PCG 201 Introduction To Pharmacognosy PDF

B.Pharm PCG 201: INTRODUCTION TO PHARMACOGNOSY Dr. Ibrahim Malami Department of Pharmacognosy & Ethnopharmacy, Faculty of Pharmaceutical Sciences, Usmanu Danfodiyo University, Sokoto Centre For Advanced Medical R...

B.Pharm PCG 201: INTRODUCTION TO PHARMACOGNOSY Dr. Ibrahim Malami Department of Pharmacognosy & Ethnopharmacy, Faculty of Pharmaceutical Sciences, Usmanu Danfodiyo University, Sokoto Centre For Advanced Medical Research and Training (CAMRET), Usmanu Danfodiyo University, Sokoto  Highlight Introduction to Pharmacognosy Dr. Ibrahim Malami Mal. Mansur Lawal Pharm. A.H Ahmed Cytomorphology Microscopy Cytology and Introduction to Cytogenesis Cell Pharmacognosy inclusions 10 hours 13 hours 7 hours  Objectives To introduce:  the scope and significance of pharmacognosy and area of applications.  Important natural products and phytomedicines in medicine and pharmacy.  different classification natural drugs.  collection and preparation of natural drugs  adulteration and evaluation of crude drugs  various publications in pharmacognosy  Learning outcomes At the end of this set of lectures, you should be able to:  understand a general scientific field of pharmacognosy and its main applications.  provides an overview of the historical development of plants in pharmacy and medicine.  understand how natural drugs are collected and prepared as well as their adulteration.  understand pharmacognosy is an essential discipline within the field of pharmacy and medicine  Introduction  The use of natural drugs (especially terrestrial higher plants) have long been considered as the alternative to effective anti- infective agents.  They played a prominent role in ancient traditional medicine systems, e.g.,  Traditional Chinese Medicine – Chinese  Ayurvedic Medicine – Indians  Egyptian Traditional Medicine – Ancient Egyptian  WHO – up to 80% of the world population uses traditional herbal medicine for primary healthcare.  Almost 50% of modern medicines were either obtained natural origin or were derived from the natural products.  Most of the new natural product-derived drugs that have reached the market over the last decade have been obtained:  terrestrial microbe sources  higher plant  marine animal origin  E.g.,  atropine – Atropa belladonna  Aspirin – Salix spp  Quinine – Cinchona spp  Paclitaxel – Taxus brevifolia  Penicillin – Penicillium spp  Doxorubicin – Streptomyces spp  Streptomycin – Streptomyces spp  Morphine – Papava somniferum  Artemisinin – Artemisia annua  Vinca alkaloids – Catharanthus roseus  Drugs derived from organisms continue to be important for the treatment and prevention of many diseases.  The subject area – PHARMACOGNOSY: pharmakon ‘remedy’ and gignosco, ‘knowledge’ – coined in the early 19th century by the Austrian Professor Johann Adam Schmidt.  Pharmacognosy, has been an established pharmaceutical science taught in institutions of pharmacy education >100 yrs  The subject area has changed considerably since its initiation, having metamorphosed from a largely from 19th and early 20th centuries, to having much more of a chemical and biological focus within the last 60 years.  Pharmacognosy has evolved relatively recently to include the topics:  Phytotherapy  Phytomedicine  Phytochemistry  Nutraceuticals.  Pharmacognosy has become more relevant than previously over the last 20 years – a substantially increased use of herbal remedies by the public, particularly in Europe, North America and Australasia.  Pharmacognosy and its history  The history of pharmacy was for centuries identical to the history of pharmacognosy – materia medica  Materia medica – Latin word from the history of pharmacy meaning “medical material” or “medical substance” which were obtained from natural sources – mostly plants, but also minerals, animals and fungi.  Humans have always used plants in a multitude of ways in a tradition spanning human evolution.  The selection of medicinal plants – has led to an enormous number of medicinal plants being used by the numerous cultures of the world.  The sources available for understanding the history of medicinal plant use – archaeological records and written documents.  The earliest documented record – dates from 60,000 BC and was found in the grave of a Neanderthal man from Shanidar IV (an archaeological site in Iraq).  Ephedra altissima – ephedrine  The plant species are still important today in the phytotherapy of Iraq and are also known from other cultural traditions.  Ancient Egyptians – similar documents have survived.  The Egyptians documented their knowledge on papyrus – sort of paper made from Cyperus papyrus L.  found throughout southern Europe and Northern Africa.  