The effects of luteolin on orthodontic tooth movement and relapse.

Introduction: Luteolin is a natural flavonoid compound that widely exists in human food. Studies have demonstrated luteolin has powerful anti-inflammatory properties and can affect bone remodeling in an inflammatory environment. This study aimed to investigate the effect of luteolin on orthodontic tooth movement (OTM) and relapse after OTM.

Methods: Male Sprague Dawley rats were randomly divided into 3 groups (n = 8): OTM, 50 mg/kg/d luteolin, and 100 mg/kg/d luteolin. Then, 50 g of orthodontic force was applied to all animals. A saline solution or corresponding concentration of luteolin was given orally. For the OTM experiment, after 14 days of force application, rats were killed, the maxilla was dissected, and then microcomputed tomography, histologic staining, and western blotting were performed. For the relapse experiment, the spring was removed, and a silicone impression was made to record the relapse status.

Results: Compared with the OTM alone group, systemic administration of luteolin inhibited OTM and tooth relapse (P <0.05). Increased bone volume, reduced osteoclast activity, and a decrease in osteoclastogenesis-related protein expression were observed in luteolin-treated groups. These effects may be attributed to the inhibition of the nuclear factor-kappa B pathway.

Conclusions: Luteolin can significantly inhibit OTM and relapse after OTM. Thus, luteolin is a prospective candidate for enhancing tooth anchorage and preventing relapse in orthodontic treatment.