Vitexin reduces epilepsy after hypoxic ischemia in the neonatal brain via inhibition of NKCC1

Challenges and prospects in geriatric epilepsy treatment: the role of the blood-brain barrier in pharmacotherapy and drug delivery

The blood-brain barrier (BBB) is pivotal in maintaining neuronal physiology within the brain. This review delves into the alterations of the BBB specifically in the context of geriatric epilepsy. We examine how age-related changes in the BBB contribute to the pathogenesis of epilepsy in the elderly and present significant challenges in pharmacotherapy. Subsequently, we evaluate recent advancements in drug delivery methods targeting the BBB, as well as alternative approaches that could bypass the BBB's restrictive nature. We particularly highlight the use of neurotropic viruses and various synthetic nanoparticles that have been investigated for delivering a range of antiepileptic drugs. Additionally, the advantage and limitation of these diverse delivery methods are discussed. Finally, we analyze the potential efficacy of different drug delivery approaches in the treatment of geriatric epilepsy, aiming to provide insights into more effective management of this condition in the elderly population.

Correlation between inflammatory markers over time and disease severity in status epilepticus: a preliminary study

Objectives

Convulsive status epilepticus (CSE) is a major subtype of status epilepticus that is known to be closely associated with systemic inflammation. Some important inflammatory biomarkers of this disorder include the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), systemic immune inflammation index (SII), and pan-immune inflammation value (PIV). This study aimed to determine the NLR, PLR, MLR, SII, and PIV levels before and after treatment in adult patients with CSE and investigated the relationship of these parameters with disease severity.

Methods

This retrospective study analyzed data from 103 adult patients with CSE and 103 healthy controls. The neutrophil, monocyte, platelet, and lymphocyte counts, as well as the NLR, PLR, MLR, SII, and PIV, were compared in adult patients with CSE during acute seizures (within 2 h of admission) and after treatment relief (1-2 weeks of complete seizure control). Furthermore, multivariate linear regression analysis investigated the relationship between NLR, PLR, MLR, SII, and PIV with the Status Epilepticus Severity Score (STESS).

Results

The data revealed significant differences (p < 0.05) in neutrophils, monocytes, lymphocytes, NLR, PLR, MLR, SII, and PIV between adult patients with CSE during acute seizures and after treatment relief. The average neutrophil count was high during acute seizures in the patient group and decreased after remission. In contrast, the average lymphocyte count was lower after remission (p < 0.05). Furthermore, significant differences (p < 0.05) were observed in monocytes, lymphocytes, platelets, NLR, PLR, MLR, and PIV levels between adult patients with CSE after remission and the healthy control group. Multivariate linear regression analysis showed no significant correlation between NLR, PLR, MLR, SII, and PIV with STESS.

Conclusion

The results of this study indicated that adult patients with CSE experienced a transient systemic inflammatory response during acute seizures, which gradually returned to baseline levels after remission. However, there was a lack of robust clinical evidence correlating the severity of adult CSE and systemic inflammatory response.

Mechanisms of ferroptosis in hypoxic-ischemic brain damage in neonatal rats

This study was to explore the mechanism of ferroptosis and hypoxic-ischemic brain damage in neonatal rats. The neonatal rat hypoxic-ischemic brain damage (HIBD) model was established using the Rice-Vannucci method and treated with the ferroptosis inhibitor liproxstatin-1. Cognitive assessment was performed through absentee field experiments to confirm the successful establishment of the model. Brain tissue damage was evaluated by comparing regional cerebral blood flow and quantifying tissue staining. Neuronal cell morphological changes in the rats' cortical and hippocampal regions were observed using HE and Nissl staining. ELISA was performed to determine GPX4, GSH and ROS expression levels in the rats' brain tissues, and Western blotting to assess the expression levels of 4-HNE, GPX4, GSS, ACSL4, SLC7A11, SLC3A2, TFRC, FHC, FLC, HIF-1α, and Nrf2 proteins in rat brain tissues. Compared to the Sham group, the HIBD group exhibited a significant decrease in cerebral blood perfusion, reduced brain nerve cells, and disordered cell arrangement. The use of the ferroptosis inhibitor effectively improved brain tissue damage and preserved the shape and structure of nerve cells. The oxidative stress products ROS and 4-HNE in the brain tissue of the HIBD group increased significantly, while the expression of antioxidant indicators GPX4, GSH, SLC7A11, and GSS decreased significantly. Furthermore, the expression of iron metabolism-related proteins TFRC, FHC, and FLC increased significantly, whereas the expression of the ferroptosis-related transcription factors HIF-1α and Nrf2 decreased significantly. Treatment with liproxstatin-1 exhibited therapeutic effects on HIBD and downregulated tissue ferroptosis levels. This study shows the involvement of ferroptosis in hypoxic-ischemic brain damage in neonatal rats through the System Xc--GSH-GPX4 functional axis and iron metabolism pathway, with the HIF-1α and Nrf2 transcription factors identified as the regulators of ferroptosis involved in the HIBD process in neonatal rats.

