Institute of Basic Theory, China Academy of Chinese Medical Sciences, 16 Dong Zhi Men Nei Nan Xiao Jie, Dong Cheng District, Beijing 100700, China.
Neurochem Res. 2012 Oct;37(10):2235-48. doi: 10.1007/s11064-012-0852-8. Epub 2012 Aug 7.
Geniposide, an iridoid glycoside isolated from Gardenia, has neuroprotective activities against oxidative stress and inflammation. The present study investigated the in vivo protective effect of geniposide on ischemia/reperfusion-injured rats by middle cerebral artery occlusion (MCAO), and the inhibitory effects of geniposide and mechanisms against activation of microglial cells by oxygen-glucose deprivation (OGD) in vitro. Male SD rats were subjected to treatment with geniposide at 15, 30 and 60 mg/kg immediately after MCAO. Cerebral infarct volume and microglial cell activation were assessed following 24 h reperfusion. Cultured primary rat microglial cells were exposed to geniposide at the concentrations of 12.5, 25 and 50 μg/mL during 4 h of OGD. The effects of geniposide were evaluated in terms of (1) cell viability; (2) secretion of TNF-α, IL-1β, IL-6, IL-8 and IL-10 into culture media; (3) TLR4 mRNA expression; (4) protein expression of TLR4, p-ERK1/2, p-IκB, p-p38, nuclear and cytoplasmic fraction NF-κB p65; and (5) nuclear transfer of NF-κB p65. Geniposide reduced the infarct volume and inhibited the activation of microglial cells in ischemic penumbra in vivo. OGD increased cell viability and release of TNF-α, IL-1β, IL-6, IL-8 and IL-10, these effects were suppressed by geniposide. Geniposide also attenuated the increases in the OGD-induced TLR4 mRNA and protein levels. In addition, geniposide at 25 and 50 μg/mL downregulated the phosphorylation of ERK, IκB and p38, as well as inhibited nuclear transcriptional activity triggered via NF-κB p65 in microglial cells by OGD. In conclusion, geniposide displays a neuroprotective effect on ischemia/reperfusion-injured rats in vivo and inhibits OGD-induced activation of microglial cells by attenuating inflammatory factors and NF-κB activation in vitro.
栀子苷是从栀子中分离得到的环烯醚萜苷，具有抗氧化应激和抗炎作用。本研究通过大脑中动脉闭塞（MCAO）观察栀子苷对缺血再灌注损伤大鼠的体内保护作用，以及栀子苷对氧葡萄糖剥夺（OGD）体外小胶质细胞激活的抑制作用和机制。雄性 SD 大鼠在 MCAO 后立即给予 15、30 和 60mg/kg 的栀子苷治疗。再灌注 24 小时后评估脑梗死体积和小胶质细胞激活。在 OGD 4 小时期间，将培养的原代大鼠小胶质细胞暴露于 12.5、25 和 50μg/mL 的栀子苷。根据以下方面评估栀子苷的作用：（1）细胞活力；（2）细胞培养上清液中 TNF-α、IL-1β、IL-6、IL-8 和 IL-10 的分泌；（3）TLR4 mRNA 表达；（4）TLR4、p-ERK1/2、p-IκB、p-p38、核和细胞质 NF-κB p65 蛋白表达；（5）NF-κB p65 的核转移。栀子苷减少梗死体积并抑制体内缺血半影区小胶质细胞的激活。OGD 增加细胞活力和 TNF-α、IL-1β、IL-6、IL-8 和 IL-10 的释放，这些作用被栀子苷抑制。栀子苷还减弱了 OGD 诱导的 TLR4 mRNA 和蛋白水平的增加。此外，栀子苷在 25 和 50μg/mL 时下调了 OGD 诱导的 ERK、IκB 和 p38 的磷酸化，并抑制了 NF-κB p65 通过 OGD 在小胶质细胞中触发的核转录活性。总之，栀子苷对体内缺血再灌注损伤大鼠表现出神经保护作用，并通过减轻体外炎症因子和 NF-κB 激活来抑制 OGD 诱导的小胶质细胞激活。
