The effect of some immunomodulatory and anti-inflammatory drugs on Li-pilocarpine-induced epileptic disorders in Wistar rats

Dexamethasone attenuates low-frequency brainwave disturbances following acute seizures induced by pentylenetetrazol in Wistar rats

Seizures are neurological disorders triggered by an imbalance in the activity of excitatory and inhibitory neurotransmitters in the brain. When triggered chronically, this imbalance can lead to epilepsy. Critically, many of the affected individuals are refractory to treatment. Given this, anti-inflammatory drugs, in particular glucocorticoids, have been considered as a potential antiepileptogenic therapy. Glucocorticoids are currently used in the treatment of refractory patients, although there have been contradictory results in terms of their use in association with antiepileptic drugs, which reinforces the need for a more thorough investigation of their effects. In this context, the present study evaluated the effects of dexamethasone (DEX, 0.6 mg/kg) on the electroencephalographic (EEG) and histopathological parameters of male Wistar rats submitted to acute seizure induced by pentylenetetrazol (PTZ). The EEG monitoring revealed that DEX reduced the total brainwave power, in comparison with PTZ, in 12 h after the convulsive episode, exerting this effect in up to 36 h (p < 0.05 for all comparisons). An increase in the accommodation of the oscillations of the delta, alpha, and gamma frequencies was also observed from the first 12 h onwards, with the accommodation of the theta frequency occurring after 36 h, and that of the beta frequency 24 h after the seizure. The histopathological analyses showed that the CA3 region and hilum of the hippocampus suffered cell loss after the PTZ-induced seizure (control vs. PTZ, p < 0.05), although DEX was not able to protect these regions against cell death (PTZ vs. DEX + PTZ, p > 0.05). While DEX did not reverse the cell damage caused by PTZ, the data indicate that DEX has beneficial properties in the EEG analysis, which makes it a promising candidate for the attenuation of the epileptiform wave patterns that can precipitate refractory seizures.

Effect of Rosiglitazone, the Peroxisome Proliferator-Activated Receptor (PPAR)-γ Agonist, on Apoptosis, Inflammatory Cytokines and Oxidative Stress in pentylenetetrazole-Induced Seizures in Kindled Mice

A growing body of evidence has shown that seizure can trigger inflammatory cascades through increasing the expression of several inflammatory cytokines. It has been proved that peroxisome proliferator-activated receptor-γ agonists have immunomodulatory, anti-inflammatory, and neuroprotective effects beyond the putative hypoglycemic effects. Thus, we investigated the inhibitory effect of rosiglitazone on the development of pentylenetetrazol (PTZ)-induced kindling via affecting the inflammatory pathway. Male C57BL/6 mice were randomly divided into vehicle group (0.1% DMSO), PTZ-group and rosiglitazone-PTZ-group. Kindling was induced by the administration of PTZ (40 mg/kg, i.p) every other day and mice were observed for 20 min after each PTZ injection. Twenty-four hours after the last dose, animals were euthanized and hippocampus was isolated. The level of Malondialdehyde (MDA), Superoxide Dismutase (SOD), and Catalase (CAT) activity were quantified in hippocampus by biochemical methods. The protein levels of IL-1β, IL-6, IL-10, IFN-γ, TNF-α, caspase-3, iNOS, PPAR-γ, Bcl-2, or Bax factors were measured with western blotting. Also, the quantitative real-time PCR were used to evaluate the mRNA expression of those factors. Pretreatment with rosiglitazone significantly prevented the progression of kindling in comparison with control group. The rosiglitazone significantly decreased the MDA level and increased the CAT, and SOD levels in the rosiglitazone treated mice compared to those in the PTZ group (P < 0.01). Using real-time PCR and Western blotting assay, similar results were obtained. The expression levels of IL-1β, IL-6, IL-10, IFN-γ, TNF-α, Bax or PPAR-γ were significantly changed in the brain. The results of this study suggest that effect of rosiglitazone may be crucial in its ability to protect against the neuronal damage caused by PTZ induced seizure.

Glia and extracellular matrix molecules: What are their importance for the electrographic and MRI changes in the epileptogenic zone?

