ruscogenin and Infarction--Middle-Cerebral-Artery

Ruscogenin, an important steroid sapogenin derived from Ophiopogon japonicus, has been shown to inhibit cerebral ischemic injury. However, its potential molecular action on blood-brain barrier (BBB) dysfunction after stroke remains unclear. This study aimed to investigate the effects of ruscogenin on BBB dysfunction and the underlying mechanisms in middle cerebral artery occlusion/reperfusion (MCAO/R)-injured mice and oxygen-glucose deprivation/reoxygenation (OGD/R)-injured mouse brain microvascular endothelial cells (bEnd.3). The results demonstrated that administration of ruscogenin (10 mg/kg) decreased the brain infarction and edema, improved neurological deficits, increased cerebral brain flow (CBF), ameliorated histopathological damage, reduced evans blue (EB) leakage and upregulated the expression of tight junctions (TJs) in MCAO/R-injured mice. Meanwhile, ruscogenin (0.1-10 µM) treatment increased cell viability and trans-endothelial electrical resistance (TEER) value, decreased sodium fluorescein leakage, and modulated the TJs expression in OGD/R-induced bEnd.3 cells. Moreover, ruscogenin also inhibited the expression of interleukin-1β (IL-1β) and caspase-1, and markedly suppressed the expression of Nucleotide-binding domain (NOD)-like receptor family, pyrin domain containing 3 (NLRP3) and thiredoxin-interactive protein (TXNIP) in vivo and in vitro. Furthermore, ruscogenin decreased reactive oxygen species (ROS) generation and inhibited the mitogen-activated protein kinase (MAPK) pathway in OGD/R-induced bEnd.3 cells. Our findings provide some new insights into its potential application for the prevention and treatment of ischemic stroke.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Blood-Brain Barrier; Carrier Proteins; Caspase 1; Cell Hypoxia; Cell Line; Infarction, Middle Cerebral Artery; Inflammasomes; Interleukin-1beta; Male; MAP Kinase Signaling System; Mice; Mice, Inbred C57BL; NLR Family, Pyrin Domain-Containing 3 Protein; Ophiopogon; Reactive Oxygen Species; Spirostans; Thioredoxins; Tight Junctions

Transient cerebral ischemia initiates a complex series of inflammatory events, which has been associated with an increase in behavioral deficits and secondary brain damage. Ruscogenin is a major steroid sapogenin in the traditional Chinese herb Ophiopogon japonicus that have multiple bioactivities. Recent studies have demonstrated that Ruscogenin is involved in down-regulation of intercellular adhesion molecule-1 (ICAM-1) and nuclear factor-κB (NF-κB) activation in anti-inflammatory pathways. We hypothesized that Ruscogenin protects against brain ischemia by inhibiting NF-κB-mediated inflammatory pathway. To test this hypothesis, adult male mice (C57BL/6 strain) were pretreated with Ruscogenin and then subjected to transient middle cerebral artery occlusion (MCAO)/reperfusion. After 1 h MCAO and 24 h reperfusion, neurological deficit, infarct sizes, and brain water content were measured. Ruscogenin markedly decreased the infarct size, improved neurological deficits and reduced brain water content after MCAO. The activation of NF-κB Signaling pathway was observed after 1h of ischemia and 1h of reperfusion, and Ruscogenin significantly inhibited NF-κB p65 expression, phosphorylation and translocation from cytosol to nucleus at this time point in a dose-dependent manner. NF-κB DNA binding activity, and the expression of NF-κB target genes, including ICAM-1, inducible nitric oxide synthase (iNOS), cyclooxygenase (COX-2), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), were also suppressed by Ruscogenin pretreatment after 1 h MCAO and 24 h reperfusion. The results indicated that Ruscogenin protected the brain against ischemic damage caused by MCAO, and this effect may be through downregulation of NF-κB-mediated inflammatory responses.

Topics: Animals; Brain Ischemia; Cytokines; Disease Models, Animal; Infarction, Middle Cerebral Artery; Inflammation; Male; Mice; Mice, Inbred C57BL; Neuroprotective Agents; NF-kappa B; Signal Transduction; Spirostans; Stroke