Effect of atorvastatin on behavioral alterations and neuroinflammation during epileptogenesis

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.

Adverse neurobehavioral changes with reduced blood and brain cholinesterase activities in mice treated with statins

Background and Aim

Pleiotropic effects of hypolipidemic statins with behavioral outcomes have been suggested in humans and laboratory animals. There is limited information on the neurobehavioral effects of statins in mice. The aim of the present study was to examine changes in neurobehavioral performance and cholinesterase (ChE) activity in mice after high doses of three commonly used statins (atorvastatin, simvastatin, and rosuvastatin).

Materials and Methods

Two hours after vehicle (control) or statin dosing at 250, 500, 750, or 1000 mg/kg orally, each mouse was subjected to 5 min open-field activity, negative geotaxis at an angle of 45°/60 s, 5 min head pocking, and forced swimming endurance. Plasma, erythrocyte, and brain ChE activities were determined spectrophotometrically 2 and 24 h after oral dosing of statins at 500 and 1000 mg/kg.

Results

The statins variably, but dose-dependently and significantly (p < 0.05) delayed the latency to move in the open-field arena, decreased locomotion and rearing, reduced head pocking, and delayed negative geotaxis performance. However, statins significantly increased the duration of forced swimming and decreased the duration of immobility in the swimming tank. Statins significantly and dose-dependently decreased plasma, erythrocyte, and brain ChE activity 2 and 24 h after dosing. Plasma and brain ChE activities recovered by 5%-32.9% and 5.7%-14.4% 24 h later from the 2 h ChE values, respectively.

Conclusion

High doses of statins differentially modulate neurobehavioral outcomes in mice in association with reduced plasma, erythrocyte, and brain ChE activity. Plasma or erythrocyte ChE may be used for biomonitoring of the adverse/therapeutic effects of statins.

N-Formyl-Methionyl-Leucyl-Phenylalanine Plays a Neuroprotective and Anticonvulsant Role in Status Epilepticus Model

Status epilepticus (SE) is described as continuous and self-sustaining seizures, which triggers hippocampal neurodegeneration, inflammation, and gliosis. N-formyl peptide receptor (FPR) has been associated with inflammatory process. N-formyl-methionyl-leucyl-phenylalanine (fMLP) peptide plays an anti-inflammatory role, mediated by the activation of G-protein-coupled FPR. Here, we evaluated the influence of fMLP peptides on the behavior of limbic seizures, memory consolidation, and hippocampal neurodegeneration process. Male Wistar rats (Rattus norvegicus) received microinjections of pilocarpine in hippocampus (H-PILO, 1.2 mg/μL, 1 μL) followed by fMLP (1 mg/mL, 1 μL) or vehicle (VEH, saline 0.9%, 1 μL). During the 90 min of SE, epileptic seizures were analyzed according to the Racine's Scale. After 24 h of SE, memory impairment was assessed by the inhibitory avoidance test and the neurodegeneration process was evaluated in hippocampal areas. There was no change in latency and number of wet dog shake (WDS) after administration of fMLP. However, our results showed that the intrahippocampal infusion of fMLP reduced the severity of seizures, as well as the number of limbic seizures. In addition, fMLP infusion protected memory dysfunction followed by SE. Finally, the intrahippocampal administration of fMLP attenuated the process of neurodegeneration in both hippocampi. Taken together, our data suggest a new insight into the functional role of fMLP peptides, with important implications for their potential use as a therapeutic agent for the treatment of brain disorders, such as epilepsy. Schematic drawing on the neuroprotective and anticonvulsant role of fMLP during status epilepticus. Initially, a cannula was implanted in hippocampus and pilocarpine/saline was administered into the hippocampus followed by fMLP/saline (A-C). fMLP reduced seizure severity and neuronal death in the hippocampus, as well as protecting against memory deficit (D).