The important – Ebers Papyrus, which originates from around 1500 BC.  The Ebers Papyrus is a medical handbook covering all sorts of illnesses and includes empirical as well as symbolic forms of treatment and the diagnostic precision is well documented.  Greek medicine has been the focus of historical pharmaceutical research for many decades.  The Greek scholar – Pedanius Dioscorides is considered to be the ‘father of (Western) medicine’.  His works were a doctrine governing pharmaceutical and medical practice >1500 years  His works heavily influenced European pharmacy.  He was an excellent pharmacognosist and described >600 medicinal plants.  Other Greek and Roman scholars were also influential in developing related fields of healthcare and the natural sciences.  Hippocrates – a Greek medical doctor (ca. 460–375 BC) heavily influenced European medical traditions. He was the first of a series of authors who produced the so-called Corpus Hippocraticum (a collection of works on medical practice).  The Graeco-Roman – medical doctor Claudius Galen (Galenus) (130–201 CE) summarized the complex body of Graeco-Roman pharmacy and medicine, and his name survives in the pharmaceutical term ‘galenical’.  Pliny the Elder was the first to produce a ‘cosmography’ (a detailed account) of natural history, which included cosmology, mineralogy, botany, zoology and medicinal products derived from plants and animals.  Asia – writings pointing to a long tradition of plant use.  In China, the field developed as an element of Taoist thought:  meditation, special diets, medicinal plants, and exercise.  Important work – the Shen nong ben cao jing (the ‘Drug treatise of the divine countryman’) – 2200 years.  The work – earliest classical sources on Chinese traditional medicine including 365 drugs, most of botanical origin.  Geographical origin, optimum period for collection, therapeutic properties and forms of preparation and dose.  Scholarly ideas – passed on from master to student  Another treatise on herbal drugs – 16th century, Ben Cao Gang Mu (‘Drugs’, by Li Shizhen).  The work contains information about 1892 drugs (52 chapters) and more than 11,000 recipes are given in an appendix.  The drugs are classified into 16 categories e.g. herbs, cereals, fruits etc. For each drug provided:  Definition of the drug  Selected commentaries  Classification according to the four characteristics of temperatures and the five types of taste   Uses – according to the criteria of Chinese medicine  Corrections of previous mistakes  Methods of preparing the drug  New features  Examples of recipes  Today – TCM has become a medical system used in many countries and the governments of the People’s Republic of China and Taiwan actively promote it.  India – oldest form of traditional is Ayurveda, which is basically Hindu in origin  ‘Ayurveda’ – ayur meaning ‘life’ and veda meaning ‘knowledge’.  Ayurveda – one of the most ancient of all recorded medicinal traditions. It is considered to be the origin of systemized medicine, because ancient Hindu writings on medicine contain no references to foreign medicine.  It’s composed of the elements:  earth (prithvi), water (jala), fire (tejac), air (vaju) and space (akasa).  Others – traditional system of medicine from other cultures:  Jamu – Indonesia (Javanese)  Kampo (low-dose TCM) – Japan  Others – very little or no documentation:  South American traditional system of medicine Quinine – Cinchona officinalis L. Tubocurarine (from arrow poisons)  African traditional system of medicine Physostigmine – calabar bean Importance of plants in modern pharmacy and medicine Why are plants and their extracts still important in pharmacy and medicine?  The scientific importance of pharmacognosy and natural product research was highlighted globally.  Historically – plants have yielded some of our most important drugs in many drug discovery programmes.  The development of drugs using natural products as ‘lead’ molecules continues, and many plant-derived natural products are used in modern, conventional medicine; other compounds are potentially useful to humans or are of toxicological relevance. Artemisinin  The discovery and development of artemisinin – one of the most important antimalarial drugs we have today.  Prof. Youyou Tu was awarded the Nobel Prize in Physiology or Medicine ‘for her discoveries concerning a novel therapy against malaria’.  