Dexamethasone promotes regeneration of crushed inferior alveolar nerve by inhibiting NF-κB activation in adult rats.

PURPOSE: Nuclear factor kappa B (NF-κB), which is closely related to inflammation, has become a topic of interest for research. The aim of this study is to investigate the effects of dexamethasone (Dex), an inhibitor of NF-κB, on inferior alveolar nerve injury in adult rats.

MATERIALS AND METHODS: The crushed inferior alveolar model is established in Wistar rats and they are randomly divided into three groups according to treatment: pyrrolidine dithiocarbamate (PDTC), dexamethasone (Dex), and saline (physiological saline). After treatment, the rats are respectively sacrificed at 3, 7, and 14d, and inferior alveolar nerves are extracted for histochemical and western blot analysis.

RESULT: Compared with the PDTC and saline groups, nerve fibers in the Dex group are regularly arranged with few vacuoles, which is similar to normal inferior alveolar nerves. Immunofluorescent results show significantly decreased NF-κB expression in the Dex group. Western bolt shows higher expression of GAP-43 and lower expression of NF-κB.

CONCLUSION: Taken together, all results show that dexamethasone significantly improved the regeneration of crushed inferior alveolar nerves by inhibiting NF-κB activation in adult rats.