Mechanism of Castor Oil as a Purgative
Castor oil exerts its purgative action through:
- Direct colonic irritation
- Na⁺K⁺-ATPase inhibition
- Osmotic water retention
- Ricinoleic acid, lipase — Correct Answer
Explanation:
Correct Answer: Ricinoleic acid produced by pancreatic lipase hydrolysis
Castor oil is a bland vegetable oil obtained from seeds of Ricinus communis. It is cleaved by pancreatic lipases in the small intestine to yield irritant ricinoleates (ricinoleic acid), which stimulate peristalsis and reduce fluid absorption.
Key Points
- Ricinoleic acid is polar → poorly absorbed → acts in the ileum and colon.
- Primary action: decreased intestinal absorption of water and electrolytes + enhanced secretion (detergent-like action on mucosa).
- Causes morphological damage of villus tip and increases peristalsis.
- Due to unpalatability, frequent cramping, violent action, possibility of dehydration, and mucosal damage — it is no longer favored.
📚 About this Topic — Veterinary Pharmacology and Toxicology
This multiple choice question is from Veterinary Pharmacology and Toxicology, Veterinary Science. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Veterinary Pharmacology and Toxicology to strengthen your preparation.
