The effects of atorvastatin on memory deficit and seizure susceptibility in pentylentetrazole-kindled rats

Krüppel-like factors: potential roles in blood-brain barrier dysfunction and epileptogenesis

Epilepsy is a chronic and debilitating neurological disorder, known for the occurrence of spontaneous and recurrent seizures. Despite the availability of antiseizure drugs, 30% of people with epilepsy experience uncontrolled seizures and drug resistance, evidencing that new therapeutic options are required. The process of epileptogenesis involves the development and expansion of tissue capable of generating spontaneous recurrent seizures, during which numerous events take place, namely blood-brain barrier (BBB) dysfunction, and neuroinflammation. The consequent cerebrovascular dysfunction results in a lower seizure threshold, seizure recurrence, and chronic epilepsy. This suggests that improving cerebrovascular health may interrupt the pathological cycle responsible for disease development and progression. Krüppel-like factors (KLFs) are a family of zinc-finger transcription factors, encountered in brain endothelial cells, glial cells, and neurons. KLFs are known to regulate vascular function and changes in their expression are associated with neuroinflammation and human diseases, including epilepsy. Hence, KLFs have demonstrated various roles in cerebrovascular dysfunction and epileptogenesis. This review critically discusses the purpose of KLFs in epileptogenic mechanisms and BBB dysfunction, as well as the potential of their pharmacological modulation as therapeutic approach for epilepsy treatment.

Atorvastatin mitigates memory deficits and brain monocyte infiltration in chronic hypercholesterolemia

Mild cognitive impairment (MCI) is a common symptom observed in people over 60 years old and is found to be aggravated by hypercholesterolemia. Severe neuroinflammation induced by BBB dysfunction and monocyte infiltration might be responsible for neuron damage and cognitive impairment. Atorvastatin is a lipid-lowering drug that is widely applied for the treatment of cardiovascular diseases. However, the potential function of Atorvastatin in hypercholesterolemia-induced MCI remains uncertain. Our research will explore the potential therapeutic function of Atorvastatin in memory deficits induced by chronic hypercholesterolemia. ApoE-/- mice were utilized to mimic the state of chronic hypercholesterolemia and were divided into four groups. Animals in the WT and ApoE-/-groups were orally administered with normal saline, while WT mice in the Atorvastatin group and ApoE-/- mice in the ApoE-/-+ Atorvastatin group were orally administered with 10 mg/kg/day Atorvastatin. Markedly increased plasma cholesterol levels reduced RI in the long-term memory test and the spatial short-term memory test, declined mobility in the open field test, and downregulated PSD-95 and BDNF were observed in ApoE-/- mice, all of which were signally reversed by Atorvastatin. Moreover, the percentages of brain Ly6Chi CD45+ cells and CD3+ CD45+ cells, as well as the blood Ly6Chi CD45+ cells, plasma IL-12/IL-23 levels and IL-17 level were found notably increased in ApoE-/- mice, all of which were largely repressed by Atorvastatin. Lastly, the increased BBB permeability, decreased ZO-1 and occludin levels, and reduced KLF2 level were markedly abolished by Atorvastatin. Collectively, Atorvastatin mitigated memory deficits and brain monocyte infiltration in ApoE-/- mice.

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

AIM OF THE STUDY

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

Beneficial Effects of Statins on Seizures Independent of Their Lipid-Lowering Effect: A Narrative Review

Among the many types of central nervous system (CNS) disorders, seizures and epilepsy severely affect the quality of life and routine daily activity of the sufferers. We aimed to review research studies that investigated the effect of statins on the prevention and treatment of seizures and epilepsy. Both animal models and human studies were included in this review. This article starts with a brief introduction about seizure, its prevalence, treatment, and various animal models of seizures and epilepsy. Next, we discuss statin's mechanism of action, side effects, and effects on neurological disorders with a specific focus on seizures. Finally, the effects of different types of statins on seizures are compared. The present review gives a better understanding of the therapeutic effects of statins on neurological disorders in animal models and human studies. This permits researchers to set up study designs to resolve current ambiguities and contradictions on the beneficial effects of statins on neurological disorders.

