Effect of whey protein on the proliferation and differentiation of osteoblasts

Effects of whey protein on osteoblasts were evaluated. The whey protein was added to the culture medium at concentrations of 0.02 and 0.1 mg/mL. In vitro, whey protein stimulated the proliferation and differentiation of osteoblasts cultured in different concentrations of whey protein. The levels of osteocalcin and insulin-like growth factor-I in the culture medium also increased. Real-time reverse transcription-PCR results showed that the mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor-kappa B ligand (RANKL) increased in the cells in a dose-dependent manner, and when the results were expressed as OPG/RANKL ratio, a significant increase could be seen in the 0.1 mg/mL whey protein group. These results showed that the active component in the whey protein plays an important role in bone formation and a potential therapeutic role in osteoporosis by activating osteoblasts.