Investigation of the cyclooxygenase inhibition by polyphenol extracts derived from monocultivar oils from olive tree varieties from the Maltese islands

Abstract

Cyclooxygenase (COX) is the enzyme responsible for the conversion of twenty carbon fatty acids such as arachidonic acid (AA) into prostaglandins (PGs). In humans, PGs play a role in various important processes such as inflammation, labour initiation, kidney function and blood clotting (Dubois et al., 1998). Today it is recognised that inflammation plays an important role in leading to numerous other diseases, such as cancer (Rakoff-Nahoum, 2007). Hence there is interest in modulating this pathway through natural means. Two isoforms of the enzyme exist, these being COX-1 and COX-2. While the two are similar in primary protein structure and in the catalytic reaction they perform, they differ in their tissue expression patterns, inhibitor selectivity and in the substrates they utilise. Moreover, while COX-1 is constitutive, COX-2 is inducible (Vane et al., 1998). Non steroidal anti-inflammatory drugs (NSAIDs) inhibit COX, resulting in a decline in PG formation. Though greatly beneficial, NSAIDs cause renal and gastrointestinal side effects, such as damage to the mucosa and ulceration (Hawkey, 2001). In this study, the inhibition of COX by polyphenols extracted from autochtonous Maltese olive oil varieties was investigated.