Galium aparine L. protects against acetaminophen-induced hepatotoxicity in rats

The toxicity of acetaminophen (N-acetyl-para-aminophenol (APAP)) is the most frequent cause of drug-induced liver damage. Galium aparine L. (GA) is traditionally used to treat jaundice. We aimed to investigate the hepatoprotective potential of GA in the APAP-induced hepatic encephalopathy (HE) rat model. Qualitative phytochemical characterization of GA was performed by LC/Q-TOF/MS analysis. Wistar rats were pretreated with GA (250 and 500 mg/kg b.wt. per oral) for five days. On the 6th day, the rats were exposed to APAP (1500 mg/kg b.wt. oral gavage) and behavioral tests (open field and passive avoidance tests) were applied on the 7th and 8th days. The animals were killed, and biochemical and histopathological parameters were assessed in blood and hepatic specimens. GA pretreated rats exhibited a significant reduction in APAP-induced liver damage, evidenced by the reduction in liver necrosis and alanine aminotransferase (ALT), aspartate aminotransferase (AST), and bilirubin (BIL). GA demonstrated an anxiolytic effect, as seen in the acquisition trial and grooming behavior. The short-term memory performances of animals were not changed in all groups, suggesting that APAP intoxication did not affect hippocampal function. These results show that GA extract markedly exerts hepatoprotective activity, while its effect on hepatic encephalopathy was limited.

Statins as antiepileptogenic drugs: analysing the evidence and identifying the most promising statin

Many brain insults and injuries are “epileptogenic”: they increase the risk of developing epilepsy. It is desirable to identify treatments that are “antiepileptogenic”: treatments that prevent the development of epilepsy, if administered after the occurrence of an epileptogenic insult. Current antiepileptic drugs are not antiepileptogenic, but evidence of antiepileptogenic efficacy is accumulating for a growing number of other compounds. From among these candidate compounds, statins are deserving of particular attention because statins are reported to be antiepileptogenic in more published studies and in a wider range of brain insults than any other individual or class of compounds. Although many studies report the antiepileptogenic effect of statins, it is unclear how many studies provide evidence that statins exhibit the following two essential features of a clinically viable antiepileptogenic drug: the drug must exert an antiepileptogenic effect even if it is initiated after the epileptogenic brain insult has already occurred, and the antiepileptogenic effect must endure even after the drug has been discontinued. In the current work, we interrogate published preclinical and clinical studies, to determine if statins fulfill these essential requirements. There are eight different statins in clinical use. To enable the clinical use of one of these statins for antiepileptogenesis, its antiepileptogenic effect will have to be established through future time‐ and resource‐intensive clinical trials. Therefore, it is desirable to review the published literature to determine which of the statins emerges as the most promising candidate for antiepileptogenic therapy. Hence, in the current work, we also collate and analyze published data—clinical and pre‐clinical, direct and indirect—that help to answer the question: Which statin is the most promising candidate to take forward into an antiepileptogenesis clinical trial?

Thiamine alleviates cognitive impairment and epileptogenesis by relieving brain inflammation in PTZ-induced kindling rat model

OBJECTIVE

Epileptogenesis, the process by which the brain becomes epileptic, is related to neuroinflammation, hyperexcitability cognitive deficits. Evidence suggests that improving brain inflammation can inhibit the epileptogenesis process and help the emergence of new drugs for the treatment of epilepsy. Therefore, the PTZ kindling model of epilepsy was utilized to assess the neuroprotective role of thiamine in epileptogenesis.

METHODS

Male rats were exposed to PTZ-induced kindling and pretreated with low thiamine (25 mg/kg) or high thiamine (50 mg/kg). Cyclooxygenase (COX-1 and COX-2), interleukin 1-beta (IL-1β), tumor necrosis factor-alpha (TNF-α), and nuclear factor-κB (NF-κB) concentrations in the brain were analyzed using biochemical assays. Cognitive function was evaluated using the passive avoidance test.

