Abstract: OBJECTIVE: To elucidate whether Danzhi Jiangtang capsule(丹蛭降糖胶囊, DJC) has treatment effects on diabetic periodontitis and the potential mechanism.METHODS: One week after the induction of diabetes by streptozotocin(STZ), 60 male Wistar rats were ligated by orthodontic ligation thread in cervical portion of bilateral maxillary first molar to induce diabetic periodontitis. Periodontitis was exanimated by tooth tissue morphology after 4 weeks.And then all rats were divided into 5 groups: diabetic periodontitis group(DP, n = 20), periodontal basic treatment group(DP + BT, n = 20), periodontal basic treatment+DJC treatment group(DP + BT +DJC, n = 20) and additional Wnt/β-catenin inhibitor group(DP + BT + DJC + WIKI4/21 H7, n = 20). Eight weeks after different interventions, fasting plasma glucose(FPG), C-peptide and glycosylated hemoglobin(Hb Alc) of rats were measured and then all rats were sacrificed. The paraffin sections of periodontal tissue were executed hematoxylin-eosin (HE) staining and immunohistochemical examination. The m RNA and protein levels of inflammatory cytokines were evaluated by quantitative polymerase chain reaction(Q-PCR) and Western blotting(WB). The protein levels of Wnt/β-catenin signaling molecules were measured by WB.RESULTS: The blood glucose and C-peptide concentrations in DP, DP + BT and DP + BT + DJC groups were gradually reduced, with gradually decreased distance of CEJ-A and the percentage of periodontal ligament(PDL), as well as gradually increased Hb Alc. The number of monocytes and leukocytes in the junctional epithelium and periodontal connective tissue was markedly decreased in DP+ BT+ DJC group(P < 0.05), which was slightly reduced in DP+BT group comparing to DP group. The protein levels of Wnt1 and β-catenin were obviously up-regulated with DJC treatment, while the SOST and DDK1 were markedly down-regulated with DJC treatment. The expression levels of BGP were lowest in DP group and highest in DP + BT + DJC group, while the tumor necrosis factor-α(TNF-α), interferon-γ(IFN-γ) and metalloproteinase-3(MMP-3)were highest in DP group and lowest in DP + BT +DJC group. All these changes could be reversed by Wnt/β-catenin inhibitor.CONCLUSION: DJC can improve the hyperglycemia and both distal alveolar bone loss and alveolar bone loss in furcation area of diabetic periodontitis rats by reducing the inflammation of gingival tissue and regulating the expressions of BGP, TNF-α, IFN-γand MMP-3 potentially through Wnt/β-catenin signaling.

Key words: hyperglycemia, periodontitis, alveolar bone loss, Wnt signaling pathway, beta catenin, Danzhi Jiangtang capsule