[Genistein inhibits the promotive effect of IL-1beta on osteoclastic bone resorption].

Objective: To investigate the effect of genistein, a soybean-derived isoflavone, on the stimulating effect on bone resorption of IL-1beta.

Methods: The osteoclasts (OCs) were isolated with the methods of Yu Shifeng. The rat calvaria were cultured as an organ. The cells in the experiment were grown in four respectively: Control (without genistein or IL-1beta), 10(-6) mol/L genistein,10 microg/L IL-1beta and 10(-6)mol/L genisteine + 10 microg/L IL-1beta. The area of bone resorption, the concentration of Ca(2+) in the supernatant liquid of OCs cultures and mice calvaria were tested. The contents of acid phosphatase(ACP) were also examined by biochemistry method. The index of bone resorption was counted as the ratio of the experiment average and control ones, which indicated the increase in bone resorption when it was above 1.0.

Results: The area of bone resorption of 10(-6) mol/L genisteine + 10 microg//L IL-1beta increased compared with that of 10(-6) mol/L genistein, while the concentration of Ca(2+) in the supernatant liquid of OCs cultures decreased significantly. The index of bone resorption of 10(-6) mol/L genisteine + 10 microg//L IL-1beta lied between 10(-6) mol/L genistein and 10 mug/L IL-1beta. In the organ culture, there was no difference in the content of ACP among all the groups. The index of bone resorption of 10(-6) mol/L genisteine + 10 microg//L IL-1beta was below that of 10 mug/L IL-1beta, but both were above 1.0. The index of bone resorption was below 1.0 in the group of 10(-6) mol/L genistein.

Conclusion: Genistein can suppress obviously the bone resorption simulated by single IL-1beta.