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

Abstract 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 50 mg/kg (Group 6: OVX + FRC + CAR 50); ovariectomy + femoral fracture + carnitine 100 mg/kg (Group 7: OVX + FRC + CAR 100); ovariectomy + femoral fracture + Mg‐silicate + carnitine 50 mg/kg (Group 8: OVX + FRC + INF + CAR 50); and ovariectomy + femoral fracture + Mg‐silicate + carnitine 100 mg/kg (Group 9: OVX + FRC + INF + CAR 100). 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 α, interleukin 1β 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.