RESULTS

Thiamine ameliorated epileptogenesis and enhanced the rats' performance in the passive avoidance test. Also, thiamine significantly decreased the level of neuroinflammatory mediators in the brain induced by PTZ.

CONCLUSION

These results provide evidence that thiamine alleviates PTZ-induced neuroinflammation and cognitive impairments.

The effects of regular swimming exercise during sodium valproate treatment on seizure behaviors and EEG recordings in pentylenetetrazole-kindled rats

We investigated the effects of alone/combined regular swimming exercise and sodium valproate on epileptic seizure behaviors and EEG recordings, anti-oxidative mechanism, learning, and memory in pentylenetetrazole (PTZ)-kindled rats. Forty-eight healthy rats were randomly divided into eight equal groups as control (CONT), swimming exercise (EX), sodium valproate (SV), SV+EX, PTZ, EX+PTZ, SV+PTZ and SV+EX+PTZ. The rats were forced to regular swimming exercise for 60 min every other day, 13 doses of PTZ (40 mg/kg) were given to induce epileptic seizures and 200 mg/kg SV was given for 28 days. Epileptic seizures were evaluated by visual observation and EEG recordings (total spike numbers and number of epileptiform discharges). Memory and learning skills were assessed with passive avoidance test. According to our visual seizure observations, seizure latency was prolonged only in SV+EX+PTZ (p < 0.001) group, seizure severity score decreased in SV+PTZ (p < 0.05) and SV+EX+PTZ (p < 0.001) groups and seizure frequency was reduced in SV+PTZ (p < 0,001), EX+PTZ (p < 0,001), and SV+EX+PTZ (p < 0,001) groups. Total spike numbers and number of epileptiform discharges highly increased in PTZ group, whereas they decreased in swimming exercise and/or SV treatment groups. The most effective result was seen in the combined therapy group. Memory deficit was observed in PTZ -kindling group, but it didn't change with exercise or SV. Based on our results, regular swimming exercise had positive effects on PTZ-induced seizure frequency, and combined therapy of regular swimming exercise and SV is the most effective way to ameliorate visual seizure behaviors and decrease spike numbers and number of epileptiform discharges according to EEG recordings. Regular swimming exercise could be an alternative option to reduce the dose of SV and the side effects of SV can be avoided in clinical aspects.

Protective effects of lamotrigine and vitamin B12 on pentylenetetrazole-induced epileptogenesis in rats

Epileptogenesis is a process that includes molecular and cellular events that foster the establishment of hyperexcitable neuronal networks in the brain. Pentylenetetrazole (PTZ)-induced kindling model in rodents has added new information to the knowledge about the pathogenesis of epilepsy and potential targets of novel antiepileptic agents. Evidence from animal and human studies suggests that oxidative and inflammatory events may play important roles in the initiation and maintaining seizure activities. Vitamin B12 has beneficial effects on the nervous system and presents pleiotropic effects with antioxidant and anti-inflammatory aspects. In the present study, we aimed to test the hypothesis that vitamin B12 and their combination with lamotrigine prevents behavioral deficits, hippocampal damage, oxidation, and proinflammatory state during epileptogenesis. Male rats were subjected to PTZ-induced epileptogenesis and pretreated with vitamin B12 (50 µg/kg) or Lamotrigine (LTG) (25 mg/kg) or B12 (50 µg/kg) + LTG (25 mg/kg). Vitamin B12 and its combination with LTG suppressed epileptogenesis and improved the performance of rats in the passive avoidance test. In addition, Vitamin B12 and its combination with LTG decreased levels of total oxidative status (TOS), oxidative stress index (OSI), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and increased total antioxidant status (TAS) levels in the hippocampus and cerebral cortex. Furthermore, it reduced hippocampal neuronal damage. Current findings support the beneficial actions of vitamin B12 due to its antioxidative and anti-inflammatory properties during the course of disease.

