Zhu Li-Hong, Bi Wei, Qi Ren-Bin, Wang Hua-Dong, Wang Zhi-Gang, Zeng Qi, Zhao Yan-Ru, Lu Da-Xiang
Department of Pathophysiology, Institute of Brain Research, Key Laboratory of State Administration of Traditional Chinese Medicine of the People's Republic of China.
Neurol Res. 2011 Nov;33(9):927-34. doi: 10.1179/1743132811Y.0000000023.
This study examined whether luteolin may exert an anti-inflammatory effect in microglia and may be neuroprotective by regulating microglia activation.
We treated BV2 microglia with 1.0 μg/ml lipopolysaccharide (LPS) after incubation with luteolin for 1 hour, the nitric oxide (NO) levels were determined by a Griess reaction, the inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-alpha), and interleukin 1beta (IL-1beta) mRNA expression were determined by real-time PCR analysis, the iNOS and COX-2 protein induction were determined by Western blot analysis, and the levels of prostaglandin E(2) (PGE(2)), TNF-alpha, and IL-1beta were determined by enzyme-linked immunosorbent assay (ELISA) kits. Rat primary hippocampal neurons were co-cultured with LPS-activated BV2 microglia with 20 μM luteolin for 24 hours, the hippocampal neurons viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the number of apoptotic hippocampal neurons was determined by immunofluorescence detection.
Luteolin significantly inhibited the expression of iNOS and COX-2 in LPS-induced BV2 microglia. Moreover, the compound down-regulated the proinflammatory cytokines (TNF-alpha and IL-1beta) as well as the production of NO and PGE(2) in these cells. When hippocampal neurons were co-cultured with LPS-stimulated BV2 microglia, the administration of 20 μM luteolin increased the neurons viability and reduced the number of apoptotic neurons.
These data demonstrate that anti-inflammatory activity of luteolin in microglia contributes to its neuroprotective effect and suggest that it may have a potential therapeutic application in the treatment of neurodegenerative diseases.
本研究探讨木犀草素是否可在小胶质细胞中发挥抗炎作用，并通过调节小胶质细胞活化而具有神经保护作用。
用木犀草素孵育BV2小胶质细胞1小时后，用1.0μg/ml脂多糖（LPS）处理，通过格里斯反应测定一氧化氮（NO）水平，通过实时PCR分析测定诱导型NO合酶（iNOS）、环氧化酶-2（COX-2）、肿瘤坏死因子-α（TNF-α）和白细胞介素1β（IL-1β）mRNA表达，通过蛋白质印迹分析测定iNOS和COX-2蛋白诱导情况，通过酶联免疫吸附测定（ELISA）试剂盒测定前列腺素E2（PGE2）、TNF-α和IL-1β水平。将大鼠原代海马神经元与经LPS激活的BV2小胶质细胞及20μM木犀草素共培养24小时，通过3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴盐（MTT）法测定海马神经元活力，通过免疫荧光检测测定凋亡海马神经元数量。
木犀草素显著抑制LPS诱导的BV2小胶质细胞中iNOS和COX-2的表达。此外，该化合物下调了这些细胞中促炎细胞因子（TNF-α和IL-1β）以及NO和PGE2的产生。当海马神经元与LPS刺激的BV2小胶质细胞共培养时，给予20μM木犀草素可提高神经元活力并减少凋亡神经元数量。
这些数据表明木犀草素在小胶质细胞中的抗炎活性有助于其神经保护作用，并提示其在神经退行性疾病治疗中可能具有潜在的治疗应用。