Bumetanide Attenuates Cognitive Deficits and Brain Damage in Rats Subjected to Hypoxia-Ischemia at Two Time Points of the Early Postnatal Period

Neonatal hypoxia-ischemia (HI) is one of the main causes of tissue damage, cell death, and imbalance between neuronal excitation and inhibition and synaptic loss in newborns. GABA, the major inhibitory neurotransmitter of the central nervous system (CNS) in adults, is excitatory at the onset of neurodevelopment and its action depends on the chloride (Cl-) cotransporters NKCC1 (imports Cl-) and KCC2 (exports Cl-) expression. Under basal conditions, the NKCC1/KCC2 ratio decreases over neurodevelopment. Thus, changes in this ratio caused by HI may be related to neurological disorders. The present study evaluated the effects of bumetanide (NKCC cotransporters inhibitor) on HI impairments in two neurodevelopmental periods. Male Wistar rat pups, 3 (PND3) and 11 (PND11) days old, were submitted to the Rice-Vannucci model. Animals were divided into 3 groups: SHAM, HI-SAL, and HI-BUM, considering each age. Bumetanide was administered intraperitoneally at 1, 24, 48, and 72 h after HI. NKCC1, KCC2, PSD-95, and synaptophysin proteins were analyzed after the last injection by western blot. Negative geotaxis, righting reflex, open field, object recognition test, and Morris water maze task were performed to assess neurological reflexes, locomotion, and memory function. Tissue atrophy and cell death were evaluated by histology. Bumetanide prevented neurodevelopmental delay, hyperactivity, and declarative and spatial memory deficits. Furthermore, bumetanide reversed HI-induced brain tissue damage, reduced neuronal death and controlled GABAergic tone, maintained the NKCC1/KCC2 ratio, and synaptogenesis close to normality. Thereby, bumetanide appears to play an important therapeutic role in the CNS, protecting the animals against HI damage and improving functional performance.

Postischemic Infusion of Apigenin Reduces Seizure Burden in Preterm Fetal Sheep

Seizures are common in preterm newborns and are associated with poor neurodevelopmental outcomes. Current anticonvulsants have poor efficacy, and many have been associated with upregulation of apoptosis in the developing brain. Apigenin, a natural bioactive flavonoid, is a potent inhibitor of hyaluronidase and reduces seizures in adult animal models. However, its impact on perinatal seizures is unclear. In the present study, we examined the effect of apigenin and S3, a synthetic, selective hyaluronidase inhibitor, on seizures after cerebral ischemia in preterm fetal sheep at 0.7 gestation (98-99 days, term ~147 days). Fetuses received sham ischemia (n = 9) or ischemia induced by bilateral carotid occlusion for 25 min. Immediately after ischemia, fetuses received either a continuous infusion of vehicle (0.036% dimethyl sulfoxide, n = 8) or apigenin (50 µM, n = 6). In a pilot study, we also tested infusion of S3 (2 µM, n = 3). Fetuses were monitored continuously for 72 h after ischemia. Infusion of apigenin or S3 were both associated with reduced numbers of animals with seizures, total seizure time, and mean seizure burden. S3 was also associated with a reduction in the total number of seizures over the 72 h recovery period. In animals that developed seizures, apigenin was associated with earlier cessation of seizures. However, apigenin or S3 treatment did not alter recovery of electroencephalographic power or spectral edge frequency. These data support that targeting brain hyaluronidase activity with apigenin or S3 may be an effective strategy to reduce perinatal seizures following ischemia. Further studies are required to determine their effects on neurohistological outcomes.