Glial cells and extracellular matrix (ECM) molecules are crucial for the maintenance of brain homeostasis. Especially because of their actions regarding neurotransmitter and ionic control, and synaptic function, these cells can potentially contribute to the hyperexcitability seen in the epileptogenic, while ECM changes are linked to synaptic reorganization. The present review will explore glial and ECM homeostatic roles and their potential contribution to tissue plasticity. Finally, we will address how glial, and ECM changes in the epileptogenic zone can be seen in magnetic resonance imaging (MRI), pointing out their importance as markers for the extension of the epileptogenic area. This article is part of the Special Issue "NEWroscience 2018".

Knockdown of Lingo-1 by short hairpin RNA promotes cognitive function recovery in a status convulsion model

The purpose of this study was to determine the dynamic changes of the Nogo-66 receptor 1 (NgR1) pathway during epileptogenesis and the potential beneficial of leucine-rich repeat and Ig-like domain-containing Nogo receptor interacting protein 1 (Lingo-1) inhibition on epilepsy rats. The hippocampal changes of the NgR1 pathway during epileptogenesis were determined by western blot analysis of multiple proteins, including neurite outgrowth inhibitor protein A (NogoA), myelin-associated glycoprotein (MAG), oligodendrocyte-myelin glycoprotein (OMgp), Lingo-1, ras homolog family member A (RhoA) and phosphorylated RhoA (p-RhoA). Lentivirus-mediated short hairpin RNA (shRNA) was used to knockdown the hippocampal expression of Lingo-1. Novel object recognition (NOR) test and Morris Water Maze (MWM) test were employed to determine the cognitive functions of rats. Hematoxylin and eosin (H&E) staining, protein expressions of RhoA, p-RhoA, and myelin basic protein (MBP), as well as convulsion susceptibility test were additionally performed. Our results showed that the NgR1 pathway was activated during epileptogenesis, characterized by up-regulation of NogoA, MAG, OMgp, and Lingo-1, which was especially significant at the chronic phase of epilepsy. The cognitive function, convulsion susceptibility and hippocampal neuronal survival of rats were impaired at the chronic phase of epileptogenesis but all improved by Lingo-1 inhibition; besides, the hippocampal protein expressions of p-RhoA and MBP were significantly decreased at the chronic phase of SC rats but increased after Lingo-1 inhibition. Our results demonstrated that Lingo-1 shRNA can improve epilepsy-induced cognitive impairment, which may be related with the pro-myelination and neuroprotection effects of Lingo-1 inhibition.

CB2 receptors modulate seizure-induced expression of pro-inflammatory cytokines in the hippocampus but not neocortex

We compared neuroinflammatory responses induced by nonconvulsive and convulsive seizures and analyzed the role that may be played by cannabinoid CB2 receptors in the neuroinflammatory response induced by generalized tonic-clonic seizures (GTCS). Using quantitative PCR, we analyzed expression of interleukin-1b, CCL2, interleukin-6, tumor necrosis factor (TNF), transforming growth factor beta 1 (TGFb1), fractalkine, and cannabinoid receptor type 2 in the neocortex, dorsal and ventral hippocampus, cortical leptomeninges, dura mater, and spleen in 3 and 6 h after induction of GTCS by a high dose of pentylenetetrazole (PTZ, 70 mg/kg) and absence-like activity by a low dose of PTZ (30 mg/kg). The low dose of PTZ had no effect on the gene expression 3 and 6 h after PTZ injection. In 3 and 6 h after high PTZ dose, the expression of CCL2 and TNF increased in the neocortex. Both ventral and dorsal parts of the hippocampus responded to seizures by elevation of CCL2 expression 3 h after PTZ. Cortical leptomeninges but not dura mater also had elevated CCL2 level and decreased TGFb1 expression 3 h after GTCS. Activation of CB2 receptors by HU308 suppressed an inflammatory response only in the dorsal hippocampus but not neocortex. Suppression of CB2 receptors by AM630 potentiated expression of inflammatory cytokines also in the hippocampus but not in the neocortex. Thus, we showed that GTCS, but not the absence-like activity, provoke inflammatory response in the neocortex, dorsal and ventral hippocampus, and cortical leptomeninges. Modulation of CB2 receptors changes seizure-induced neuroinflammation only in the hippocampus but not neocortex.

