N-acylated glucosamines for bone and joint disorders: effects of N-butyryl glucosamine on ovariectomized rat bone

The benefit of glucosamine (GIcN) in bone and joint disorders remains controversial. N-acetylation and other N-acylations of GIcN alter its biological properties fundamentally. We have shown previously that N-butyryl glucosamine (GIcNBu) preserved strikingly the subchondral bone structure in a destructive arthritis rat model. Here, we examine whether GIcNBu preserves bone in the ovariectomized (OVX) rat, a model for postmenopausal osteoporosis. Rats were randomized into 4 groups: group 1, sham OVX glucose (Glc) fed; group 2, sham OVX GIcNBu fed; group 3, OVX Glc fed; and group 4, OVX GIcNBu fed. A single, oral, 200-mg/kg dose of GIcNBu or Glc was administered daily for 6 months. Bone mineral content (BMC) and bone mineral density, and biomechanical properties of the femurs and spines were determined by standardized techniques. Two-way analysis of variance with a Bonferroni post hoc test was used for statistical analysis. Ovariectomy in group 3 resulted either in significant or highly significant effects in a number of the tests. For spinal BMCs the interaction between GIcNBu and OVX was significant. For the femurs, this interaction was also seen in energy to failure, and ultimate displacement and ultimate strain tests. In general, ovariectomy was necessary to show significant preventive effects of GIcNBu on mineral content and some biomechanical properties. We conclude that GIcNBu feeding in the OVX rat preserves bone mineral and some biomechanical properties. Translationally, GIcNBu can be positioned between nutriceuticals and pharmaceuticals for the prevention and treatment of osteoporosis. Advantages include low production costs and a favorable safety profile. (Translational Research 2013;162:93-101)