Fig. 1

Local administration of 4-OI ameliorates periodontal inflammation and alveolar bone loss in vivo. a Timeline for the operation process in C57BL/6 male mice. b Micro-CT image of the alveolar bone. The red part displayed the exposure of root. c Representative images of H&E staining of the periodontitis areas. (Scale bar = 400 μm). d, e IF staining of M1 polarization-related markers (iNOS/F4/80) and M2 polarization-related markers (CD206/F4/80) and in macrophages across the periodontal region at 14 days post-operation. (Scale bar = 50 μm). f Representative images of TRAP staining and the IHC staining of IL-6 in the periodontal tissue. (Scale bar = 100 μm). g CEJ-ABC distance. h BV/TV. i Tb.Th. j, k Semi-quantitative analyses of iNOS⁺ ratio in F4/80⁺ cells and CD206⁺ ratio in F4/80⁺ cells. l Quantitative analysis of osteoclast number per view at alveolar bone. m Positive area of IL-6 above threshold. Values are presented as mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.000 1. Lig ligature, ab alveolar bone, R root