Treatment with Carnitine Enhances Bone Fracture Healing under Osteoporotic and/or Inflammatory Conditions

The aim of this study was to examine the effects of carnitine on bone healing in ovariectomy (OVX) and inflammation (INF)-induced osteoporotic rats. The rats were randomly divided into nine groups (n=8 animals per group): sham-operated (Group 1: SHAM); sham+magnesium silicate (Mg-silicate) (Group 2: SHAM+INF); ovariectomy (Group 3: OVX); ovariectomy+femoral fracture (Group 4: OVX+FRC); ovariectomy+femoral fracture+Mg-silicate (Group 5: OVX+FRC+INF); ovariectomy+femoral fracture+carnitine 50mg/kg (Group 6: OVX+FRC+CAR50); ovariectomy+femoral fracture+carnitine 100mg/kg (Group 7: OVX+FRC+CAR100); ovariectomy+femoral fracture+Mg-silicate+carnitine 50mg/kg (Group 8: OVX+FRC+INF+CAR50); and ovariectomy+femoral fracture+Mg-silicate+carnitine 100mg/kg (Group 9: OVX+FRC+INF+CAR100). Eight weeks after OVX, which allowed for osteoporosis to develop, INF was induced with subcutaneous Mg-silicate. On day 80, all of the rats in groups 4-9 underwent fracture operation on the right femur. Bone mineral density (BMD) showed statistically significant improvements in the treatment groups. The serum markers of bone turnover (osteocalcin and osteopontin) and pro-inflammatory cytokines (tumour necrosis factor , interleukin 1 and interleukin 6) were decreased in the treatment group. The X-ray images showed significantly increased callus formation and fracture healing in the groups treated with carnitine. The present results show that in a rat model with osteoporosis induced by ovariectomy and Mg-silicate, treatment with carnitine improves the healing of femur fractures.