Casein hydrolysates enhance osteoblast proliferation and differentiation in mouse bone marrow culture

• This paper analyzes the bone health promoting role of casein hydrolysates from buffalo milk.
• The markers of osteoblast differentiation are studied.
• Effect of casein hydrolysates on calcium mineralization in osteoblast is analyzed.

Osteoporosis is characterized by low bone mass with micro-architectural deterioration of bone tissue leading to enhanced bone fragility, thus increasing the susceptibility to fracture. Osteoporosis is most common in women after menopause, and is referred to as postmenopausal osteoporosis. Extensive scientific evidence has been provided for the existence of biologically active peptides derived from milk that may have beneficial effects on bone health. In the present study casein was separated from buffalo milk and was hydrolyzed with trypsin to form casein hydrolysates. Angiotensin Converting Enzyme (ACE) inhibitory activities of casein hydrolysates were measured and its effect on osteoblast proliferation and differentiation was studied. Casein hydrolysates at 50 and 250 µg/mL concentration stimulated the proliferation and differentiation of osteoblasts in vitro which was confirmed by MTT proliferation assay. Casein hydrolysates also increased calcium mineralization in osteoblast cells in comparison to control. Likewise, the expression of osteocalcin, osteoprotegerin and alkaline phosphatase genes which are known marker of osteoblast differentiation has also been significantly (P<0.05) increased in treatment groups as compared with the control. These results showed that, the casein hydrolysates with ACE inhibitory activity are anabolic to bone, an effect that is consequent upon their potent proliferative and differentiated actions in osteoblasts.