Cyclooxygenase-1 (COX-1)

Cyclooxygenase-1 (COX-1) is an enzyme responsible for the conversion of arachidonic acid into prostaglandins, which play a key role in maintaining physiological homeostasis.

• Gastrointestinal Protection
  • Produces prostaglandins (PGE₂, PGI₂) that protect the gastric mucosa by increasing mucus and bicarbonate secretion, reducing acid secretion, and promoting mucosal blood flow.
  • COX-1 inhibition can lead to gastric ulcers and bleeding (a major side effect of NSAIDs).
• Platelet Aggregation (Blood Clotting)
  • Produces thromboxane A₂ (TXA₂) in platelets, which promotes platelet aggregation and vasoconstriction.
  • Aspirin irreversibly inhibits COX-1, reducing thromboxane formation, preventing blood clots (used in cardiovascular disease prevention).
• Renal Function
  • Helps regulate renal blood flow and sodium excretion.
  • COX-1 inhibitors may reduce renal perfusion, leading to kidney damage, especially in patients with compromised kidney function.
• Vascular Homeostasis
  • Helps maintain blood vessel integrity and regulates vascular tone.

• NSAIDs (Nonsteroidal Anti-Inflammatory Drugs) like aspirin, ibuprofen, and naproxen inhibit COX enzymes to reduce pain and inflammation.
• COX-1 inhibition (especially with non-selective NSAIDs) is associated with an increased risk of gastric ulcers and bleeding.
• COX-2 selective inhibitors (e.g., celecoxib) were developed to minimize GI side effects while maintaining anti-inflammatory effects.

Cyclooxygenase-1 inhibitor