Orange Pulp Increases Antioxidant Status and Improves Bone Quality in Orchidectomized Rats

An experiment was conducted to evaluate the effect of feeding orange pulp on plasma antioxidant status and bone quality in orchidectomized rats. Forty-five one-year-old male rats were randomly placed in a sham-control group and four orchidectomized groups. Orchidectomized rats were assigned to one of the following treatments: orchidectomy (ORX), ORX+2.5% orange pulp (OP); ORX+5.0% OP; ORX+10.0% OP. Four months after the study began, all rats were killed, blood was collected, and the plasma was harvested for antioxidant status and IGF-I. Orchidectomy did not (P>0.1) affect red blood cell hemolysis percentage, but decreased (P<0.05) the plasma IGF-I concentration, bone density, femoral strength, time induced femoral fracture, calcium and magnesium concentrations in the femur and the 5th lumbar, and increased (P<0.05) urinary deoxypyridinoline, calcium and magnesium excretions compared to the sham group. Feeding 2.5% OP tended to increase IGF-I and increased (P<0.05) bone density, femoral strength, and time induced femoral fracture. Feeding 10% OP profoundly (P<0.05) improved antioxidant status by protecting red blood cells against hemolysis, increased (P<0.05) the plasma IGF-I, bone density and bone mineral content, and decreased (P<0.05) urinary magnesium excretion and urinary deoxypyridinoline concentration. In conclusion, orange pulp significantly affects bone quality by enhancing calcium and magnesium deposition in bones and by slowing-down bone turnover rate.