Effect of Dietary Caseinphosphopeptide Levels on Bone Metabolism in Ovariectomized Rats

ABSTRACT

The effect of the level of casein phosphopeptide (CPP) on mineral (Ca and P) bioavailabilties and bone biomarker of aged ovariectomized (OVX) Sprague-Dawley rats were studied as a model for postmenopausal bone loss. Forty five Spargue dawley rats, 220-230g of body weight were fed a control diet (AIN 93M) or containing different level of CPP diet for 7 weeks 0% (sham control; SC, OVX control; OC), 1% (OVX low CPP diet; OL), 2% (OVX medium CPP diet; OM), 3% (OVX high CPP diet; OH) Ca absorption was unaffected by increasing CPP content from 0 to 3%. Urinary Ca excretion was increased by OVX, and decreased by CPP significantly (p<0.05) with no evident dose-relationship. The urinary P excretion was increased by CPP intake in OVX rats. The fecal excretion of P given CPP decreased in OVX with dose dependent manner. Ca and P contents of femur significantly increased by adding 2 or 3% of CPP when compared with OC group and OL group (p<0.05). There were no significant differences in serum alkaline phosphatase activity and c-terminal telopeptide excretion in experimental groups. Although ovariectomy induced the increase in urinary c-terminal telopeptide excretion, 2 or 3% of CPP in the diet decreased urinary c-terminal telopetide excretion significantly. These finding suggest the usefulness of CPP in the prevention of postmenopausal bone loss by decreasing urinary Ca excretion and bone resorption. Over 2 percent of CPP in the diet was effective to prevent postmenopausal bone loss.