PHG 101 Handout Fall 2024 PDF

1- Definition of Botany: Botany is the scientific study of plant and plant life. Plants are classified as: What are Medicinal Plants? Medicinal plants are plants that have a therapeutic or curative effect. Medicinal plants can also be called: herbal medicinal plants, herbal...

1- Definition of Botany: Botany is the scientific study of plant and plant life. Plants are classified as: What are Medicinal Plants? Medicinal plants are plants that have a therapeutic or curative effect. Medicinal plants can also be called: herbal medicinal plants, herbal remedies, herbal drugs, or herbs. 2- Pharmacognosy Definition: It means the study of natural substances, mainly plants, that have medicinal uses. The word ‘’Pharmacognosy’’ is derived from the Greek: Pharmacon = a drug, Gnosis = to acquire knowledge. So, Pharmacognosy means the entire knowledge of drugs. Therefore, Pharmacognosy studies the scientific basis for the use of plants in pharmacy. 1 3- Crude (raw) drug The plant or animal material before it is subjected to extensive processing or modification. Crude drugs are used as therapeutic agents (of medicinal use). Crude drugs are derived from: plant, animal, or mineral origins. 4-Classification of Medicinal plants Medicinal plants (drugs) are classified in different ways to make their study easy. Each of these ways has advantages and disadvantages. Classification Methods Alphabetical Taxonomical Morphological Chemical Pharmacological 2  Classification methods include the following: A- Alphabetical: (According to Latin or English names) This type of classification is employed for dictionaries, pharmacopoeias ……….,..etc. B- Taxonomical: Medicinal plants (drugs) are arranged based on an accepted system of botanical classification, they can be classified in classes, orders, families, genera, and species. C - Morphological: i- Organized drugs: Medicinal plants are divided according to plant organs such as leaves, flowers, herbs, roots, fruits, & seeds. ii- Unorganized drugs: include plant products e.g., dried latex, extracts, gums, resins, oils, waxes… etc. D - Chemical: Medicinal plants (drugs) are arranged according to the main active constituents that the plants contain, e.g. alkaloids, glycosides, tannins, & volatile oils. E - Pharmacological or Therapeutical: The herbal drugs are classified according to their therapeutic uses. Example: Drugs affecting GIT (gastrointestinal tract), heart, kidney, nervous system, …………etc. 5- Origin of drugs A- Biological origin Biological origin or source of a drug is the plant or animal yielding it. Indicates the name of plant & family from which the drug is obtained. The Binomial system for plants naming was devised by Linnus (a Swedish scientist) who gave each plant a name formed of two words. 3  The first word indicates the Genus name and is written with the first letter capital. The second word indicates the species name and is written with the first letter small. Both words must be either underlined or written in italics. Example: e.g. Atropa belladonna Fam. Solanaceae Sometimes, the genus name may be chosen to indicate a special meaning. Example for a genus: Glycyrrhiza glabra → (from glucos=sweet, riza=root) Also, the species name may be chosen to indicate a special meaning or some striking characteristics of the plant. B - Commercial origin C- Geographical origin Habitat: is the region in which the plant grows. Indigenous = Natural habitat:→ plants growing in their native countries. Exotic = acclimatized:→ plants growing in a country other than their native home. The climate (temp., wind, rainfall, light) affects the active constituents. Thus, the active constituents are greatly affected by the region in which the plant grows. 4 6- Official & Unofficial drugs Official drugs: are the drugs listed in a book, recognized by the government such as the Egyptian Pharmacopeia. Unofficial drugs: are the drugs not listed in a book recognized by the government. The Pharmacopoeia It is a governmental book that contains a listing of all official drugs, along with their effects & directions for their use. A drug that is not listed in the pharmacopoeia is said to be unofficial. 5