Medicinal Plants Lecture Notes PDF

MEDICINAL PLANTS Dr Mai Abdelhadi mai.abdelhadi @pharm.aun.edu.eg The course consists of 10 lectures. The total marks of the course is 150 (Final exam 75, practical exam 40, midterm exam 20, and oral exam 15)  Definitions Aims Pharmacognosy Nomenclatur...

MEDICINAL PLANTS Dr Mai Abdelhadi mai.abdelhadi @pharm.aun.edu.eg The course consists of 10 lectures. The total marks of the course is 150 (Final exam 75, practical exam 40, midterm exam 20, and oral exam 15)  Definitions Aims Pharmacognosy Nomenclature of drugs Powders of natural occurrence Production of crude drugs DEFINITIONS & BASIC PRINCIPLES  Pharmacognosy The word "Pharmacognosy" is derived from the Greek name "Pharmakon", a drug "gnosis", to acquire knowledge of. Pharmacognosy is defined as a branch of bioscience which treats in detail medicinal drugs obtained from plant, animal, marine, microbial and mineral origins. Natural product: is a chemical compound or substance produced by a living organism found in nature that usually has a pharmacological or biological activity to be used in pharmaceutical drug discovery & drug design. Phytochemistry: the study of chemicals derived from plants including the isolation, purification, identification of the chemical structure and biological activity of phytochemicals, in addition to the biosynthesis of these compounds. Drug: according to FDA (food and drug administration) the drug is any synthetic or natural substance or mixture at substances which may be utilized for the cure, prevention or mitigation of disease in human or other animals. The drug should be included in the official pharmacopoeia. Pharmacopeia: is a book containing an official list of medicinal drugs together with articles on their preparation and use. e.g., British Pharmacopeia B.P., European Pharmacopeia and United states Pharmacopeia U.S.P., and national formulary N.F. Natural drug: obtained from natural source. Synthetic drugs: obtained from chemical synthesis and whose source is the laboratory e.g., aspirin and paracetamol. Semi-synthetic drugs: Unlike fully synthetic medicines, which are created entirely in the laboratory using a stepwise combination of small chemical building blocks. Semi -synthetic medicines are derived from naturally occurring substances extracted from sources such as plants, bacteria or animal cells followed by chemical modification e.g., etoposide and hyoscine butyl bromide. Crude drugs Crude drugs are unmodified natural preparations from plants, animals, fungi, bacteria, and minerals that are used for the prevention or treatment of an ailment.  Sources of Crude Drugs Plant sources, e. g., Digitalis, Datura, Cascara, Ginger, Clove. Animal sources, e. g., Cochineal, honey, cod liver oil, musk, thyroxin. Marine sources, e. g., sponges, red algae, agar. Mineral sources, e. g., talc, kaolin, kieselguhr.  Medicinal plants A medicinal plant is that species of the plant kingdom, whose parts (flowers, leaves, roots, stems, fruits, or seeds) are directly used or used in some preparation as a medicine to treat a condition or disease.  Official drugs Non-official drugs An official drug is one that is listed and described in a book Drugs that have never been recognized by the government included in the pharmacopeia. as the legal authority of standards. e.g. Egyptian Pharmacopoeia (E.P.)  Aims Acquiring knowledge on medicinal and poisonous plants including the following: 1- Natural origin, sources and nomenclature according to U. S. P. and B. P. 2- Identification of the crude drug either in entire or powdered forms. 3- Active constituents, their chemical natures and detection of them. 4- Medicinal uses and toxic effects if present. Classification of drugs 1- Alphabetical: using either Latin name or English name e.g., Pharmacopoeias 2- Taxonomical: family, genus, species 3- Morphological: leaves, bark, flower …etc 4- Pharmacological: according to pharmacology of the plant Taxonomy: is the science that deals with the description, identification, nomenclature, and classification of organisms. The names of plants are given in binomial form.  Nomenclature of Drugs Binomial system of classification The binomial system was founded by the Swedish biologist Linnaeus. In this system, the first name start with a capital letter denotes the genus and the second name denotes the species, followed by the family name. Origin of medicinal plants Cassia acutifolia, family: Fabaceae Genus Species Family (italic) Genus and species name is followed by author’s name who first described the species or variety. e.g., Vinca rosea L. Sometimes, species name is derived from author’s name Cinchona named after Charles Ledger, who brought its seeds from Brazil, is known as Cinchona ledgeriana The species name is usually chosen to indicate certain Characteristics of the plant: Senna------ Cassia acutifolia (sharp pointed leaflets) Liquorice----- Glycyrrhiza glabra (glabrous smooth) Black pepper----- Piper nigrum Digitalis----- Digitalis purpurea Nutmeg----- Myristica fragrans Geographical source Hydrastis canadensis (growing in Canada) Tamarindus indica (growing in India) Pharmacological activity Papaver sominferum (inducing sleep) Strychnos nux vomica (causing vomiting) Ipomoea purga (purgative effect) DUSTING POWDERS  HOW TO MAKE A WET-MOUNT SLIDE Place your sample on a clean, dry slide. (Make sure your sample is very thin, or your coverslip will float, and you won’t get a very good view of your sample.) Place one drop of diluted glycerin over your sample. (Be sure not to use too much or your coverslip will float away, and you won’t be able to see your sample.) Place the coverslip at a 45-degree angle with one edge touching the liquid and let go. The coverslip will fall over the sample and be held in place by surface tension. (This method should prevent any air bubbles under the coverslip, as these will affect your ability to view the sample.) Precipitated chalk Condition: powder Colour: white Odour: odourless Taste: tasteless Touch: smooth Homogeneity: homogenous Solubility: insoluble in cold water In dilute HCl: effervescence occurs due to evolution of CO2 gas. Preparation of chalk CaCl2 + Na2CO3 CaCO3 + 2NaCl  Uses Calcium carbonate is found in antacids, which is chewed to provide relief for gastro-intestinal discomfort. Mechanism of action: Weak base that reacts with gastric HCl to form water & a salt, thereby lowering the acidity in the stomach.  