CONICET | Buscador de Institutos y Recursos Humanos

Los Endocannabinoids have known anti-inflammatory effects. Our laboratory developed an experimental model of periodontitis induced by injections of lipopolysaccharide (LPS) of Escherichia coli in the gingival tissue of the rat. The AIM of the present work was to assess the effect of the application of methanandamide (M-AEA), a synthetic cannabinoid, on periodontal disease developed by using the mentioned model. METHODS: Four groups of rats were employed (n=7): 1) control; 2) injected with 10ìL of physiologic solution (vehicle of LPS) in the vestibular and lingual/palatine gum of the first molar and in the interdental space between the first and the second molar of both maxillaries, 3 times a week, during 6 weeks (in days 1, 3 and 5); 3) injected with 10ìL LPS (1mg/mL) in the sites described for group 2; and 4) injected with LPS and treated daily with M-AEA (500ng/mL) in the sites of injection. Finished the treatments, after sacrifice, gums and submandibular glands (SMG) were extracted, to measure nitric oxide synthase (iNOS) activity by radio-conversion. Also, upper and lower maxillaries were extracted to assess bone loss measuring the distance between the cemento-enamel junction and the alveolar bone crest of the first molars roots. RESULTS: the rats injected with LPS showed increased iNOS activity both in gums (P<0.01) and in GSM (P<0.01) as compared to controls and to rats injected with vehicle, while this activity was lower in rats additionally treated with M-AEA (P<0.01 and P<0.001, respectively). Also, rats injected with LPS and treated with M-AEA showed similar bone loss than rats injected with vehicle and lower bone loss than rats injected with LPS exclusively, both in lower and in upper molars (P<0.05). CONCLUSION: the local application of M-AEA prevents, at least partially, alveolar bone loss and attenuates inflammatory parameters increased by experimental periodontitis induced by LPS. Endocannabinoids have known anti-inflammatory effects. Our laboratory developed an experimental model of periodontitis induced by injections of lipopolysaccharide (LPS) of Escherichia coli in the gingival tissue of the rat. The AIM of the present work was to assess the effect of the application of methanandamide (M-AEA), a synthetic cannabinoid, on periodontal disease developed by using the mentioned model. METHODS: Four groups of rats were employed (n=7): 1) control; 2) injected with 10ìL of physiologic solution (vehicle of LPS) in the vestibular and lingual/palatine gum of the first molar and in the interdental space between the first and the second molar of both maxillaries, 3 times a week, during 6 weeks (in days 1, 3 and 5); 3) injected with 10ìL LPS (1mg/mL) in the sites described for group 2; and 4) injected with LPS and treated daily with M-AEA (500ng/mL) in the sites of injection. Finished the treatments, after sacrifice, gums and submandibular glands (SMG) were extracted, to measure nitric oxide synthase (iNOS) activity by radio-conversion. Also, upper and lower maxillaries were extracted to assess bone loss measuring the distance between the cemento-enamel junction and the alveolar bone crest of the first molars roots. RESULTS: the rats injected with LPS showed increased iNOS activity both in gums (P<0.01) and in GSM (P<0.01) as compared to controls and to rats injected with vehicle, while this activity was lower in rats additionally treated with M-AEA (P<0.01 and P<0.001, respectively). Also, rats injected with LPS and treated with M-AEA showed similar bone loss than rats injected with vehicle and lower bone loss than rats injected with LPS exclusively, both in lower and in upper molars (P<0.05). CONCLUSION: the local application of M-AEA prevents, at least partially, alveolar bone loss and attenuates inflammatory parameters increased by experimental periodontitis induced by LPS.