Administration Of Pentylenetetrazol Research Articles

Oral Administration of Probiotic Bifidobacterium breve Ameliorates Tonic-Clonic Seizure in a Pentylenetetrazole-Induced Kindling Mouse Model via Integrin-Linked Kinase Signaling.

Epilepsy is a chronic neurological disorder characterized by recurrent seizures that affects over 70 million people worldwide. Although many antiepileptic drugs that block seizures are available, they have little effect on preventing and curing epilepsy, and their side effects sometimes lead to serious morbidity. Therefore, prophylactic agents with anticonvulsant properties and no adverse effects need to be identified. Recent studies on probiotic administration have reported a variety of beneficial effects on the central nervous system via the microbiota-gut-brain axis. In this study, we investigated the effects of the oral administration of Bifidobacterium breve strain A1 [MCC1274] (B. breve A1) on tonic-clonic seizure in a pentylenetetrazole (PTZ)-induced kindling mouse (KD mouse) model. We found that the oral administration of B. breve A1 every other day for 15 days significantly reduced the seizure score, which gradually increased with repetitive injections of PTZ in KD mice. The administration of B. breve A1, but not saline, to KD mice significantly increased the level of Akt Ser473 phosphorylation (p-Akt) in the hippocampus; this increase was maintained for a minimum of 24 h after PTZ administration. Treatment of B. breve A1-administered KD mice with the selective inhibitor of integrin-linked kinase (ILK) Cpd22 significantly increased the seizure score and blocked the antiepileptic effect of B. breve A1. Moreover, Cpd22 blocked the B. breve A1-induced increase in hippocampal p-Akt levels. These results suggest that the ILK-induced phosphorylation of Akt Ser473 in the hippocampus might be involved in the antiepileptic effect of B. breve A1.

Disruption of adenosine metabolism increases risk of seizure-induced death despite decreased seizure severity.

Respiratory arrest plays an important role in sudden unexpected death in epilepsy (SUDEP). Adenosine is of interest in SUDEP pathophysiology due to its influence on seizures and breathing. The objective of this investigation was to examine the role of adenosine in seizure severity, seizure-induced respiratory disruption, and seizure-induced death using mouse models. Understanding adenosinergic contributions to seizure cessation and seizure-induced death may provide insights into how SUDEP can be prevented while avoiding increased seizure severity. Our approach was to examine: (1) seizure severity and seizure-induced death after 15 mA electroshock seizures and during repeated pentylenetetrazol (PTZ) administration in wild-type mice (Adk +/+) and transgenic mice with reduced adenosine metabolism (Adk +/-); (2) the postictal hypercapnic ventilatory response (HCVR) in wild-type mice (the postictal HCVR could not be examined in Adk +/- mice due to their high mortality rate); and (3) the effects of adenosinergic drugs on seizure severity and seizure-induced death following maximal electroshock (MES). Adk +/- mice were more vulnerable to seizure-induced death in the 15 mA electroshock and repeated PTZ models. Despite increased mortality, Adk +/- mice had comparable seizure severity in the PTZ model and reduced seizure severity in the 15 mA electroshock model. Breathing and HCVR were suppressed by 15 mA electroshock seizures in wild-type mice. Pharmacological inhibition of adenosine metabolism decreased MES seizure severity but did not increase mortality. A1 selective and nonselective adenosine receptor antagonists increased seizure-induced death following MES. Adenosine has opposing effects on seizure severity and seizure-induced death. On the one hand, our seizure severity data highlight the importance of adenosine in seizure suppression. On the other hand, our mortality data indicate that excessive extracellular adenosine signaling can increase the risk of seizure-induced respiratory arrest.

Brain connectivity analysis in preictal phases of seizure induced by pentylenetetrazol in rats

Abnormal patterns of brain connectivity characterize epilepsy. However, little is known about these patterns during the stages preceding a seizure induced by pentylenetetrazol (PTZ). To investigate brain connectivity in male Wistar rats during the preictal phase of PTZ-induced seizures (60 mg/kg), we recorded local field potentials in the primary motor (M1) cortex, the ventral anterior (VA) nucleus of the thalamus, the hippocampal CA1 area, and the dentate gyrus (DG) during the baseline period and after PTZ administration. While there were no changes in power density between the baseline and preictal periods, we observed an increase in directional functional connectivity in theta from the hippocampal formation to M1 and VA, as well as in middle gamma from DG to CA1 and from CA1 to M1, and also in slow gamma from M1 to CA1. These findings are supported by increased phase coherence between DG-M1 in theta and CA1-M1 in middle gamma, as well as enhanced phase-amplitude coupling of delta-middle gamma in M1 and delta-fast gamma in CA1. Interestingly, we also noted a slight decrease in phase synchrony between CA1 and VA in slow gamma. Together, these results demonstrate increased functional connectivity between brain regions during the PTZ-induced preictal period, with this increase being particularly driven by the hippocampal formation.