Inhibition of UTX/KDM6A improves recovery of spinal cord injury by attenuating BSCB permeability and macrophage infiltration through the MLCK/p-MLC pathway

Spinal cord injury (SCI) can prompt an immediate disruption to the blood-spinal cord barrier (BSCB). Restoring the integrity of this barrier is vital for the recovery of neurological function post-SCI. The UTX protein, a histone demethylase, has been shown in previous research to promote vascular regeneration and neurological recovery in mice with SCI. However, it is unclear whether UTX knockout could facilitate the recovery of the BSCB by reducing its permeability. In this study, we systematically studied BSCB disruption and permeability at different time points after SCI and found that conditional UTX deletion in endothelial cells (ECs) can reduce BSCB permeability, decrease inflammatory cell infiltration and ROS production, and improve neurological function recovery after SCI. Subsequently, we used RNA sequencing and ChIP-qPCR to confirm that conditional UTX knockout in ECs can down-regulate expression of myosin light chain kinase (MLCK), which specifically mediates myosin light chain (MLC) phosphorylation and is involved in actin contraction, cell retraction, and tight junctions (TJs) protein integrity. Moreover, we found that MLCK overexpression can increase the ratio of p-MLC/MLC, further break TJs, and exacerbate BSCB deterioration. Overall, our findings indicate that UTX knockout could inhibit the MLCK/p-MLC pathway, resulting in decreased BSCB permeability, and ultimately promoting neurological recovery in mice. These results suggest that UTX is a promising new target for treating SCI.

Layer-specific changes of KCC2 and NKCC1 in the mouse dentate gyrus after entorhinal denervation

The cation-chloride cotransporters KCC2 and NKCC1 regulate the intracellular Cl^- concentration and cell volume of neurons and/or glia. The Cl^- extruder KCC2 is expressed at higher levels than the Cl^- transporter NKCC1 in mature compared to immature neurons, accounting for the developmental shift from high to low Cl^- concentration and from depolarizing to hyperpolarizing currents through GABA-A receptors. Previous studies have shown that KCC2 expression is downregulated following central nervous system injury, returning neurons to a more excitable state, which can be pathological or adaptive. Here, we show that deafferentation of the dendritic segments of granule cells in the outer (oml) and middle (mml) molecular layer of the dentate gyrus via entorhinal denervation in vivo leads to cell-type- and layer-specific changes in the expression of KCC2 and NKCC1. Microarray analysis validated by reverse transcription-quantitative polymerase chain reaction revealed a significant decrease in Kcc2 mRNA in the granule cell layer 7 days post-lesion. In contrast, Nkcc1 mRNA was upregulated in the oml/mml at this time point. Immunostaining revealed a selective reduction in KCC2 protein expression in the denervated dendrites of granule cells and an increase in NKCC1 expression in reactive astrocytes in the oml/mml. The NKCC1 upregulation is likely related to the increased activity of astrocytes and/or microglia in the deafferented region, while the transient KCC2 downregulation in granule cells may be associated with denervation-induced spine loss, potentially also serving a homeostatic role via boosting GABAergic depolarization. Furthermore, the delayed KCC2 recovery might be involved in the subsequent compensatory spinogenesis.

Vitexin Improves Cerebral ischemia‑reperfusion Injury by Attenuating Oxidative Injury and Ferroptosis via Keap1/Nrf2/HO-1signaling

Cerebral ischemia/reperfusion involves multiple pathological processes and ferroptosis played a crucial role in the disease progression. Nevertheless, whether Vitexin could ameliorate ischemia/reperfusion injury via meditate the ferroptosis still remains unknown. In this study, we established the oxygen-glucose deprivation and reoxygenation (OGD/R) neuron cell and middle cerebral artery occlusion/reperfusion (MCAO/R) rat model. The cell viability, cell apoptosis and reactive oxygen species (ROS) levels were tested by CCK-8 assay and Flow cytometry, respectively. Hematoxylin-eosin staining, TTC, TEM, immunofluorescence analysis and western blot were used to investigate the effects of Vitexin. The results demonstrated that Vitexin could enhanced the cell viability and decreased the cell apoptosis in OGD/R cell model. Meanwhile, incubation with Vitexin maintained the neuroprotective effects in OGD/R induced generation of lipid ROS and neuronal cell ferroptosis via regulated the expressions of Keap1/Nrf2/HO-1 relative protein levels. Moreover, treatment with Vitexin reversed brain infracted volume, the normal histopathology and mitochondrial function in MCAO/R rat model. Vitexin significantly decreased the Nrf2 transfer ration from nuclear to cytosol and regulated the expression of Keap1/Nrf2/HO-1 signaling both in vitro and in vivo. Nevertheless, the protective effects of Vitexin were blocked with the Nrf2 inhibitor ML385. Vitexin could protect the neuron cell and brain related with the Keap1/Nrf2/HO-1 signaling pathway. Vitexin was a useful candidate for stroke therapy and our research may provide an attractive therapeutic target for the treatment of stroke.