Celecoxib Decrease Seizures Susceptibility in a Rat Model of Inflammation by Inhibiting HMGB1 Translocation

The risk of developing epilepsy is strongly linked to peripheral inflammatory disorders in humans. High-mobility group box protein 1 (HMGB1) has the most focus for being a suspect in this scenario. The current study aimed to detect the celecoxib effect, an anti-inflammatory drug, on decreasing seizure susceptibility and organ damage in lipopolysaccharides (LPS)/pilocarpine (PILO) pretreated Wistar rats. Rats were divided into 6 groups (8 each): group 1 (control), group 2 (PILO), group 3 (PILO+LPS), group 4 (PILO+LPS+(VPA) Valproic acid), group 5 (PILO+LPS+Celecoxib), and group 6 (PILO+LPS+VPA+Celecoxib). LPS was used to induce sepsis and PILO to induce seizures. Oxidative stress markers, pro-inflammatory cytokines, and HMGB1 levels in serum and brain homogenate were evaluated. Histopathological studies were conducted on the hippocampus, liver, lung, and kidney. Treatment with celecoxib either alone or in combination with VPA significantly reduced Racine score and delays latency to generalized tonic-clonic seizures onset with a significant decrease in hippocampal levels of pro-inflammatory cytokines, oxidative stress markers, and increase in reduced glutathione. In addition, celecoxib treatment either alone or in combination with VPA suppressed HMGB1translocation into peripheral circulation more than treatment with VPA alone. Furthermore, hippocampus, liver, lung, and kidney histopathological changes were improved in contrast to other epileptic groups. Celecoxib either alone or combined with VPA has antiepileptic and multiorgan protective effects on acute seizures and inflammatory models induced by PILO with LPS. It decreased histopathological findings, oxidative, and inflammatory effects induced by VPA and LPS. This might be due to its anti-oxidative, anti-inflammatory and anti-HMGB1 mediated effects.

Perillyl alcohol decreases the frequency and severity of convulsive-like behavior in the adult zebrafish model of acute seizures

This research aimed to assess the effect of perillyl alcohol (PA) on convulsive behavior in vivo using adult zebrafish (Danio rerio, both sexes). The seizures were induced with pentylenetetrazole (PTZ) intraperitoneally at 170 mg/kg, and diazepam (DZP) was used as the control anticonvulsant (2 mg/kg, oral); PA was tested at 10, 50, and 100 mg/kg orally. The groups had ten animals per group (total n = 60), observed for 10 minutes after seizure induction. We manually appraised typical seizure phenotypes for quantification and used an animal tracking software (Toxtrac) to assess the motor parameters. Next, we sought to find a mechanism of action for PA anticonvulsant activity in silico using a structure-based activity prediction server and molecular docking. The results show that PTZ induced seizure-like behavior in all untreated animals with hyperlocomotion episodes, seizure itself, posture loss, and immobility. DZP inhibited the seizures in all animals of the positive control group. PA, in turn, inhibited the occurrence of seizures in a dose-dependent manner, with frequencies of 90%, 70%, and 40% (for 10, 50, and 100 mg/kg, respectively). The PA treatments also decreased several seizure endpoints in a dose-dependent manner. Also, the difference of the group treated with highest dose of PA was statistically significant compared with the negative control group for all the endpoints assessed (p < 0.05, Kruskal-Wallis). The in silico analyses suggested that PA can affect the GABAergic system, which might be involved in its anticonvulsant activity, but other mechanisms cannot be ruled out. Overall, our results suggest an anticonvulsant potential in perillyl alcohol.

