Dietary Natural N-Acetyl-d-Glucosamine Prevents Bone Loss in Ovariectomized Rat Model of Postmenopausal Osteoporosis

Abstract

Postmenopausal osteoporosis has seriously affected the life quality of elderly women. A natural polymer, chitin, obtained from shells of crab and shrimp, has been widely used in the biomedical field owing to its nontoxicity, biocompatibility, and biodegradability. In this study, natural N-acetyl-d-glucosamine (NAG) was prepared from liquefied chitin. The protective activities of NAG in postmenopausal osteoporosis were evaluated on Sprague Dawley rats and osteoblast-based models. Results showed that oral administration of NAG boosted trabecular bone volume and trabecular numbers. Additionally, the calcium content in the femur and tibia increased, and femoral biomechanical properties improved. Furthermore, NAG supplementation significantly lowered alkaline phosphatase levels and increased calcium content in the serum of ovariectomized rats. In vitro studies showed that NAG markedly promoted cell proliferation and stimulated osteoblast differentiation of mouse calvaria origin MC3T3-E1 cells with increased alkaline phosphatase activity in a concentration-dependent manner. Moreover, NAG effectively protected osteoblasts from oxidative damage induced by hydrogen peroxide. In conclusion, our data provide an additional foundation for dietary supplementation of NAG, which could protect and reverse osteopenia in postmenopausal women.