Impellizzieri D.

Oleuropein olive oil compound in acute and chronic inflammation models: facts and perspectives

Rivista : Anno 42/Numero 1

The regular consumption of olive oil has been suggested to be one of the factors associated with a lower incidence of several disease in Mediterranean countries. A group of olive oil phenolic compounds, such as oleuropein has attracted considerable attention because of its antioxidant activity, anti-atherosclerotic and anti-inflammatory properties.We illustrate the effects of oleuropein aglycone (3,4-DHPEA-EA), a hydrolysis product of oleuropein, in a mouse model of carrageenan-induced pleurisy (acute inflammation model) and on the modulation of the inflammatory response in mice subjected to collagen-induced arthritis (CIA) (chronic inflammation model).
Acute inflammation model.
Mice were anaesthetized and subjected to a skin incision at the level of the left sixth intercostal space. The underlying muscle was dissected and saline or saline containing 2% λ-carrageenan was injected into the pleural cavity. Injection of carrageenan elicited an acute inflammatory response characterized by: infiltration of neutrophils in lung tissues and subsequent lipid peroxidation, increased production of tumor necrosis factor-α and interleukin-1β, increased expression of adhesion molecules, increased synthesis of nitric oxide, nitrotyrosine and poly-ADP-ribose.
Administration of 3,4-DHPEA-EA 30 min after the challenge with carrageenan, caused a significant reduction of all the parameters of inflammation measured.
Chronic inflammation model.
CIA was induced in mice by an intradermally injection of 100 μl of the emulsion (containing 100 μg of bovine type II collagen) (CII) and complete Freund’s adjuvant (CFA) at the base of the tail. On day 21, a second injection of CII in CFA was administered. margins. Mice developed erosive hind paw arthritis when immunized with CII in CFA. Macroscopic clinical evidence of CIA first appeared as peri-articular erythema and edema in the hind paws. The incidence of CIA was 100% by day 27 in the CII challenged and the severity of CIA progressed over a 35-day period with a resorption of bone. The histopathology of CIA included erosion of the cartilage at the joint . Treatment with 3,4-DHPEA-EA starting at the onset of arthritis (day 25), ameliorated the clinical signs at days 26-35 and improved histological status in the joint and paw. The degree of oxidative and nitrosative damage was significantly reduced in 3,4-DHPEA-EA - treated mice as indicated by elevated expression of inducible oxide nitric synthase (iNOS), nitrotyrosine and poly (ADP-ribose) polymerase (PARP). Plasma levels of the pro-inflammatory cytokines were also significantly reduced by 3,4-DHPEA-EA.

In the mammal body the normal production of oxidants is counteracted by several antioxidative mechanisms. Food constituents are the normal substrate for energy generation but a hypercaloric diet may result in higher production of oxidants thus inducing oxidative stress.Epidemiological studies have shown that populations consuming a predominantly olive oil-based Mediterranean-style diet exhibit lower incidencesof various diseases. In our study, we confirm that habitual intakes of olive oil provide a continuous supply of antioxidants and anti-inflammatory substances which may be protective in acute and chronic inflammation.

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