Fructooligosaccharides (FOS) and hormonal replacement therapy (HRT) by estrogen suppressed bone resorption in the ovariectomized rat

Abstract

The present investigation aims to compare the effects of fructooligosaccharides (FOS) and the hormonal replacement therapy (HRT) by estrogen on bone metabolism in ovariectomized rats. Three-month-old (276,0±3,4g body weight) Wistar female rats were submitted to an ovariectomy (OVT) procedure and after 30 days, the animals were randomLy assigned (n=10) to treatment groups for 20 days. The animals were treated with FOS (RAFTILOSE® P95) (5g/100g of diet intake/day) through intragastric intubations and/or not with hormonal replacement therapy (HRT) by synthetic β-estradiol (SIGMA/E-4389) (30μg/kg of body weight) daily administrated by subcutaneous injection (G1 = OVT + FOS + HRT; G2 = OVT + FOS + saline; G3 = OVT + water + HRT; G4 = OVT + water + saline). The rats were fed with standard diet contend 1.3% of Ca and received deionized water ad libitum. The data are expressed as the mean values ± standard error means (SEM) and analyzed by two-way ANOVA Tukey’s post-hoc test (p < 0.05). Both treatments alone reduced total alkaline phosphatase activity. The FOS treatment increased the tibiae calcium, but the effect of FOS + HRT was more powerful. Radiodensity analysis supports this result too. In femur biomechanical properties, the proportional limit and resilience of FOS + HRT and FOS animals group suggest an increased effect on the bone capacity in absorbing energy. These results are also observed in the qualitative analysis of the SEM. Prebiotics substances consumption should be introduced for prevention or treatment of osteoporosis.