Additive Anticonvulsive Effects of Sumatriptan and Morphine on Pentylenetetrazole-Induced Clonic Seizures in Mice.

Sumatriptan protects the brain from damage and enhance the anti-seizure effect of morphine. There is evidence that nitric oxide (NO) may mediate these effects of both drugs. In the present study, we investigated the effects of sumatriptan (0.1-20 mg/kg, intraperitoneal [i.p.]) and morphine (0.1-20 mg/kg, i.p.) alone or in combination on seizure thresholds in an in vivo model of seizure in mice. Using various NO synthase inhibitors as well as the NO precursor, we assessed possible involvement of NO signaling in these effects. Clonic seizures were induced in male Naval Medical Research Institute mice by intravenous administration of pentylenetetrazol (PTZ). Acute sumatriptan administration exerted anti-convulsive effects at 0.5 (p<0.01) and 1 mg/kg (p<0.05), but pro-convulsive effects at 20 mg/kg (p<0.05). Morphine had anti-convulsive effects at 0.5 (p<0.05) and 1 mg/kg (p<0.001), but exerted pro-convulsive effect at 20 mg/kg (p<0.05). Combination treatment with sub-effective doses of sumatriptan (0.1 mg/kg) and morphine (0.1 mg/kg) significantly (p<0.05) exerted an anti-convulsive effect. Co-administration of the NO precursor L-arginine (60 mg/kg) with sub-effective doses of sumatriptan and morphine significantly (p<0.05) increased seizure threshold compared with sumatriptan alone, but not sumatriptan+morphine group. While concomitant administration of either the non-selective NO synthase (NOS) inhibitor L-NG-nitroarginine methyl ester (5 mg/kg) or the selective inducible NOS inhibitor aminoguanidine (50 mg/kg) with combined sub-effective doses of morphine and sumatriptan produced significant anticonvulsive effects, concomitant administration with the selective neuronal NOS inhibitor 7-nitroindazole (30 mg/kg) inhibited this effect. Our data suggest a possible role for the NO signaling in the anticonvulsive effects of combined sumatriptan and morphine on the PTZ-induced clonic seizures in mice.

Synthesis and Psychotropic Properties of Novel Condensed Triazines for Drug Discovery.

The exploration of heterocyclic compounds and their fused analogs, featuring key pharmacophore fragments like pyridine, thiophene, pyrimidine, and triazine rings, is pivotal in medicinal chemistry. These compounds possess a wide array of biological activities, making them an intriguing area of study. The quest for new neurotropic drugs among derivatives of these heterocycles with pharmacophore groups remains a significant research challenge. The aim of this research work was to develop a synthesis method for new heterocyclic compounds, evaluate their neurotropic and neuroprotective activities, study histological changes, and perform docking analysis. Classical organic synthesis methods were used in the creation of novel heterocyclic systems containing pharmacophore rings. To evaluate the neurotropic activity of these synthesized compounds, a range of biological assays were employed. Docking analysis was conducted using various software packages and methodologies. The neuroprotective activity of compound 13 was tested in seizures with and without pentylenetetrazole (PTZ) administration. Histopathological examinations were performed in different experimental groups in the hippocampus and the entorhinal cortex. As a result of chemical reactions, 16 new, tetra- and pentacyclic heterocyclic compounds were obtained. The biologically studied compounds exhibited protection against PTZ seizures as well as some psychotropic effects. The biological assays evidenced that 13 of the 16 studied compounds showed a high anticonvulsant activity by antagonism with PTZ. The toxicity of the compounds was low. According to the results of the study of psychotropic activity, it was found that the selected compounds have a sedative effect, except compound 13, which exhibited activating behavior and antianxiety effects (especially compound 13). The studied compounds exhibited antidepressant effects, especially compound 13, which is similar to diazepam. Histopathological examination showed that compound 13 produced moderate changes in the brain and exhibited neuroprotective effects in the entorhinal cortex against PTZ-induced damage, reducing gliosis and neuronal loss. Docking studies revealed that out of 16 compounds, 3 compounds bound to the γ-aminobutyric acid type A (GABAA) receptor. Thus, the selected compounds demonstrated anticonvulsant, sedative, and activating behavior, and at the same time exhibited antianxiety and antidepressant effects. Compound 13 bound to the GABAA receptor and exhibited antianxiety, antidepressant, and neuroprotective effects in the entorhinal cortex against PTZ-induced changes.