Artemisinin – Artemisia annua  Commonly – sweet wormwood or Qinghao (Chinese). Artemisia annua Artemisinin Morphine  Morphine – Papaver somniferum (Opium poppy)  It is a potent analgesic and smooth muscle relaxant. Papaver somniferum Morphine Quinine  Quinine – cinchona bark (Cinchona succirubra)  It is an potent anti-malaria Cinchona succirubra Quinine Aspirin  Aspirin – Salix spp  It nonsteroidal anti-inflammatory drug used to relieve pain, fever, and inflammation Aspirin Tubocurarine  Tubocurarine – American arrow poison Curare (Chondrodendron tomentosum).  Potent analgesic – in anesthesiology as a myorelaxant Tubocurarine Taxol  Taxol (Paclitaxel) – bark of the Pacific yew (Taxus brevifolia)  Potent antitumor – breast, lung and Taxol (Paclitaxel) ovarian cancer. Physostigmine  Physostigmine – Calabar bean (Esere) (Physostigma venenosum).  Used to manage and treat antimuscarinic toxicity and glaucoma Physostigmine  Definition of Terms used in Pharmacognosy Pharmacognosy  Definitions:  Pharmacognosy is a branch of pharmacy that deals with the study of medicinal drugs derived from natural sources, such as plants, animals, and minerals. It involves the identification, isolation, and characterization of biologically active compounds from these sources, as well as the study of their biological, chemical, and physical properties  Pharmacognosy is the study of drugs of natural origin, whether they are derived from plants, bacteria, fungi, or animals.  Definitions:  Pharmacognosy is the science of biogenic or nature-derived pharmaceuticals and poisons. It deals with all medicinal plants, including those yielding complex mixtures, which are used in the form of crude herbs (comminuted herbal substance) or extracts (phytotherapy), pure compounds such as morphine, and foods having additional health benefits only in the context of having preventive effects (nutraceuticals). Phytotherapy  Definitions:  Phytotherapy is commonly defined as the study of the use of extracts of natural origin as medicines or health- promoting agents.  Phytotherapy is an integral part of the traditional medicinal system and has been utilized extensively as complementary medicine for the treatment of obstinate diseases Phytomedicine  Definitions:  Phytomedicine can be defined as the herbal medicine with therapeutic and healing properties.  Botanical drugs that form the basis for herbal remedies include, for example: The aerial parts The leaves The flowers The roots The barks The rizhomes etc. Phytochemistry  Definitions:  Phytochemistry is the study of chemicals and compounds found in plants, eg., morphine, taxol, artemisinin, etc. Natural product  Definitions:  Natural products are compounds isolated from natural origin, whether they are derived from plants, bacteria, fungi, or animals. Pure compound  Definitions:  Pure compound is a single well-defined chemical entity with a specific structure and composition that is isolated and purified from natural sources. Synthetic compounds  Definitions:  A synthetic compounds derived from a natural origin are substances that are chemically synthesized in a laboratory but is based on a naturally occurring compound found in nature. Semi-synthetic compounds  Definitions:  Semi-synthetic compounds of natural origin are substances that are partially synthesized in a laboratory using natural compounds as starting materials.  In this case, only a portion of the final compound is derived from natural sources, while the remaining part is chemically modified or added through synthetic processes. Nutraceuticals  Definitions:  A nutraceutical is defined as any substance that is a food or part of a food and provides medical or health benefits, including the prevention and treatment of disease.  Many foods are known to have beneficial effects on health. Garlic, ginger, turmeric and many other herbs and spices. Anthocyanin or flavonoid-containing plants such as bilberries, cocoa and zobo (Hibiscus sabdariffa). Carotenoid-containing plants such as tomatoes, carrots and many other vegetables. Crude drugs  Definitions:  A plant crude drug is a vegetable drug prepared from plant organs or exudates from plants without changes or modifications in its chemical composition.  Crude drugs are typically obtained from various parts of: Plants, e.g., leaves, stems, roots, bark, or seeds Animal sources Mineral sources Organised vegetable crude drugs  Definitions:  Organised (cellular) drugs are therapeutic substances that are extracted from plants. E.g., leaves, roots, stems, flowers, and seeds – used to treat or alleviate certain health conditions. Unorganised vegetable crude drugs  Definitions:  Unorganised (non-cellular) drugs are solids, liquid or semi- solid therapeutic substances that are extracted from plants. E.g., dry latex, gums, resins, volatile oils, juices, etc.