Glucosamines Attenuate Bone Loss Due to Menopause by Regulating Osteoclast Function in Ovariectomized Mice

Area of Science:

• Bone Metabolism
• Endocrinology
• Nutritional Science

Background:

• Ovariectomized (OVX) mice are a model for postmenopausal osteoporosis.
• Glucosamine (GlcN) and N-acetylglucosamine (GlcNAc) are components of glycosaminoglycans involved in bone structure.
• The effects of GlcN and GlcNAc on bone metabolism in OVX models require further elucidation.

Purpose of the Study:

• To investigate the impact of dietary glucosamine (GlcN) and N-acetylglucosamine (GlcNAc) on bone metabolism in ovariectomized (OVX) mice.
• To determine if GlcN and GlcNAc can mitigate bone loss through nonestrogenic mechanisms.

Main Methods:

• OVX mice were fed diets containing 0.2% GlcN or 0.2% GlcNAc for 12 weeks.
• Femoral bone mineral density (BMD) was measured.
• Histomorphometric analysis of tibial bone was performed.
• Osteoclast differentiation and activity were assessed using tartrate-resistant acid phosphatase (TRAP) staining and erosion depth measurements.

Main Results:

• GlcN and GlcNAc supplementation significantly increased femoral BMD in OVX mice compared to controls.
• Histomorphometry revealed reduced osteogenesis and bone resorption rates in GlcN-fed mice.
• Osteoclast erosion depth and TRAP-positive osteoclast numbers were significantly reduced in GlcN- and GlcNAc-fed OVX mice.
• Uterine weight loss and increased serum calcium were observed in supplemented groups.

Conclusions:

• Dietary intake of GlcN and GlcNAc effectively suppresses bone loss in OVX mice.
• The mechanism involves the inhibition of osteoclast differentiation and activity.
• GlcN and GlcNAc offer a potential nonestrogenic therapeutic strategy for managing bone loss.