Milk Basic Protein Facilitates Increased Bone Mass in Growing Mice.

Area of Science:

• Biochemistry
• Bone Biology
• Nutritional Science

Background:

• Milk basic protein (MBP) is known to prevent bone loss in adults by balancing bone formation and resorption.
• Previous studies demonstrated MBP's efficacy in adult and postmenopausal bone loss models.
• The effect of MBP on bone mass during the growth phase, characterized by high bone formation, remained unclear.

Purpose of the Study:

• To investigate the impact of Milk basic protein (MBP) supplementation on bone mass accrual in growing mice.
• To determine if MBP influences bone remodeling processes during skeletal development.

Main Methods:

• 6-week-old mice were administered water supplemented with varying concentrations of MBP (0.01%, 0.1%, 1.0%) or control water for 10 weeks.
• Bone mass was assessed using micro-computerized tomography (micro-CT).
• In vitro studies evaluated MBP's direct effects on osteoblast and osteoclast precursor cells.

Main Results:

• MBP supplementation significantly increased tibia cortical bone mineral density and femur trabecular bone volume in growing mice.
• In vitro experiments showed MBP directly promotes osteoblast proliferation and inhibits osteoclastogenesis.
• MBP administration led to increased plasma levels of insulin-like growth factor-1.

Conclusions:

• Milk basic protein (MBP) effectively increases bone mass in growing mice.
• MBP enhances bone formation and suppresses bone resorption through both direct and indirect mechanisms, including IGF-1 signaling.
• These findings suggest MBP's potential role in optimizing bone mass development during critical growth periods.