Pentylenetetrazole-induced Seizures In Rats Research Articles

Lippia origanoides essential oil possesses anticonvulsant effect in pentylenetetrazol-induced seizures in rats: a behavioral, electroencephalographic, and electromyographic study

Epilepsy is a neuronal disorder characterized by abnormal excitability of the brain, leading to seizures. Only around 66% of the epileptic patients respond adequately to treatment with existing conventional anticonvulsants, making it necessary to investigate new antiepileptic drugs. The growing research into natural products and their pharmacological properties has become increasingly promising, particularly in the study of essential oils, which are already widely used in popular culture for treating various diseases. The present study evaluated the anticonvulsant effects of Lippia origanoides essential oil (LOEO) (100 mg/kg i. p.) compared to diazepam (DZP) (5 mg/kg i. p.), and the combined administration of these two substances to control convulsions induced by pentylenetetrazol (PTZ) (60 mg/kg i. p.). This evaluation was carried out using 108 male Wistar rats, which were divided into two experiments. Experiment 1–Behavioral assessment: The animals were divided into 4 groups (n = 9): (I) saline solution + PTZ, (II) DZP + PTZ, (III) LOEO + PTZ, (IV) LOEO + DZP + PTZ. The convulsive behavior was induced 30 min after the administration of the tested anticonvulsant drugs, and the observation period lasted 30 min. Experiment 2- Electrocorticographic evaluation: The animals were divided into 8 groups (n = 9): (I) saline solution; (II) LOEO; (III) DZP; (IV) LOEO + DZP; (V) saline + PTZ, (VI) DZP + PTZ (VII) LOEO + PTZ, (VIII) LOEO + DZP + PTZ. PTZ was administered 30 min after LOEO and DZP treatments and electrocorticographic activity was assessed for 15 min. For the control groups, electromyographic recordings were performed in the 10th intercostal space to assess respiratory rate. The results demonstrated that Lippia origanoides essential oil increased the latency time for the appearance of isolated clonic seizures without loss of the postural reflex. The animals had a more intense decrease in respiratory rate when combined with LOEO + DZP. EEG recordings showed a reduction in firing amplitude in the LOEO-treated groups. The combining treatment with diazepam resulted in increased anticonvulsant effects. Therefore, treatment with Lippia origanoides essential oil was effective in controlling seizures, and its combination with diazepam may represent a future option for the treatment of difficult-to-control seizures.

(-)-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.

The Role of Captopril on Pentylenetetrazole-Induced Seizures in Rats

ABSTRACT: 
 Purpose: In recent years, experimental studies have shown that some angiotensin-converting enzyme (ACE) inhibitors with antihypertensive effects have anticonvulsant effects against seizures. After the seizure, the process of inflammation begins in the brain and body, with the production of free radicals. Renin has some effects on the central nervous system of the angiotensin system. The current study's objective was to examine how captopril, an ACE inhibitor, affects neuroinflammation in the hippocampus and cortical areas in acute epileptic seizures and post-seizures induced by pentylenetetrazole (PTZ).
 Material and Methods: Eighteen Wistar Albino rats were separated into three groups: control, PTZ (serum physiologic 1 ml/kg as solvent), and captopril (50 mg/kg/day for 7days). To produce epileptic seizures, PTZ (45 mg/kg) was delivered thirty minutes after the drug was administered. The animals were monitored during 30 minutes to record seizures scoring scale and the onset time of first myoclonic jerk (FMJ). In the brain tissue, the activity of TNF- α, IL-1 β, NF-kB, COX-1, and COX-2 were examined.
 Results: Captopril increased FMJ onset time and reduced seizure stage as compared to the PTZ group (p

Beneficial effects of sennoside B on pentylenetetrazole-induced seizures in rats.

