Following ischemic stroke, blood-brain barrier (BBB) is disrupted and is further aggravated with the corresponding incidence of hyperlipidemia. BBB breakdown promotes inflammation infiltration into the brain, which exacerbates cerebral ischemic injury as a result. Here, we report that 10-O-(N,N-dimethylaminoethyl)-ginkgolide B methanesulfonate (XQ-1H), a novel analog of ginkgolide B, alleviates BBB breakdown in hyperlipidemic rats and protects endothelial cells against inflammatory response. Middle cerebral artery occlusion (MCAO) modeled ischemic stroke in rats. Before surgery, these rats were fed a cholesterol-rich diet to induce an experimental hyperlipidemic condition. Additionally, lipopolysaccharide (LPS) incubation with rat brain microvessel endothelial cells (rBMECs) was applied to mimic hyperlipidemia-induced inflammatory injury of BBB. The results indicated more severe infarct size, increased BBB permeability, excessive secretion of pro-inflammatory cytokines, and exaggerated inflammation infiltration of the brain in hyperlipidemic rats following MCAO when compared to rats fed with normal diet. XQ-1H protected BBB integrity, lessoned brain edema and inflammation penetration, downregulated MMP-9 and VCMA-1 expressions, and extenuated ischemic infarction. XQ-1H alleviated LPS-induced inflammatory response in rBMECs, characterized by promoting cell viability, inhibiting TNF-α, IL-1β, and IL-6 releasing, and downregulating NF-κB inflammatory signal and downstream proteins, such as VCAM-1 and iNOS. In conclusion, the present study shows that XQ-1H stabilizes BBB function following ischemic stroke in hyperlipidemic rats, and the possible mechanisms may be related to inflammation inhibition.

The blood-brain barrier (BBB) greatly limits the efficacy of many neuroprotective drugs' delivery to the brain, so improving drug penetration through the BBB has been an important focus of research. Here we report that platelet activating factor (PAF) transiently opened BBB and facilitated neuroprotectant edaravone penetration into the brain. Intravenous infusion with PAF induced a transient BBB opening in rats, reflected by increased Evans blue leakage and mild edema formation, which ceased within 6 h. Furthermore, rat regional cerebral blood flow (rCBF) declined acutely during PAF infusion, but recovered slowly. More importantly, this transient BBB opening significantly increased the penetration of edaravone into the brain, evidenced by increased edaravone concentrations in tissue interstitial fluid collected by microdialysis and analyzed by Ultra-performance liquid chromatograph combined with a hybrid quadrupole time-of-flight mass spectrometer (UPLC-MS/MS). Similarly, incubation of rat brain microvessel endothelial cells monolayer with 1 lM PAF for 1 h significantly increased monolayer permeability to 125 I-albumin, which recovered 1 h after PAF elimination. However, PAF incubation with rat brain microvessel endothelial cells for 1 h did not cause detectable cytotoxicity, and did not regulate intercellular adhesion molecule-1, matrix-metalloproteinase-9 and P-glycoprotein expression. In conclusion, PAF could induce transient and reversible BBB opening through abrupt rCBF decline, which significantly improved edaravone penetration into the brain. Keywords: blood-brain barrier, edaravone, microdialysis, platelet activating factor. J. Neurochem. (2014) 128, 662-671.The blood-brain barrier (BBB) is a gatekeeper and modulatory interface for the CNS, which prevents 98% of small molecules and 100% of large molecules from freely entering the brain (Weiss et al. 2009). Therefore, BBB plays a crucial role in maintaining the homeostasis of the CNS, but limits the number of potential therapeutic drugs capable of gaining access to the brain. Since neurological disorders, such as stroke, neurodegenerative diseases and brain tumors, are becoming more prevalent, developing novel strategies to improve drug delivery across the BBB has been an important focus of research (Kanwar et al. 2012). Platelet activating factor (PAF, b-Acetyl-c-O-hexadecyl-La-phosphatidylcholine) is a lipid mediator, released by many types of cells such as platelets, monocytes/macrophages, neutrophils and endothelial cells (Bazan 2003). Under physiological conditions, the level of PAF remains very low in the circulation due to its low production and rapid metabolism by PAF acetylhydrolase, a Ca 2+ -independent phospholipase A2 that catalyzes the conversion of PAF to the inactive metabolite lyso-PAF (Karasawa et al. 2003). However, under inflammatory conditions, the concentration of circulating PAF can be significantly increased, which Received July 6, 2013; revised manuscript received October 2, 2013; accepted October 21, 2013.Address correspon...

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Cerebral ischemia/reperfusion injury plays an important role in the development of tissue injury after acute stroke, including neutrophils adhesion and infiltration, inflammation and oxidative stress. 10-O-(N,N-dimethylaminoethyl)-ginkgolide B methanesulfonate (XQ-1H) is a novel ginkdolide B derivative. In this study, we investigated the anti-inflammatory and anti-oxidative activities of XQ-1H in vivo and vitro. In our study, rats were treating with XQ-1H (31.2, 15.6 and 7.8 mg/kg) after middle cerebral artery occlusion surgery. Primary cultured cortical rat neurons were treated with NaSO for 1.5 h to mimic hypoxia and reoxygenation injury in vitro. Cortical neurons were preincubated with XQ-1H (100, 10, 1 μM) 24 h before hypoxic injury. Brain edema was evaluated by brain water content. Neutrophil infiltration was determined by fluorescence imaging method and myeloperoxidase assay. Intercellular adhesion molecule 1 (ICAM-1) and matrix metallopeptidase 9 (MMP-9) expressions were examined by immunohistochemistry analysis. Neuronal injury was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide, lactate dehydrogenase releasing and lactic acid content. The anti-oxidative effects of XQ-1H were evaluated by superoxide dismutase (SOD) activity and malondialdehyde content in ischemic brain and neuron cultures subjected to hypoxia/reoxygenation procedure. Results showed that XQ-1H reduced neutrophils infiltration to ischemic brain, which might result from down regulation of inflammatory mediators, such as ICAM-1 and MMP-9. In addition, an antioxidative effect of XQ-1H was observed in cortical neuron and brain homogenates by enhancing SOD activity and inhibiting lipid peroxidation. These results indicated that XQ-1H possessed a protective effect against cerebral ischemia, especially on neutrophil infiltration and oxidative stress.