The nutritional evaluation of globin on maintenance of bone metabolism in ovariectomized osteoporotic rats

In our previous study, globin was found to be an effective dietary source for increasing bone mineral density (BMD) and mechanical strength. In this study, the bioavailability of the globin preparation was examined to clarify the mechanism of increase in bone density and strength. Six-week-old Sprague-Dawley female rats were ovariectomized and were fed on a low Ca diet for 30 days to produce the experimental osteoporotic rats. Thereafter they were divided into two groups. The BMD and the mechanical strength of bone of the rat group, whose diet was supplemented with globin, were significantly higher than those of the control group. The levels of the serum calcitonin and the bone-type alkaline phosphatase (Alp) activity in serum and bone were also higher, and the tartrate-resistant acid phosphatase (Tr-Acp) activity in serum and bone was lower in the globin group. Moreover, the bone morphogenetic protein activity in bone in the globin group was found to be greater. From these results, it is concluded that alimentary globin is effective for the acceleration of bone formation and the prevention of bone resorption.