Effect of Equol on Osteoporosis in Rats after Ovarian Removal

Postmenopausal osteoporosis (PMOP) is a common disease that occurs mainly in postmenopausal women. Due to the decrease in ovarian estrogen secretion and accelerated bone loss in postmenopausal women, the incidence of osteoporosis increases further, and the prevalence of OP in women is three times higherthan that in men.

 Subgroup analysis of the prevalence of OP in postmenopausal women

Equol is one of the metabolic end-products of soy isoflavones in vivo, its structure and biological activity are very similar to estrogen, and it is the most stable in the organism, with slow excretion, and has stronger physiological activity than its precursor,soy glycosides. In order to study the effect of Equol on postmenopausal osteoporosisthe experimenters used in vivo experiments to remove the ovaries of female rats in order to establish a PMOP model and then intervened with Equol in order to clarifythe effect of Equol on osteoporosis in rats after ovarian removal. The results of the experiment are as follows:

Equol significantly reduced bone loss in de-ovulated rats

BMD of femoral epiphysis was significantly decreased in OVX group compared with sham group, and BMD was significantly increased in OVX+Eq group compared with OVX group (P<0.05).

Equol treatment significantly increases estrogen and blood calcium levels and decreases blood phosphorus and osteocalcin in OVX rats

Equol Treatment significantly increased OPG secretion and down-regulated RANKL levels inOVX rats

Equol treatment significantly increased the expression level of OPG mRNA and down-regulated the expression level of RANKL mRNA in OVX rats.

In summary, the study showed that Equol can significantly reduce bone loss in de-ovulated rats, and also stimulate osteoblast activity to promote bone formation and repair, and inhibit osteolytic action of osteoclasts in order to reduce bone resorption and inhibit the hyperconversion state of bone, which leads to an increase in bone mass. After ovary removal in rats, the RANKL content continued to increase while the OPG content gradually decreased, and there was an imbalance between RANKL and OPG, which led to an imbalance between bone formation and bone resorption in rats. Equol may realize its protective effect on PMOP by maintaining the balance between RANKL and OPG; Equol has significant estrogen-like effects and may improve PMOP by regulating the expression of RANKL and OPG.

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