Lim Sun Ha, Lee Jongwon
Department of Biochemistry, School of Medicine, Catholic University of Daegu, 33 Duryugongwon-ro 17-gil, Nam-gu, Daegu 42472, Korea.
Nutr Res Pract. 2017 Oct;11(5):381-387. doi: 10.4162/nrp.2017.11.5.381. Epub 2017 Sep 28.
BACKGROUND/OBJECTIVES: Vascular dementia (VaD) caused by reduced blood supply to the brain manifests as white matter lesions accompanying demyelination and glial activation. We previously showed that arabinoxylan consisting of arabinose and xylose, and arabinose itself attenuated white matter injury in a rat model of VaD. Here, we investigated whether larch arabinogalactan (LAG) consisting of arabinose and galactose could also reduce white matter injury.
MATERIALS/METHODS: We used a rat model of bilateral common carotid artery occlusion (BCCAO), in which the bilateral common carotid arteries were exposed and ligated permanently with silk sutures. The rats were fed a modified AIN-93G diet supplemented with LAG (100 mg/kg/day) for 5 days before and 4 weeks after being subjected to BCCAO. Four weeks after BCCAO, the pupillary light reflex (PLR) was measured to assess functional consequences of injury in the corpus callosum (cc). Additionally, Luxol fast blue staining and immunohistochemical staining were conducted to assess white matter injury, and astrocytic and microglial activation, respectively.
We showed that white matter injury in the the cc and optic tract (opt) was attenuated in rats fed diet supplemented with LAG. Functional consequences of injury reduction in the opt manifested as improved PLR. Overall, these findings indicate that LAG intake protects against white matter injury through inhibition of glial activation.
The results of this study support our hypothesis that cell wall polysaccharides consisting of arabinose are effective at protecting white matter injury, regardless of their origin. Moreover, LAG has the potential for development as a functional food to prevent vascular dementia.
背景/目的：大脑血液供应减少导致的血管性痴呆（VaD）表现为伴有脱髓鞘和胶质细胞激活的白质病变。我们之前表明，由阿拉伯糖和木糖组成的阿拉伯木聚糖以及阿拉伯糖本身可减轻VaD大鼠模型中的白质损伤。在此，我们研究了由阿拉伯糖和半乳糖组成的落叶松阿拉伯半乳聚糖（LAG）是否也能减轻白质损伤。
材料/方法：我们使用双侧颈总动脉闭塞（BCCAO）大鼠模型，其中暴露双侧颈总动脉并用丝线永久结扎。在进行BCCAO之前5天和之后4周，给大鼠喂食添加了LAG（100毫克/千克/天）的改良AIN - 93G饮食。BCCAO后4周，测量瞳孔对光反射（PLR）以评估胼胝体（cc）损伤的功能后果。此外，分别进行Luxol固蓝染色和免疫组织化学染色以评估白质损伤以及星形胶质细胞和小胶质细胞的激活情况。
我们发现，喂食添加LAG饮食的大鼠中，cc和视束（opt）的白质损伤减轻。opt中损伤减轻的功能后果表现为PLR改善。总体而言，这些发现表明摄入LAG可通过抑制胶质细胞激活来预防白质损伤。
本研究结果支持我们的假设，即由阿拉伯糖组成的细胞壁多糖无论其来源如何，都能有效保护白质免受损伤。此外，LAG有开发成为预防血管性痴呆的功能性食品的潜力。
