Epimedium-derived phytoestrogen flavonoids exert beneficial effect on preventing bone loss in late postmenopausal women: a 24-month randomized, double-blind and placebo-controlled trial

Abstract

Epimedium brevicornum maxim, a nonleguminous medicinal plant, has been found to be rich in phytoestrogen flavonoids. Results from a 24-month randomized double-blind placebo-controlled clinical trial showed that Epimedium-derived phytoestrogen flavonoids were able to exert beneficial effects on preventing bone loss in late postmenopausal women, without resulting in a detectable hyperplasia effect on the endometrium.

Introduction: We performed a 24-mo randomized double-blind placebo-controlled clinical trial for evaluating the effect of the Epimedium-derived phytoestrogen flavonoids (EPFs) on BMD, bone turnover biochemical markers, serum estradiol, and endometrial thickness in postmenopausal women.

Materials and methods: One hundred healthy late postmenopausal women, with a natural menopausal history within 10 approximately 18 yr and with a BMD T-score at the lumbar spine between -2 and -2.5 SD, were randomized into EPF treatment group (n = 50; a daily dose of 60 mg Icariin, 15 mg Daidzein, and 3 mg Genistein) or placebo control group (n = 50). All participants received 300 mg element calcium daily. BMD, bone turnover biochemical markers, serum estradiol, and endometrial thickness were measured at baseline and 12 and 24 mo after intervention.

Results: Eighty-five participants completed the trial. The patterns of BMD changes were significantly different between the EPF treatment group and placebo control group by repeated-measures ANOVA (p = 0.045 for interaction between time and group at femoral neck; p = 0.006 for interaction between time and group at lumbar spine). BMD was found with a decreased tendency in the placebo control group at 12 (femoral neck: -1.4%, p = 0.104; lumbar spine: -1.7%, p = 0.019) and 24 mo (femoral neck: -1.8%, p = 0.048; lumbar spine: -2.4%, p = 0.002), whereas EPF treatment maintained BMD at 12 (femoral neck: 1.1%, p = 0.285; lumbar spine:1.0%, p = 0.158) and 24 mo (femoral neck: 1.6%, p = 0.148; lumbar spine: 1.3%, p = 0.091). The difference in lumbar spine between the two groups was significant at both 12 (p = 0.044) and 24 mo (p = 0.006), whereas the difference in the femoral neck was marginal at 12 mo (p = 0.061) and significant at 24 mo (p = 0.008). Levels of bone biochemical markers did not change in the placebo control group. In contrast, EPF intervention significantly decreased levels of deoxypyrdinoline at 12 (-43%, p = 0.000) and 24 mo (-39%, p = 0.000), except for osteocalcin at 12 (5.6%, p = 0.530) and 24 mo (10.7%, p = 0.267). A significant difference in deoxypyrdinoline between the two groups was found at both 12 (p = 0.000) and 24 mo (p = 0.001). Furthermore, neither serum estradiol nor endometrial thickness was found to be changed in either groups during the clinical trial.

Conclusions: EPFs exert a beneficial effect on preventing bone loss in late postmenopausal women without resulting in a detectable hyperplasia effect on the endometrium.