Experimental Models for the Discovery of Novel Anticonvulsant Drugs: Focus on Pentylenetetrazole-Induced Seizures and Associated Memory Deficits

Epilepsy is a chronic neurological disorder characterized by irregular, excessive neuronal excitability, and recurrent seizures that affect millions of patients worldwide. Currently, accessible antiepileptic drugs (AEDs) do not adequately support all epilepsy patients, with around 30% patients not responding to the existing therapies. As lifelong epilepsy treatment is essential, the search for new and more effective AEDs with an enhanced safety profile is a significant therapeutic goal. Seizures are a combination of electrical and behavioral events that can induce biochemical, molecular, and anatomic changes. Therefore, appropriate animal models are required to evaluate novel potential AEDs. Among the large number of available animal models of seizures, the acute pentylenetetrazole (PTZ)-induced myoclonic seizure model is the most widely used model assessing the anticonvulsant effect of prospective AEDs, whereas chronic PTZ-kindled seizure models represent chronic models in which the repeated administration of PTZ at subconvulsive doses leads to the intensification of seizure activity or enhanced seizure susceptibility similar to that in human epilepsy. In this review, we summarized the memory deficits accompanying acute or chronic PTZ seizure models and how these deficits were evaluated applying several behavioral animal models. Furthermore, major advantages and limitations of the PTZ seizure models in the discovery of new AEDs were highlighted. With a focus on PTZ seizures, the major biochemicals, as well as morphological alterations and the modulated brain neurotransmitter levels associated with memory deficits have been illustrated. Moreover, numerous medicinal compounds with concurrent anticonvulsant, procognitive, antioxidant effects, modulating effects on several brain neurotransmitters in rodents, and several newly developed classes of compounds applying computer-aided drug design (CADD) have been under development as potential AEDs. The article details the in-silico approach following CADD, which can be utilized for generating libraries of novel compounds for AED discovery. Additionally, in vivo studies could be useful in demonstrating efficacy, safety, and novel mode of action of AEDs for further clinical development.

Liquid Crystalline Nanoparticles for Nasal Delivery of Rosuvastatin: Implications on Therapeutic Efficacy in Management of Epilepsy

In the present study we investigated the protective role of intranasal rosuvastatin liquid crystalline nanoparticles (Ros-LCNPs) against pentylenetetrazole (PTZ) induced seizures, increasing current electroshock (ICES) induced seizures, and PTZ-induced status epilepticus. From the dose titration study, it was evident that intranasal rosuvastatin (ROS), at lower dose, was more effective than oral and intraperitoneal ROS. The Ros-LCNPs equivalent to 5 mg/kg ROS were developed by hydrotrope method using glyceryl monooleate (GMO) as lipid phase. The high resolution TEM revealed that the formed Ros-LCNPs were cubic shaped and multivesicular with mean size of 219.15 ± 8.14 nm. The Ros-LCNPs showed entrapment efficiency of 70.30 ± 1.84% and release was found to be biphasic following Korsmeyer–Peppas kinetics. Intranasal Ros-LCNPs (5 mg/kg) showed significant increase in latency to PTZ-induced seizures and ICES seizure threshold compared to control and intranasal ROS solution. Additionally, intranasal Ros-LCNPs provided effective protection against PTZ-induced status epilepticus. No impairment in cognitive functions was observed following intranasal Ros-LCNPs. The results suggested that Ros-LCNPs could be an effective and promising therapeutics for the epilepsy management.