Scorpion venom heat-resistant synthesized peptide ameliorates epileptic seizures and imparts neuroprotection in rats mediated by NMDA receptors

Finding new and effective natural products for designing antiepileptic drugs is highly important in the scientific community. The scorpion venom heat-resistant peptide (SVHRP) was purified from Buthus martensii Karsch scorpion venom, and subsequent analysis of the amino acid sequence facilitated the synthesis of a peptide known as scorpion venom heat-resistant synthesis peptide (SVHRSP) using a technique for peptide synthesis. Previous studies have demonstrated that the SVHRSP can inhibit neuroinflammation and provide neuroprotection. This study aimed to investigate the antiepileptic effect of SVHRSP on both acute and chronic kindling seizure models by inducing seizures in male rats through intraperitoneal administration of pentylenetetrazole (PTZ). Additionally, an N-methyl-D-aspartate (NMDA)-induced neuronal injury model was used to observe the anti-excitotoxic effect of SVHRSP in vitro. Our findings showed that treatment with SVHRSP effectively alleviated seizure severity, prolonged latency, and attenuated neuronal loss and glial cell activation. It also demonstrated the prevention of alterations in the expression levels of NMDA receptor subunits and phosphorylated p38 MAPK protein, as well as an improvement in spatial reference memory impairment during Morris water maze (MWM) testing in PTZ-kindled rats. In vitro experiments further revealed that SVHRSP was capable of attenuating neuronal action potential firing, inhibiting NMDA receptor currents and intracellular calcium overload, and reducing neuronal injury. These results suggest that the antiepileptic and neuroprotective effects of SVHRSP may be mediated through the regulation of NMDA receptor function and expression. This study provides new insight into therapeutic strategies for epilepsy.

Antiseizure effects of Lilii Bulbus on pentylenetetrazol kindling-induced seizures in mice: Involvement of Reelin, Netrin-1, and semaphorin

Lilii Bulbus (Lilium lancifolium Thunberg) has a proneurogenic effect on the hippocampus. However, its effects on epilepsy and associated pathological features remain unknown. In this study, we investigated the antiseizure effects of a water extract of Lilii Bulbus (WELB) in mouse model of pentylenetetrazol (PTZ)-induced seizure. Mice were injected with PTZ once every 48 h until full kindling was achieved. WELB (100 and 500 mg/kg) was orally administered once daily before PTZ administration and during the kindling process. We found that WELB treatment protected against PTZ-induced low seizure thresholds and high seizure severity. Further, WELB-treated mice showed attenuated PTZ kindling-induced anxiety and memory impairment. Immunostaining and immunoblots showed that hyperactivation and ectopic migration of dentate granule cells (DGCs) were significantly reduced by WELB treatment in PTZ kindling-induced seizure mice. Staining for mossy fiber sprouting (MFS) using Timm staining and ZnT3 showed that WELB treatment significantly decreased PTZ kindling-induced MFS. Furthermore, the increased or decreased expression of proteins related to ectopic DGCs (Reelin and Dab-1), MFS (Netrin-1, Sema3A, and Sema3F), and their downstream effectors (ERK, AKT, and CREB) in the hippocampus of PTZ kindling mice was significantly restored by WELB treatment. Overall, our findings suggest that WELB is a potential antiseizure drug that acts by reducing ectopic DGCs and MFS and modulating epileptogenesis-related signaling in the hippocampus.