Effects of prednisolone on behavioral and inflammatory profile in animal model of PTZ-induced seizure

Epilepsy is a chronic neurological condition that affects 1%-2% of the world population. Although research about the disease is advancing and a wide variety of drugs is available, about 30 % of patients have refractory epilepsy which cannot be controlled with the most common drugs. This highlights the need for a better understanding of the disorder and new types of treatment for it. Against this backdrop, a growing body of evidence has reported that inflammation may play a role both in the origin and in the progression of seizures. It has shown a tendency to be both the root and the result of epilepsy. This investigation aimed to assess the impact of prednisolone, a steroidal anti-inflammatory drug, in an animal model of pentylenetetrazole (PTZ)-induced seizures, at 1 mg/kg and 5 mg/kg doses. We also examined the degree of seizure severity and the modulation of pro-inflammatory cytokines in the treated animals. Four treatment groups were used (saline, diazepam, prednisolone 1 mg/kg, and prednisolone 5 mg/kg) and, in addition to their own daily treatments, subconvulsant doses of pentylenetetrazole (25 mg/kg) were administered every other day during a test protocol that lasted 14 days. After treatment, the cytokines interleukin 1 beta (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) were measured in the animals' sera, hippocampi, and prefrontal cortices. Animals treated with prednisolone presented less severe seizures than the animals in the saline group, and there was a decrease in pro-inflammatory cytokine levels in central structures, but not peripheral ones. In short, an animal model of chemically-induced epileptic seizures was used, in which the animals were treated with doses of prednisolone, and these animals presented less severe seizures than the negative control group (saline), in addition to showing decreased levels of pro-inflammatory cytokines IL-6, IL-1β and TNF-α, in the hippocampi and prefrontal cortices, but not the sera.

Magnolia officinalis Reduces Inflammation and Damage Induced by Recurrent Status Epilepticus in Immature Rats

BACKGROUND

Neuroinflammation induced in response to damage caused by status epilepticus (SE) activates the interleukin (IL)1-β pathway and proinflammatory proteins that increase vulnerability to the development of spontaneous seizure activity and/or epilepsy.

OBJECTIVES

The study aimed to assess the short-term anti-inflammatory and neuroprotective effects of Magnolia officinalis (MO) on recurrent SE in immature rats.

METHODS

Sprague-Dawley rats at PN day 10 were used; n = 60 rats were divided into two control groups, SHAM and KA, and two experimental groups, MO (KA-MO) and Celecoxib (KA-Clbx). The anti-inflammatory effect of a single dose of MO was evaluated at 6 and 24 hr by Western blotting and on day 30 PN via a subchronic administration of MO to assess neuronal preservation and hippocampal gliosis by immunohistochemistry for NeunN and GFAP, respectively.

RESULTS

KA-MO caused a decrease in the expression of IL1-β and Cox-2 at 6 and 24 h post-treatment, a reduction in iNOS synthase at 6 and 24 hr post-treatment and reduced neuronal loss and gliosis at postnatal day 30, similar to Clbx.

CONCLUSION

The results indicating that Magnolia officinalis is an alternative preventive treatment for early stages of epileptogenesis are encouraging.

Neuroinflammation impact in epileptogenesis and new treatment strategy

Epilepsy is considered a major serious chronic neurological disorder, characterized by recurrent seizures. It is usually associated with a history of a lesion in the nervous system. Irregular activation of inflammatory molecules in the injured tissue is an important factor in the development of epilepsy. It is unclear how the imbalanced regulation of inflammatory mediators contributes to epilepsy. A recent research goal is to identify interconnected inflammation pathways which may be involved in the development of epilepsy. The clinical use of available antiepileptic drugs is often restricted by their limitations, incidence of several side effects, and drug interactions. So development of new drugs, which modulate epilepsy through novel mechanisms, is necessary. Alternative therapies and diet have recently reported positive treatment outcomes in epilepsy. Vitamin D (Vit D) has shown prophylactic and therapeutic potential in different neurological disorders. So, the aim of current study was to review the associations between different brain inflammatory mediators and epileptogenesis, to strengthen the idea that targeting inflammatory pathway may be an effective therapeutic strategy to prevent or treat epilepsy. In addition, neuroprotective effects and mechanisms of Vit D in clinical and preclinical studies of epilepsy were reviewed.

Montelukast ameliorates Concanavalin A-induced autoimmune hepatitis in mice via inhibiting TNF-α/JNK signaling pathway

BACKGROUND

Concanavalin A (ConA) is a well-established model to induce autoimmune hepatitis (AIH) in mice which mimics pathological alterations that occur in human. The pathogenesis of ConA-induced AIH involves many signaling pathways. Montelukast is a leukotriene receptor antagonist that is mainly used in the management of asthma. The antioxidant, anti-inflammatory and anti-apoptotic effects of montelukast have been reported in previous studies. Lately, montelukast has been documented to confer protection against various inflammatory diseases. Up to date, no study has explored the effect of montelukast on AIH induced by ConA.

