Decreased TNF-α gene expression in periodontal ligature in MSG-obese rats: a possible protective effect of hypothalamic obesity against periodontal disease?

The prevalence of obesity is increasing globally. There is evidence that the uncontrolled energetic metabolism in obese patients can accelerate periodontal disease. Therefore, the aim of this study was evaluate the possible relationship between hypothalamic obesity induced by neonatal treatment with MSG and experimental periodontal disease. Newborn male Wistar rats received subcutaneous injections in the cervical region, of 4g/Kg/day of body weight (BW) of MSG (MSG group) or hypertonic saline solution, 1.25/kg/day BW (control group, CTL). At 70 days of life periodontal disease was induced in these animals. After they were sacrificed, radiographic analyses of alveolar bone resorption and Tumor Necrosis Factor α (TNFα) gene expression in gingival tissue were performed. The neonatal treatment with MSG did not affect the concentration of plasma glucose and cholesterol (CHOL). However, plasma insulin, non-esterified fatty acids (NEFA) and triglycerides (TG) leves were higher in MSG compared with CTL group. The alveolar bone resorption was 44% lower in MSG-obese rats compared with CTL rats. In the presence of periodontal ligature, there was an increase in this parameter in all groups. The TNFα gene expression, an inflammatory marker, in periodontal tissue was similar in obese and CTL rats. The presence of ligature increased TNFα gene expression in both groups, but in a lower extension in MSG-obese rats. In conclusion these results suggested that hypothalamic obesity may produce a protective effect against periodontal disease, however further research is needed to understand the mechanisms involved in this process.

Selective cyclooxygenase-2 inhibition prevents bone resorption.

The aim of the present work was to evaluate the effect of a selective cyclooxygenase-2 (COX-2) inhibitor (meloxicam) on the alveolar bone loss progression in experimentally induced periodontitis. Forty (40) Wistar rats were separated into 8 experimental groups (n = 5). Cotton ligatures were placed at the gingival margin level of the lower right first molars of some rats. Four groups were treated for 5 or 15 days with an oral dose of 15 mg/kg of body weight/day of the selective COX-2 inhibitor. The other groups were used as positive control (sham) or negative control in each experimental period. Standardized digital radiographs were taken after sacrifice at 5 and 15 days to measure the amount of bone loss at the mesial root surface of the first molar tooth in each rat. The treatment with meloxicam did not induce weight alteration or other visible systemic manifestations. One way analysis of variance (ANOVA) indicated that groups treated with meloxicam, after 5 days, had significantly less alveolar bone loss (p < 0.05) when compared with control groups. On the other hand, no significant differences in bone loss were observed after 15 days of treatment with meloxicam. These data provide evidence that systemic therapy with meloxicam can modify the progression of experimentally induced periodontitis in rats during the initial experimental period.

Selective cyclooxygenase-2 inhibition prevents bone resorption

O objetivo deste trabalho foi avaliar o efeito de um inibidor seletivo da cicloxigenase-2 (COX-2) (meloxicam) na progressão da perda óssea alveolar durante o desenvolvimento da doença periodontal experimental induzida. Quarenta (40) ratos Wistar foram separados em 8 grupos experimentais (n = 5). Ligaduras de fio de algodão foram colocadas na margem gengival do primeiro molar inferior direito de alguns ratos. Quatro grupos foram tratados por 5 ou 15 dias com uma dose oral de 15 mg/kg de peso corporal/dia do inibidor seletivo de COX-2. Os outros grupos foram usados como controle positivo (sham) e controle negativo dentro de cada período experimental. Radiografias digitais padronizadas foram realizadas para medir a perda óssea na região mesial do primeiro molar inferior de cada rato. O efeito do tratamento com meloxicam não induziu alteração de peso ou outras manifestações sistêmicas visíveis. A Análise de Variância (ANOVA) indicou que os grupos tratados com meloxicam após 5 dias apresentaram perda óssea alveolar significativamente menor (p < 0,05). Por outro lado, a perda óssea não foi significativa após 15 dias de tratamento com meloxicam. Os dados apresentados no presente trabalho sugerem que o tratamento sistêmico com meloxicam pode modificar a progressão da periodontite experimental em ratos no período experimental inicial.