Anticonvulsant Effects and Histopathological Changes in the Hippocampus of Pentylenetetrazole (PTZ)-induced Epileptic Mice Model following Mentat Treatment

Abstract Background: Epilepsy is a neurological illness that disturbs the central nervous system and is characterized by regular convulsions. Over 70 million people worldwide are thought to have epilepsy, with the prevalence rate estimated to be around 1%. Aims: The objective of this study was to assess antiepileptic activities and histological changes after Mentat administration in the hippocampus of pentylenetetrazole (PTZ)-induced seizure mice. Materials and Methods: Twenty Swiss albino mice (18–28 g) were divided into four groups (n = 5) and were given the following intraperitoneally, 2 ml/kg distilled water and 50 mg/kg PTZ to Groups 1 and 2 animals, respectively. Groups 3 and 4 animals were given 200 mg/kg and 400 mg/kg of Mentat, respectively, 1 h before the administration of PTZ and were observed for 300 s. After the experiment, all surviving animals in the various groups were humanely sacrificed and the brains were harvested and preserved in 10% buffered formalin. The brain tissues were processed using routine histological procedures and stained with hematoxylin and eosin. Results: Results of this revealed that Mentat was able to delay the onset time of seizure and offered quantal protection to the animals. Mentat also showed a dose-dependent ameliorative effect against histological changes following PTZ administration in mice. Conclusion: Mentat attenuates PTZ-induced seizure in mice.

Anticonvulsant effect of glycitin in pentylenetetrazol induced male Wistar rat model by targeting oxidative stress and Nrf2/HO-1 signaling.

Epilepsy, characterized by recurrent seizures, poses a significant health challenge globally. Despite the availability of anti-seizure medications, their adverse effects and inadequate efficacy in controlling seizures propel the exploration of alternative therapeutic measures. In hypothesis, glycitin is a phytoestrogenic compound found in soybeans and due to its estrogenic properties may have anti-epileptic and neuroprotective effects. This study investigates the potential anti-epileptic properties of glycitin in the context of pentylenetetrazol (PTZ) induced seizures in male Wistar rats. The rats were pretreated with varying doses of glycitin (5, 10, and 20mg/kg) before PTZ (35mg/kg) administration, and assessments included behavioral observations and histological evaluation via hematoxylin and eosin (H&E) staining. Additionally, oxidative stress markers, such as malondialdehyde (MDA), glutathione peroxidase (GPx), and superoxide dismutase (SOD) levels, were quantified to examine glycitin's impact on oxidative stress. Molecular analysis was conducted to assess the activation of the Nuclear factor erythroid 2-related factor (Nrf2)/Heme oxygenase 1 (HO-1) signaling pathway. Results indicated that glycitin pretreatment effectively mitigated PTZ-induced convulsive behaviors, supported by histological findings from H&E staining. Furthermore, glycitin administration led to significant alterations in MDA, GPx, and SOD levels, suggestive of its ability to modulate oxidative stress. Notably, glycitin treatment induced activation of the Nrf2/HO-1 signaling pathway. These findings underscore the potential of glycitin as an anticonvulsant agent, elucidating its mechanism of action through histological protection, modulation of oxidative stress markers, and activation of the Nrf2/HO-1 signaling pathway.

Quercetin Exerts Anticonvulsant Effect through Mitigation of Neuroinflammatory Response in Pentylenetetrazole-induced Seizure in Mice.

Epilepsy is a chronic disease of the brain characterized by seizures. The currently available anticonvulsants only treat symptoms with serious adverse drug reactions. Therefore, there is need for new therapeutic intervention that will prevent epileptogenesis with greater therapeutic success. Quercetin (QT) is a flavonoid with known neuroprotective and anti-inflammatory properties. The study aimed to investigate its effects against pentylenetetrazole (PTZ)-induced seizures. Animals were divided into four groups (n = 10). Group 1(control) only received vehicle (10 mL/kg), group 2 received vehicle, groups 3 and 4 received QT 12.5 mg/kg and 25 mg/kg respectively. Sixty minutes after treatments, animals in groups 2 to 4 were injected with sub-convulsive dose of pentylenetetrazole (35 mg/kg, i.p.) on every alternate day (48±2h) for 21 days. The mice were observed for 30 minutes after each PTZ injection for seizure activity. Brain samples were collected for biochemical assays. Administration of PTZ caused significant increase in the intensity of seizures, neuronal degeneration and level of proinflammatory cytokines in animals compared to control. These behavioural alterations were attenuated significantly by QT (12.5 and 25 mg/kg). The PTZ-induced increase in IL-12, TNF-α and IFN-ɣ were significantly reduced by pre-treatment with the QT (12.5 and 25 mg/kg, p.o). Quercetin also reduced neuronal loss compared to control. Quercetin attenuates seizures in kindled mice and reduces neuroinflammation and neurodegeneration. This neuroprotective effect may be attributed to its ability to inhibit inflammatory mediators in the brain.

