The effects of oleuropein aglycone, an olive oil compound, in a mouse model of carrageenan-induced pleurisy.

Background & Aims: Several olive oil phenolic compounds, such us oleuropein have attracted considerable attention because of their antioxidant activity, anti-atherosclerotic and anti-inflammatory properties. The aim of this study was to investigate the effects of oleuropein aglycone, a hydrolysis product of oleuropein, in a mouse model of carrageenan-induced pleurisy.

Methods: Mice were anaesthetized and subjected to a skin incision at the level of the left sixth intercostals space. The underlying muscle was dissected and saline or saline containing 2% λ-carrageenan was injected into the pleural cavity.

Results: Injection of carrageenan elicited an acute inflammatory response characterized by: infiltration of neutrophils in lung tissues (P < 0.01 versus sham. P < 0.01 versus carrageenan) and subsequent lipid peroxidation (P < 0.01 versus sham. P < 0.01 versus carrageenan), increased production of tumor necrosis factor-α and interleukin-1β (P < 0.01 versus sham. P < 0.01 versus carrageenan), increased expression of adhesion molecules, increased synthesis of nitric oxide (P < 0.01 versus sham. P < 0.01 versus carrageenan), nitrotyrosine and poly-ADP-ribose (P < 0.01 versus sham. P < 0.01 versus carrageenan). Administration of oleuropein aglycone 30 min after the challenge with carrageenan, caused a significant reduction of all the parameters of inflammation measured.

Conclusions: Thus, we propose that olive oil phenolic constituents may be useful in the treatment of various inflammatory diseases.