Which hormone is known to decrease the synthesis of prostaglandins and leukotrienes?

• A. Aldosterone
• B. Dehydroepiandrosterone
• C. Cortisol
• D. Pregnenolone

Answer: (C)

Cortisol is the hormone responsible for decreasing the synthesis of prostaglandins and leukotrienes. It is a glucocorticoid that exerts its effects primarily through its anti-inflammatory properties. Cortisol achieves this by inducing the expression of lipocortin, a protein that inhibits phospholipase A2. This inhibition prevents the release of arachidonic acid from membrane phospholipids, which is the precursor for both prostaglandins and leukotrienes. By reducing the availability of arachidonic acid, cortisol effectively decreases the production of these inflammatory mediators, leading to its well-known anti-inflammatory and immunosuppressive effects.

This action is particularly important in conditions characterized by excessive inflammation, where corticosteroids like cortisol are often employed therapeutically to manage symptoms and control inflammatory processes.