Uses It may also be used to increase calcium levels in your body. Inert filler for tablets In cosmetics Mild abrasive in toothpastes  Talc (French chalk) Is a clay mineral composed of purified hydrated magnesium silicate, with the chemical formula Mg₃Si₄O₁₀(OH)₂. Physical characters Condition: fine powder Colour: grey Odour: odourless Taste: tasteless Touch: smooth and slippery Homogeneity: homogenous Solubility: insoluble in cold water and dilute HCl  Active constituents Hydrated magnesium silicate Mg₃Si₄O₁₀(OH)₂ 2% Iron oxide (imparts the greyish colour) Traces of aluminum oxide Microscopical characters Particles of various sizes and shapes. Irregular in shape with sharp angular, jagged ends.  Uses In a variety of cosmetic and personal care products. It is added to absorb moisture, smooth or soften products, prevent caking. Clarification and filtration of cloudy fluids. Lubricant for massaging. In manufacture of tablets.  Diatoms (Diatomite, Kieselguhr, Diatomaeceous earth) Origin: Physical characters Condition: fine powder Colour: greyish white The siliceous skeleton of fossil Odour: odourless diatoms, family Bacillariaceae. Taste: tasteless Touch: smooth Homogeneity: homogenous Solubility: insoluble in cold water and dilute HCl It is the fossilized skeletal remains of single-cell aquatic algae known as 'diatoms'. Types: (centric diatoms) are radially symmetric, while (pennate diatoms) are broadly bilaterally symmetric. Active constituents: Up to 92% silica 1-6% calcium oxide 0.2-1.5% magnesium and iron oxide Traces of aluminum oxide Uses: Clarification, filtration and decolorization Manufacture of toothpastes, face powders and soaps. In chromatography as support for column and thin layer chromatography.  Uses Clarification, filtration and decolorization Manufacture of toothpastes, face powders and soaps. In chromatography as support for column and thin layer chromatography.  Kaolin Origin: Contains mainly the clay mineral kaolinite (Al2Si2O5(OH)4), a hydrous aluminosilicate.  Uses In treatment of enteritis, dysentery and food poisoning. It adsorbs water, toxins and bacteria, contributing to firmer stools, reducing fluid loss from diarrhea. In pharmaceutical preparations e.g., toothpastes and cosmetics.  Lycopodium Origin: Consists of the spores of clubmoss, Lycopodium clavatum L., family Lycopodiaceae.  Lycopodium Physical characters Condition: fine powder, light weight (floats on the surface of water) Colour: pale yellow Odour: odourless Taste: tasteless Homogeneity: homogenous Solubility: insoluble in cold water, dilute acids or bases.  Microscopical characters Each spore is tetrahedral; three faces are flat and triangular while the fourth is rounded-triangular and convex. The convex surface is entirely covered with a fine network of raised ridges which produces a honeycomb appearance.  Active constituents Uses Dusting powder in pill manufacturing 40-50% fixed oil In quantitative microscopy; 3% sugars and sterols as 1 mg contains 94000 Traces of alkaloids (lycopodine) spore. Manufacture of firework due to its fixed oil content.  Kamala Origin: Consists of the glands and hairs that cover the fruits of Mallotus philippinensis Mull., family Euphorbiaceae. Physical characters Colour: dull red Odour: odourless. Taste: tasteless Float on water surface  Microscopical characters: Glands: depressed globular, filled with a deep red resin, secreted by several club-shaped cells radiating from a center. Hairs: thick–walled curved, unicellular and arranged in small radiating groups. The walls are lignified. Glands Hairs  Active constituents Uses Effective anthelmintic for tape 11% Phloroglucin derivatives as worms. Taenicide rottlerin and iso-rottlerin For dying silk (anthelmintic). 60% resin 2% wax  Lupulin Origin: Consists of the glands obtained from the strobiles of Humulus lupulus Family: Cannabinaceae.  Lupulin (Hops) Origin: Consists of the glands obtained from the strobiles of Humulus lupulus Family: Cannabinaceae.  Physical characters: Colour: brownish yellow. Odour: aromatic Taste: bitter Darken in colour during storage.  Microscopical characters Each gland consists of a cup- shaped layer of cells, the cuticle of the concave surface of which has been raised, dome-like, by the secretion of oil or oleo-resin between it and the cell wall.  Active constituents Uses Volatile oil (terpenes and sesquiterpene esters) Stomachic Bitter principles (phloroglucinol (promotes appetite and digestion) derivatives e.g., humulone and lupulone) Hypnotic (promotes sleep) Resin & wax In beer preparation Choline base References 1- Evans, W.C. “Trease and Evans’ Pharmacognosy” Saunders Elsevier, Edinburgh, London, New York, Philadelphia, St Louis, Sydney, Toronto, (16th Ed., 2009) 2- Wallis, T.A. “A Textbook in Pharmacognosy”, 6th. Ed., (1967). 3- Singh, G.K and Bhandari, A. “Textbook of Pharmacognosy” CBS publisher & Distributers, New Delhi, India, First edition 2000, reprint (2008)