Effects of Bushen Huoxue Fang on estrogen receptor alpha mRNA in pituitary body of ovariectomized rats with collagen-induced arthritis / 中国组织工程研究

ABSTRACT

BACKGROUND: Pharmacological researches demonstrate that Chinese crude drugs of invigorating the kidney contain flavonoids such as prepared rhizome of rehmannia and kudzuvine root, they possess phytoestrogenic effect, among them, isoflavone acts as a regulator of estrogen receptor.OBJECTIVE: To approach the effects of self-planned Bushen Huoxue Fang (BSHXF) on the serum estradiol and estrogen receptor α mRNA expression in pituitary gland in rats with collagen-induced arthritis. DESIGN, TIME AND SETTING: Randomized grouping controlled animal experiment was performed in the central laboratory of Bethune Intemational Peace Hospital of Chinese PLA between May 2006 and May 2008. MATERIALS: Sixty female and healthy Wistar rats were randomly divided into sham operated group (n=10) and operation group (n=50). Operation group was reproduced collagen-induced arthritis model at 2 weeks following ovariectomy. The rats of arthritic index ≥ 5 were assigned into model group, BSHXF group, methotrexate (MTX) group, and MTX + BSHXF group, each group included 10 rats. The Chinese crude drugs were bought from LERENTANG drugstore in Shijiazhuang, including rhizoma drynariae, safflower, prepared rhizome of rehmannia, Herba Epimedii, danshen root, kudzuvine root and so on. After routine decoction, centrifugalization, rogue and condensing 1.3 kg/L decoction, the solution was sealed up, divided pack and reserved at 4℃.METHODS: Sham operated group and model group were intragastrically administered with normal saline 2 mL per day; BSHXF group with BSHXF decoction 2 mL per day; MTX group with MTX 2.6 mg/kg (2 mL) once a week, and normal saline 2 mL per day at other time points; MTX + BSHXF group with MTX 2.6 mg/kg (2 mL) once a week and BSHXF juice 2 mL per day. Each group was given 6 weeks.MAIN OUTCOME MEASURES: After blooding by abdominalis aorta, magnetic-split enzyme linked immunosorbent assay was applied to detect the level of serum estradiol. Reverse transcription-polymerase chain reaction detected the expression of estrogen receptor a mRNA in rat pituitary gland.RESULTS: Compared with model group, the expression of estrogen receptor a mRNA in pituitary gland increased in the MTX group, but there was not statistically significant. BSHXF + MTX group showed a significantly increased expression (P < 0.01). The expression of estrogen receptor α mRNA in BSHXF group was higher than MTX group, but lower than BSHXF + MTX group (P < 0.05). No significant difference existed between BSHXF group, BSHXF + MTX group and sham operation group. Compared with sham operation group, there were statistically significant decrease of estradiol in the model group. Compared with model group, the estradiol levels were shown to increase in three treatment groups. Among them, MTX group had slightly slower level with no significant difference (P > 0.05), while BSHXF + MTX group had the most obvious increase, which was close to normal level (P < 0.01). There was a significantly positive correlation between estradiol and the expression of estrogen receptor o mRNA (r=0.483, P < 0.05).CONCLUSION: Serf-planned BSHXF possessing oestrogenic hormonelike role can elevate the level of serum estradiol and upregulate the expression of estrogen receptor a mRNA in pituitary gland.