Thermoresponsive Gel-loaded Oxcarbazepine Nanosystems for Nose- To-Brain Delivery: Enhanced Antiepileptic Activity in Rats

BACKGROUND

Oxcarbazepine (OXC) is a frequently prescribed antiepileptic drug for managing focal and generalized seizures. Its therapeutic benefits are limited by its dose-dependent side effects. Nose-to-brain delivery is a novel route for improving the efficacy of antiepileptics. Drug encapsulation in mucoadhesive nanoparticles offers even more advantages for the nasal route.

OBJECTIVE

The study aimed to develop oxcarbazepine-loaded chitosan nanoparticles (OXC-NP) added to a mucoadhesive thermo-reversible gel for intranasal delivery and enhancement of antiepileptic activity.

METHODS

The formulation was optimized based on entrapment efficiency, polydispersity index, particle size, zeta potential, and in vitro release analysis. The therapeutic efficacy of OXC-NP was assessed in an epileptic rat model and compared to intranasal OXC and oral OXC.

RESULTS

The optimized OXC-NPs with chitosan exhibited particle size, zeta potential, and entrapment efficiency of 189 nm, + 31.4 mV ± 2.5 and 97.6% ± 0.14, respectively. The release of OXC was prolonged, reaching 47.1% after 6 h and 55% after 24 h. Enhanced antiepileptic activity of OXC-NP was manifested as decreased seizure score and prolonged survival. Halting of hippocampal TNF-α and IL-6 together with upregulated IL-10 could explain its anti-inflammatory mechanisms.

CONCLUSIONS

Intranasal OXC-NP-loaded in situ gel represents a promising formulation for enhanced antiepileptic potential achieved at low drug concentrations.

Prior Statin vs In-Hospital Statin Usage in Severe COVID-19: Review and Meta-Analysis

Studies have shown that statins can decrease COVID-19 mortality in hospitalized patients. This paper evaluates these studies and reviews the possible mechanism of how statins modulate COVID-19 severity. Meta-analysis of 31 retrospective studies demonstrated a reduction in mortality rate among statin users (OR 0.69, 95% CI 0.56-0.86, p =0.0008) (HR 0.83, 95% CI 0.72-0.95, p =0.0078). Meta-analysis of 8 randomized control studies demonstrated a nonsignificant reduction in mortality (OR 0.90, 95% CI 0.69-1.18, p =0.461), including four studies with medications other than statins, and four studies with only statins (OR 0.88, 95% CI 95% CI 0.64-1.21, p =0.423). Prolonged statin usage decreases the extracellular localization of ACE2, along with statins' immunomodulating effects and reduction of oxidative stress, decreases COVID-19 mortality. Hospitalized patients with COVID-19 should continue statin treatment if previously prescribed, and patients should not be started on statins, as they do not seem to provide any mortality benefit.

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.

Association between statin use during hospitalisation and mortality in patients with intracerebral haemorrhage: a propensity score-matched cohort study

OBJECTIVES

We examined the relationship between statin use during hospitalisation and mortality in patients with intracerebral haemorrhage (ICH).

DESIGN

Retrospective propensity-matched cohort study.

SETTING

Patients with ICH (≥18 years old) admitted to Beth Israel Deaconess Medical Center (Boston, Massachusetts, USA) from 2001 to 2012 registered in the Medical Information Mart for Intensive Care III database.

PARTICIPANTS

1043 patients with ICH (≥18 years) were evaluated for the relationship between statin use during hospitalisation and mortality.

INTERVENTIONS

Statin use.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was 90-day mortality. We used multivariable Cox regression analyses to calculate the adjusted HR with 95% CI and used propensity score analysis and an inverse probability weighting (IPW) model to ensure the robustness of our findings.

RESULTS

We included 1043 patients with ICH (362 and 681 were statins and non-statin users, respectively) between 2001 and 2012. The overall 90-day mortality was 29.8% (311/1043); it was 33.3% (227/681) and 23.2% (84/362) for non-statin and statin users, respectively. After adjusted for potential confounders, we found that statin use was associated with 29% lower of 90-day mortality (HR=0.71, 95% CI 0.52 to 0.97, p<0.05). IPW also demonstrated a significantly lower 90-day mortality in statin users. The HR was 0.69 (95% CI 0.54 to 0.88, p<0.01). The results remain stable in subgroup analyses and propensity score matching.

