A Pharmacological Review on Cyclooxygenase Enzyme

• Author Details:   
• D.S. Mohale
• A. S. Tripathi
• J. B. Wahane
• A.V. Chandewar

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 This review provides brief summary of structure, physiology and pharmacological role of Cyclooxygenase. Cyclooxygenase, an enzyme involved in the production of prostaglandins, exists in two isoforms, third isoform has been recently encountered. COX-1 is constitutively expressed and has a gastroprotective function. COX-2, induced at the site of injury, is responsible for the expression of pro-inflammatory prostaglandins. Despite overall similarities, COX-1 and COX-2 show subtle differences in amino acid composition at the active sites. COX-2 has valine at positions 89 and 523, while COX-1 has isoleucine, resulting in larger space availability in the former. Further, the presence of valine at position 434 in COX-2 as against isoleucine in COX-1 allows a gate mechanism to operate in favour of the former. The activity of cyclo-oxygenase-1 and 2 results in the production of a variety of potent biological mediators (the prostaglandins) that regulate homeostatic and disease processes.