Preventive effects of genistein on leukocyte adhesion in femur venules and on bone-loss induced in ovariectomized female rats

Abstract

This study was aimed to examine effects of genistein on leukocyte adhesion in femur microcirculation in relation to bone-loss induced in ovariectomized female rats. Sixty-four female Wistar rats were divided into 4 groups: sham (daily treated with vehicle; DMSO, sc; 100 μl/day), ovariectomized rat treated with vehicle (OVX_veh), 17β-estradiol treated-ovariectomized rat (OVX_E2, 5 μg/kg/day, sc) and genistein treated-ovariectomized rat (0.25 mg/kg/day, sc; OVX_gen). One and three weeks after the ovariectomy, blood flow perfusion (BF) in femur tissue was measured using laser Doppler flowmetry. Leukocyte adhesion in femur venules (15–30 μm in diameter) of each group was evaluated by intravital fluorescence videomicroscopy. The bone mineral content (BMC) was measured and expressed in terms of ratio of ash-to-dry matter weight. Serum osteocalcin and alkaline phosphatase levels were determined using chemiluminescence immunoassay. In both one and three week-OVX_veh, leukocyte adhesion increased significantly, compared to their age-matched sham groups, but it decreased significantly in OVX_gen, compared to OVX_veh (p<0.05). In three week-OVX_gen, both BF and BMC increased significantly, but osteocalcin and alkaline phosphatase levels decreased, compared to those of three week-OVX_veh. In conclusion, genistein supplementation could effectively prevent bone-loss and microvascular endothelial dysfunction induced by estrogen deficiency.