Efeito da calendula officinalis em ratos submetidos a periodontite experimental: participação das vias RANK-RANKL-OPG e WNT B-CATENINA

Abstract

Periodontitis is an infecto-inflammatory disease that leads to connective tissue and alveolar bone loss. Calendula officinalis (CLO) has been used due to its anti-inflammatory effects. Therefore the aim of this study was to evaluate the effect of CLO on alveolar bone loss (ABL) in rats focusing on RANK-RANKL-OPG and WNT signaling pathways. Experimental periodontitis (EP) was induced through placement of a nylon ligature around the upper left 2nd molar, and the hemimaxilla used as control. The animals were divided in groups: Normal, subjected to no treatment; Saline (SAL), that received 2 ml/kg of 0,9% saline solution orally; or CLO at 90 mg/kg orally, 30 minutes before EP and daily for 11 days until euthanasia. In order to evaluate the periodontal tissue, it macroscopic, micro-tomographic, electron scanning microscopy (SEM), confocal microscopy and polarized light microscopy analyses were performed, as well as immunohistochemistry for WNT 10b, β-catenin, DKK-1, RANK, RANKL, and OPG. During euthanasia the gingival tissue was removed for malonaldehyde (MDA) assay. Treatment with CLO significantly prevented ABL, preserved bone internal microstructure (p<0.05) and topography, and also preserved collagen fibers from the periodontal ligament, when compared to SAL. CLO significantly increased the number of immunopositive cells for WNT 10b, β-catenin and OPG and reduced DKK-1, RANK (p>0.05) and RANKL. CLO reduced the gingival levels of MDA compared to SAL (p<0.05). In this way, we can conclude that CLO prevented ABL via RANK-RANKL-OPG and WNT signaling pathway.