大豆异黄酮对β淀粉样肽诱导的大鼠脑组织炎症相关因子表达的影响

目的研究大豆异黄酮(SIF)对β淀粉样肽1-42(Aβ1-42)诱导的大鼠脑炎症损伤的作用。方法将健康雄性Wistar大鼠按体重随机分成对照组、Aβ模型组,SIF干预组(SIF+Aβ组)和SIF组(SIF单独处理组)。SIF干预组和SIF组大鼠每日给予大豆异黄酮(80 mg/kg)灌胃处理,共14 d。然后Aβ模型组和SIF干预组采用微型注射泵在大鼠侧脑室区持续注射Aβ1-42 14 d,建立大鼠脑炎症损伤模型。采用RT-PCR方法和Western blot方法检测脑组织白介素-1β(IL-1β)、诱导型一氧化氮合成酶(iNOS)以及白介素-10(IL-10)基因和蛋白水平的表达。结果与模型组比较,SIF干预组大鼠脑组织IL-1β、iNOS及IL-10基因和蛋白表达水平显著下调(P<0.05)。结论大豆异黄酮可能是通过影响大鼠脑组织炎症相关因子及酶基因/蛋白水平的表达来拮抗Aβ1-42介导的脑炎症反应。

Effect of soybean isoflavones on the expression of inflammatory mediators in the brain of rats induced by p_amyloid peptides

Objective To investigate the protective mechanism of soybean isoflavones(SIF) against the inflammatory impairment in the brain of rats induced by β-amyloid peptide1-42(Aβ1-42).Methods Based on the body weight of rats,32 healthy Wistar rats(male,aged 3 months) were randomly divided into four groups(control,Aβ,SIF+Aβ and SIF groups).The inflammatory impairment model was established by injecting Aβ1-42(10 μg) into the lateral cerebral ventricle of rats with micropump for 14 days.The rats in SIF+Aβ and SIF groups were treated with SIF(80 mg/kg bw) per day by gavaging for 14 days before the injection of Aβ,while the rats in control group and Aβ group were treated with 0.5 % CMC-Na.On the 15th day after Aβ injection,the rats were killed for the mRNA and protein expression of interleukin-1β(IL-1β),inducible nitric oxide synthase(iNOS) and interleukin-10(IL-10) in brain tissue tested by RT-PCR and western blot.Results Comparing with the Aβ group,the mRNA and protein expression of IL-1β,iNOS and IL-10 of SIF treated groups were decreased significantly(P<0.05).Conclusion The expression of IL-1β,iNOS and IL-10 at gene and peotein level could be down-regulated by soy isoflavones,therefore the inflammatory damage induced by Aβ1-42 was inhibitd.