黄芪多糖对感染型脑室周围白质软化新生大鼠的脑保护作用

The cerebral protective effects of astragalus polysaccharides on neonatal rats with LPS-induced periventricular leukomalacia

目的观察黄芪多糖对感染型脑室周围白质软化新生大鼠的脑保护作用,并初步探讨其作用机制。方法通过脑内注射脂多糖(LPS)1 mg/kg,建立2日龄感染型脑室周围白质转化(PVL)新生大鼠动物模型。将新生大鼠分为假手术对照组(Sham组)、PVL组、黄芪多糖治疗组。黄芪多糖组于模型制备后,通过腹腔注射黄芪多糖100 mg·kg-1·d-1,连续治疗3 d。在LPS脑内注射后第5天,观察脑病理组织学变化,检测脑组织TLR-4、i NOS蛋白表达以及一氧化氮含量。结果脑病理显示黄芪多糖组的脑白质病变较PVL组明显改善,其中重度白质病变的发生率较PVL组降低了30%,另有16.7%的脑白质完全正常;与PVL组比较,黄芪多糖治疗组的TLR-4、i NOS蛋白表达量较PVL组明显减少,一氧化氮含量明显降低。结论黄芪多糖对LPS引起的脑白质损伤具有良好的保护作用,与其抑制TLR4信号通路、减少i NOs和一氧化氮生成有关。

Objective To study the cerebral protective effects and preliminary mechanism of astragalus polysaccharides in model neonatal rats with lipopolysaccharide( LPS)-induced periventricular leukomalacia( PVL). Methods The models of infection-type were established by injecting LPS into ventricles of two-day-old neonatal rats. The neonatal rats were divided into sham group,PVL group,and astragalus polysaccharides group. The neonatal rats were given astragalus polysaccharides at a dose of 100 mg·kg-1·d-1after injecting LPS for3 days. The assessment of cerebral pathology was undertaken in 5 days after surgery. The analysis of the expression of TLR-4 and i NOS were determined by Western blot,and NO was determined by biochemistry. Results The pathological change in cerebral white matter was improved significantly in the astragalus polysaccharides group compared to that in PVL group with 30% of severe pathological change and 16.7% of normal white matters. The expression of TLR-4 and i NOS decreased significantly,and thelevel of NO decreased in astragalus polysaccharides groups compared to those in PVL group. Conclusion Astragalus polysaccharides exerts well protection on LPS-induced white matter injury,and the effect may be related with its inhibiting TLR-4 signaling pathway and decreasing the level of i NOs and NO.