Genistein replacement therapy on endothelial dysfunction and bone loss in bilateral ovariectomized rats

The objective of this study is to examine roles of genistein in postmenopausal induced-endothelial dysfunction and bone loss, the ovariectomized (OVX) rat model was used. The animals were divided into three groups of sham treated with vehicle (DMSO 100 microl/day; Sham(veh)), OVX treated with vehicle (OVX(veh)) and OVX treated with genistein (0.25 mg/kg/day; OVX(gen)). At 3 and 7 weeks after the surgery, endothelial dysfunction in mesenteric microcirculation of each group was determined by using intravital fluorescence microscopy and analyzed with digital image software. The parameters of bone mass density (BMD) and bone formation marker were represented by percentage of ash/dry matter and osteocalcin activity (using radioimmunoassay (RIA)), respectively. Mean arterial pressures (MAP) in OVX(veh) groups were significantly increased compared to their aged-matched sham groups (p<0.05). Interestingly, the treatment of genistein could significantly attenuate this abnormality (p<0.001). Besides, it could increase the vascular response to acetylcholine (Ach; 10(-6) M) significantly compared to OVX-rats (p<0.05). Moreover, BMD and osteocalcin activity were significantly increased in Ovx(gen) as well. Therefore, our findings suggested that genistein supplementation could effectively prevent endothelial dysfunction and bone loss in OVX-rat model.