Effects of atorvastatin and metformin on development of pentylenetetrazole-induced seizure in mice

Recent studies have shown that statins and Metformin may have beneficial effects on seizure through different mechanisms. In the current study, we investigated whether Metformin, Atorvastatin, and concomitant uses of them have beneficial effects on pentylenetetrazole (PTZ)-induced kindling. Adult male C57BL/6 mice were randomly divided into four experimental groups with seven mice in each group. Group 1, control group; group 2, received Metformin (200 mg/kg, i.p); group 3, received Atorvastatin (10 mg/kg, i.p.); group 4, received Atorvastatin (10 mg/kg, i.p.) plus Metformin (200 mg/kg, i.p.). Twenty minutes after injection of the mentioned drugs, the experimented mice received 37/5 mg/kg of PTZ intraperitoneally on alternating days. Then the convulsive behavior signs were evaluated for 20 min after each PTZ injection. There were significant differences in the stage 2 latency parameter among group 2 (p = 0.033, F = 8.46)/group 3 (p = 0.032, F = 10.42)/group 4 (p = 0.008, F = 24.57) as compared to the control group, while no significant differences were found comparing only group 2,3, and 4 with eachother excluding the control group. Pretreatment with Atorvastatin (p = 0.002, F = 33), Atorvastatin + Metformin (p = 0.006, F = 20.77), and Metformin alone increased stage 5 latency as compared to the PTZ group, significantly. Also, our results have shown that pretreatment with Atorvastatin (p = 0.013, F = 14.48), Metformin (p = 0.015, F = 16.67), and concomitant usage of them significantly decreased stage 5 duration as compared to the control group. Our findings clearly demonstrate that concomitant use of Metformin and Atorvastatin has no more protective effect against the development of kindling as compare to these drugs alone. Thus, we concluded that, these drugs may inhibit kindling via a similar mechanism and we suggested that it is probably through regulation of autophagy.

Antagonism of Histamine H3 receptors Alleviates Pentylenetetrazole-Induced Kindling and Associated Memory Deficits by Mitigating Oxidative Stress, Central Neurotransmitters, and c-Fos Protein Expression in Rats

Histamine H3 receptors (H3Rs) are involved in several neuropsychiatric diseases including epilepsy. Therefore, the effects of H3R antagonist E177 (5 and 10 mg/kg, intraperitoneal (i.p.)) were evaluated on the course of kindling development, kindling-induced memory deficit, oxidative stress levels (glutathione (GSH), malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD)), various brain neurotransmitters (histamine (HA), acetylcholine (ACh), γ-aminobutyric acid (GABA)), and glutamate (GLU), acetylcholine esterase (AChE) activity, and c-Fos protein expression in pentylenetetrazole (PTZ, 40 mg/kg) kindled rats. E177 (5 and 10 mg/kg, i.p.) significantly decreased seizure score, increased step-through latency (STL) time in inhibitory avoidance paradigm, and decreased transfer latency time (TLT) in elevated plus maze (all P < 0.05). Moreover, E177 mitigated oxidative stress by significantly increasing GSH, CAT, and SOD, and decreasing the abnormal level of MDA (all P < 0.05). Furthermore, E177 attenuated elevated levels of hippocampal AChE, GLU, and c-Fos protein expression, whereas the decreased hippocampal levels of HA and ACh were modulated in PTZ-kindled animals (all P < 0.05). The findings suggest the potential of H3R antagonist E177 as adjuvant to antiepileptic drugs with an added advantage of preventing cognitive impairment, highlighting the H3Rs as a potential target for the therapeutic management of epilepsy with accompanied memory deficits.

Identifying new antiepileptic drugs through genomics-based drug repurposing

Currently available antiepileptic drugs (AEDs) fail to control seizures in 30% of patients. Genomics-based drug repurposing (GBR) offers the potential of savings in the time and cost of developing new AEDs. In the current study, we used published data and software to identify the transcriptomic signature of chornic temporal lobe epilepsy and the drugs that reverse it. After filtering out compounds based on exclusion criteria, such as toxicity, 36 drugs were retained. 11 of the 36 drugs identified (>30%) have published evidence of the antiepileptic efficacy (for example, curcumin) or antiepileptogenic affect (for example, atorvastatin) in recognised rodent models or patients. By objectively annotating all ∼20,000 compounds in the LINCS database as either having published evidence of antiepileptic efficacy or lacking such evidence, we demonstrated that our set of repurposable drugs is ∼6-fold more enriched with drugs having published evidence of antiepileptic efficacy in animal models than expected by chance (P-value <0.006). Further, we showed that another of our GBR-identified drugs, the commonly-used well-tolerated antihyperglycemic sitagliptin, produces a dose-dependent reduction in seizures in a mouse model of pharmacoresistant epilepsy. In conclusion, GBR successfully identifies compounds with antiepileptic efficacy in animal models and, hence, it is an appealing methodology for the discovery of potential AEDs.

