RESUMO
AIM: The aim of this study was to evaluate the effect of telmisartan (TELM) on inflammation, oxidation and the expression of matrix metalloproteinases (MMPs) and the expression RANKL/RANK/OPG in the periodontal tissue of a rat model for ligature-induced periodontitis. MATERIALS AND METHODS: Male Wistar albino rats were randomly divided into five groups of 10 rats each: (i) non-ligated, given water; (ii) ligated, given water; (iii) ligated, given 1 mg/kg TELM; (iv) ligated, given 5 mg/kg TELM; and (v) ligated, given 10 mg/kg TELM. All groups were treated with saline or TELM for 10 days. Periodontal tissue was analysed by histopathology; by the immunohistochemical examination of COX-2, MMP-2, MMP-9 and the RANKL/RANK/OPG pathway; and by ELISA analysis of the levels of IL-1ß, IL-10, TNF-α, myeloperoxidase (MPO), malonaldehyde (MDA) and glutathione (GSH). RESULTS: Treatment with 10 mg/kg TELM resulted in reduced concentrations of MPO, MDA (p < 0.05) and the pro-inflammatory cytokine IL-1ß (p < 0.05); reduced expression of MMP-2, MMP-9, RANK, RANKL and COX-2; and an increase in OPG. The levels of TNF-α were significantly reduced in all TELM-treated groups. CONCLUSIONS: These findings confirm the involvement of TELM in reducing the inflammatory response, oxidative stress and bone loss in ligature-induced periodontitis in rats.