naphthoquinones and Infarction--Middle-Cerebral-Artery

Benzoxepane derivatives were designed and synthesized, and one hit compound emerged as being effective in vitro with low toxicity. In vivo, this hit compound ameliorated both sickness behavior through anti-inflammation in LPS-induced neuroinflammatory mice model and cerebral ischemic injury through anti-neuroinflammation in rats subjected to transient middle cerebral artery occlusion. Target fishing for the hit compound using photoaffinity probes led to identification of PKM2 as the target protein responsible for anti-inflammatory effect of the hit compound. Furthermore, the hit exhibited an anti-neuroinflammatory effect in vitro and in vivo by inhibiting PKM2-mediated glycolysis and NLRP3 activation, indicating PKM2 as a novel target for neuroinflammation and its related brain disorders. This hit compound has a better safety profile compared to shikonin, a reported PKM2 inhibitor, identifying it as a lead compound in targeting PKM2 for the treatment of inflammation-related diseases.

Topics: Animals; Anti-Inflammatory Agents; Dibenzoxepins; Disease Models, Animal; Infarction, Middle Cerebral Artery; Interleukin-1beta; Ischemic Stroke; Lipopolysaccharides; Macrophages; Mice; Microglia; Naphthoquinones; NLR Family, Pyrin Domain-Containing 3 Protein; Pyruvate Kinase; Rats; RAW 264.7 Cells; Structure-Activity Relationship; Tumor Necrosis Factor-alpha

Of late, researchers have taken interest in alternative medicines for the treatment of brain ischemic stroke, where full recovery is rarely seen despite advanced medical technologies. Due to its antioxidant activity, Echinochrome A (Ech A), a natural compound found in sea urchins, has acquired attention as an alternative clinical trial source for the treatment of ischemic stroke. The current study demonstrates considerable potential of Ech A as a medication for cerebral ischemic injury. To confirm the effects of Ech A on the recovery of the injured region and behavioral decline, Ech A was administered through the external carotid artery in a rat middle cerebral artery occlusion model after reperfusion. The expression level of cell viability-related factors was also examined to confirm the mechanism of brain physiological restoration. Based on the results obtained, we propose that Ech A ameliorates the physiological deterioration by its antioxidant effect which plays a protective role against cell death, subsequent to post cerebral ischemic stroke.

Topics: Animals; Antioxidants; Apoptosis; Behavior Observation Techniques; Behavior, Animal; Brain; Cell Survival; Disease Models, Animal; Humans; Infarction, Middle Cerebral Artery; Male; Middle Cerebral Artery; Naphthoquinones; Neuroprotective Agents; Oxidative Stress; Rats; Reperfusion Injury; Sea Urchins; Treatment Outcome

Deregulation of glutamate homeostasis is associated with degenerative neurological disorders. Glutamate dehydrogenase (GDH) is important for glutamate metabolism and plays a central role in expanding the pool of tricarboxylic acid (TCA) cycle intermediate alpha-ketoglutarate (α-KG), which improves overall bioenergetics. Under high energy demand, maintenance of ATP production results in functionally active mitochondria. Here, we tested whether the modulation of GDH activity can rescue ischemia/reperfusion-induced neuronal death in an in vivo mouse model of middle artery occlusion and an in vitro oxygen/glucose depletion model. Iodoacetate, an inhibitor of glycolysis, was also used in a model of energy failure, remarkably depleting ATP and α-KG. To stimulate GDH activity, the GDH activator 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid and potential activator beta-lapachone were used. The GDH activators restored α-KG and ATP levels in the injury models and provided potent neuroprotection. We also found that beta-lapachone increased glutamate utilization, accompanied by a reduction in extracellular glutamate. Thus, our hypothesis that mitochondrial GDH activators increase α-KG production as an alternative energy source for use in the TCA cycle under energy-depleted conditions was confirmed. Our results suggest that increasing GDH-mediated glutamate oxidation represents a new therapeutic intervention for neurodegenerative disorders, including stoke.

Topics: Animals; Astrocytes; Brain; Brain Ischemia; Cell Death; Cells, Cultured; Coculture Techniques; Disease Models, Animal; Glutamate Dehydrogenase; Infarction, Middle Cerebral Artery; Male; Mice, Inbred ICR; Mitochondria; Naphthoquinones; Neurons; Neuroprotective Agents; Random Allocation; Reperfusion Injury

