大豆异黄酮抑制大鼠前列腺增生及其作用机制

目的观察大豆异黄酮(SI)对良性前列腺增生(BPH)大鼠体内性激素、生长因子及细胞凋亡相关基因的影响,探讨SI对BPH的防治及作用机制。方法选择SPF级健康成年雄性SD大鼠100只,随机分为正常对照(NC)组、BPH模型组、低剂量6 mg/(kg·d)]SI组、中剂量12 mg/(kg·d)]SI组及高剂量24 mg/(kg·d)]SI组,每组各20只。灌胃给药4周后麻醉处理大鼠,腹主动脉取血,制备血清;完整摘取大鼠前列腺组织。称重测定前列腺组织湿质量,计算前列腺指数(PI);酶联免疫吸附法(ELISA)测定大鼠血清雌二醇(E2)、睾酮(T)水平;免疫质印迹法(Western blotting)检测前列腺组织Fas、Fas L、Bax、Bcl-2、表皮生长因子(EGF)及其受体EGFR的表达。结果与NC组比,BPH组前列腺组织湿质量及PI均较明显增加(P<0.05);血清E2及T水平均显著升高(P<0.05);前列腺组织中Fas L、Bcl-2、EGF及EGFR表达水平均显著升高(P<0.05),而Fas和Bax表达水平均显著降低(P<0.05)。与BPH组比,中、高剂量SI组前列腺组织湿质量及PI均明显减少(P<0.05);血清E2及T水平均显著下降(P<0.05);前列腺组织中Fas L、Bcl-2、EGF及EGFR表达水平均显著降低(P<0.05),而Fas和Bax表达水平显著升高(P<0.05);其中,中剂量SI组各指标变化较低、高剂量组更显著(P<0.05)。结论 SI对BPH具有较好的抑制作用,其中中剂量SI作用效果更佳,其作用机制可能与调节机体性激素水平,下调生长因子及其受体表达以及调控细胞凋亡基因表达有关。

Inhibitory effect of soybean isoflavone on benign prostatic hyperplasia and its mechanism

Objective To observe the effects of soy isoflavones (SI) on sex hormones, growth factors and apoptosis related genes in benign prostatic hyperplasia (BPH) rats, and to explore the prevention and mechanism of SI on BPH. Methods One hundred healthy adult male SD rats (SPF) were randomly divided into the normal control (NC) group (n=20), BPH model group (n=20), low-dose of SI group (n=20), medium-dose of SI group (n=20) and high-dose of SI group (n=20). After intragastric administration for 4 weeks, the rats were anesthetized and the abdominal aorta blood collected for preparing serum. The prostate tissues were obtained from the rats after blood collection and weighed, and the prostatic indexes (PI) were calculated. Enzyme linked immunosorbent assay (ELISA) was performed to detect the levels of estradiol (E2) and testosterone (T) in serum of the rats. The expressions of Fas, FasL, Bax, Bcl-2, epidermal growth factor (EGF) and EGF receptor (EGFR) were detected by Western blotting. Results Compared with the NC group, the wet weight of prostate and PI of rats in the BPH group increased obviously (P＜0.05), the levels of E2 and T in serum enhanced significantly (P＜0.05), the expressions of FasL, Bcl-2, EGF and EGFR in the prostate tissues up-regulated evidently (P＜0.05), while the expressions of Fas and Bax in the prostate tissues down-regulated evidently (P＜0.05). Compared with the BPH group, the wet weight of prostate and PI of rats in the medium-dose of SI and high-dose of SI groups decreased obviously (P＜0.05), the levels of E2 and T in serum decreased significantly (P＜0.05), the expressions of FasL, Bcl-2, EGF and EGFR in the prostate tissues down-regulated evidently (P＜0.05), while the expressions of Fas and Bax in the prostate tissues up-regulated evidently (P＜0.05). In addition, the changes of all the above mentioned indexes in the medium-dose of SI group showed more significant than that in the low dose of SI and high dose of SI groups (P＜0.05). Conclusion SI has an inhibitory effect on BPH, especially with the medium dose. The mechanism may be related to regulating the level of sex hormones, the expression of growth factor and its receptors, as well as the expression of apoptosis genes.