CONCLUSION

Statin use during hospitalisation may be associated with reduced risk-adjusted mortality in patients with ICH. Further randomised controlled trials are needed to clarify this association.

Rutin prevents seizures in kainic acid-treated rats: evidence of glutamate levels, inflammation and neuronal loss modulation

Rutin, a naturally derived flavonoid molecule with known neuroprotective properties, has been demonstrated to have anticonvulsive potential, but the mechanism of this effect is still unclear. The current study aimed to investigate the probable antiseizure mechanisms of rutin in rats using the kainic acid (KA) seizure model. Rutin (50 and 100 mg kg^-1) and carbamazepine (100 mg kg^-1) were administered daily by oral gavage for 7 days before KA (15 mg kg^-1) intraperitoneal (i.p.) injection. Seizure behavior, neuronal cell death, glutamate concentration, excitatory amino acid transporters (EAATs), glutamine synthetase (GS), glutaminase, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits GluA1 and GluA2, N-methyl-D-aspartate (NMDA) receptor subunits GluN2A and GluN2B, activated astrocytes, and inflammatory and anti-inflammatory molecules in the hippocampus were evaluated. Supplementation with rutin attenuated seizure severity in KA-treated rats and reversed KA-induced neuronal loss and glutamate elevation in the hippocampus. Decreased glutaminase and GluN2B, and increased EAATs, GS, GluA1, GluA2 and GluN2A were observed with rutin administration. Rutin pretreatment also suppressed activated astrocytes, downregulated the protein levels of inflammatory molecules [interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), high mobility group Box 1 (HMGB1), interleukin-1 receptor 1 (IL-1R1), and Toll-like receptor-4 (TLR-4)] and upregulated anti-inflammatory molecule interleukin-10 (IL-10) protein expression. Taken together, the results indicate that the preventive treatment of rats with rutin attenuated KA-induced seizures and neuronal loss by decreasing glutamatergic hyperactivity and suppressing the IL-1R1/TLR4-related neuroinflammatory cascade.

The Clinical Characteristics of New-Onset Epilepsy in the Elderly and Risk Factors for Treatment Outcomes of Antiseizure Medications

Objective

To describe the clinical characteristics of elderly patients with new-onset epilepsy in a Class A tertiary comprehensive hospital in north China and evaluate the treatment outcomes of antiseizure medications (ASMs). This study focuses on investigating the factors affecting the treatment outcomes, guiding the drug treatment, and judging the prognosis of elderly epilepsy patients.

Methods

We included patients aged 60 years or older at the time of their first seizure between January 2014 and August 2020. Demographic characteristics, effects of ASM, and the proportion of 1-year and long-term seizure freedom were reported. The univariate analysis and binary logistic regression were used to identify factors potentially influencing treatment outcomes.

Results

A total of 326 patients (median age 65 years, 67.2% men) were included. Moreover, 185 (56.7%) patients who received the first ASM monotherapy achieved 1 year of seizure freedom in the early stage. Compared with structural etiology, unknown etiology was associated with a higher likelihood of early seizure freedom (odds ratio [OR] = 0.545; p < 0.05). Conversely, comorbid intracranial malignant tumors, taking carbamazepine (CBZ), and sodium valproate (VPA) were associated with a lower likelihood of seizure freedom (OR = 3.527 vs. 6.550 vs. 8.829; p < 0.05). At long-term follow-up, 263 (80.6%) patients achieved seizure freedom, with 79.8% on monotherapy.

Conclusions

Elderly patients with new-onset epilepsy responded well to the initial ASMs treatment. Patients with intracranial malignant tumors and prescribed VPA and CBZ were less likely to achieve early seizure freedom, while those with unknown etiology had higher probabilities of achieving early seizure freedom than those with structural etiology.