Inflammatory damage plays an important role in cerebral ischemic pathogenesis and represents a new target for treatment of stroke. Shikonin has gained attention for its prominent anti-inflammatory property, but up to now little is known about shikonin treatment in acute ischemic stroke. The aim of this study was to evaluate the potential neuroprotective role of shikonin in cerebral ischemic injury, and investigate whether shikonin modulated inflammatory responses after stroke. Focal cerebral ischemia in male ICR mice was induced by transient middle cerebral artery occlusion. Shikonin (10 and 25 mg/kg) was administered by gavage once a day for 3 days before surgery and another dosage after operation. Neurological deficit, infarct volume, brain edema, blood-brain barrier (BBB) dysfunction, and inflammatory mediators were evaluated at 24 and 72 h after stroke. Compared with vehicle group, 25 mg/kg shikonin significantly improved neurological deficit, decreased infarct volume and edema both at 24 and 72 h after transient ischemic stroke, our data also showed that shikonin inhibited the pro-inflammatory mediators, including TLR4, TNF-α, NF-κB, and phosphorylation of p38MAPK in ischemic cortex. In addition, shikonin effectively alleviated brain leakage of Evans blue, up-regulated claudin-5 expression, and inhibited the over-expressed MMP-9 in ischemic brain. These results suggested that shikonin effectively protected brain against ischemic damage by regulating inflammatory responses and ameliorating BBB permeability.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Blood-Brain Barrier; Brain Ischemia; Claudin-5; Down-Regulation; Infarction, Middle Cerebral Artery; Male; Matrix Metalloproteinase 9; Mice; Mice, Inbred ICR; Naphthoquinones; Neuroprotective Agents; NF-kappa B; p38 Mitogen-Activated Protein Kinases; Stroke; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha; Up-Regulation

Many phytochemicals function as noxious agents that protect plants against insects and other damaging organisms. However, at subtoxic doses, the same phytochemicals may activate adaptive cellular stress response pathways that can protect cells against a variety of adverse conditions. We screened a panel of botanical pesticides using cultured human and rodent neuronal cell models, and identified plumbagin as a novel potent activator of the nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway. In vitro, plumbagin increases nuclear localization and transcriptional activity of Nrf2, and induces the expression of the Nrf2/ARE-dependent genes, such as heme oxygenase 1 in human neuroblastoma cells. Plumbagin specifically activates the Nrf2/ARE pathway in primary mixed cultures from ARE-human placental alkaline phosphatase reporter mice. Exposure of neuroblastoma cells and primary cortical neurons to plumbagin provides protection against subsequent oxidative and metabolic insults. The neuroprotective effects of plumbagin are abolished by RNA interference-mediated knockdown of Nrf2 expression. In vivo, administration of plumbagin significantly reduces the amount of brain damage and ameliorates-associated neurological deficits in a mouse model of focal ischemic stroke. Our findings establish precedence for the identification and characterization of neuroprotective phytochemicals based upon their ability to activate adaptive cellular stress response pathways.

Topics: Animals; Cell Line, Tumor; Cell Survival; Cells, Cultured; Cerebral Cortex; Cerebral Infarction; Disease Models, Animal; Embryo, Mammalian; Gene Expression Regulation; Glucose; Heme Oxygenase-1; Humans; Hypoxia; Infarction, Middle Cerebral Artery; Mice; Mice, Inbred C57BL; Naphthoquinones; Neuroblastoma; Neurologic Examination; Neurons; Neuroprotective Agents; NF-E2-Related Factor 2; Oxidative Stress; Rats; Rats, Sprague-Dawley; Transcription Factor AP-1; Transfection

The aim of our study was to investigate the neuroprotective properties of shikonin, a naphthoquinone pigment isolated from the roots of the traditional Chinese herb Lithospermum erythrorhizon. In the present study, mice were divided randomly into sham, model, shikonin and edaravone-treated groups. Shikonin (50, 25, and 12.5mg/kg, i.g.) or maize oil was administered three times before ischemia and once at 2h after the onset of ischemia. Mice were anesthetized with chloral hydrate and subjected to middle cerebral artery 2h of occlusion and then 22h of reperfusion. Different antioxidant assays were employed in order to evaluate the antioxidant activities of shikonin in vitro. Neurological deficit, infarct size, histopathology changes and oxidative stress markers were evaluated after 22h of reperfusion. In comparison with the model group, treatment with shikonin significantly decreased neurological deficit scores, infarct size, the levels of malondialdehyde(MDA), carbonyl and reactive oxygen species, and attenuated neuronal damage, up-regulated superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px) activities and reduced glutathione (GSH)/glutathione disulfide (GSSG) ratio. Taken together, these results suggested that the neuroprotective effects of shikonin against cerebral ischemia/reperfusion injury may be attributed to its antioxidant effects.

Topics: Animals; Antioxidants; Biomarkers; Brain Ischemia; Dose-Response Relationship, Drug; Glutathione; Infarction, Middle Cerebral Artery; Male; Malondialdehyde; Mice; Mitochondria; Naphthoquinones; Neuroprotective Agents; Oxidative Stress; Oxidoreductases; Protein Carbonylation; Random Allocation; Reactive Oxygen Species; Reperfusion Injury; Up-Regulation