Attenuated Blood-Brain Barrier Dysfunction by XQ-1H Following Ischemic Stroke in Hyperlipidemic Rats

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-alpha, IL-1 beta, and IL-6 releasing, and downregulating NF-kappa B 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.