Epilepsy is a common disorder affecting approximately 50 million people worldwide. Oxidative stress is known to play an important role in the pathophysiology of diseases, including epilepsy. In this study, we investigated the effects of sennoside B on PTZ-induced seizures in rats. The rats were grouped into Group Electroencephalography and Group Behavioral. Both Groups were divided into eight subgroups, and these subgroups were compared in terms of the time of first myoclonic jerk, Racine's Convulsion Scale, malondialdehyde levels, and brain superoxide dismutase activity. The experimental seizure model was performed with pentylenetetrazol. The spike percentage was significantly lower in groups that received sennoside B, and this beneficial effect was shown to be associated with the dose of sennoside B received. The RCS score was lower and the FJM onset time was higher in the sennoside B-administered groups. Additionally, brain MDA and brain aquaporin-3 levels were lower and brain SOD activity was higher in the sennoside-administered groups. The present study shows the beneficial effects of sennoside B on PTZ-induced convulsion in rats. It is considered that sennoside B which is a natural and safe product would be a good candidate for strengthening the management of epilepsy without serious side effects.

Stem bark chloroform extract of Bombax costatum Pellegr. & Vuillet exhibit anticonvulsant and neuroprotective effects in pentylenetetrazole-induced seizures in rats

The study aimed at evaluating the potentials of stem bark extracts of Bombax costatum (B.costatum) on seizure, pentylenetetrazole (PTZ) induced kindling and associated changes in wistar albino rats. Phase 1 evaluated which extract of B.costatum (chloroform, ethanol and n-hexane) is most effective in preventing seizure in acute PTZ-induced (85mg/kg) seizure in rats. Phase 2 evaluated the potentials of stem bark chloroform extract of B.costatum in PTZ-kindled rats at a dose 250 and 500mg/kg in comparison to diazepam. As its effects on memory, oxidative stress markers, neurotransmitters and brain histology were evaluated. Phase 3 determined the probable curative effects of B.costatum on fully kindled rats. In phase 1, Chloroform extract of B.coststum 500mg/kg is the most effective (P<0.05) in preventing seizure as compared to ethanol and n-hexane extracts. In phase 2, chloroform extract of B.costatum delayed the development of kindling, improved kindling associated cognitive impairment and alterations of glutamate and gamma-aminobutyric acid (GABA). Further, it attenuated oxidative stress besides the maintenance of neuronal architecture of the hippocampus. Conclusively, chloroform stem bark extract of B.costatum antagonizes PTZ-induced seizure progression, protects against kindling induced cognitive impairment and oxidative stress. Additionally, it also increases the brain level of GABA at high dose and prevented against kindling-induced hippocampal disruptions. Hence, this justifies its use traditionally in the treatment of epileptic seizures.

Efficacy of hydroalcoholic Petroselinum crispum L. leaf extract on pentylenetetrazole-induced seizure in rats

Efficacy of hydroalcoholic Petroselinum crispum L. leaf extract on pentylenetetrazole-induced seizure in rats

Electrophysiological, histopathological, and biochemical evaluation of the protective effect of probiotic supplementation against pentylenetetrazole-induced seizures in rats.

Research on the relationship between the gut microbiome and epilepsy is accumulating. The present study was conducted to evaluate the effect of probiotic supplementation on pentylenetetrazole (PTZ)-induced seizures in rats. Twenty-one adult male Wistar albino rats were included. The animals were divided into three groups of seven rats. Group 1 was a control group, whereas Group 2 rats received PTZ treatment and Group 3 rats had PTZ+PB (probiotic) treatment. For 6weeks, Groups 1 and 2 were given saline (1ml), whereas Group 3had probiotic supplement. In the 5th week, tripolar electrodes were attached to the rats. Electrophysiological, behavioral, biochemical, and immunohistochemical evaluations were performed in the 6weeks after the treatment. PB treatment significantly reduced seizures. In the PTZ group, expression levels of brain-derived neurotrophic factor, nerve growth factor (NGF), and Sox2 (SRY sex-determining region Y-box 2) in rat brains decreased significantly compared to the control group, whereas the expression levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), total oxidant status (TOS), and nitric oxide (NO) levels increased. In the PTZ+PB group, NGF expression increased significantly compared to the PTZ group, whereas TNF-α, IL-6, TOS, and NO levels decreased. In histopathological examination, an abundance of necrotic neurons was notable in the PTZ group, which was less in the PTZ+PB group. In addition, body weight of the group supplemented with probiotics decreased after the treatment. Our results suggest that probiotic supplementation may alleviate seizure severity and exert neuroprotective effects by reducing neuroinflammation and oxidative stress and altering the expression of neurotrophins in epileptogenic brains.