COMORBID DISORDERS OF THE SLEEP CYCLE – AWAKENESS IN KINDLING RATS UNDER THE CONDITIONS OF USING THE H₃ RECEPTOR ANTAGONIST PITOLISANT

Studies of the neuropathophysiological mechanisms of chronic epileptic activity, whicharise with the participation of the endogenous histaminergic system of the brain, allowus to justify effective complex means of controlling both convulsive manifestations andcomorbid states, which include sleep and wakefulness disorders.Aim of the work – to study the characteristics of the sleep-wake cycle in rats with PTZinduced kindling under the condition of using the H3 receptor antagonist pitolisant.Methods. The kindling syndrome was induced in Wistar rats by daily administration ofpentylenetetrazole (PTZ) (35.0 mg/kg, i. p.) for three weeks. In rats in the course of kindlingdevelopment, pitolisant (5,0 mg/kg, i. p.) was used for 30 min before epileptogen administration.Research results. In rats with developed kindling, the paradoxical sleep phase wasreduced to 7,1% of the total observation period (4 hours) and its fragmentation increased39,7% and the latent period of paradoxical sleep was 24,0% less compared to the controlgroup (P&lt;0,05). Pitolizant treatment was accompanied by an increase in the durationof the awake phase, which was 29% of the total observation time (P&gt;0,05). At the sametime, the duration of paradoxical sleep was 11,6% (P&gt;0,05), and the slow-wave sleepphase was 71,0% (P&gt;0,05). The number of sleep-wake cycles unreliably exceeded theindicator in the control group 17,2% (P&gt;0,05). Latent periods of falling asleep exceededthe indicator in the control group 44,1% (P&lt;0,05) and at the same time was higher thanin kindling rats 60,2% (P&lt;0,05). The latency period of paradoxical sleep was 34.2%higher than kindling rats (P&lt;0.05). &#x0D; Conclusions. The formation of PTZ-kindling is accompanied by a reduction in the latent period of emergence and the total duration of the paradoxical phase of sleep, as well as an increase in its fragmentation. Blocking of H3 histamine receptors by pitolisan during the formation of kindling by administration of pentylenetetrazol prevents the occurrence of wake-sleep cycle disorders.

Neuroprotective Effect of Chlorogenic Acid against Pentylenetetrazol Induced Kindled Epilepsy in Mice

Background: Epilepsy is a group of chronic neurological disorders characterized by seizures. Kindling, a chronic epileptic mouse model that was used to explore the epileptogenic mechanism and seeking new anti-epileptics. In kindling, sub-convulsive (chemical/ electrical) stimuli are delivered repeatedly and erratically, eventually causes massive convulsions. The aim of this study was to investigate the neuroprotective effects of chlorogenic acid, a phenolic acid derived from coffee, on seizure severity and kindling progression. Memory impairment inflammation due to oxidative stress by pentylenetetrazol (PTZ). Objective: This study was used to investigate the neuroprotective effect of chlorogenic acid against pentylenetetrazol induced kindled epilepsy in mice. Methods: Kindling was provoked by subsequent (one-day-gap) injections of PTZ (subconvulsive; 35 mg/kg; s.c.) for 29 days in mice. The experimental protocol included six groups (n=6) receiving proconvulsant doses of PTZ (35 mg/kg i.p.) every other day for 31 days. Alternating subcutaneous injections of PTZ induced priming with 15 injections of PTZ. Compared with the PTZ group, pre-treatment with chlorogenic acid (5 and 10 mg/kg) 1 h before PTZ administration reduced seizure score, reduced metastasis latency due to increased normal maze, and decreased metastasis latency extension at FST. PTZ-induced biochemical changes were enhanced in chlorogenic acid-treated animals, as indicated by decreased lipid peroxidation (MDA), nitric oxide and AChE levels, and increased SOD, GSH, catalase level. Following PTZ injection, convulsive behaviours were noted for 30 minutes. Open-field-test (locomotor activity), force swimming test (depressive behaviors), elevated plus-maze and passive avoidance tests were employed to evaluate cognition. Brain homogenate was used to estimate oxidative stress (glutathione,superoxide-dismutase, lipid-peroxidation), and acetylcholinesterase activity. Results: This result suggest the neuroprotective potential of chlorogenic acid. This may be correlated with its ability to inhibit oxidative damage and reduce the occurrence of seizures and other related damage. It may be a promising candidate for mitigating the consequences of events. Conclusion: Our findings suggest effect of chlorogenic acid against pentylenetetrazol-induced kindled epilepsy in mice which were established by behavioral and biochemical paradigms