Impact of drug treatment and drug interactions in post-stroke epilepsy

Stroke is a huge burden on our society and this is expected to grow in the future due to the aging population and the associated co-morbidities. The improvement of acute stroke care has increased the survival rate of stroke patients, and many patients are left with permanent disability, which makes stroke the main cause of adult disability. Unfortunately, many patients face other severe complications such as post-stroke seizures and epilepsy. Acute seizures (ASS) occur within 1 week after the stroke while later occurring unprovoked seizures are diagnosed as post-stroke epilepsy (PSE). Both are associated with a poor prognosis of a functional recovery. The underlying neurobiological mechanisms are complex and poorly understood. There are no universal guidelines on the management of PSE. There is increasing evidence for several risk factors for ASS/PSE, however, the impacts of recanalization, drugs used for secondary prevention of stroke, treatment of stroke co-morbidities and antiseizure medication are currently poorly understood. This review focuses on the common medications that stroke patients are prescribed and potential drug interactions possibly complicating the management of ASS/PSE.

New approaches for developing multi-targeted drug combinations for disease modification of complex brain disorders. Does epilepsy prevention become a realistic goal?

Over decades, the prevailing standard in drug discovery was the concept of designing highly selective compounds that act on individual drug targets. However, more recently, multi-target and combinatorial drug therapies have become an important treatment modality in complex diseases, including neurodegenerative diseases such as Alzheimer's and Parkinson's disease. The development of such network-based approaches is facilitated by the significant advance in our understanding of the pathophysiological processes in these and other complex brain diseases and the adoption of modern computational approaches in drug discovery and repurposing. However, although drug combination therapy has become an effective means for the symptomatic treatment of many complex diseases, the holy grail of identifying clinically effective disease-modifying treatments for neurodegenerative and other brain diseases remains elusive. Thus, despite extensive research, there remains an urgent need for novel treatments that will modify the progression of the disease or prevent its development in patients at risk. Here we discuss recent approaches with a focus on multi-targeted drug combinations for prevention or modification of epilepsy. Over the last ~10 years, several novel promising multi-targeted therapeutic approaches have been identified in animal models. We envision that synergistic combinations of repurposed drugs as presented in this review will be demonstrated to prevent epilepsy in patients at risk within the next 5-10 years.

Neuroinflammation as a Therapeutic Target for Mitigating the Long-Term Consequences of Acute Organophosphate Intoxication

Acute intoxication with organophosphates (OPs) can cause a potentially fatal cholinergic crisis characterized by peripheral parasympathomimetic symptoms and seizures that rapidly progress to status epilepticus (SE). While current therapeutic countermeasures for acute OP intoxication significantly improve the chances of survival when administered promptly, they are insufficient for protecting individuals from chronic neurologic outcomes such as cognitive deficits, affective disorders, and acquired epilepsy. Neuroinflammation is posited to contribute to the pathogenesis of these long-term neurologic sequelae. In this review, we summarize what is currently known regarding the progression of neuroinflammatory responses after acute OP intoxication, drawing parallels to other models of SE. We also discuss studies in which neuroinflammation was targeted following OP-induced SE, and explain possible reasons why such therapeutic interventions have inconsistently and only partially improved long-term outcomes. Finally, we suggest future directions for the development of therapeutic strategies that target neuroinflammation to mitigate the neurologic sequelae of acute OP intoxication.

Statin use for the prevention of seizure and epilepsy in the patients at risk: A systematic review and meta-analysis of cohort studies

OBJECTIVE

Statin use for the prevention of seizure and epilepsy had been suggested but remained controversial. We sought to search existing literature to determine whether prophylactic use of statin reduced the incidence of seizure and epilepsy in the patients at risk.

METHODS

Three electronic databases were thoroughly searched to identify clinical studies investigating the effects of statin use on patients at the risk of seizure or epilepsy. Regardless of heterogeneity quantified, a random effects meta-analyses were used to synthesize the evidence, to pool odds ratios (ORs) and corresponding 95 % confidence intervals (CIs).

