OBJECTIVETo investigate the effect of Tiangui Gengnian soft capsule (TGC), which mainly consists of seabuckthorn fatty acid, on serum estrogen and estrogen receptor (ER) in multiple target tissues as uterus, liver and bone, in aged female rats, in order to explore its mechanism from the aspects of receptor and cytokines.

METHODSLow (0.72 g/kg), middle (1.80 g/kg) and high (4.50 g/kg) dose of TGC were administered by gastrogavage to young and aged (22 months old) female rats with osteoporosis for 45 days, and diethylstilbestrol (0.02 mg/kg) was used as a positive control. The levels of serum estradiol (E2), transforming growth factor beta1 (TGF-beta1), insulin-like growth factor-1 (IGF-1) were measured by radioimmunoassay and ELISA method, the protein expression of their receptor in bone, uterus and liver was detected by SABC immunohistochemistry, and the mRNA expression of E2 in uterus and liver detected by in situ hybridization with digoxin probe.

RESULTSIntervention of TGC could cause increase of serum E2, IGF-1 and TGF-beta1 levels, the TGF-beta1 reached 90.63 +/- 18.71 pg/L in the group administered with high dose, which was significantly different to that in the aged group (P < 0.01). There was no obvious effect of the mRNA expression of E2 in uterus and liver, and no effect of TGF-beta1 and IGF-1 in liver in rats.

CONCLUSIONTGC could improve the postmenopausal bone metabolism, alleviate and correct the bone loss, it is possibly realized by way of side-secreting/auto-secreting of E2 receptor and cytokines (TGF-beta1 and IGF-1) to improve the osteogenesis and inhibit the destruction of bone.