Phytoestrogen-rich herb formula "xLGB" prevents OVX-induced deterioration of musculoskeletal tissues at the hip in old rats

This study investigated a phytoestrogen-rich herb formula, Xianlinggubao (XLGB) μncluding genistein 510μg/g and daidzein 2500μg/g), concerning prevention of OVX-induced deterioration of musculoskeletal tissues in 11-month-old female Wistar rats, which were randomized into Sham, OVX, and XLGB groups. Daily oral administration of XLGB (250mg/kg/day) started after OVX for 3 months. mRNA of MHC-I IIa IIb of abductor muscle was determined by RT-PCR. The proximal femoral BMD and geometry, microarchitecture, and mechanical strength were evaluated by pQCT, micro-CT, and compressive testing, respectively. The bone turnover biochemical markers serum osteocalcin (OC) and urinary deoxypyridinoline (DPD) were evaluated. The results showed that (1) XLGB-treated OVX rats showed no difference compared to the Sham group, whereas OVX induced significant deterioration in variables related to bone density, microarchitecture, and mechanical strength (P < 0.05); (2) biochemical markers showed no difference between sham and XLGB groups as compared with higher bone turnover in OVX rats (P < 0.05); (3) mRNA expression of MHC-I IIa IIb was downregulated in OVX rats but upregulated after XLGB treatment (P < 0.05); and (4) as compared with the OVX group, no uterine hypertrophy was found in XLGB-treated rats. In conclusion, findings of this study suggested that the herbal preparation XLGB was able to prevent OVX-induced deterioration of musculoskeletal tissues at the hip without causing uterine stimulation.