RESULTS

Seven cohort studies involving 26,042 patients with newly-onset epileptogenic brain insults and no history of seizure and epilepsy before were included. Compared with patients didn't receive statin treatment after epileptogenic brain insults, those treated with statin had a lower risk of epilepsy (5 studies; 22,849 patients; pooled OR, 0.48; 95 % CI, 0.31 to 0.73; p =  0.001) and seizure (4 studies; 6076 subjects; pooled OR, 0.35; 95 % CI, 0.25 to 0.48; p =  0.001).

CONCLUSIONS

Evidence from this meta-analysis suggested that the use of statin should as primary prevention for patients with risk of seizures and epilepsy. Considering the limited number and quality of available studies, future randomized controlled trials are required to further demonstrate the association between statin use and incident of seizure and epilepsy.

Systematic evaluation of rationally chosen multitargeted drug combinations: a combination of low doses of levetiracetam, atorvastatin and ceftriaxone exerts antiepileptogenic effects in a mouse model of acquired epilepsy

Epileptogenesis, the gradual process that leads to epilepsy after brain injury or genetic mutations, is a complex network phenomenon, involving a variety of morphological, biochemical and functional brain alterations. Although risk factors for developing epilepsy are known, there is currently no treatment available to prevent epilepsy. We recently proposed a multitargeted, network-based approach to prevent epileptogenesis by rationally combining clinically available drugs and provided first proof-of-concept that this strategy is effective. Here we evaluated eight novel rationally chosen combinations of 14 drugs with mechanisms that target different epileptogenic processes. The combinations consisted of 2-4 different drugs per combination and were administered systemically over 5 days during the latent epileptogenic period in the intrahippocampal kainate mouse model of acquired temporal lobe epilepsy, starting 6 h after kainate. Doses and dosing intervals were based on previous pharmacokinetic and tolerability studies in mice. The incidence and frequency of spontaneous electrographic and electroclinical seizures were recorded by continuous (24/7) video linked EEG monitoring done for seven days at 4 and 12 weeks post-kainate, i.e., long after termination of drug treatment. Compared to vehicle controls, the most effective drug combination consisted of low doses of levetiracetam, atorvastatin and ceftriaxone, which markedly reduced the incidence of electrographic seizures (by 60%; p<0.05) and electroclinical seizures (by 100%; p<0.05) recorded at 12 weeks after kainate. This effect was lost when higher doses of the three drugs were administered, indicating a synergistic drug-drug interaction at the low doses. The potential mechanisms underlying this interaction are discussed. We have discovered a promising novel multitargeted combination treatment for modifying the development of acquired epilepsy.

Statin use and the risk of post-stroke seizures: A meta-analysis

PURPOSE

The magnitude of association between statin use and post-stroke seizures (PSS) risk remains unclear. Therefore, the aim of this meta-analysis was to evaluate this issue.

METHODS

We systematically searched electronic libraries, including Medline, Embase, and Cochrane databases, for relevant clinical studies. The main outcome was the risk of early PSS and the risk of post-stroke epilepsy (PSE). The pooled relative risks (RRs) and the corresponding 95% confidence intervals (CIs) were used to calculate the association between statin treatment and risks of early PSS and PSE.

RESULTS

A total of 7 articles met our inclusion criteria and were included. For early PSS risk, statin use was associated with a lower risk of early PSS (RR 0.36, 95% CI 0.25-0.53; p < 0.001). Subgroup analyses based on the prescribing timing of statins showed that pre-stroke statin use was not associated with the risk of early PSS; post-stroke statin use was associated with a lower risk of early PSS (RR 0.37, 95% CI 0.25-0.54; p < 0.001). For PSE risk, statin use was associated with a lower risk of PSE (RR 0.62, 95% CI 0.42-0.92; p = 0.017). Further subgroup analyses based on the prescribing timing of statins indicated that pre-stroke statin use was not associated with the risk of PSE; post-stroke statin use was associated with a lower risk of PSE (RR 0.59, 95% CI 0.49-0.70; p < 0.001).