Blood-CNS barrier dysfunction in amyotrophic lateral sclerosis: Proposed mechanisms and clinical implications

There is strong evidence for blood-brain and blood-spinal cord barrier dysfunction at the early stages of many neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). Since impairment of the blood-central nervous system barrier (BCNSB) occurs during the pre-symptomatic stages of ALS, the mechanisms underlying this pathology are likely also involved in the ALS disease process. In this review, we explore how drivers of ALS disease, particularly mitochondrial dysfunction, astrocyte pathology and neuroinflammation, may contribute to BCNSB impairment. Mitochondria are highly abundant in BCNSB tissue and mitochondrial dysfunction in ALS contributes to motor neuron death. Likewise, astrocytes adopt key physical, transport and metabolic functions at the barrier, many of which are impaired in ALS. Astrocytes also show raised expression of inflammatory markers in ALS and ablating ALS-causing transgenes in astrocytes slows disease progression. In addition, key drivers of neuroinflammation, including TAR DNA-binding protein 43 (TDP-43) pathology, matrix metalloproteinase activation and systemic inflammation, affect BCNSB integrity in ALS. Finally, we discuss the translational implications of BCNSB dysfunction in ALS, including the development of biomarkers for disease onset and progression, approaches aimed at restoring BCNSB integrity and in vitro modelling of the neurogliovascular system.

A Comprehensive Review on Anti-Inflammatory Response of Flavonoids in Experimentally-Induced Epileptic Seizures

Flavonoids, a group of natural compounds with phenolic structure, are becoming popular as alternative medicines obtained from plants. These compounds are reported to have various pharmacological properties, including attenuation of inflammatory responses in multiple health issues. Epilepsy is a disorder of the central nervous system implicated with the activation of the inflammatory cascade in the brain. The aim of the present study was to summarize the role of various neuroinflammatory mediators in the onset and progression of epilepsy, and, thereafter, to discuss the flavonoids and their classes, including their biological properties. Further, we highlighted the modulation of anti-inflammatory responses achieved by these substances in different forms of epilepsy, as evident from preclinical studies executed on multiple epilepsy models. Overall, the review summarizes the available evidence of the anti-inflammatory potential of various flavonoids in epilepsy.

Potential implications of polyphenolic compounds in neurodegenerative diseases

Neurodegenerative diseases are common chronic diseases related to progressive damage to the nervous system. Current neurodegenerative diseases present difficulties and despite extensive research efforts to develop new disease-modifying therapies, there is still no effective treatment for halting the neurodegenerative process. Polyphenols are biologically active organic compounds abundantly found in various plants. It has been reported that plant-derived dietary polyphenols may improve some disease states and promote health. Emerging pieces of evidence indicate that polyphenols are associated with neurodegenerative diseases. This review aims to overview the potential neuroprotective roles of polyphenols in most common neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, epilepsy, and ischemic stroke.

Anti-Inflammatory Effects of Phytochemical Components of Clinacanthus nutans

Recent studies on the ethnomedicinal use of Clinacanthus nutans suggest promising anti-inflammatory, anti-tumorigenic, and antiviral properties for this plant. Extraction of the leaves with polar and nonpolar solvents has yielded many C-glycosyl flavones, including schaftoside, isoorientin, orientin, isovitexin, and vitexin. Aside from studies with different extracts, there is increasing interest to understand the properties of these components, especially regarding their ability to exert anti-inflammatory effects on cells and tissues. A major focus for this review is to obtain information on the effects of C. nutans extracts and its phytochemical components on inflammatory signaling pathways in the peripheral and central nervous system. Particular emphasis is placed on their role to target the Toll-like receptor 4 (TLR4)-NF-kB pathway and pro-inflammatory cytokines, the antioxidant defense pathway involving nuclear factor erythroid-2-related factor 2 (NRF2) and heme oxygenase 1 (HO-1); and the phospholipase A₂ (PLA₂) pathway linking to cyclooxygenase-2 (COX-2) and production of eicosanoids. The ability to provide a better understanding of the molecular targets and mechanism of action of C. nutans extracts and their phytochemical components should encourage future studies to develop new therapeutic strategies for better use of this herb to combat inflammatory diseases.