The effect of a novel anticonvulsant chemical Q808 on gut microbiota and hippocampus neurotransmitters in pentylenetetrazole-induced seizures in rats

BackgroundThe gut microbiota can modulate brain function and behavior and is increasingly recognized as an important factor in mediating the risk of epilepsy and the effects of seizure interventions. Drug therapy is one of the factors that influence the composition of the intestinal microbiota. Q808 is an innovative chemical with strong anticonvulsant activity and low neurotoxicity. However, studies evaluating the effect of Q808 on gut microbial communities are lacking. In this study, we aimed to evaluate the anticonvulsant activity of Q808 on a pentylenetetrazol (PTZ)—induced seizure model and analyze and compare the intestinal microbiota composition of non-PTZ vehicle control group, the PTZ-induced seizure model rats with and without Q808, through 16S rDNA sequencing. Neurotransmitter levels in the hippocampus were quantitatively estimated using HPLC–MS.ResultsThe results suggest that Q808 effectively alleviates seizures in chronic PTZ-kindled model rats. Additionally, based on the analyzed abundance of the gut microbiota, dysbacteriosis of model rats was found to be corrected after Q808 treatment at the phylum level. The unique bacterial taxa (e.g., Lactobacillus) that are associated with acetylcholine production, were significantly increased. Several short-chain fatty acids (SCFAs)-producing bacteria, including Roseburia, Alloprevptella, Prevotellaceae_NK3B31_group, Prevotellaceae_UCG-001, and Prevotella_9, were enriched. In the hippocampus, the contents of acetylcholine increased, whereas the levels of 3-methoxytyramine, glutamine, and 5-hydroxyindole acetic acid (5-HIAA) decreased after Q808 treatment.ConclusionsThis study demonstrates that Q808 can be used to remodel the dysbiosis of the gut microbiome and influence neurotransmitter levels in the hippocampus of PTZ-induced seizure model rats. We hope that these novel findings prompt further research on the interaction between gut microbiota and seizures and the mechanism of Q808.

A hydrogen sulfide donor suppresses pentylenetetrazol-induced seizures in rats via PKC signaling

Epilepsy is a serious neurological disorder. Available antiepileptic drugs are still lacking. Hydrogen sulfide (H2S), a neuron-protective endogenous gasotransmitter, is reported to have effect on epilepsy. But it remains to be determined for its mechanism. In the present study, we found that a novel carbazole-based H2S donor could effectively suppress pentylenetetrazol-induced seizures in rats. The H2S donor could alleviate not only the epileptic behavior of animals but also the hippocampal EEG activity of seizures. The H2S donor down-regulated the expression of aquaporin 4 in the hippocampus of epilepsy rats. The H2S donor also decreased the seizure-induced release of inflammatory cytokines including IL-1β, IL-6 and TNF-α. In addition, the H2S donor increased protein kinase C (PKC) expression in the hippocampus of epilepsy rats. These effects of the H2S donor on epilepsy rats were attenuated after blockade of PKC signaling by Go6983, suggesting that PKC signaling participated in the antiepileptic process of H2S donor. Taken together, the H2S donor has a beneficial effect on epilepsy control in a PKC-dependent manner.

The effect of sulfasalazine in pentylenetetrazole-induced seizures in rats.

We aimed to reveal the anti-convulsant effects sulfasalazine and its mechanism in pentylenetetrazole (PTZ)-induced seizures in rats. Forty-eight male Wistar albino rats (200-250 g) were randomly divided into two groups: 24 for electroencephalography (EEG) recording (group A) and 24 for behavioral studies (group B). About 70 mg/kg PTZ was used for behavioral studies after sulfasalazine administration and 35 mg/kg PTZ was used for EEG recording after sulfasalazine administration. Electrodes were implanted on the dura mater over the left frontal cortex and the reference electrode was implanted over the cerebellum for EEG recording. Racine’s convulsion scale, first myoclonic jerk onset time, spike percentages, brain malondialdehyde (MDA), superoxide dismutase (SOD), and prostaglandin F2α (PGF2α) levels were evaluated between the groups. First myoclonic jerk onset time was significantly shorter in the saline group than both 250 and 500 mg/kg sulfasalazine groups (P<0.05). Racine's convulsion scores were significantly lower in the 250 and 500 mg/kg sulfasalazine groups than the saline group (P<0.05, P<0.001). The two sulfasalazine groups had lower spike percentages than the saline group (P<0.05). Significantly lower MDA and PGF2α levels were observed in the 250 and 500 mg/kg sulfasalazine groups compared with the saline group (P<0.05, P<0.001, respectively). SOD increased significantly in both sulfasalazine groups compared with the PTZ+saline group (P<0.05). Our study demonstrated that sulfasalazine had protective effects on PTZ-induced convulsions by protecting against oxidative and inflammatory damage associated with PTZ.