CONCLUSIONS

Statin treatment, especially the post-statin treatment, was associated with lower risks of early PSS and PSE.

Repurposed molecules for antiepileptogenesis: Missing an opportunity to prevent epilepsy?

Prevention of epilepsy is a great unmet need. Acute central nervous system (CNS) insults such as traumatic brain injury (TBI), cerebrovascular accidents (CVA), and CNS infections account for 15%-20% of all epilepsy. Following TBI and CVA, there is a latency of days to years before epilepsy develops. This allows treatment to prevent or modify postinjury epilepsy. No such treatment exists. In animal models of acquired epilepsy, a number of medications in clinical use for diverse indications have been shown to have antiepileptogenic or disease-modifying effects, including medications with excellent side effect profiles. These include atorvastatin, ceftriaxone, losartan, isoflurane, N-acetylcysteine, and the antiseizure medications levetiracetam, brivaracetam, topiramate, gabapentin, pregabalin, vigabatrin, and eslicarbazepine acetate. In addition, there are preclinical antiepileptogenic data for anakinra, rapamycin, fingolimod, and erythropoietin, although these medications have potential for more serious side effects. However, except for vigabatrin, there have been almost no translation studies to prevent or modify epilepsy using these potentially "repurposable" medications. We may be missing an opportunity to develop preventive treatment for epilepsy by not evaluating these medications clinically. One reason for the lack of translation studies is that the preclinical data for most of these medications are disparate in terms of types of injury, models within different injury type, dosing, injury-treatment initiation latencies, treatment duration, and epilepsy outcome evaluation mode and duration. This makes it difficult to compare the relative strength of antiepileptogenic evidence across the molecules, and difficult to determine which drug(s) would be the best to evaluate clinically. Furthermore, most preclinical antiepileptogenic studies lack information needed for translation, such as dose-blood level relationship, brain target engagement, and dose-response, and many use treatment parameters that cannot be applied clinically, for example, treatment initiation before or at the time of injury and dosing higher than tolerated human equivalent dosing. Here, we review animal and human antiepileptogenic evidence for these medications. We highlight the gaps in our knowledge for each molecule that need to be filled in order to consider clinical translation, and we suggest a platform of preclinical antiepileptogenesis evaluation of potentially repurposable molecules or their combinations going forward.

The influence of statins on the risk of post-stroke epilepsy

BACKGROUND

Currently, statins are widely used for secondary prevention of stroke due to their pleiotropic neuroprotective effects. Epilepsy is a common complication of cerebrovascular diseases. The purpose of this study was to evaluate the effect of statin therapy on the occurrence of post-stroke epilepsy (PSE).

METHODS

In this prospective cohort study, patients who suffered an ischemic stroke and without history of epilepsy before stroke were enrolled. At baseline, patients were classified according to the particularities of statin therapy. Statin use onset and adherence to treatment were registered as well. After a follow-up period of 1 year, we assessed the occurrence of seizures and PSE.

RESULTS

Among the 477 patients included in our cohort, there were 91 (19.1%) patients without statins, 160 (33.5%) with simvastatin 20 mg, 180 (37.7%) with simvastatin 40 mg, and 46 (9.6%) with high-potency statins. Overall, PSE emerged in 53 (11.1%) patients. PSE was significantly more prevalent among those who did not receive statins and those with lower doses of simvastatin. Acute onset of statin use was associated with reduced odds of having PSE.

CONCLUSION

Adequate treatment with statins after stroke may lower the risk of PSE.

Nerolidol ameliorates cyclophosphamide-induced oxidative stress, neuroinflammation and cognitive dysfunction: Plausible role of Nrf2 and NF- κB

AIM

Cyclophosphamide (CP) is a potent anticancer and immunosuppressant drug. Studies have shown significant oxidative stress and cognitive impairment but neuroinflammatory and histological aberrations with its administration is underexplored. Nerolidol (NER) is a lipophilic bioactive molecule with antioxidant and anti-inflammatory properties but it has not been explored for neuroprotective potential in CP-induced neurotoxic manifestations. Therefore, in the present study, we aimed to evaluate the neuroprotective potential of NER in CP-induced neuroinflammation and associated comorbid conditions like depression and cognitive dysfunctions.