Glycyrrhizin Attenuates Hypoxic-Ischemic Brain Damage by Inhibiting Ferroptosis and Neuroinflammation in Neonatal Rats via the HMGB1/GPX4 Pathway

With unknown etiology and limited treatment options, neonatal hypoxic-ischemic brain damage (HIBD) remains a major cause of mortality in newborns. Ferroptosis, a recently discovered type of cell death triggered by lipid peroxidation, is closely associated with HIBD. High-mobility group box 1 (HMGB1), a molecule associated with inflammation damage, can induce neuronal death in HIBD. However, it remains unknown whether HMGB1 contributes to neuronal ferroptosis in patients with HIBD. Herein, glycyrrhizin (GL), an HMGB1 inhibitor, was used to investigate the relationship between ferroptosis and HMGB1. RAS-selective lethal 3(RSL3), a ferroptosis agonist, was administered to further confirm the changes in the signaling pathway between HMGB1 and ferroptosis. Western blot analysis revealed that GL markedly suppressed the expression of HMGB1 and increased the level of GPX4 in the context of HIBD. We observed changes in neuronal ultrastructure via transmission electron microscopy to further confirm the occurrence of ferroptosis. Real-time PCR indicated that GL inhibited the expression of ferroptosis-related genes and inflammatory factors. Immunofluorescence and immunohistochemistry staining confirmed GL inhibition of neuronal damage and ferroptosis in HIBD associated with GPX4 and ROS. GL not only inhibited ferroptosis induced by RSL3 and oxygen-glucose deprivation in vitro but also inhibited ferroptosis induced by HIBD in vivo. More importantly, GL may improve oxidative stress imbalance and mitochondrial damage, alleviate the downstream production of inflammatory factors, and ultimately reduce ferroptosis and damage to cortical neurons following HIBD via the HMGB1/GPX4 pathway. In conclusion, we showed for the first time that GL could suppress the occurrence of neuronal ferroptosis and reduce neuronal loss in HIBD via the HMGB1/GPX4 pathway. These findings highlight the potential of HMGB1 signaling antagonists to treat neuronal damage by suppressing ferroptosis, provide new and unique insights into GL as a neuroprotective agent, and suggest new prevention and treatment strategies for HIBD.

Neurovascular unit dysfunction as a mechanism of seizures and epilepsy during aging

The term neurovascular unit (NVU) describes the structural and functional liaison between specialized brain endothelium, glial and mural cells, and neurons. Within the NVU, the blood‐brain barrier (BBB) is the microvascular structure regulating neuronal physiology and immune cross‐talk, and its properties adapt to brain aging. Here, we analyze a research framework where NVU dysfunction, caused by acute insults or disease progression in the aging brain, represents a converging mechanism underlying late‐onset seizures or epilepsy and neurological or neurodegenerative sequelae. Furthermore, seizure activity may accelerate brain aging by sustaining regional NVU dysfunction, and a cerebrovascular pathology may link seizures to comorbidities. Next, we focus on NVU diagnostic approaches that could be tailored to seizure conditions in the elderly. We also examine the impending disease‐modifying strategies based on the restoration of the NVU and, more in general, the homeostatic control of anti‐ and pro‐inflammatory players. We conclude with an outlook on current pre‐clinical knowledge gaps and clinical challenges pertinent to seizure onset and conditions in an aging population.

