Preventive effects of trehalose on osteoclast differentiation in rat periodontitis model

Aim Trehalose, which is a disaccharide formed by a 1,1 linkage of two glucose molecules, was suggested to have a suppressive effect on bone resorption. In this study, we examined the effects of topical application of trehalose on osteoclast differentiation in a rat periodontitis model. Material and Methods Rats were divided into four groups. One group received no treatment. In the other groups, experimental periodontitis was induced by ligature placement. These rats with experimental periodontitis received topical application of pure water (vehicle group), 30 mg/ml trehalose solution (30 mg/ml trehalose group) or 60 mg/ml trehalose solution (60 mg/ml trehalose group) to the gingival sulcus respectively. Results The vehicle group showed higher numbers of polymorphonuclear leucocytes, receptor activator of nuclear factor kappa B ligand (RANKL)-positive cells and osteoclasts compared with the no treatment group respectively. Trehalose-applied groups exhibited lower numbers of these cells compared with the vehicle group. Gene expressions of tumour necrosis factor-a, RANKL and toll-like receptor 4 were suppressed by trehalose. In addition, protein expressions of RANKL inducing pathway were less activated by trehalose. Conclusion Topical application of trehalose could suppress osteoclast differentiation by inactivation of RANKL inducing pathway in the rat periodontitis model.