The effects of hydrogen sulfide, carbon monoxide and nitric oxide on pentylenetetrazole-induced seizures in rats

Objective: It is aimed to investigate the anti-convulsant effects of bioactive gas mediators hydrogen sulfide (H2S), carbon monoxide (CO) and nitric oxide (NO) in pentylenetetrazole-induced convulsions in rats. Material Methods: Eighty male Wistar-Albino rats randomly divided into ten groups. Convulsions was induced by administering 60 mg/kg pentylentetrazole intraperitonally. Diazepam, NaHS, CORM-2, L-arginine and L-NAME were administred 60 minutes after pentylentetrazole. Seizure latency, seizure duration and seizure score were evaluated. Data were analyzed by the Kruskal Wallis test followed by posthoc analyses with Tukey. P &amp;lt;0.05 was considered statistically significant. Results: Diazepam (2 mg/kg) extended the seizure latency and no significant difference was found in other groups. Diazepam (1 and 2 mg/kg) and NaHS (10 mg/kg) reduced seizure duration. NaHS (5 mg/kg), CORM-2 (5 and 10 mg/kg), L-arginine (30 and 100 mg/kg) and L-NAME (30 mg/kg) increased the seizure score significantly as compared to diazepam (1 and 2 mg/kg) groups. Conclusion: NaHS (10 mg/kg) may be protective in pentylentetrazole-induced seizures.

Anticonvulsant activity of Valeriana edulis roots and valepotriates on the pentylenetetrazole-induced seizures in rats

Ethnopharmacological relevanceFor many centuries, Mexican Valerian (Valeriana edulis ssp. procera) has been an important plant in folk medicine. It has been considered useful to control epilepsy; however, electroencephalographic evidence of its anticonvulsant activity is missing in literature.Aim of the study: In the present study, in situ electroencephalographic (EEG) analysis was performed along with administration of a crude ethanol extract of V. edulis and its valepotriate fraction on the pentylenetetrazole (PTZ)-induced convulsive behavior in rats. Materials and methodsExperiments were performed using male Wistar rats with nail-shaped electrodes implanted in the frontal and parietal cortices for EEG recording. All animals received a single dose of PTZ (35 mg/kg, i.p.) to test the anticonvulsant activity of V. edulis crude extract and valepotriate fraction (100 mg/kg, i.p.) 15 and/or 30 min after administration. EEG recordings were obtained from the cortices and were evaluated to assess ictal behavior over 60–75 min. Chromatographic analysis of the valepotriate fraction and in silico predictions of pharmacodynamic properties were also explored. The latency, frequency and duration of seizures evaluated using EEG recordings from the frontal and parietal cortices of rats showed significant changes demonstrating the inhibition of paroxystic activity. ResultsThe spectral analysis confirmed the reduction of excitatory activity induced by V. edulis extract, which was improved in the presence of the valepotriate fraction as compared to that induced by ethosuximide (a reference anticonvulsant drug). The presence of valepotriates such as: isodihydrovaltrate (18.99%), homovaltrate (13.51%), 10-acetoxy-valtrathydrin (4%) and valtrate (1.34%) was identified by chromatographic analysis. Whereas, not only GABAA receptor participation but also the cannabinoid CB2 receptor was found to be likely involved in the anticonvulsant mechanism of action after in silico prediction. ConclusionsOur data support the anticonvulsant properties attributed to this plant in folk medicine, due to the presence of valepotriates.

The anticonvulsant effect of sparteine on pentylenetetrazole-induced seizures in rats: a behavioral, electroencephalographic, morphological and molecular study.

