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Positive effect of compound amino acid chelated calcium from the shell and skirt of scallop in an ovariectomized rat model of postmenopausal osteoporosis.

BACKGROUND
Osteoporosis has become an important public health issue with the increase of aging population, and afflicted millions of people worldwide, particularly in elderly or in post-menopausal women. In present study, we prepared compound amino acid chelated calcium (CAA-Ca) from processing by-products of Chlamys farreri, and evaluated its effect on postmenopausal osteoporosis with ovariectomized (OVX) rat model.


RESULTS
A 60-day treatment of OVX rats with CAA-Ca significantly enhanced the bone mineral density (BMD) and the bone calcium content. Meanwhile, some bone morphometric parameters, trabecular bone number (Tb.N), trabecular bone volume fraction (BV/TV), trabecular bone thickness (Tb.Th) and cortical bone wall thickness (Ct.Th), were also increased by 8.20%, 118.18%, 32.99% and 19.10%, respectively. In addition, the alkaline phosphatase (ALP) levels in serum were significantly reduced after CAA-Ca treatment, while the blood calcium levels were increased. Mechanistically, CAA-Ca down-regulated the levels of receptor activator of nuclear factor-κB (RANK) and receptor activator of nuclear factor-κB ligand (RANKL), and up-regulated osteoprotegerin (OPG) levels in osteoclasts, inhibiting bone resorption and bone loss. Meanwhile, CAA-Ca treatment raised β-catenin levels and lowered Dickkopf1 (DKK1) levels in the Wnt signaling pathway of osteoblasts, which can promote calcium absorption and bone formation through.


CONCLUSION
The results suggested that CAA-Ca promoted bone formation, inhibited bone resorption and improved bone microstructure. Therefore, this study supplied the potential application of CAA-Ca as a functional food resource in the treatment of postmenopausal osteoporosis. This article is protected by copyright. All rights reserved.