Pharmacognosy Lecture

PharmDD Program (2023/2024)

Introduction to Pharmacognosy

• Students will acquire knowledge about cytology, physiology, and taxonomy of medicinal leafy plants, dusting powders, and preparation of natural products derived drugs.
• The course will introduce students to different classes of secondary metabolites and pharmacologically active substances in certain official medicinal plants.

Definition of Pharmacognosy

• Pharmacognosy is a branch of pharmacy that deals with the study of medicines from natural sources (plant and animal) and their uses as medicaments from ancient times to present day.
• It involves the study of structural, physical, chemical, and biochemical characters of natural drugs of plant and animal origin.

Scope of Pharmacognosy

• Pharmacognosy is a multidisciplinary subject that requires knowledge of botany, ethnobotany, phytochemistry, microbiology, pharmacology, pharmaceutics, etc.
• It involves the studies of plants, animals, and other natural sources that yield crude drugs and drug substances, including their taxonomic identity, chemical, physical, and biological properties.

Pharmacognosists' Role

• Pharmacognosists isolate and characterize active constituents, evaluate the pharmacology of crude extracts and active constituents, and evaluate the quality of natural medicines.

Medicinal Plants

• Medicinal plants refer to the use of plant parts (seeds, berries, roots, leaves, bark, or flowers) for medicinal purposes.
• Many species of plants contain substances of medicinal value that have yet to be discovered.

Classification of Plants

• Kingdom Plantae consists of over 325,000 species of plants with different characteristics and sizes.
• Classification of plants is based on water requirements, habitat or environmental location, life duration, and natural system of classification.

Classification Based on Habit of Body Appearance

• Trees: woody plants with a single usually elongated stem.
• Shrubs: low, usually several stemmed woody plants.
• Herbs: plants with soft or succulent stem.

Vascular Plants

• Vascular plants with seed are classified into different groups.

References

• Joy, P.P., et al. (2001) Medicinal Plants. In: Bose, T.K., et al. (Eds.), Tropical Horticulture, Naya Prokash, Calcutta, 449-632.
• Joy, P.P., et al. (1998) Medicinal Plants. Tropical Horticulture, 2, 449-632.
• Evans, W.C. (2009) Trease and Evans' Pharmacognosy.