Abnormal synchronous activity in neurons generates epileptic seizures. Antiepileptic drugs (AEDs) are effective in 70% of patients, but this percentage is drastically lower in developing countries. Sparteine is a quinolizidine alkaloid synthesized from most Lupine species and has a probable anticonvulsive effect. For this reason, the objective of the present work was to study the anticonvulsant effect of sparteine using a dose-effect curve and to determine its effectiveness against seizures using behavioral, electroencephalographic, morphological and molecular data. Wistar rats were grouped into control [saline solution (0.9%), pentylenetetrazole (90mg/kg), and sparteine (13, 20 and 30mg/kg), intraperitoneal (i.p.)] and experimental (sparteine + pentylenetetrazole) groups. The rats were implanted with surface electrodes to register electrical activity, and convulsive behavior was evaluated according to Velisek's scale. The rats were perfused to obtain brain slices for cresyl violet staining and cellular density quantification as well as for immunohistochemistry for NeuN and GFAP. Other animals were used to determine the hippocampal mRNA expression of the M2 and M4 acetylcholine receptors by qPCR. Sparteine exhibited a better anticonvulsant effect at a dose of 30mg/kg (i.p.) than at the other doses used. This anticonvulsant effect was characterized by a decrease in the severity of convulsive behavior, 100% survival, an inhibitory effect on epileptiform activity 75min after pentylenetetrazole administration, and the conservation of the cellular layers of CA1, CA3 and the dentate gyrus (DG); however, astrogliosis was observed after 30mg/kg sparteine treatment. In addition, sparteine treatment increased the mRNA expression of the M4 receptor three hours after administration. According to our findings, the effective dose of sparteine as an anticonvulsant agent by i.p. injection is 30mg/kg. The astrogliosis that was observed after sparteine administration may be a compensatory mechanism to diminish excitability and maintain neuronal homeostasis, possibly through redistributing potassium and glutamate. The increase in the mRNA expression of the M4 receptor may suggest the participation of the M4 receptor in the anticonvulsive effect of sparteine, as the activation of this receptor may inhibit acetylcholine release and facilitate the subsequent release of GABA. However, the precise mechanisms by which sparteine produces these effects are not known, and therefore, further experiments are necessary.

Recording of spontaneous vagus nerve activity during Pentylenetetrazol-induced seizures in rats

BackgroundVagus nerve stimulation is a treatment for refractory epilepsy. The vagus nerve carries parasympathetic information and innervates multiple organs. As seizures are commonly associated with autonomic manifestations, we believe that biomarkers for diseases affecting autonomic functions such as epilepsy can be found in vagus nerve signals. New methodWe present a method to record vagus nerve electroneurogram (VENG) and detect in the VENG single unit activity in anesthetized rats during Pentylenetetrazol induced seizures using a true tripolar cuff electrode. ResultsThe VENG consisted of high amplitude bursts and lower amplitude bursts synchronous to respiration and heartbeat respectively. The average spikes exhibited a triphasic shape with duration below 1.5ms and root mean square amplitude varied between 5.5 +/- 0.2 μV and 11.4 +/- 3.1 μV depending on the type of recording. An increase of the contact distance resulted in a signal amplitude increase. Application of Lidocaine led to a total disappearance of the recorded spontaneous spiking of the nerve. Comparison with existing methodsTrue tripolar cuff electrodes exhibited a better performance in terms of artefact rejection, stability and reproducibility of the signal compared to commonly used hook electrodes which is of special interest in seizures where important motion and EMG artifacts are expected. ConclusionWe present a new method to record single unit activity of the vagus nerve during acute chemically induced seizures in rats and verified the neural origin of the recorded signals. This recording method might be a powerful tool to develop seizure biomarkers based on VENG.

Triptolide Inhibits Neuronal Apoptosis in a Rat Model of Pentylenetetrazol-Induced-Epilepsy via Upregulation of miR-187 Expression

Epilepsy is one of the most common diseases of the nervous system. Neuronal apoptosis is closely involved in the development and progression of epilepsy. Triptolide is a widely used immunosuppressive agent in traditional Chinese medicine. However, a neuroprotective role of triptolide in epilepsy has been suggested but not fully explored. To this end, using pentylenetetrazol-induced seizures in rats as a model for epilepsy, we explored the effect of triptolide on seizure and its associated mechanisms. The results showed that triptolide significantly decreased the seizure severity and inhibited the apoptosis of neurons, accompanied by an improvement in the expression of miR-187 in the hippocampus region in pentylenetetrazol-treated rats. The up-regulation of miR-187 expression could inhibit neuronal apoptosis in the hippocampus. Finally, the results showed that miR-187 antagomir significantly reversed the protective effects of triptolide in pentylenetetrazol-treated rats. To the best of our knowledge, this is the first study demonstrating that triptolide inhibits neuronal apoptosis, at least partially, through up-regulating miR-187.