The beneficial effects of HMG-CoA reductase inhibitors in the processes of neurodegeneration

Statins, cholesterol lowering drugs, have been demonstrated to exert beneficial effects in other conditions such as primary and progressing neurodegenerative diseases beyond their original role. Observation that statins ameliorate the neurodegenerative diseases such as Parkinson's disease (PD), Alzheimer's disease (AD), multiple sclerosis (MS) and cerebral ischemic stroke, the neuroprotective effects of these drugs are thought to be linked to their anti-inflammatory, anti-oxidative, and anti-excitotoxic properties. Despite the voluminous literature on the clinical advantages of 3-hydroxy-3-methylglutaryl Co-enzyme A reductase (HMGCR) inhibitors (statins) in cardiovascular system, the neuroprotective effects and the underlying mechanisms are little understood. Hence, the present review tries to provide a critical overview on the statin-induced neuroprotection, which are presumed to be associated with the ability to reduce cholesterol, Amyloid-β and apolipoprotein E (ApoE) levels, decrease reactive oxygen and nitrogen species (ROS and RNS) formation, inhibit excitotoxicity, modulate matrix metalloproteinases (MMPs), stimulate endothelial nitric oxide synthase (eNOS), and increase cerebral blood perfusion. This review is also aimed to illustrate that statins protect neurons against the neuro-inflammatory processes through balancing pro-inflammatory/anti-inflammatory cytokines. Ultimately, the beneficial role of statins in ameliorating the development of PD, AD, MS and cerebral ischemic stroke has been separately reviewed.

Atorvastatin enhances kainate-induced gamma oscillations in rat hippocampal slices

Atorvastatin has been shown to affect cognitive functions in rodents and humans. However, the underlying mechanism is not fully understood. Because hippocampal gamma oscillations (γ, 20-80 Hz) are associated with cognitive functions, we studied the effect of atorvastatin on persistent kainate-induced γ oscillation in the CA3 area of rat hippocampal slices. The involvement of NMDA receptors and multiple kinases was tested before and after administration of atorvastatin. Whole-cell current-clamp and voltage-clamp recordings were made from CA3 pyramidal neurons and interneurons before and after atorvastatin application. Atorvastatin increased γ power by ~ 50% in a concentration-dependent manner, without affecting dominant frequency. Whereas atorvastatin did not affect intrinsic properties of both pyramidal neurons and interneurons, it increased the firing frequency of interneurons but not that of pyramidal neurons. Furthermore, whereas atorvastatin did not affect synaptic current amplitude, it increased the frequency of spontaneous inhibitory post-synaptic currents, but did not affect the frequency of spontaneous excitatory post-synaptic currents. The atorvastatin-induced enhancement of γ oscillations was prevented by pretreatment with the PKA inhibitor H89, the ERK inhibitor U0126, or the PI3K inhibitor wortmanin, but not by the NMDA receptor antagonist D-AP5. Taken together, these results demonstrate that atorvastatin enhanced the kainate-induced γ oscillation by increasing interneuron excitability, with an involvement of multiple intracellular kinase pathways. Our study suggests that the classical cholesterol-lowering agent atorvastatin may improve cognitive functions compromised in disease, via the enhancement of hippocampal γ oscillations.