AIM AND METHOD

This study aims to detect the protective effects of montelukast (10 mg/kg) on ConA (20 mg/kg)- induced AIH in mice and to demonstrate its hepatoprotective mechanisms. Hepatic function, histological changes, oxidative stress, inflammation, autophagy, and apoptotic markers were investigated.

RESULTS

Hepatic function and histological data revealed that treatment with montelukast significantly attenuated ConA-induced hepatic damage. Montelukast significantly reduced JNK level and NFκB p65 expression, and inhibited proinflammatory cytokines (TNF-α and IL-6) as well as oxidative stress (MDA, NO, and GSH). Moreover, inflammatory cells (CD4+ infiltration and the levels of apoptotic markers (Bax and caspase-3) besides autophagy biomarkers (Beclin1 and LC3) were reduced.

CONCLUSION

Our results suggest that montelukast could be a potential therapeutic drug against the ConA-induced AIH through its anti-oxidant, anti-inflammatory, anti- autophagy as well as anti-apoptotic properties.

Effects of Dexamethasone on Remodeling of the Hippocampal Synaptic Filamentous Actin Cytoskeleton in a Model of Pilocarpine-induced Status Epilepticus

The filamentous actin (F-actin) cytoskeleton is progressively damaged after status epilepticus (SE), which is related to delayed neuronal death, aberrant recurrent circuits and epileptogenesis. Glucocorticoids regulate dendritic spine remodeling by acting on glucocorticoid receptors and the dynamics of the F-actin cytoskeleton. Our previous study showed that administration of dexamethasone (DEX) in the latent period of the pilocarpine epileptic model reduces damage to the hippocampal filamentous actin cytoskeleton and the loss of hippocampal neurons and aids in maintaining the synaptic structures, but it is not sufficient to stop epileptogenesis. In this work, we focused on the role of glucocorticoids in regulating the hippocampal F-actin cytoskeleton during SE. We examined the abundance of synaptic F-actin, analyzed the hippocampal F-actin/G-actin (F/G) ratio and pCofilin, and evaluated the number of hippocampal neurons and pre/postsynaptic markers in pilocarpine-induced status epilepticus mice with or without administration of dexamethasone (DEX). We found that the latency of Stage 3 seizures increased, the mortality decreased, the damage to the synaptic F-actin cytoskeleton in the hippocampal subfields was significantly attenuated, and a greater number of postsynaptic structures were retained in the hippocampal subfields after treatment with DEX. These results indicate that treatment with dexamethasone stabilizes the synaptic F-actin cytoskeleton and reduces the damage to the brain due to SE. This approach is expected to be beneficial in alleviating delayed neuron damage and the process of epileptogenesis.

Dexamethasone ameliorates the damage of hippocampal filamentous actin cytoskeleton but is not sufficient to cease epileptogenesis in pilocarpine induced epileptic mice

Rogressive deconstruction of filament actin (F-actin) in hippocampal neurons in the epileptic brain have been associated with epileptogenesis. Previous clinical studies suggest that glucocorticoids treatment plays beneficial roles in refractory epilepsy. Glucocorticoids treatment affects dendritic spine morphology by regulating local glucocorticoid receptors and F-actin cytoskeleton dynamics. However, how glucocorticoids regulate epileptogenesis by controlling F-actin cytoskeleton is not clear yet. Here we study the function of glucocorticoids in epileptogenesis by examining F-actin abundance, hippocampal neuron number, and synaptic markers in pilocarpine-induced epileptic mice in the presence or absence of dexamethasone (DEX) treatment. We found that spontaneous seizure duration was significantly reduced; F-actin damage in hippocampal subfields was remarkably attenuated; loss of pyramidal cells was dramatically decreased; more intact synaptic structures indicated by pre- and postsynaptic markers were preserved in multiple hippocampal regions after DEX treatment. However, the number of ZNT3 positive particles in the molecular layer in the hippocampus of pilocarpine epileptic mice was not altered after DEX treatment. Although not sufficient to cease epileptogenesis, our results suggest that dexamethasone treatment ameliorates the damage of epileptic brain by stabilizing F-actin cytoskeleton in the pilocarpine epileptic mice.

