Effects of Ezetimibe, Simvastatin, and their Combination on Inflammatory Parameters in a Rat Model of Adjuvant-Induced Arthritis.

Statins are hypocholesterolemic drugs that are prescribed for patients with an increased risk of cardiovascular and cerebrovascular complications. Ezetimibe has an atheroprotective activity through inhibition of the expression of vascular adhesion molecule-I and vascular CD14, a marker of the infiltration of mononuclear leukocytes. Ezetimibe reduces the amount of chemoattractant protein-1 that is available for monocytes and macrophages and alters the activity of nuclear factor κB in leukocytes. The mechanisms of action of statins complement those of ezetimibe. Previous studies have demonstrated that the combination of statins and ezetimibe has beneficial effects, including antiinflammatory activity. The present study evaluated the effects of monotherapy with ezetimibe and simvastatin compared with ezetimibe + simvastatin combined on the evolution of the inflammatory response in a rat model of Complete Freund's Adjuvant-induced arthritis. The animals were treated with 10 mg/kg ezetimibe, 40 mg/kg simvastatin, or 10 mg/kg ezetimibe + 40 mg/kg simvastatin for 1, 7, 14, or 28 days. We analyzed leukocyte rolling behavior, leukocyte adhesion to the endothelium, the number of leukocytes that were recruited to the knee joint cavity, and the concentration of cytokines that are involved in the inflammatory response. The data were analyzed using paired t tests or analysis of variance followed by Bonferroni post hoc test. The treatments reduced leukocyte rolling behavior and leukocyte adhesion. The monotherapies did not change the number of leukocytes that were recruited to the knee joint cavity, whereas the ezetimibe + simvastatin combination significantly reduced this parameter. The treatments reduced the levels of proinflammatory cytokines and increased the levels of the antiinflammatory cytokine IL-10, indicating antiinflammatory properties of these drugs in this experimental model of inflammation.

Fish Oil and Adjuvant-Induced Arthritis: Inhibitory Effect on Leukocyte Recruitment.

Fish oil, a rich source of n-3 fatty acids, has been studied for its beneficial effects in many diseases. Recent studies have shown the robust anti-inflammatory activity of fish oil (FO), when administered orally to rats, in models of acute inflammation. Herein, we investigated if treatment with fish oil preparation (FOP) could interfere with the recruitment of leukocytes into the joint cavity of arthritic rats. We also evaluated the effect of treatment on rolling behavior and leukocyte adhesion in vivo and on leukocyte chemotaxis in vitro. Treatment with FOP (75, 150, and 300 mg/kg) initiated on the day of induction of arthritis (day 0) and maintained for 21 days reduced the total number of leukocytes recruited into the joint cavity, the number of rolling and adhered leukocytes in arthritic rats, and leukocyte migration in response to stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP) and leukotriene B4 (LTB4). Together, our data provide evidence that FOP plays an important inhibitory role in the recruitment of leukocytes into the joint cavity of arthritic rats.