eChapter Name: Analytical Pharmacognosy
9789372193596
eBook Name: NATURAL DRUGS: HERBAL MEDICINES AND PHARMACOGNOSY
by Liza Handique, Biswadeep Gogoi
1. Introduction
Pharmacognosy, formerly known as materia medica, is the study of unrefined medications derived from minerals, plants, and animals. Although C. A. Seydler coined the phrase in 1815, J. A. Schmidt used it in 1811 to refer to the study of medicinal plants and their characteristics. The word refers to the study or knowledge of medicines and is derived from the Latin terms gignoso, which means “to acquire knowledge of,” and pharmakon, which means “a drug.” Plants, animals, or their parts that have just been dried, sliced longitudinally or transversely, or infrequently peeled after collecting are considered crude pharmaceuticals. The majority of the basic drugs used in medicine are derived from plants, with only a minor portion coming from the animal and mineral kingdoms. Drugs made from plants are full plants, however cinchona bark, ginger rhizome, nux vomica seeds, and senna leaves and pods are plant components. Some medications, such as orange and lemon peels and colchicum corm, are used fresh, but the majority are dried after harvesting. Crude pharmaceuticals can also be obtained by straightforward physical processes like drying or water extraction. Aloe is the dried juice of Aloe species’ leaves, opium is the dried latex from poppy capsules, and black catechu is the dried aqueous extract from Acacia catechu’s wood. Plant exudates such as gums, resins, balsams, volatile oils, and fixed oils are also considered crude medicines. Additional drugs that physicians, surgeons, or pharmacists use directly or indirectly include diatomite for filtering gums or turbid liquids; cotton, silk, jute, and nylon for surgical dressings or kaolin; wax, gelatin, and agar for use as pharmaceutical auxiliaries of flavoring or sweetening agents; and drugs used as insecticides or vehicles. Animal medications can be extracts, like liver extracts, glandular products, such thyroid organs, or whole animals, like can-tharides. Similarly, goods that come from animals include fish liver oils, bee wax, musk, certain hormones, enzymes, and antitoxins. Drugs can be classified as either organized or disorganized. Organized medications come directly from plants and are composed of biological tissues. Unorganized pharmaceuticals are generated by physical intermediary procedures such as cutting, drying, or extraction with water, and although being derived from plants, they do not contain cellular tissue. Thus, unstructured medications include gums, resins, aloe, catechu, opium, and other plant exudates. Kaolin, chalk, diatomite, and other Ayurvedic bhasmas are examples of mineralbased medicines.