Effects of Energy Drink and Alcohol Mixed with Energy Drink on Pentylenetetrazol-Induced Seizures in Rats.

Energy drink consumption is on an upswing with reportedly significant health problems associated with its consumption. Additionally, it is one of the most preferred products used in combination with alcohol. The present study aimed to investigate the effects of energy drink and alcohol mixed energy drink (AmED) on epileptic seizures. Adult female (250-350 g) Wistar rats were divided into five groups (n=8 for each group). Caffeine (3.43 mg/kg) was injected through the intraperitoneal (IP) route and alcohol (3.4 g/kg), energy drink (10.71 ml/kg), and AmED were given to the rats via intragastric intubation for 14 days. On the first, seventh, and fourteenth days of the experiment, pentylenetetrazole (PTZ) (60 mg/kg IP) was injected into the rats. The onset time and severity of seizures were evaluated immediately after PTZ. Both caffeine and energy drink caused a significant decrease in the onset time of the seizures. Energy drink showed a significantly shorter onset time than caffeine on the seventh (p=0.045) and fourteenth (p=0.048) day. Energy drink significantly increased the severity of PTZ-induced seizures (p s<0.01). Caffeine also produced significant increase in the severity of the seizures on the first (p=0.013) and fourteenth (p=0.047) day. Alcohol and AmED significantly shortened onset time of the seizures on the seventh (p=0.028 and p=0.016) and fourteenth day (p=0.039 and p=0.04), respectively. Both alcohol and AmED significantly decreased the severity of PTZ-induced seizures all observation intervals (p s<0.0001). Our results suggest that energy drink and AmED produced some significant unfavorable effects on PTZ-induced seizures. They may be dangerous in patient with epilepsy and individuals prone to seizure.

Modulatory effects of neuropeptides on pentylenetetrazol-induced epileptic seizures and neuroinflammation in rats.

We aimed to explore the effects of neuropeptides ghrelin, obestatin, and vasoactive intestinal peptide (VIP) on seizures and plasma concentrations of neuroinflammation biomarkers including calcitonin gene-related peptide (CGRP), substance-P (SP), and interleukin-1 beta (IL-1β) in pentylenetetrazol-induced seizures in rats. Ghrelin (80 µg/kg), obestatin (1 µg/kg), VIP (25 ng/kg) or saline were administered to rats intraperitoneally 30 min before pentylenetetrazole (PTZ, 50 mg/kg) injections. Stages of epileptic seizures were evaluated by Racine's scale, and plasma CGRP, SP, and IL-1β concentrations were measured using ELISA. Both obestatin and VIP shortened onset-time of generalized tonic-clonic seizure, respectively, moreover VIP also shortened the onset-time of first myoclonic-jerk induced by PTZ. While PTZ increased plasma CGRP, SP and IL-1β concentrations, ghrelin reduced the increases evoked by PTZ. While VIP further increased PTZ-evoked CGRP levels, it diminished IL-1β concentrations. However, obestatin did not change CGRP, SP, and IL-1β concentrations. Our results suggest that ghrelin acts as an anticonvulsant, obestatin acts as a proconvulsant, and VIP has dual action on epilepsy. Receptors of those neuropeptides may be promising targets for epilepsy treatment.

