RÉSUMÉ
This study evaluated the effect of systemic administration of omega-3 on the expression of interleukins IL-1ß and IL-10 and tumour necrosis factor alpha (TNF-α) and on the thickness of cartilage in the temporomandibular joint (TMJ) inflammatory model induced by complete Freund's adjuvant (CFA). Thirty-two adult rats were divided equally into four groups: control, CFA (induced arthritis), and induced arthritis animals treated with dexamethasone or omega-3. The TMJs were then removed and assigned to histomorphometric analysis or immunoassay. The Kruskal-Wallis test with Dunn post hoc test was applied to the data; the significance level was set at 5%. IL-1ß levels (median; interquartile range) were higher (P<0.0001) in the CFA group (46.4 ng/ml; 39.4-53.3) than in the control group (1.81 ng/ml; 1.5-5.4), but there were no differences between the control, omega-3, and dexamethasone groups. TNF-α levels were also higher (P<0.0001) in the CFA group (122.7 ng/ml; 92.9-284.7) than in the control group (29.1 ng/ml; 23.7-31.3). IL-10 levels were lowest (P<0.0001) in the CFA group (73.5 ng/ml; 52.8-90.5), and no differences were found amongst the other groups. In conclusion, omega-3 successfully reduced the damage in the TMJ of induced arthritis rats. Further investigations are warranted to confirm whether the administration of omega-3 has a comparable effect to glucocorticoids in rheumatoid arthritis patients.