Role of some phytoestrogens in recovering bone loss: histological results from experimental ovariectomized rat models

Background/aim Osteoporosis is a disease characterized by a decrease in bone mass and is widely recognized as a major health problem. Ovarian hormone deficiency is a major risk factor for osteoporosis. A sharp decrease in ovarian estrogen production is the predominant cause of rapid bone loss and deterioration of bone architecture, resulting in increased bone fragility during the first decade after menopause. Materials and methods A total of 70 albino rats were used, divided into seven groups of 10 rats each. Group 1 was subjected to sham operation and used as a control group. In group 2, rats were ovariectomized (OVX) and used as a model of postmenopausal osteoporosis. Three months after the operation the OVX rats (group 2) were divided into six subgroups: one was considered the positive control group; another one was treated with synthetic estrogen compound; and the other four subgroups were fed a diet containing red clover, fennel, carob, and a combination of the three plants. At the end of the experiment (after 3 months' treatment) the animals were killed, and the femur shafts were extracted, decalcified, and processed into paraffin blocks. Sections were stained with hematoxylin and eosin for histopathological, image analysis, and morphometric studies. Other sections were stained with periodic acid Schiff for histochemical investigations. Results The histopathological results of this study revealed that ovariectomy caused a decrease in thickness of the cortical compact bone in the middle shaft of the femur and of the trabeculae in cancellous bone in the head of the femur bone. Histochemical results showed new bone formation in sections of rats treated with plants. The best results were detected in sections of rats treated with a combination of the three plants. Red clover, fennel, and carob individually or combined have a better ameliorating effect on ovariectomy-induced osteoporosis than does synthetic estrogen compound. Conclusion Treatment of OVX rats with phytoestrogens such as red clover, fennel, and carob might improve the histopathological and histochemical changes and morphometric parameters in bone with ovariectomy-induced osteoporosis.