JNTU Pharm. D II Year PHARMACOGNOSY AND PHYTOPHARMACEUTICALS Previous Question Paper (January/February - 2021 - R08)

Pharmacognosy is the study of medicinal drugs derived from plants or other natural sources. Its history is deeply rooted in ancient civilizations, evolving from empirical observation to a rigorous scientific discipline.

The history of pharmacognosy can be divided into several key eras:

• Ancient Era: Early records from the Sumerians, Egyptians (Ebers Papyrus), and Chinese (Pen Tsao) documented the use of natural substances for healing.
• Classical Period: Figures like Hippocrates, Dioscorides (author of De Materia Medica), and Galen established the foundations of systematic botanical classification and drug preparation.
• Middle Ages: Contributions from Arab scholars like Avicenna preserved and expanded knowledge of medicinal plants through texts like The Canon of Medicine.
• Modern Era: The 19th century marked a turning point with the isolation of pure active constituents (e.g., morphine from opium by Sertürner in 1806). The term 'Pharmacognosy' was coined by C.A. Seydler in 1815.

The scope of pharmacognosy has expanded significantly beyond simple identification to include:

• Drug Discovery: Identifying novel bioactive compounds from natural sources to serve as lead molecules for synthetic drug development.
• Quality Control and Standardization: Utilizing advanced analytical techniques (HPLC, HPTLC, GC-MS, DNA fingerprinting) to ensure the purity, safety, and efficacy of herbal medicines.
• Phytochemistry: Investigating the biosynthetic pathways and chemical structures of secondary metabolites like alkaloids, glycosides, and terpenoids.
• Pharmacology and Toxicology: Evaluating the biological activity and safety profiles of natural products through pharmacological screening.
• Cultivation and Biotechnology: Improving the yield of medicinal plants through tissue culture, genetic engineering, and optimized agricultural practices.
• Regulatory Affairs: Establishing guidelines for the registration and clinical validation of traditional and herbal medicinal products.

A crude drug is a natural product of plant, animal, or mineral origin that has undergone no processes other than collection and drying. These substances contain complex chemical constituents and serve as the raw material for the production of pharmaceutical preparations.

Crude drugs are classified into the following categories:

• Alphabetical classification: Drugs are arranged in alphabetical order (e.g., Acacia, Benzoin, Cinchona).
• Taxonomical classification: Based on the botanical classification of plants (e.g., Umbelliferae family includes Fennel, Coriander).
• Morphological classification: Based on the part of the plant used (e.g., Leaves: Senna; Roots: Rauwolfia; Bark: Cinchona).
• Pharmacological/Therapeutic classification: Based on the action of the drug (e.g., Laxatives: Senna; Cardiotonics: Digitalis).
• Chemical classification: Based on the nature of chemical constituents (e.g., Alkaloids: Opium; Glycosides: Senna; Volatile oils: Peppermint).
• Chemotaxonomical classification: Based on the relationship between chemical constituents and botanical classification.

Notes on two drugs of plant origin:

1. Senna (Cassia angustifolia): Consists of dried leaflets of the plant belonging to the family Leguminosae. It contains anthraquinone glycosides, specifically sennosides A and B. It is primarily used as a stimulant laxative to treat constipation.
2. Rauwolfia (Rauwolfia serpentina): Consists of dried roots of the plant belonging to the family Apocynaceae. It contains indole alkaloids, notably reserpine. It is used as an antihypertensive and as a sedative in the treatment of mental disorders.