ABSTRACT
BACKGROUND:Lycium barbarum polysaccharide, the main active component of leaves of lycium barbarum, has a remarkable therapeutic effect on osteoporosis in adult ovariectomized female rats. OBJECTIVE:To explore effects of leaves ofLycium barbarum on serum estradiol and bone estrogen receptor expressions in adult oxariectomized female rats. METHODS: Thirty-two 6-month-od female rats were randomized into sham-surgery, model, and treatment groups, respectively. Rat models of postmenopausal osteoporosis were induced by ovariotomy folowed by oraly administration of water solution of leaves ofLycium barbarum (500 or 1 000 mg/kg) or distiled water once daily for consecutive 12 weeks in treatment and model groups, respectively. Serum estradiol level was detected by radiation immunoassaymethod. Estrogen receptor α, β immunoreactivities in bone tissue were determined by immunohistochemical staining. RESULTS AND CONCLUSION:Serum estradiol level in the model group was significantly decreased compared with the sham-surgery group (P < 0.01), but that was significantly increased in the treatment groups, particularly at high dose, compared with the model group (P< 0.01). Estrogen receptor α, βimmunoreactivities were weaker in the model group than the sham-surgery group (P < 0.01), and those were stronger in the treatment groups than the model group (P < 0.01). Our results suggest that leaves of Lycium barbarum treat osteoporosis through enhancing serum estradiol and estrogen receptor expressions in adult ovariectomized rats.