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 microl/day), ovariectomized rat treated with vehicle (OVX(veh)), 17beta-estradiol treated-ovariectomized rat (OVX(E2), 5 microg/kg/day, s.c.) and genistein treated-ovariectomized rat (0.25 mg/kg/day, s.c.; 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 microm 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.