Long-term eggshell membrane supplementation contributes to sustained bone mass by suppressing bone resorption in rats

Area of Science:

• Bone Biology
• Nutritional Science
• Animal Models

Background:

• Eggshell membrane (ESM) supplementation is known to enhance bone mass during skeletal growth.
• However, the long-term effects of ESM on bone health extending to skeletal maturity remain largely uninvestigated.

Purpose of the Study:

• To investigate the long-term effects of continuous eggshell membrane (ESM) supplementation on bone health in rats.
• To determine if 16 weeks of ESM intake supports bone health from growth to skeletal maturity.

Main Methods:

• Seven-week-old male Wistar rats were administered oral ESM for 16 weeks.
• Micro-computed tomography and histology were used to assess trabecular microarchitecture and marrow adiposity.
• Immunohistochemistry and gene expression analyses were performed to evaluate osteoblast and osteoclast parameters.

Main Results:

• ESM supplementation significantly increased trabecular bone volume and improved microarchitecture, while concurrently reducing marrow adiposity.
• ESM intake suppressed adipogenic gene expression (Pparg) and reduced osteoclast activity, indicated by decreased tartrate-resistant acid phosphatase-positive osteoclasts and downregulated osteoclast-related genes (Ctsk, Tnfsf11, Nfatc1).
• No significant differences were observed in osteoblast numbers or osteogenic gene expression (Sp7, Col1a1) between groups.

Conclusions:

• Long-term eggshell membrane (ESM) supplementation effectively maintains trabecular bone volume.
• This maintenance is achieved by suppressing marrow adipogenesis and reducing bone resorption, highlighting ESM's role beyond early growth.
• ESM shows potential as a functional food ingredient for promoting overall skeletal health.