An overview on therapeutic and medicinal potential of poly-hydroxy flavone viz. Heptamethoxyflavone, Kaempferitrin, Vitexin and Amentoflavone for management of Alzheimer's and Parkinson's diseases: a critical analysis on mechanistic insight

Neurodegenerative disorders occur when nerve cells in the brain or peripheral nervous system partial or complete fail in their functions and sometimes even die due to some injuries or aging. Neurodegenerative disorders such as Alzheimer's Disease (AD) and Parkinson's Disease (PD), have been majorly resulted due to degeneration of neurons and neuroinflammation progressively. There are many similarities that correlates both AD and PD on a cellular and sub-cellular level. Therefore, a hope for therapeutic advancement for simultaneous upgradation in both the diseases are directly depending on the discovery of common mechanism at molecular and cellular level. Recent and past evidences from scientific literature supporting the efficacy of plants flavonoids in treatment and protection of both AD and PD. Further, dietary flavones, specially Heptamethoxyflavone, Kaempferitrin, Vitexin and Amentoflavone gains recently much more attention for producing many health beneficiary effects including neuroprotection. Despite of these evidence a detailed updated overview of neuroprotective effects against both AD and PD by Heptamethoxyflavone, Kaempferitrin, Vitexin and Amentoflavone are still missing. In this context several published studies were assessed by using various online electronic search engines/databases to meet the objective from 1981 to 2021 (Approx. 224). Therefore, present review was designed to deliver the detailed description on these flavones including therapeutic benefits in AD, PD and other CNS complications with critical analysis on underlying mechanisms.

Inhibition of the p‑SPAK/p‑NKCC1 signaling pathway protects the blood‑brain barrier and reduces neuronal apoptosis in a rat model of surgical brain injury

Surgical brain injury (SBI) can disrupt the function of the blood‑brain barrier (BBB), leading to brain edema and neurological dysfunction. Thus, protecting the BBB and mitigating cerebral edema are key factors in improving the neurological function and prognosis of patients with SBI. The inhibition of WNK lysine deficient protein kinase/STE20/SPS1‑related proline/alanine‑rich kinase (SPAK) signaling ameliorates cerebral edema, and this signaling pathway regulates the phosphorylation of the downstream Na⁺‑K⁺‑Cl^‑ cotransporter 1 (NKCC1). Therefore, the purpose of the present study was to investigate the role of SPAK in SBI‑induced cerebral edema and to determine whether the SPAK/NKCC1 signaling pathway was involved in SBI via regulating phosphorylation. An SBI model was established in male Sprague‑Dawley rats, and the effects of SPAK on the regulation of the NKCC1 signaling pathway on BBB permeability and nerve cell apoptosis by western blotting analysis, immunofluorescence staining, TUNEL staining, Fluoro‑Jade C staining, and brain edema and nervous system scores. The results demonstrated that, compared with those in the sham group, phosphorylated (p)‑SPAK and p‑NKCC1 protein expression levels were significantly increased in the SBI model group. After inhibiting p‑SPAK, the expression level of p‑NKCC1, neuronal apoptosis and BBB permeability were significantly reduced in SBI model rats. Taken together, these findings suggested that SBI‑induced increases in p‑SPAK and p‑NKCC1 expression exacerbated post‑traumatic neural and BBB damage, which may be mediated via the ion‑transport‑induced regulation of cell edema.

Clinical Implications of Epigenetic Dysregulation in Perinatal Hypoxic-Ischemic Brain Damage

Placental and fetal hypoxia caused by perinatal hypoxic-ischemic events are major causes of stillbirth, neonatal morbidity, and long-term neurological sequelae among surviving neonates. Brain hypoxia and associated pathological processes such as excitotoxicity, apoptosis, necrosis, and inflammation, are associated with lasting disruptions in epigenetic control of gene expression contributing to neurological dysfunction. Recent studies have pointed to DNA (de)methylation, histone modifications, and non-coding RNAs as crucial components of hypoxic-ischemic encephalopathy (HIE). The understanding of epigenetic dysregulation in HIE is essential in the development of new clinical interventions for perinatal HIE. Here, we summarize our current understanding of epigenetic mechanisms underlying the molecular pathology of HI brain damage and its clinical implications in terms of new diagnostic, prognostic, and therapeutic tools.

Absorption, metabolism, and bioactivity of vitexin: recent advances in understanding the efficacy of an important nutraceutical

vitexin, an apigenin-8-C-glucoside, is widely present in numerous edible and medicinal plants. vitexin possesses a variety of bioactive properties, including antioxidation, anti-inflammation, anti-cancer, neuron-protection, and cardio-protection. Other beneficial health effects, such as fat reduction, glucose metabolism, and hepatoprotection, have also been reported in recent studies. This review briefly discusses the absorption and metabolism of vitexin, as well as its influence on gut microbiota. Recent advances in understanding the pharmacological and biological effects of vitexin are then reviewed. Improved knowledge of the absorption, metabolism, bioactivity, and molecular targets of vitexin is crucial for the better utilization of this emerging nutraceutical as a chemopreventive and chemotherapeutic agent.

