Introduction to Pharmacognosy
Pharmacognosy: The study of medicinal drugs derived from natural sources (plants, animals, microbes).
The term comes from two Greek words: 'pharmakon' (drug) and 'gnosis' (knowledge). It is one of the oldest branches of pharmacy and medicine.
It involves the study of the botanical (scientific name, family), chemical (active principles), and biological (medicinal use) properties of "crude drugs" (raw, unprocessed natural materials).
Systematic position, distinguishing features and uses of following herbs in curing various ailments
Exam Format: This section is perfect for "short notes" questions. Be prepared to write a 1-page note on any of these plants, covering all three required points: Systematic Position, Features, and Uses.
| Herb (Common Name) | Systematic Position | Distinguishing Features | Uses in Curing Ailments |
|---|---|---|---|
| Tulsi (Holy Basil) |
Botanical Name: Ocimum sanctum (or Ocimum tenuiflorum) Family: Lamiaceae (Mint family) |
An aromatic, erect herb. Leaves are opposite, simple, and toothed. Flowers are small, purplish, in small whorls. The entire plant has a strong, characteristic aroma. |
|
| Ginger |
Botanical Name: Zingiber officinale Family: Zingiberaceae (Ginger family) |
A herbaceous perennial. The "drug" part is the rhizome (underground stem), which is knotty, branched, and pungent. Leaves are long, slender, and sheath the stem. |
|
| Fenugreek (Methi) |
Botanical Name: Trigonella foenum-graecum Family: Fabaceae (Legume family) |
An annual herb. Leaves are trifoliate (like clover). The "drug" part is the seed, which is small, hard, yellowish-brown, and has a characteristic "furrow" dividing it. |
|
| Indian Gooseberry (Amla) |
Botanical Name: Emblica officinalis (or Phyllanthus emblica) Family: Euphorbiaceae |
A small to medium-sized tree. Leaves are small, feathery, and arranged on branchlets. The "drug" part is the fruit: a pale green, globular, fleshy fruit with 6 faint vertical stripes. It is very sour and astringent. |
|
| Ashoka |
Botanical Name: Saraca asoca Family: Caesalpiniaceae (Fabaceae) |
A small evergreen tree. Leaves are pinnately compound. Flowers are in dense, bright orange-red clusters. The "drug" part is the bark. |
|
| Arjun |
Botanical Name: Terminalia arjuna Family: Combretaceae |
A large, deciduous tree, often found on river banks. The "drug" part is the bark, which is smooth, greyish-white, and peels off in large flakes. |
|
Herbs as health food
This category includes plants or supplements that are consumed not just to "cure" a disease, but to maintain overall health, provide essential nutrients, and prevent illness. They are often called "functional foods" or "nutraceuticals."
- Alfaalfa (Medicago sativa):
- A legume, often consumed as "sprouts."
- Extremely rich in vitamins (A, C, E, K) and minerals (Calcium, Potassium, Iron).
- Used as a nutritional supplement and for detoxification.
- Chicory (Cichorium intybus):
- The root is roasted and ground.
- Famously used as a coffee substitute/adulterant.
- Rich in inulin, a prebiotic fiber that promotes the growth of healthy gut bacteria (probiotics).
- Garlic (Allium sativum):
- A "superfood." Eaten raw or cooked.
- Contains the active compound allicin.
- Known to lower cholesterol and blood pressure, acting as a cardio-protective food. Also has strong antimicrobial properties.
- Ginseng (Panax ginseng):
- The root is the "drug" part.
- A famous adaptogen (like Ashwagandha) – helps the body resist physical and mental stress.
- Used to improve stamina, concentration, and overall vitality.
- Ashwagandha (Withania somnifera):
- The root is the "drug" part.
- The premier *Rasayana* of Ayurveda.
- Used as an adaptogen to combat stress, anxiety, and insomnia, and to boost energy and vitality.
- Spirulina (Arthrospira platensis):
- A blue-green alga (cyanobacterium), not a "herb."
- Sold as a dark green powder or tablet.
- An incredible "superfood," containing >60% complete protein.
- Rich in vitamins (B12), minerals (iron), and pigments (phycocyanin). Used as a nutritional supplement.
Future of pharmacognosy
Pharmacognosy is experiencing a major resurgence. While it was once seen as an "old" science, its future is bright and high-tech.
- New Drug Discovery: The vast, unexplored biodiversity (e.g., in rainforests, oceans) is a "treasure chest" of novel chemical compounds that could become future drugs for cancer, antibiotic-resistant bacteria, etc.
- Phytomedicine & Standardization: The future is in moving from "crude drugs" to "standardized extracts" – herbal products that are scientifically validated and guaranteed to contain a specific amount of the active principle.
- Biotechnology: Using plant tissue culture to grow rare or endangered medicinal plants in a lab, or to produce their active compounds in bioreactors.
- Ethnopharmacology: Systematically studying the traditional knowledge of indigenous peoples to find new medical leads.
- Nutraceuticals: A booming industry, as the public moves towards "natural" products and health foods (like those listed above) for disease prevention.