The effects of taxifolin on alveolar bone in experimental periodontitis in rats

•Taxifolin accelerated osteoblast numbers and decreased osteoclast numbers.•Taxifolin induced the expressions of Col-1 OCN, BMP-2 and ALP.•Taxifolin induced Bcl-2 expressions and reduced Bax expressions.•Taxifolin reduced RANKL-dependent osteoclastogenesis and bone loss in periodontitis. This study aimed to evaluate the effect of taxifolin, a powerful antioxidant, on the progression of periodontitis by immunohistochemical and cone-beam computed tomography (CBCT) examination. This study was performed with 32 rats in four experimental groups: a non-ligated group (Control, n = 8), periodontitis group (Perio, n = 8), periodontitis with 1 mg/kg/day taxifolin group (Taxi-1, n = 8), and periodontitis with 10 mg/kg/day taxifolin group (Taxi-10, n = 8). A ligature-induced experimental periodontitis design was used. All rats were sacrificed at 30 days. Alveolar bone loss was determined by CBCT. Hematoxylin–eosin stained slides were examined. The expression levels of bone morphogenetic protein 2 (BMP-2), osteocalcin (OCN), alkaline phosphatase (ALP), collagen type I (Col 1), Bcl-2, Bax, and receptor activator of NF-κB ligand (RANKL) were determined immunohistochemically. Both doses of taxifolin showed a decrease in alveolar bone loss. The inflammatory reaction was higher in the Perio group and lower in the taxifolin groups. BMP-2, OCN, ALP, and Col 1 expression were dose-dependently elevated in the taxifolin groups. RANKL immunoexpression decreased with both doses of taxifolin. Bcl-2 expression increased and Bax expression decreased in the taxifolin groups. Taxifolin successfully reduced apoptosis and improved bone formation in alveolar bone in this experimental periodontitis model.