Rice Bran Phenolic Extract Protects against Alcoholic Liver Injury in Mice by Alleviating Intestinal Microbiota Dysbiosis, Barrier Dysfunction, and Liver Inflammation Mediated by the Endotoxin-TLR4-NF-κB Pathway

Alcoholic liver injury, known as the most general result of chronic alcohol intake, is induced by inflammatory responses, which is activated by intestine-derived endotoxins formed from intestinal dysbiosis. The hepatoprotective activity of rice bran phenolic extract (RBPE) on ethanol-fed mice was investigated for the first time in this study, and the underlying mechanism was explored from gut microbiota, barrier function, and hepatic inflammation. Mice were fed an alcohol-containing liquid diet alone or in mixture with RBPE for 8 weeks. RBPE treatment mitigated ethanol-induced liver damage, evidenced by the declined lipid profile levels and hepatic function markers. Moreover, ethanol intake induced intestinal microbiota dysbiosis, which was attenuated by RBPE supplementation. RBPE treatment improved the alcohol-induced decrease in the expression of ZO-1, Claudin-1, Claudin-4, and Reg3g, revealing the ameliorative effect of RBPE on intestinal barrier dysfunction. Furthermore, RBPE treatment repressed the alcohol-induced trigger of the hepatic endotoxin-TLR4-NF-κB pathway, followed by the mitigated liver inflammation. The findings indicate that RBPE supplementation ameliorates intestinal microbiota dysbiosis and barrier dysfunction, inactivates the endotoxin-TLR4-NF-κB pathway, and represses inflammatory responses in liver, and therefore, intake of RBPE or brown rice may be an effective way to mitigate alcoholic liver injury.

Immune Challenges and Seizures: How Do Early Life Insults Influence Epileptogenesis?

The development of epilepsy, a process known as epileptogenesis, often occurs later in life following a prenatal or early postnatal insult such as cerebral ischemia, stroke, brain trauma, or infection. These insults share common pathophysiological pathways involving innate immune activation including neuroinflammation, which is proposed to play a critical role in epileptogenesis. This review provides a comprehensive overview of the latest preclinical evidence demonstrating that early life immune challenges influence neuronal hyperexcitability and predispose an individual to later life epilepsy. Here, we consider the range of brain insults that may promote the onset of chronic recurrent spontaneous seizures at adulthood, spanning intrauterine insults (e.g. maternal immune activation), perinatal injuries (e.g. hypoxic–ischemic injury, perinatal stroke), and insults sustained during early postnatal life—such as fever-induced febrile seizures, traumatic brain injuries, infections, and environmental stressors. Importantly, all of these insults represent, to some extent, an immune challenge, triggering innate immune activation and implicating both central and systemic inflammation as drivers of epileptogenesis. Increasing evidence suggests that pro-inflammatory cytokines such as interleukin-1 and subsequent signaling pathways are important mediators of seizure onset and recurrence, as well as neuronal network plasticity changes in this context. Our current understanding of how early life immune challenges prime microglia and astrocytes will be explored, as well as how developmental age is a critical determinant of seizure susceptibility. Finally, we will consider the paradoxical phenomenon of preconditioning, whereby these same insults may conversely provide neuroprotection. Together, an improved appreciation of the neuroinflammatory mechanisms underlying the long-term epilepsy risk following early life insults may provide insight into opportunities to develop novel immunological anti-epileptogenic therapeutic strategies.

NFAT5 and HIF-1α Coordinate to Regulate NKCC1 Expression in Hippocampal Neurons After Hypoxia-Ischemia