MATERIALS AND METHOD

In-silico study using Schrödinger software was used to assess the binding affinity of NER with Nrf2. In the In vivo study, NER 200 and 400 mg/kg p.o. were given from 1st day to 14th day. CP 200 mg/kg, i.p., was administered on the 7th day. After 24 h of the last dosing, neurobehavioral tests like spontaneous body alternation, passive avoidance and forced swim test were performed. On completion of study, mice were sacrificed, hippocampus and cortex were removed for biochemical estimations, histopathology and immunohistochemistry of p65 NF- κB and Nrf2.

KEY FINDINGS

In-silico study showed significant binding of NER into the pocket domain of Nrf2. In-vivo study showed protective effect of NER against CP-induced neuroinflammation, oxidative stress, cognitive impairment and structural abnormalities in the hippocampus and cortex regions.

SIGNIFICANCE

Findings of the study suggested that NER is a potential therapeutic molecule which can mitigate CP-induced neurotoxic manifestations via Nrf2 and NF-κB pathway. However, more detailed studies are needed to explicate the mechanism underlying its neuroprotective effect.

Propionate relieves pentylenetetrazol-induced seizures, consequent mitochondrial disruption, neuron necrosis and neurological deficits in mice

The present research was designed to evaluate the protective effects and underlying mechanisms of propionate, a bioactive food additive, on mitochondrial disruption, neuron necrosis and neurological deficits after epilepsy seizures. Epilepsy seizures was induced by repetitive injections of pentylenetetrazol at a dose of 37 mg per kg. Propionate (37.5, 50 and 75 mg/kg) as well as sodium valproate (300 mg/kg) were administrated intragastrically (i.g.) 1 h before each PTZ injection and continued for 40 days. The influence of propionate was assessed by many biochemical assays and neurobehavioral experiments. The results of gas chromatography (GC) analysis indicated that increased concentration of propionate can be explored in hippocampus area of propionate + PTZ treated animals. Propionate decreased epilepsy seizure intensity, increased latency of seizures. Meanwhile, propionate treatment reversed the structure disruption of the mitochondria, improved ATP level and lessened 8-OHdG level in the brains of animals with seizures. In addition, we find propionate pretreated can increase activities of the antioxidant enzymes (CAT, SOD, as well as GSH-Px) in mitochondria. Additionally, propionate reduced neuronal loss in hippocampus and our results suggest that HIF-1α/ERK pathway and neuron necrosis exists potential linkage during epileptogenesis. Moreover, as a result, propionate administration can significantly improve the neurological function estimated by a battery of functional tests. In conclusion, treatment with propionate attenuates mitochondrial disruption, hippocampal apoptosis and neurological deficits in a mouse model of epilepsy seizures. Therefore, propionate, currently used as a food preservative, has a potential additional advantage of ameliorating epilepsy seizures.

The Effect of Statins in Epilepsy: A Systematic Review

Background and Objectives

Statins are inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, used for the management of hypercholesterolemia and related atherosclerotic diseases. Several studies have indicated the neuroprotective effects of statins on several neuropathological conditions. However, the role of these medications in epilepsy is still unclear. The purpose is to evaluate and summarize the level of evidence on the efficacy of statins in neuronal hyperexcitability and the neuroinflammatory processes of epilepsy.

Methods

A systematic review was performed. Eligibility Criteria: This review involved studies conducted in humans and nonhuman experimental models, covering the use of an inhibitor of HMG-CoA reductase, alone or accompanied by another medication, in epilepsy. Information Sources: A systematic literature search was performed in PubMed, Embase, Ebsco Host, Scopus, Science Direct, Medline, and LILACS. Risk of Bias: It was evaluated with the Newcastle-Ottawa Scale and the experimental studies were evaluated using the GRADE tool.