(-)-α-bisabolol exerts neuroprotective effects against pentylenetetrazole-induced seizures in rats by targeting inflammation and oxidative stress

Epilepsy is the most common neurological disorder which is accompanied with behavioral and psychiatric alternations. Current evidences have shown that (-)-α-bisabolol (BSB) possess anti-inflammatory and antioxidative effects in several animal studies. Here, we conducted present study to evaluate its neuroprotective effects against pentylenetetrazole (PTZ)-induced seizures in rats. We used fifty male rats and they were randomly assigned into 5 groups control, BSB100, PTZ, BSB50 + PTZ, BSB100 + PTZ. The animals intraperitoneally received PTZ (45 mg/kg) for ten consecutive days to induce epilepsy model. BSB in doses of 50 and 100 mg/kg was administrated orally one hour before PTZ administration for ten days. The elevated plus maze (EPM) test was carried out to assess anxiety-like behavior. The seizure intensity was evaluated according to modifies Racine's convulsion scale (RCS). Y-maze and passive avoidance were utilized to assess working memory and aversive memory. The expression of pro-inflammatory cytokines and oxidative stress factors were measured using the enzyme-linked immunosorbent assay (ELISA). The neuronal cell loss in the hilar region was assessed using Nissl staining. Results showed that PTZ-treated rats had more seizure intensity, anxiety-like behavior, memory deficits, higher levels of TNF-α, IL-1β, and oxidative markers. Pre-treatment with BSB 100 significantly inhibited seizure intensity, anxiety-like behavior, and memory deficits; reduced levels of TNF-α, IL-1β, and MDA oxidative markers. Collectively, outcome of this work shows that BSB at the dose of 100 mg/kg may exert neuroprotective effects by mitigating seizures, oxidative stress, and neuroinflammation, and ameliorates memory and anxiety disorders in the PTZ-induced seizure rats.

Suppressive Effects of Docosahexaenoic Acid Intake on Increased Seizure Susceptibility after Growth Due to Febrile Seizures in Infancy.

Febrile seizures are seizures accompanied by a fever and frequently occur in children six months to five years of age. Febrile seizures are classified as simple or complex, and complex febrile seizures increase the risk of temporal lobe epilepsy after growth. Therefore, it is important to interfere with epileptogenesis after febrile seizures to prevent post-growth epilepsy. The present study challenged nutritional intervention using docosahexaenoic acid (DHA). Febrile seizures were induced in mice at the age of 10 d using a heat chamber, and seizure sensitivity was examined using pentylenetetrazol (PTZ) administration after growth. PTZ increased the seizure score and shortened the latency in the complex febrile seizure group compared to the control, hyperthermia and simple febrile seizure groups. Mice in the complex febrile seizure group showed abnormal electroencephalograms pre- and post-PTZ administration. Therefore, seizure susceptibility increases the episodes of complex febrile seizures. DHA supplementation after febrile seizures clearly suppressed the increased seizure susceptibility due to complex febrile seizures experienced in infancy. DHA also attenuated microglial activation after complex febrile seizures. Taken together, DHA suppressed microglial activation following complex febrile seizures, which may contribute to protecting the brain from post-growth seizures. The intake of DHA in infancy may protect children from high fever-induced developmental abnormalities.

Pentylenetetrazole Induced Kindling Model of Refractory Epilepsy: A Proof-of-concept Study to Explore Dose and Time Range of Phenobarbital in Rats.

