Symbol effects of optimal dose of estradiol combined with puerarin on bone in ovariectomized rats

Low dose of puerarin combined with estradiol shows similar effects to high dose of puerarin or estradiol on treatment of osteoporosis in rats. To search the optimal doses for estradiol and puerarin for treatment of type I osteoporosis. Sixty-four healthy female rats were randomly divided into eight experimental groups (n = 8): sham-operated, ovariectomized, puerarin-50, estradiol-200, puerarin+estradiol-5, 50, 10, 150. All rats were subjected to ovariectomy except those in the sham-operated group. Rats in the puerarin-50 group were subcutaneously injected with 50 mk/kg puerarin, once a day. Rats in the estradiol-200 group were subcutaneously injected with 200 μg/kg estradiol, twice a week. Rats in the puerarin+ estradiol-5, 50, 10, 150 groups were subcutaneously injected with 25 mg/kg puerarin, once a day and simultaneously injected with 5, 50, 10, 150 μg/kg estradiol, twice a week. Compared with sham-operated group, bone mineral density, bone calcium, and bone phosphorous of rats were significantly lower in the ovariectomized group (P < 0.05), and bone tissue presented with the pathological change of osteoporosis. After treatment with puerarin and/or estradiol for 10 and 20 weeks, bone mineral density, bone calcium, and bone phosphorous levels were significantly increased (P < 0.05), and puerarin+estradiol-100 group acquired the most obvious curative effects on osteoporosis. The results showed that 25 mg/kg puerarin (once a day) and 100 μg/kg estradiol (twice a day) is the best dose for treatment of osteoporosis in ovariectomized rats.