Inhibition of the expression and activity of cyclooxygenase-2 by chicory extract

Abstract

Chicory is a major source of fructans with reported prebiotic–bifidogenic properties. In the present study, the potential anti-inflammatory activities of chicory were investigated. Ethyl acetate chicory root extract produced a marked inhibition of prostaglandin E 2 (PGE 2) production in human colon carcinoma HT29 cells treated with the pro-inflammatory agent TNF-α. Two independent mechanisms of action were identified: (1) a drastic inhibition of the induction by TNF-α of cyclooxygenase 2 (COX-2) protein expression and (2) a direct inhibition of COX enzyme activities with a significantly higher selectivity for COX-2 activity. The inhibition of TNF-α-dependent induction of COX-2 expression was mediated by an inhibition of NF-κB activation. A major sesquiterpene lactone of chicory root, the guaianolide 8-deoxylactucin, was identified as the key inhibitor of COX-2 protein expression present in chicory extract. Altogether, the data presented strongly support chicory root as a promising source of functional food ingredient, combining prebiotic and anti-inflammatory properties.