Effects of Doxycycline on Mechanical Properties of Bones in Rats with Ovariectomy-Induced Osteopenia

Abstract

Tetracyclines have been reported to inhibit bone resorption and intensify bone formation. The aim of the present study was to investigate the effects of doxycycline (20 mg/kg PO daily for 28 days) on bone mechanical properties in bilaterally ovariectomized and sham-operated rats. The experiment was carried out on 3-month-old Wistar rats. Mechanical properties of the whole femur (extrinsic stiffness, ultimate and breaking load, deformation caused by applied load) and the femoral neck (load at fracture) as well as bone mass and bone mineral content in the tibia, femur, and L4 vertebra were examined. Bilateral ovariectomy resulted in decreases in bone mineral content/bone mass ratio and worsening of mechanical properties of the femoral neck. The changes were counteracted by doxycycline. Doxycycline reversed the effect of ovariectomy on load at fracture of the femoral neck. Doxycycline did not significantly affect the mechanical properties of bones in the sham-operated rats.

Cell-induced response by tetracyclines on human bone marrow colonized hydroxyapatite and Bonelike®

“…Tetracyclines are broad spectrum antibiotics important in the treatment of bone and joint infections [26][27][28], and have been associated with a positive effect in bone metabolism [5][6][7][8][9][10]. In previous studies, performed in standard tissue culture plates, we reported that therapeutic levels of doxycycline and minocycline were able to induce proliferation of osteoblastic bone marrow cells while maintaining their specific phenotype [34].…”

“…Different mechanisms, distinct from the antimicrobial action, have been proposed to justify the pro-anabolic activity of these pharmacological agents regarding bone metabolism. These include enhancing bone formation, decreasing connective tissue breakdown and diminishing bone resorption [5][6][7][8][9][10]. Clinical application of these agents targeting bone might also be helped by their cation quelation activity and consequent avidity for mineralized tissue [11].…”

Thalidomide affects the skeletal system of ovariectomized rats

“…The mechanical properties of the whole femur and femoral neck were measured as previously described [31], using a set constructed at the Department of Pharmacology, Medical University of Silesia, in cooperation with Hottinger Baldwin Messtechnik GmbH.…”

Sex steroid deficiency–associated bone loss is microbiota dependent and prevented by probiotics

“…Indeed, GF mice have increased bone mass, fewer CD4 + T cells and osteoclast precursors in the BM, and lower levels of osteoclastogenic cytokines (10). In addition, antibiotic administration increases bone density in young mice (11,12), while select probiotics blunt the bone loss that normally ensues following ovariectomy (ovx) (13)(14)(15). However, the molecular mechanisms that mediate and function in probiotic-induced host responses have not yet been fully characterized.…”