RESUMO
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.
Assuntos
Ácidos Graxos Ômega-3 , Transtornos da Articulação Temporomandibular , Articulação Temporomandibular , Animais , Ácidos Graxos Ômega-3/uso terapêutico , Adjuvante de Freund , Humanos , Projetos Piloto , Ratos , Membrana Sinovial , Transtornos da Articulação Temporomandibular/tratamento farmacológicoRESUMO
Anxiolytic agents, mainly benzodiazepines, have been used to treat symptomatic disorders of the temporomandibular joint (TMJ). Our aim was to evaluate the effect of diazepam on the TMJ of rats with increased occlusal vertical dimension (iOVD). Forty male rats were randomly assigned to 4 groups: control rats were given sham iOVD plus saline solution daily for 7 days. The first experimental group was given sham iOVD plus diazepam 2.5mg/kg/intramuscularly daily for 7 days (diazepam alone group); the second had iOVD induced in molars for 7 days plus saline daily for 7 days (iOVD alone group); and the third had iOVD induced in molars for 7 days plus diazepam 2.5mg/kg/intramuscularly daily for 7 days (iOVD plus diazepam group). At the end of each experiment the animals were killed and their bilateral TMJs were removed, randomly stained with haematoxylin and eosin and sirius-red, and immunoassayed. The thickness of condylar cartilage and of fibrous, proliferating, mature, and hypertrophic layers, number of collagen fibres, and the articular area were measured. Proinflammatory cytokines (interleukin (IL)-1α, IL-1ß, IL-6, and tumour necrosis factor (TNF)-α) were also measured. ANOVA and Tukey's tests or the Kruskal-Wallis test were used to compare data among groups (α=5%). Condylar cartilage was thicker in the control group than in the other groups, the diazepam alone group being thicker than the other 2 experimental groups. There were fewer collagen fibres in the 2 groups given diazepam than in the other 2 groups, and there were no significant differences in the area of cartilage among groups. The controls had lower concentrations of all cytokines (p<0.05) than the 3 experimental groups, except for IL-6. Both iOVD groups had higher concentrations of IL-1α, IL-1ß, and IL-6 than the diazepam alone group. Diazepam alone was associated with increased concentrations of all cytokines except IL-6. We conclude that both iOVD and diazepam induced significant changes in rats' articular cartilage.