Sources of Drugs - Plants, Animals, Marine & Tissue Culture

Sources of Drugs: Derived from plants, animals, minerals, microorganisms, and synthetic processes.
Sources of Drugs: Provide active compounds for disease prevention and treatment.
The development and production of medicinal compounds have historically relied on various natural sources.
These sources include plants, animals, marine organisms, microorganisms, and tissue culture techniques.
Each source offers unique advantages and specific compounds essential for modern medicine.
Natural drugs come from a wide array of sources.
The major categories are:

Most Common Source: Historically and still today, plants remain the predominant source of natural drugs.
Examples:
- Leaves (e.g., digitalis leaves for digoxin),
- Barks (e.g., cinchona bark for quinine),
- Roots (e.g., Rauwolfia serpentina roots for reserpine),
- Seeds (e.g., nux vomica for strychnine).
Secondary Metabolites: Plants produce alkaloids, glycosides, tannins, volatile oils, resins, etc. that often display therapeutic properties.

Animal Products: Various drugs are derived from animal tissues or secretions.
Examples:
- Hormones (e.g., insulin originally obtained from the pancreas of cattle or pigs),
- Enzymes (e.g., pancreatin, pepsin),
- Biologicals (e.g., vaccines, antisera),
- Glandular products (e.g., thyroid extract).
Therapeutic Use: These substances are critical in treating certain diseases (e.g., insulin for diabetes).

Marine Organisms: Rich source of novel bioactive compounds due to unique marine biodiversity.
Examples:
- Sponges, corals, algae, marine bacteria, and fungi can produce antitumor, anti-inflammatory, and antimicrobial agents.
- Cytarabine (an anticancer drug) was inspired by marine sponges.
Challenges: Difficulties in the collection and cultivation of marine organisms have historically slowed the discovery and mass production of marine-derived drugs, but advances in aquaculture and synthetic approaches are overcoming these obstacles.

Plant Tissue Culture: In vitro techniques that involve growing plant cells, tissues, or organs in nutrient media under sterile conditions.
Importance:
- Allows for the production of secondary metabolites (bioactive compounds) without needing to cultivate whole plants in the field.
- Enables micropropagation of rare or endangered medicinal plants.
- Potential for genetic transformation and metabolic engineering to enhance yield of therapeutic compounds.