Bis-enoxacin Inhibits Bone Resorption and Orthodontic Tooth Movement

Abstract

Enoxacin inhibits binding between the B-subunit of vacuolar H + -ATPase (V-ATPase) and microfilaments, and also between osteoclast formation and bone resorption in vitro. We hypothesized that a bisphosphonate derivative of enoxacin, bis-enoxacin (BE), which was previously studied as a bone-directed antibiotic, might have similar activities. BE shared a number of characteristics with enoxacin: It blocked binding between the recombinant B-subunit and microfilaments and inhibited osteoclastogenesis in cell culture with IC 50 s of about 10 µM in each case. BE did not alter the relative expression levels of various osteoclast-specific proteins. Even though tartrate-resistant acid phosphatase 5b was expressed, proteolytic activation of the latent pro-enzyme was inhibited. However, unlike enoxacin, BE stimulated caspase-3 activity. BE bound to bone slices and inhibited bone resorption by osteoclasts on BE-coated bone slices in cell culture. BE reduced the amount of orthodontic tooth movement achieved in rats after 28 days. Analysis of these data suggests that BE is a novel anti-resorptive molecule that is active both in vitro and in vivo and may have clinical uses. Abbreviations: BE, bis-enoxacin; V-ATPase, vacuolar H + -ATPase; TRAP, tartrate-resistant acid phosphatase; αMEM D10, minimal essential media, alpha modification with 10% fetal bovine serum; SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis; RANKL, receptor activator of nuclear factor kappa B-ligand; NFATc1, nuclear factor of activated T-cells; ADAM, a disintegrin and metalloprotease domain; OTM, orthodontic tooth movement.

Bis-Enoxacin Blocks Rat Alveolar Bone Resorption from Experimental Periodontitis

“…Relatively low systemic doses may allow accumulation of therapeutic doses in the bone. We previously showed that bis-enoxacin inhibits osteoclast activity induced aseptically by mechanical force in a rat orthodontic tooth movement model [24]. The combination of a bone targeted anti-resorptive and antibiotic would seem well-suited for the treatment of PD and our data are consistent with that idea.…”

Periodontitis in Rats Induces Systemic Oxidative Stress That Is Controlled by Bone‐Targeted Antiresorptives

“…ALN, a classic nitrogen-containing bisphosphonate, reduced SOS but was less effective than BE. A previous study 23 suggested that BE inhibits osteoclast formation and bone resorption by competitively blocking an interaction between the B2-subunit of V-ATPase and microfilaments. However, it is also known that BE is an antibiotic, which could contribute to its therapeutic effect.…”

“…Forty-eight Sprague-Dawley rats were randomly divided into eight groups as follows: 1) polybacterial infection with P. gingivalis, T. denticola, and T. forsythia ; 2) polybacterial infection plus treatment with BE (5 mg · kg −1 · d −1 ); 23 3) polybacterial infection plus treatment with BE (25 mg · kg −1 · d −1 ); 23 4) polybacterial infection plus treatment with ALN (1 mg · kg −1 · d −1 ); 30 5) polybacterial infection plus treatment with ALN (10 mg · kg −1 · d −1 ); 30 6) polybacterial infection plus treatment with ENX (5 mg · kg −1 · d −1 ); 21,23 7) polybacterial infection plus treatment with DOX (5 mg/d); 31 and 8) shaminfected and untreated controls. A daily subcutaneous injection of these treatments was administered for 6 weeks after 6 weeks of initial infection.…”

“…It inhibits orthodontic tooth movement, an osteoclast-dependent process, and alveolar bone loss triggered by experimental periodontitis in rats. 23,24 …”

“…23 In addition to its antiresorptive activity, BE is also an antibiotic. 25 Alendronate (ALN) is a nitrogen-containing bisphosphonate that is a potent inhibitor of bone resorption.…”