Atorvastatin prevents development of kindling by modulating hippocampal levels of dopamine, glutamate, and GABA in mice

PURPOSE

Atorvastatin (ATV) is widely used for the treatment of dyslipidemias. Recent evidence has shown that ATV has protection effects against seizures. However, the effect of ATV on certain neurotransmitter and oxidative stress markers associated with seizures had not been reported. Therefore, the present study aimed to evaluate the effects of ATV on oxidative stress markers on whole brain and GABA, glutamate, and dopamine levels in the hippocampus of PTZ-kindled mice. Additionally, effects of ATV on animal models of seizures, anxiety, and depression were also assessed.

MATERIALS AND METHODS

Swiss albino mice were given ATV (20, 40, and 80mg/kg/p.o.) in an acute study. On the seventh day, animals were subjected to various neurological and neurobehavioral tests, viz, increasing current electroshock (ICES) test, pentylenetetrazole (PTZ)-induced seizures, Elevated Plus Maze (EPM), and Forced Swim Test (FST). For the development of kindling, a subconvulsant dose of PTZ, i.e., 25mg/kg, i.p., was administered every other day, and ATV in all the three doses was administered daily. Seizure score was continuously monitored until the development of kindling. Thiobarbituric acid reacting species (TBARS), glutathione, dopamine, GABA, and glutamate levels were also assessed in the brain tissues of mice.

RESULTS

The results showed that in the ICES test, ATV 80mg/kg increased the seizure threshold to hind limb extension (HLE), and a complete protection against HLE was observed when ATV 80mg/kg was combined with a subanticonvulsant dose of phenytoin. Atorvastatin in all the tested doses suppressed the development of kindling, reduced lipid peroxidation, and increased glutathione levels. All doses of ATV maintained the normal levels of glutamate, GABA, and dopamine in kindled mice.

CONCLUSION

Atorvastatin possesses anticonvulsant activity against electroconvulsions. It was found to suppress the development of PTZ kindling, presumably altering the redox status and hippocampal levels of dopamine, glutamate, and GABA.

Curcumin supplementation improves mitochondrial and behavioral deficits in experimental model of chronic epilepsy

The present study was aimed to investigate the potential beneficial effect of curcumin, a polyphenol with pleiotropic properties, on mitochondrial dysfunctions, oxidative stress and cognitive deficits in a kindled model of epilepsy. Kindled epilepsy was induced in rats by administering a sub-convulsive dose of pentylenetetrazole (PTZ, 40 mg/kg body weight) every alternate day for 30 days. PTZ administered rats exhibited marked cognitive deficits assessed using active and passive avoidance tasks. This was accompanied by a significant decrease in NADH:cytochrome-c reductase (complex I) and cytochrome-c oxidase (complex IV) activities along with an increase in ROS, lipid peroxidation and protein carbonyls. The levels of glutathione also decreased in the cortex and hippocampus. Electron micrographs revealed disruption of mitochondrial membrane integrity with distorted cristae in PTZ treated animals. Histopathological examination showed pyknotic nuclei and cell loss in the hippocampus as well as in the cortex of PTZ treated animals. Curcumin administration at a dose of 100 mg/kg, p.o. throughout the treatment paradigm was able to ameliorate cognitive deficits with no significant effect on seizure score. Curcumin was able to restore the activity of mitochondrial complexes. In addition, significant reduction in ROS generation, lipid peroxidation and protein carbonyls was observed in PTZ animals supplemented with curcumin. Moreover, glutathione levels were also restored in PTZ treated rats supplemented with curcumin. Curcumin protected mitochondria from seizure induced structural alterations. Further, the curcumin supplemented PTZ rats had normal cell morphology and reduced cell loss. These results suggest that curcumin supplementation has potential to prevent mitochondrial dysfunctions and oxidative stress with improved cognitive functions in a chronic model of epilepsy.