Embelin Prevents Seizure and Associated Cognitive Impairments in a Pentylenetetrazole-Induced Kindling Zebrafish Model

Epilepsy is a neuronal disorder associated with several neurological and behavioral alterations characterized by recurrent spontaneous epileptic seizures. Despite having more than 20 anti-epileptic drugs (AEDs), they only provide a symptomatic treatment. As well as, currently available AEDs also displayed cognitive alterations in addition to retarding seizure. This leads to the need for exploring new molecules that not only retard seizure but also improve cognitive impairment. Embelin (EMB) is a benzoquinone derivative which has already demonstrated its pharmacological potentials against arrays of neurological conditions. The current study developed a chronic kindling model in adult zebrafish by using repeated administration of small doses of pentylenetetrazole (PTZ) and a single dose of Kainic acid (KA) to investigate the associated memory impairment. This has been done by using the three-axis maze which is a conventional method to test the learning ability and egocentric memory in zebrafish. As well as, the ameliorative potential of EMB has been evaluated against chronic epilepsy-related memory alterations. Moreover the expression level of pro-inflammatory genes such as C-C motif ligand 2 (CCL2), toll-like receptor-4 (TLR4), tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1) and interferon-γ (IFN-γ) were evaluated. The level of several neurotransmitters such as γ-aminobutyric acid (GABA), acetylcholine (Ach) and glutamate (Glu) was evaluated by liquid chromatography-mass spectrometry (LC-MS). The results showed that daily dose of PTZ 80 mg/kg for 10 days successfully induces a kindling effect in zebrafish, whereas the single dose of KA did not. As compared to control, the PTZ and KA group demonstrates impairment in memory as demonstrated by the three-axis maze. The PTZ group treated with a series of EMB doses (ranging from 0.156 to 0.625 mg/kg) was found to have retarded seizure as well as significantly reduces epilepsy-induced memory alteration. In addition, EMB treatment reduces the expression of inflammatory markers implicating its anti-inflammatory potential. Moreover, levels of GABA, Ach, and glutamate are increased in EMB administered group as compared to the PTZ administered group. Overall, findings demonstrate that EMB might be a potential candidate against chronic epilepsy-related cognitive dysfunction as EMB prevents the seizures, so we expect it to prevent the associated neuroinflammation and learning deficit.

Magnolia officinalis reduces the long-term effects of the status epilepticus induced by kainic acid in immature rats

During critical periods of neurodevelopment, the immature brain is susceptible to neuronal hyperexcitability, alterations such as hyperthermia, hypoxia, brain trauma or a preexisting neuroinflammatory condition can trigger, promote and prolong epileptiform activity and facilitate the development of epilepsy. The goal of the present study was to evaluate the long-term neuroprotective effects Magnolia officinalis extract, on a model of recurrent status epilepticus (SE) in immature rats. Sprague-Dawley rats were treated with kainic acid (KA) (3 mg/kg, dissolved in saline solution) beginning at day 10 P N every 24 h for five days (10 P N-14PN). Two experimental groups (KA) received two treatments for 10 days (14-24 P N): one group was treated with 300 mg/kg Magnolia Officinalis (MO) (KA-MO), and another was treated with 20 mg/kg of celecoxib (Clbx) (KA-Clbx) as a control drug. A SHAM control group at day 90 P N was established. Seizure susceptibility was analyzed through an after-discharge threshold (ADT) evaluation, and electroencephalographic activity was recorded. The results obtained from the ADT evaluation and the analysis of the electroencephalographic activity under basal conditions showed that the MO and Clbx treatments protected against epileptiform activity, and decreases long-term excitability. All rats in the KA-MO and KA-Clbx groups presented a phase I seizure on the Racine scale, corresponding to the shaking of a wet dog. In contrast, the KA group showed phase V convulsive activity on the Racine scale. Similarly, MO and Clbx exerted neuroprotective effects on hippocampal neurons and reduced gliosis in the same areas. Based on these results, early intervention with MO and Clbx treatments to prevent the inflammatory activity derived from SE in early phases of neurodevelopment exerts neuroprotective effects on epileptogenesis in adult stages.

