雷公藤甲素对LPS诱导的神经炎症中星形胶质细胞和小胶质细胞激活的抑制作用

THE INHIBITORY EFFECTS OF TRIPTOLIDE ON ACTIVATION OF ASTROCYTES AND MICROGLIA IN NEUROINFLAMMATION INDUCED BY LPS

选用健康成年雄性SD大鼠,用不同剂量的雷公藤甲素[10、25、50μg/(kg·d)]预处理5d后,海马注射内毒素(LPS,4μg)24h。采用免疫组织化学和荧光组织化学方法观察海马内星形胶质细胞标记物胶质纤维酸性蛋白(GFAP)和小胶质细胞标记物蓖麻凝集素-1(RCA-1)表达的变化。结果显示:与生理盐水对照组比较,LPS注射引起注射部位GFAP表达增加,RCA-1阳性细胞增多、变大。而雷公藤甲素[50μg/(kg·d)]可明显下调LPS诱导的GFAP和RCA-1的表达,其抑制程度与药物剂量呈正相关。本研究结果提示,雷公藤甲素对海马内LPS诱导的星形胶质细胞和小胶质细胞的激活有明显的抑制作用。

In the present study, SD rats were administrated intraperitoneally with triptolide at different doses [ 10,25,50 μg,/（kg.d） ] for 5 d, followed by injection of lipopolysaccharide （ LPS, 4 μg） into hippocampus for 24 h. The sections were stained by immunohistochemistry and histochemistry to examine the expression of glial fibrillary acidic protein（GFAP） in astrocytes and ricinus communis agglutinin-1 （ RCA-1 ） in microglia of the hippocampus. Our results showed that, compared with saline-control group, injection of LPS induced increased expression of GFAP, and RCA-1-positive cells were increased in number and size in injected region. Triptolide [ 50 μg/（ kg·d ） ] can down-regulated markedly LPS-induced GFAF and RCA-1 expression, which were dose-dependently reduced by triptolide. These findings indicate that triptolide inhibits activation of astroeytes and microglia in LPS-induced neuroinflammation.