Drug-resistant epilepsy is an unmet medical condition that impacts 30% of epileptic patients. Numerous antiseizure drugs have already been developed but they provide only symptomatic relief and do not target the underlying pathogenesis. Preclinical models provide opportunities to gain insights into obscure mechanisms of drug-resistant epilepsy. Current animal models possess lacunae that need rectification and validation to discover novel antiepileptic drugs. The present study aims to validate 3 different doses of phenobarbital at 2 different periods. Pentylenetetrazole was given at a sub-convulsive dose (30 mg/kg/day/intraperitoneal [IP]) for 28 days to develop kindling in male Wistar rats. Further, kindled rats were divided into the following four groups: Pentylenetetrazole control, pentylenetetrazole and phenobarbital (20 mg/kg), pentylenetetrazole and phenobarbital 40 mg/kg, and pentylenetetrazole and phenobarbital (60 mg/kg). They were assessed on days 14 and 28 post-kindling. Seizure scoring, oxidative stress, phenobarbital plasma levels, and histopathology of hippocampal neurons were analyzed. The results showed that the combination of pentylenetetrazole and phenobarbital (40 and 60 mg/kg) remarkably decreased seizure score, elucidated higher antioxidant effect, and prevented neuronal injury on day 14, whereas increased seizure score, oxidative stress, and neuronal death was observed with chronic administration of pentylenetetrazole and phenobarbital in kindled rats at day 28. Moreover, phenobarbital levels in blood were significantly increased at day 28 of phenobarbital treatment compared to day 14. The adapted protocol with phenobarbital 40 mg/kg dose could be of great potential in screening antiseizure drugs in refractory epilepsy.

Evaluation of the anticonvulsant activity of ethanol leaf extract of Panicum maximum in pentylenetetrazole and strychnine induced seizure in mice.

Epilepsy is a chronic neurological condition affecting around 50 million people worldwide. This study evaluated the anticonvulsant effect of Panicium maxmium in pentylenetetrazole (PTZ) and strychnine (STN) induced convulsions in mice. For each model, 25 mice were divided into five groups; group 1 received 10 ml/kg distilled water, groups 2-4 received 100 mg/kg, 200 mg/kg and 400 mg/kg of extract p.o respectively. Group 5 received 3 mg/kg of diazepam p.o. Convulsion was induced intraperitoneally using PTZ and STN, thirty minutes after the extract was administered. The onset of myoclonic, tonic-clonic seizure, time of death within 60 minutes of PTZ and STN administration were monitored. Data were statistically analyzed using one-way ANOVA followed by Dunnet’s comparison tests. In STN-induced seizure model, 100 mg/kg of P. maximum exhibited a significant (p &lt; 0.001) anticonvulsant activity by delaying myoclonic seizure onset in mice when compared to the control. Significant (p &lt; 0.001) activity was also observed in the onset of tonic clonic seizure at same dose when compared to control. In PTZ-induced seizure model, 200 mg/kg exhibited more significant (p &lt; 0.001) activity followed by 100 mg/kg (p &lt; 0.05) by delaying myoclonic seizure onset in mice when compared to the control. Significant (p &lt; 0.001) activity were observed in tonic clonic phase at same doses respectively. The different doses administered couldn’t protect the mice from death. Diazepam, standard drug used, protected all the animals without any signs of convulsions. The results provide evidence that the extract possesses anticonvulsant activity.

Parvalbumin neurons in the anterior nucleus of thalamus control absence seizures.

Anterior nucleus of thalamus (ANT) has been widely accepted as a potential therapeutic target for drug-resistant epilepsy. Although atrophy of the ANT was also reported in patients with absence epilepsy, the relationship between the ANT and absence epilepsy has been barely illustrated. Using chemogenetics, we evaluated the effect of ANT parvalbumin (PV) neurons on pentylenetetrazole (PTZ)-induced absence seizures in mice. We found that intraperitoneal injection of PTZ (30 mg/kg) can stably induce absence-like seizures characterized by bilaterally synchronous spike-wave discharges (SWDs). Selective activation of PV neurons in the ANT by chemogenetics could aggravate the severity of absence seizures, whereas selective inhibition of that cannot reverse this condition and even promote absence seizures as well. Moreover, chemogenetic inhibition of ANT PV neurons without administration of PTZ was also sufficient to generate SWDs. Analysis of background EEG showed that chemogenetic activation or inhibition of ANT PV neurons could both significantly increase the EEG power of delta oscillation in the frontal cortex, which might mediate the pro-seizure effect of ANT PV neurons. Our findings indicated that either activation or inhibition of ANT PV neurons might disturb the intrinsic delta rhythms in the cortex and worsen absence seizures, which highlighted the importance of maintaining the activity of ANT PV neurons in absence seizure.