Effect of dexamethasone on seizures and inflammatory profile induced by Kindling Seizure Model

The objective of this study was to evaluate the effect of dexamethasone, on the severity of seizures and levels of pro-inflammatory interleukins in animals with kindling model induced by pentylenetetrazole (20 mg/kg) in alternated days for 15 days of treatment. The animals were divided into five groups: control group given saline, a group treated with diazepam (2 mg/kg) and groups treated with dexamethasone (1, 2 and 4 mg/kg). Open field test was conducted. The treatment with dexamethasone decreased the severity of seizures, also decreased TNF-alpha and Interleukin 1 beta levels in the hippocampus and TNF-alpha level in the serum.

Effect of dexmedetomidine on rats with convulsive status epilepticus and association with activation of cholinergic anti-inflammatory pathway

Convulsive status epilepticus (CSE) is a neurological disease with contraction and extension of limbs, leading to damage of hippocampus and cognition. This study aimed to explore the effects of dexmedetomidine (DEX) on the cognitive function and neuroinflammation in CSE rats. All rats were divided into control group, CSE group and DEX group. Morris water maze test was used to measure cognitive function. Acute hippocampal slices were made to detect long-term potentiation (LTP). Immunohistochemistry was used to determine the expression of α7-nicotinic acetylcholine receptor (α7-nAChR) and interleukin-1β (IL-1β). Enzyme-linked immunosorbent assay (ELISA) was used to measure serum levels of IL-1β, tumor necrosis factor-α (TNF-α), S-100β and brain-derived neurotrophic factor (BDNF). Our results showed that DEX improved the memory damage caused by CSE. DEX reduced seizure severity and increased the amplitudes and sustainable time of LTP, and also inhibited the hippocampal expression of α7-nAChR and IL-1β in CSE rats. DEX treatment decreased serum IL-1β, TNF-α and S-100β levels and increased BDNF levels. The effects of DEX on seizure severity and LTP could be simulated by nicotine or attenuated by concurrent α-bungarotoxin (α-BGT) treatment. In conclusions, DEX significantly improved spatial cognitive dysfunction, reduced seizure severity and increased LTP in CSE rats. Improvements by DEX were closely related to enhancement of cholinergic anti-inflammatory pathway.

Anticonvulsant Effect of Swertiamarin Against Pilocarpine-Induced Seizures in Adult Male Mice

Epilepsy is one of the common and major neurological disorders, approximately a third of the individuals with epilepsy suffer from seizures and not able to successfully respond to available medications. Current study was designed to investigate whether Swertiamarin (Swe) had anticonvulsant activity in the pilocarpine (PILO)-treated mice. Thirty minutes prior to the PILO (280 mg/kg) injection, the mice were administrated with Swe (50, 150, and 450 mg/kg) and valproate sodium (VPA, 200 mg/kg) once. Seizures and electroencephalography (EEG) were observed, and then the mice were killed for Nissl, Fluoro-jade B (FJB) staining. Astrocytic activation was examined in the hippocampus. Western blot analysis was used to examine the expressions of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10). The results indicated that pretreatment with Swe (150, 450 mg/kg) and VPA (200 mg/kg) significantly delayed the onset of the first convulsion and reduced the incidence of status epilepticus and mortality. Analysis of EEG recordings demonstrated that Swe (150, 450 mg/kg) and VPA (200 mg/kg) sharply decreased epileptiform discharges. Furthermore, Nissl and FJB staining revealed that Swe (150, 450 mg/kg) and VPA (200 mg/kg) relieved the neuronal damage. Additionally, Swe (450 mg/kg) dramatically inhibited astrocytic activation. Western blot analysis showed that Swe (450 mg/kg) significantly decreased the expressions of IL-1β, IL-6, TNF-α and elevated the expression of IL-10. Taken together, these findings revealed that Swe exerted anticonvulsant effects on PILO-treated mice. Further studies are encouraged to investigate these beneficial effects of Swe as an adjuvant in epilepsy.