Pharmacodynamic potentiation of antiepileptic drugs' effects by some HMG-CoA reductase inhibitors against audiogenic seizures in DBA/2 mice

It is known that the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are effective in both the primary and the secondary prevention of ischemic heart disease. Increasing evidence indicates that statins have protective effects in several neurological diseases including stroke, cerebral ischemia, Parkinson disease, multiple sclerosis, traumatic brain injury and epilepsy. The aim of the present research was to evaluate the effects of some HMG-CoA reductase inhibitors (i.e. lovastatin, simvastatin, atorvastatin, fluvastatin and pravastatin) commonly used for the treatment of hypercholesterolemia in the DBA/2 mice, an animal model of generalized tonic-clonic seizures. Furthermore, the co-administration of these compounds with some antiepileptic drugs (AEDs; i.e. carbamazepine, diazepam, felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, phenobarbital, phenytoin, topiramate and valproate) was studied in order to identify possible positive pharmacological interactions. Simvastatin only was active against both the tonic and clonic phase of audiogenic seizures, whereas the other statins tested were only partially effective against the tonic phase with the following order of potency: lovastatin>fluvastatin>atorvastatin; pravastatin was completely ineffective up to the dose of 150mg/kg. The co-administration of ineffective doses of all statins with AEDs generally increased the potency of the latter reducing their ED50 values. In particular, simvastatin was the most active in potentiating the activity of AEDs and the combinations of statins with carbamazepine, diazepam, felbamate, lamotrigine, topiramate and valproate were the most favorable, whereas, the co-administrations with the other AEDs studied was in most cases neutral. The increase in potency was generally associated with an enhancement of motor impairment (TD50); however, the therapeutic index (TD50/ED50) of combined treatment of AEDs with statins was predominantly more favorable than control. Statins administration did not significantly affect the total plasma but, in some cases, it increased the free plasma levels and the brain concentrations of some of the AEDs studied (i.e. carbamazepine, diazepam, phenytoin and valproate); however, these alterations where not statistically significant. Therefore, with the exception of the latter compounds, we might exclude pharmacokinetic interactions and conclude that for the most of AEDs, potentiation was of pharmacodynamic nature. In conclusion, simvastatin, fluvastatin, lovastatin and atorvastatin showed an additive anticonvulsant effect when co-administered with some AEDs, most notably carbamazepine, diazepam, felbamate, lamotrigine, topiramate and valproate, implicating a possible therapeutic relevance of such drug combinations. The present results suggest that statins, besides the beneficial cardiovascular effects, might be able to affect brain areas, which might participate in the regulation of seizure susceptibility.

Administration of simvastatin after kainic acid-induced status epilepticus restrains chronic temporal lobe epilepsy

In this study, we examined the effect of chronic administration of simvastatin immediately after status epilepticus (SE) on rat brain with temporal lobe epilepsy (TLE). First, we evaluated cytokines expression at 3 days post KA-lesion in hippocampus and found that simvastatin-treatment suppressed lesion-induced expression of interleukin (IL)-1β and tumor necrosis factor-α (TNF-α). Further, we quantified reactive astrocytosis using glial fibrillary acidic protein (GFAP) staining and neuron loss using Nissl staining in hippocampus at 4-6 months after KA-lesion. We found that simvastatin suppressed reactive astrocytosis demonstrated by a significant decrease in GFAP-positive cells, and attenuated loss of pyramidal neurons in CA3 and interneurons in dentate hilar (DH). We next assessed aberrant mossy fiber sprouting (MFS) that is known to contribute to recurrence of spontaneous seizure in epileptic brain. In contrast to the robust MFS observed in saline-treated animals, the extent of MFS was restrained by simvastatin in epileptic rats. Attenuated MFS was related to decreased neuronal loss in CA3 and DH, which is possibly a mechanism underlying decreased hippocampal susceptibility in animal treated with simvastatin. Electronic encephalography (EEG) was recorded during 4 to 6 months after KA-lesion. The frequency of abnormal spikes in rats with simvastatin-treatment decreased significantly compared to the saline group. In summary, simvastatin treatment suppressed cytokines expression and reactive astrocytosis and decreased the frequency of discharges of epileptic brain, which might be due to the inhibition of MFS in DH. Our study suggests that simvastatin administration might be a possible intervention and promising strategy for preventing SE exacerbating to chronic epilepsy.