Neuroprotective effect of Berberine Nanoparticles Against Seizures in Pentylenetetrazole Induced Kindling Model of Epileptogenesis: Role of Anti-Oxidative, Anti-Inflammatory, and Anti-Apoptotic Mechanisms.

There is an unmet need to develop alternative therapeutic strategies to not only restrain seizures but also to alleviate the underlying pathologies and sequelae. Berberine (BBR), an isoquinoline alkaloid, has shown promising effect in the kindling model of epileptogenesis, but due to the poor oral bioavailability its clinical application is limited. So, the present study was designed to study the neuroprotective effect of BBR nanoparticles (enhanced bioavailability as compared to BBR) against seizures in pentylenetetrazole (PTZ) induced kindling model of epileptogenesis. Kindling model was established in male Wistar rats by intraperitoneal (i.p.) administration of PTZ (30mg/kg) on every alternate day till the animal became fully kindled or till 6weeks. Three doses of BBR (50, 100, and 200mg/kg) and nano-BBR (25, 50, 100mg/kg) were studied for seizure score, percentage of animal kindled, histopathological score, oxidative stress, inflammation, and apoptosis in PTZ treated rats by conducting cytokines, gene expression and protein expression analysis. BBR nanoparticles showed significant effect on the seizure score and percentage of animal kindled, histopathological score, neurobehavioral parameters (Forced swim test, Rotarod), oxidative (MDA, SOD, GSH, GPx) and inflammatory (IL-1beta, TNF-alpha) parameters, apoptotic parameters (Bax and iNOS), and gene (Nrf2, NQO1, HO1) and protein expression (Nrf2) as compared to both PTZ and BBR. BBR nanoparticles showed neuroprotective effect in PTZ induced kindling model of epileptogenesis and proves to be a promising antiepileptogenic therapy for the patients who are at high risk of developing 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 (40mg/kg, i.p) every other day and mice were observed for 20min 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.

Tauroursodeoxycholic Acid (TUDCA) Regulates Inflammation and Hypoxia in Autonomic Tissues of Rats with Seizures.

Inflammation and hypoxia have an effect on the molecular mechanism of cardiovascular and respiratory pathologies accompanying seizures. Against this, Tauroursodeoxycholic Acid (TUDCA) can regulate oxidative stress, inflammation and cellular survival by suppressing endoplasmic reticulum (ER) stress. We evaluated the expression changes of NF-κB p65, TNF-α, HIF1α and Kir6.2 proteins associated with seizures in brain stem, heart and lung tissues representing the autonomous network. Additionally, we examined the protective effects of TUDCA administration against damage caused by seizures in terms of immunohistochemistry and pathology. 4 groups of Wistar Albino male rats (250-300 g, n=32) were formed as control, pentylenetetrazole (PTZ), TUDCA and PTZ+TUDCA. The epilepsy kindling model was created by intraperitoneal (i.p.) injection of PTZ chemical (35 mg/kg, every 2 days) for one month. TUDCA (500 mg/kg; every 2 days) treatment was given intraperitoneally 30 minutes before seizures for 1 month. Brain stem, heart (atria, ventricle) and lung tissues of rats were isolated. NF-κB p65, TNF-α, HIF1α and Kir6.2 proteins in the obtained tissues were evaluated by immunohistochemical staining. The immunoreactivity of the investigated proteins in the brainstem heart and lung tissues of rats with chronic PTZ administration was significantly increased. Recurrent seizures led to accumulation of inflammatory cells in tissues, hemorrhage, vasodilation, and apoptosis. Following TUDCA administration, expression of NF-κB p65, TNF-α and Kir6.2 was significantly reduced in all tissues (except the atrium of the heart) compared to control rats. HIF-1α levels were significantly suppressed in ventricular and lung tissues of epileptic rats given TUDCA. However, TUDCA pretreatment improved histopathological changes due to chronic seizures and partially reduced apoptosis. We showed that epileptic seizures may cause tissue damage with the development of inflammatory and hypoxic conditions in the brainstem and organs that represent the autonomic network. TUDCA therapy could be an effective agent in the treatment of cardiac and respiratory problems associated with seizures.