JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD Pharm. D II Year PHARMACOGNOSY AND PHYTOPHARMACEUTICALS Previous Question Paper (October - 2020 - R08)

Pharmacognosy is the branch of pharmaceutical sciences that deals with the systematic study of the physical, chemical, biochemical, and biological properties of drugs, drug substances, or potential drugs or drug substances of natural origin, as well as the search for new drugs from natural sources.

The history of Pharmacognosy dates back to ancient civilizations. Early records include the Ebers Papyrus (1550 BC) in Egypt, the Ayurvedic system in India (Charaka Samhita and Sushruta Samhita), and the Chinese Pen Tsao. Hippocrates and Dioscorides (author of De Materia Medica) laid the foundations in the West. The term 'Pharmacognosy' was coined by C.A. Seydler in 1815, derived from the Greek words 'pharmakon' (drug) and 'gnosis' (knowledge). The field evolved from simple descriptive botany to a sophisticated science integrating phytochemistry, pharmacology, and biotechnology.

The scope of Pharmacognosy is vast and includes the following areas:

• Drug Discovery: Identifying new lead compounds from plants, animals, and marine organisms for the development of modern medicines.
• Quality Control and Standardization: Establishing analytical methods, such as chromatography (HPTLC, HPLC) and spectroscopy, to ensure the purity, safety, and efficacy of herbal drugs.
• Phytochemistry: Isolating, identifying, and elucidating the structures of secondary metabolites like alkaloids, glycosides, terpenoids, and flavonoids.
• Biotechnology: Utilizing plant tissue culture, genetic engineering, and metabolic engineering to enhance the production of bioactive compounds.
• Pharmacology: Evaluating the biological activity and therapeutic potential of natural products through in vitro and in vivo studies.
• Industrial Application: Providing raw materials for the pharmaceutical, nutraceutical, cosmetic, and food industries.
• Traditional Medicine: Validating and integrating traditional systems of medicine (Ayurveda, Unani, Siddha) into evidence-based healthcare.

Crude drugs are classified to facilitate their study, identification, and systematic arrangement. The primary methods of classification include:

1. Alphabetical classification: Drugs are arranged in alphabetical order of their Latin or English names.
2. Taxonomical classification: Based on the natural relationship or phylogeny (Kingdom, Phylum, Class, Order, Family, Genus, Species).
3. Morphological classification: Based on the part of the plant used (e.g., leaves, roots, barks).
4. Chemical classification: Based on the active chemical constituents present.
5. Pharmacological classification: Based on the therapeutic action of the drug.
6. Chemotaxonomical classification: Based on the chemical constituents present in plants belonging to a specific taxon.

Chemical Classification: This method groups drugs based on the principal chemical constituents they contain, which are responsible for their therapeutic effects. This is the most popular method for phytochemical studies. Examples include:

• Alkaloids: Cinchona, Belladonna, Opium.
• Glycosides: Senna, Digitalis, Aloe.
• Volatile oils: Mentha, Clove, Fennel.
• Tannins: Catechu, Pale Catechu.
• Carbohydrates: Acacia, Agar, Honey.
• Lipids: Castor oil, Beeswax.

Pharmacological Classification: This method classifies drugs according to their therapeutic action on the human body or their specific pharmacological effect. This is highly useful for clinicians and pharmacologists. Examples include:

• Drugs acting on the Gastrointestinal tract: Carminatives (Fennel, Ginger), Purgatives (Senna, Castor oil).
• Drugs acting on the Central Nervous System: CNS stimulants (Coffee, Tea), CNS depressants (Opium, Belladonna).
• Drugs acting on the Cardiovascular system: Cardiotonics (Digitalis, Arjuna).
• Drugs acting on the Autonomic Nervous System: Adrenergics (Ephedra), Cholinergics (Pilocarpus).
• Antimicrobials/Antiseptics: Neem, Turmeric.
• Anticancer agents: Vinca, Podophyllum.