Synthetic, non-intoxicating 8,9-dihydrocannabidiol for the mitigation of seizures

There can be a fine line between therapeutic intervention and substance abuse, and this point is clearly exemplified in herbal cannabis and its products. Therapies involving cannabis have been the treatment of last resort for some cases of refractory epilepsy, and this has been among the strongest medical justifications for legalization of marijuana. In order to circumvent the narcotic effects of Δ9-tetrahydrocannabinol (THC), many studies have concentrated on its less intoxicating isomer cannabidiol (CBD). However, CBD, like all natural cannabinoids, is a controlled substance in most countries, and its conversion into THC can be easily performed using common chemicals. We describe here the anticonvulsant properties of 8,9-dihydrocannibidiol (H2CBD), a fully synthetic analogue of CBD that is prepared from inexpensive, non-cannabis derived precursors. H2CBD was found to have effectiveness comparable to CBD both for decreasing the number and reducing the severity of pentylenetetrazole-induced seizures in rats. Finally, H2CBD cannot be converted by any reasonable synthetic route into THC, and thus has the potential to act as a safe, noncontroversial drug for seizure mitigation.

Transient Morphological Alterations in the Hippocampus After Pentylenetetrazole-Induced Seizures in Rats.

The relationships between seizures, neuronal death, and epilepsy remain one of the most disputed questions in translational neuroscience. Although it is broadly accepted that prolonged and repeated seizures cause neuronal death and epileptogenesis, whether brief seizures can produce a mild but similar effect is controversial. In the present work, using a rat pentylenetetrazole (PTZ) model of seizures, we evaluated how a single episode of clonic-tonic seizures affected the viability of neurons in the hippocampus, the area of the brain most vulnerable to seizures, and morphological changes in the hippocampus up to 1week after PTZ treatment (recovery period). The main findings of the study were: (1) PTZ-induced seizures caused the transient appearance of massively shrunken, hyperbasophilic, and hyperelectrondense (dark) cells but did not lead to detectable neuronal cell loss. These dark neurons were alive, suggesting that they could cope with seizure-related dysfunction. (2) Neuronal and biochemical alterations following seizures were observed for at least 1week. The temporal dynamics of the appearance and disappearance of dark neurons differed in different zones of the hippocampus. (3) The numbers of cells with structural and functional abnormalities in the hippocampus after PTZ-induced seizures decreased in the following order: CA1 > CA3b,c > hilus > dentate gyrus. Neurons in the CA3a subarea were most resistant to PTZ-induced seizures. These results suggest that even a single seizure episode is a potent stressor of hippocampal neurons and that it can trigger complex neuroplastic changes in the hippocampus.

Acute Administration of High Dose Trimetazidine Inhibits Pentylenetetrazol-Induced Seizures in Rats

Introduction: Resistant epilepsy is widely seen in clinical settings manipulate the researchers to pursuit novel anti-epileptic treatments. Although trimetazidine (TMZ) is commonly used in the treatment of angina and ischemic diseases, it is considered that the drug may be beneficial in the treatment of epileptic seizures and convulsions. We aimed to evaluate electrophysiologically the protective effects of high dose acute TMZ on epileptic seizures and convulsions in a rat model of epilepsy induced by pentilentetrazol (PTZ). Materials and methods: Forty-eight male Sprague-Dawley rats were used for the EEG evaluation (Group-A; n=24) and behavioral assessment (Group-B; n=24). Grup-A1 and Grup-B1 were determined as control group and given no medication. 35 mg/kg (Group-A2, -A3 and -A4) and 70 mg/kg (Group-B2, -B3 and -B4) of PTZ were administered intraperitoneally (ip.) so as to generate seizures and convulsions. Group-A2 and Group-B2 were treated with saline. 40 mg/kg (Grup-A3 and Grup-B3) and 80 mg/kg of TMZ (Group-A4 and Group-B4) were administered to the treatment groups by ip. Brain malondialdehyde (MDA) levels, spike-percentage values, Racine’s Convulsion Scale (RCS) scores and first myoclonic jerk (FMJ) latencies of each rat were determined. Results: Brain MDA levels, spike-percentage values, RCS scores, and FMJ latencies of Group-A2 and Group-B2 were significantly increased compared to those of the control’s (Grup-A1 and Grup-B1) (P<0.05 for all comparisons). However, in TMZ treated groups (Group-A3 and -A4; Group-B3 and -B4) the elevated values of these parameters were found to be significantly decreased (P<0.05 for all comparisons). Conclusion: This study has demonstrated that the high dose acute TMZ administration may prevent PTZ-induced seizures and convulsions in rats. Furthermore, it can be also said that TMZ has a neuroprotective effects on oxidative stress associated with PTZ. Therefore, it may be considered for use with therapeutic purposes of TMZ in resistant epilepsy patients in the future.