Objective: To further explore the effects of genistein (GS) on cell proliferation and differentiation in adult human osteoblast.
Methods: Human osteoblast from passage 4 were harvested and seeded in phenol red-free DMEM medium containing 5% charcoal-stripped fetal bovine serum (CS-FBS) before the addition of test compounds for 4 days. DNA synthesis was tested by 3H-thymine incorporation and cell cycle was determined by flow cytometry. Collagen protein content and alkaline phosphatase (AKP) activity were examined.
Results: After treatment for 48 h, the presence of GS (10(-7) or 10(-6) mol/L) caused a significant increase in DNA content and accumulation at S and G2/M phage in a dose-dependent manner. Additionally, the anabolic effect of GS (10(-7) and 10(-6) mol/L) on the collage content and AKP activity were significantly enhanced in the presence of genistein (10(-7) or 10(-6) mol/L) . The effects of GS on osteoblast were completely abolished in the presence of estrogen receptor antagonist, 4-Hydroxy tamoxifen (TAM) (10(-7) mol/L).
Conclusion: Findings suggest that osteoblast function is promoted by genistein and that the estrogen receptors might be involved in the response, thereby playing an important role in bone remodeling. Presumably, dietary soy products are useful in the prevention of osteoporosis.