural origin and the search for new drugs from natural sources. Research problems in pharmacognosy include studies in the areas of phytochemistry, microbial chemistry, biosynthesis, biotransformation, chemotaxonomy, and other biological and chemical sciences. It involves plant-related natural health products for the benefit of human health. The other fields of the subject are concerned with the study of botany, ethnobotany, marine biology, microbiology, herbal medicine, phytochemistry, biotechnology, pharmacology, and clinical pharmacy. The following fields are now focused in the subject pharmacognosy: * Medical ethnobotany: The study of traditional uses of plants for medicinal purposes; + Ethnopharmacology: The study of pharmacological qualities of traditional medicinal substances; + Phytotherapy: The study of medicinal use of plant extracts; * Phytochemistry: The study of chemicals derived from plants, including the identification of new phytoconstituents derived from plant sources; * Marine pharmacognosy: The study of chemicals derived from marine organisms (many marine and aquatic organisms such as algae, nematodes, sponges, and fishes have soft ia cchian nen ors, bacteria, and fungi); andae chromatographic procedures. These methods have allowed the rapid compounds previously difficult to obtain by classical methods. Then isolation of factor has been the discovery of new spectroscopic techniques which are dae importang structures of the isolated compounds. Although more than 100 plants are Wsed to identity vodicine in various parts of the world. The list of the most important ones ai o™ their pharmacological properties is tabulated in Table 1.1. S along with BEBE 122200 of Pharmacognosy ioc taser 1. Dioscorea, Agave, and _Steroidal hormones Anti-inflammatory, Hormonal Solanum species Antiarthritic 4 2. Papaver somniferum Morphine, Codeine, Papaverine Sedative, Antitussive, Smooth muscle relaxant 3. Cinchona species Quinine, Quinidine Antimalarial, Antiarthythmic 4. Datura stramonium, Hyoscyamine, Hyoscine, Atropine Parasympatholytic Hyoscyamus niger, Dubosia species 5. Digitalis lanata Digitoxin, Digoxin, Lanatosides __Cardiotonic 6. Cathranthus roseus ‘Ajmalacine, Vincristine, Vinblastine Vasodilator Anticancer 7. Rauwolfia serpentina Reserpine, Rescinamine, Deserpidine Hypotensive Vasodilator 8. Camellia sinensis (Tea) Caffeine CNS stimulant 9. Erythroxylum coca Cocaine Anaesthetic 10. Ephedra species Ephedrine sympathomimetic 11, Pilocarpus jaborandi Pilocarpine Parasympathomimetic 12. Cephaelis acuminata, Emetine Antiamoebic C. ipecacuanha 13, Claviceps purpurea Ergotamine, Ergometrine, Oxytocic, Vasodilator, Vasocons- triction 14, Plantago ovata Psyllium mucilage Laxative 15. Vinca minor, Voacanga _-Vincamine Vasodilator africana 16. Glycyrrhiza glabra Glycyrthetinic acid Anti-inflammatory 17. Cassia angustifolia, Sennosides Laxative C. acutifolia 18, Berberis asiatica. _—_—-—Betberine 19, Podophyllum peltatum 20. Colchicum autumnale 21. Theobroma cacao 22, Coffea arabica Antidiarrheal ‘Podophyllotoxin Anticancer In addition to pure constituents, the crude Belladonna, Capsicum oleoresin, Cascara sagrada, Opium, Podophyllum, Rhubarb, Stramonium and Besides these, the essential oils of Anise seeds, mint, Lemongrass, and Peppermint are also e, Artemisia annua herb, a, Henbane, Ipeca* in modern medicin®- leaves, Clove, Japane* aPharmacognosy ER Liver and stomach preparations of animals are prescribed in therapy of pernicious anaemia. Bile secreted in the liver is given for biliary secretion as a sodium salt to increase diuresis. Pure active chemical constituents have been isolated from medicinal plants for the Jast 50 years. These phytoconstituents replaced the crude drugs, with the development of semisynthetic and synthetic medicine. Plant drugs, their extracts and their medicinal active constituents have become a significant market commodity in the international trade. The scope of pharmacognosy is significant in the field of medicine, bulk drugs, food supplements, pharmaceutical necessities, pesticides, dyes, tissue culture biotechnology, engineering and so on. The pharmacognosy personnel serve in various fields as follows: ‘Academics: Teaching in academic institutions, museums and botanical gardens. Private industry: Pharmaceutical companies, consumer products testing laboratories, commercial testing laboratories, herbal product industries, cosmetic and perfume industries, and marketing field. Government: Placement in federal agencies, such as the drug enforcement agency, the food and drug administration, medicinal plant research laboratories, forensic laboratories, and environmental laboratories. Drug discovery from medicinal plants continues to p: against various pharmacological targets including cancer, malaria, and pain. Several natural product/drugs of plant origin ovide new and important leads HIV/AIDS, Alzheimer’s disease, have either recently been introduced or are currently involved in late-phase clinical trials.