Hypoxic-ischemic encephalopathy (HIE) is a serious birth complication with severe long-term sequelae such as cerebral palsy, epilepsy and cognitive disabilities. Na⁺-K⁺-2Cl^– cotransporters 1 (NKCC1) is dramatically upregulated after hypoxia-ischemia (HI), which aggravates brain edema and brain damage. Clinically, an NKCC1-specific inhibitor, bumetanide, is used to treat diseases related to aberrant NKCC1 expression, but the underlying mechanism of aberrant NKCC1 expression has rarely been studied in HIE. In this study, the cooperative effect of hypoxia-inducible factor-1α (HIF-1α) and nuclear factor of activated T cells 5 (NFAT5) on NKCC1 expression was explored in hippocampal neurons under hypoxic conditions. HI increased HIF-1α nuclear localization and transcriptional activity, and pharmacological inhibition of the HIF-1α transcription activity or mutation of hypoxia responsive element (HRE) motifs recovered the hypoxia-induced aberrant expression and promoter activity of NKCC1. In contrast, oxygen–glucose deprivation (OGD)-induced downregulation of NFAT5 expression was reversed by treating with hypertonic saline, which ameliorated aberrant NKCC1 expression. More importantly, knocking down NFAT5 or mutation of the tonicity enhancer element (TonE) stimulated NKCC1 expression and promoter activity under normal physiological conditions. The positive regulation of NKCC1 by HIF-1α and the negative regulation of NKCC1 by NFAT5 may serve to maintain NKCC1 expression levels, which may shed light on the transcription regulation of NKCC1 in hippocampal neurons after hypoxia.

TRPV1 mediates astrocyte activation and interleukin-1β release induced by hypoxic ischemia (HI)

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) is a serious birth complication with high incidence in both advanced and developing countries. Children surviving from HIE often have severe long-term sequela including cerebral palsy, epilepsy, and cognitive disabilities. The severity of HIE in infants is tightly associated with increased IL-1β expression and astrocyte activation which was regulated by transient receptor potential vanilloid 1 (TRPV1), a non-selective cation channel in the TRP family.

METHODS

Neonatal hypoxic ischemia (HI) and oxygen-glucose deprivation (OGD) were used to simulate HIE in vivo and in vitro. Primarily cultured astrocytes were used for investigating the expression of glial fibrillary acidic protein (GFAP), IL-1β, Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), and activation of the nucleotide-binding, oligomerization domain (NOD)-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome by using Western blot, q-PCR, and immunofluorescence. Brain atrophy, infarct size, and neurobehavioral disorders were evaluated by Nissl staining, 2,3,5-triphenyltetrazolium chloride monohydrate (TTC) staining and neurobehavioral tests (geotaxis reflex, cliff aversion reaction, and grip test) individually.

RESULTS

Astrocytes were overactivated after neonatal HI and OGD challenge. The number of activated astrocytes, the expression level of IL-1β, brain atrophy, and shrinking infarct size were all downregulated in TRPV1 KO mice. TRPV1 deficiency in astrocytes attenuated the expression of GFAP and IL-1β by reducing phosphorylation of JAK2 and STAT3. Meanwhile, IL-1β release was significantly reduced in TRPV1 deficiency astrocytes by inhibiting activation of NLRP3 inflammasome. Additionally, neonatal HI-induced neurobehavioral disorders were significantly improved in the TRPV1 KO mice.

CONCLUSIONS

TRPV1 promotes activation of astrocytes and release of astrocyte-derived IL-1β mainly via JAK2-STAT3 signaling and activation of the NLRP3 inflammasome. Our findings provide mechanistic insights into TRPV1-mediated brain damage and neurobehavioral disorders caused by neonatal HI and potentially identify astrocytic TRPV1 as a novel therapeutic target for treating HIE in the subacute stages (24 h).

Development of a ratiometric two-photon fluorescent probe for imaging of hydrogen peroxide in ischemic brain injury

We developed a novel ratiometric two-photon fluorescent probe for tracking H₂O₂ in BV-2 cells and brain tissue. This work will help to understand the relationship between the hypoxic-ischemic process and H₂O₂.

Scabiosa Genus: A Rich Source of Bioactive Metabolites

The genus Scabiosa (family Caprifoliaceae) is considered large (618 scientific plant names of species) although only 62 have accepted Latin binominal names. The majority of the Scabiosa species are widely distributed in the Mediterranean region and some Scabiosa species are used in traditional medicine systems. For instance, Scabiosa columbaria L. is used traditionally against diphtheria while S. comosa Fisch. Ex Roem. and Schult. is used in Mongolian and Tibetan traditional medical settings to treat liver diseases. The richness of Scabiosa species in secondary metabolites such as iridoids, flavonoids and pentacyclic triterpenoids may contribute to its use in folk medicine. Details on the most recent and relevant pharmacological in vivo studies on the bioactive secondary metabolites isolated from Scabiosa species will be summarized and thoroughly discussed.