Orally Administered Liposomal Lactoferrin Inhibits Inflammation-Related Bone Breakdown Without Interrupting Orthodontic Tooth Movement

Background: Bovine lactoferrin (bLF) modulates the production of tumor necrosis factor-alpha (TNF-alpha) and inhibits alveolar bone breakdown associated with periodontitis. This study is designed to examine the effects of orally administered liposomal bLF (LbLF) on orthodontic force (OF)-induced alveolar bone remodeling during experimental tooth movement. Methods: Two groups of male Wistar rats were treated with either LbLF or control solution in drinking water 7 days before OF application. Lipopolysaccharide (LPS) was injected into the gingival sulcus in half the rats in each group. Thus, four groups: OF, OF+LbLF, OF+LPS, and OF+LPS+LbLF were established. Results: Orally administered LbLF significantly reduced apical migration of junctional epithelium in the OF and OF+LPS groups. In OF+LPS, osteoclast number in the alveolar crestal area was increased by LPS treatment, whereas osteoclast number was significantly reduced in OF+LPS+LbLF through suppression of TNF-alpha production. Osteoclastic induction in the middle part, mainly from OF application, was not affected by LbLF administration. Inhibition of tooth movement was not induced by LbLF. Conclusions: Orally administered LbLF significantly inhibits LPS-induced alveolar bone resorption but not OF-induced bone remodeling. LbLF could be a potent therapeutic and preventive agent to control periodontal inflammation in patients undergoing orthodontic treatment.