Results

Twenty articles of the 183 evaluated were included. Sixteen studies were conducted in animal models and four studies in humans. Most studies in mice reported a reduction in epileptiform activity and reduction in systemic inflammation with the treatment of statins, potentially influencing epilepsy control. Few studies in humans were performed in the geriatric population with variable results (neuroinflammation, seizure prevention, cell death, prevention of kindling, increase in convulsive threshold, increase in latency, decrease in frequency of crisis, and reduction in mortality) related to reduction in the rate of hospitalizations, mortality, and prevention of epilepsy. Studies in mice found a decrease in interleukin-1β (IL-1β), IL-6, and tumor necrosis factor alpha and an increase in IL-10 and endothelial nitric oxide synthase.

Conclusions

The possible antiepileptic mechanism of statins may be related to the reduction in neuroinflammation mediated by a decrease in pro-inflammatory cytokines and action in the nitrergic system. Further studies evaluating the impact of statins on seizure control are necessary.

The holy grail of epilepsy prevention: Preclinical approaches to antiepileptogenic treatments

A variety of acute brain insults can induce epileptogenesis, a complex process that results in acquired epilepsy. Despite advances in understanding mechanisms of epileptogenesis, there is currently no approved treatment that prevents the development or progression of epilepsy in patients at risk. The current concept of epileptogenesis assumes a window of opportunity following acute brain insults that allows intervention with preventive treatment. Recent results suggest that injury-induced epileptogenesis can be a much more rapid process than previously thought, suggesting that the 'therapeutic window' may only be open for a brief period, as in stroke therapy. However, experimental data also suggest a second, possibly delayed process ("secondary epileptogenesis") that influences the progression and refractoriness of the epileptic state over time, allowing interfering with this process even after onset of epilepsy. In this review, both methodological issues in preclinical drug development and novel targets for antiepileptogenesis will be discussed. Several promising drugs that either prevent epilepsy (antiepileptogenesis) or slow epilepsy progression and alleviate cognitive or behavioral comorbidities of epilepsy (disease modification) have been described in recent years, using diverse animal models of acquired epilepsy. Promising agents include TrkB inhibitors, losartan, statins, isoflurane, anti-inflammatory and anti-oxidative drugs, the SV2A modulator levetiracetam, and epigenetic interventions. Research on translational target validity and on prognostic biomarkers that can be used to stratify patients (or experimental animals) at high risk of developing epilepsy will hopefully soon lead to proof-of-concept clinical trials with the most promising drugs, which will be essential to make prevention of epilepsy a reality. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.

Atorvastatin prevents lipopolysaccharide-induced depressive-like behaviour in mice

Clinical and pre-clinical evidences indicate an association between inflammation and depression since increased levels of pro-inflammatory cytokines are associated with depression-related symptoms. Atorvastatin is a cholesterol-lowering statin that possesses pleiotropic effects including neuroprotective and antidepressant actions. However, the putative neuroprotective effect of atorvastatin treatment in the acute inflammation mice model of depressive-like behaviour has not been investigated. In the present study, we aimed to investigate the effect of atorvastatin treatment on lipopolysaccharide (LPS) induced depressive-like behaviour in mice. Mice were treated with atorvastatin (1 or 10 mg/kg, v.o.) or fluoxetine (30 mg/kg, positive control, v.o.) for 7 days before LPS (0.5 mg/kg, i.p.) injection. Twenty four hours after LPS infusion, mice were submitted to the forced swim test, tail suspension test or open field test. After the behavioural tests, mice were sacrificed and the levels of tumour necrosis factor-α (TNF-α), brain-derived neurotrophic factor (BDNF), glutathione and malondialdehyde were measured. Atorvastatin (1 or 10 mg/kg/day) or fluoxetine treatment prevented LPS-induced increase in the immobility time in the forced swim and tail suspension tests with no alterations in the locomotor activity evaluated in the open field test. Atorvastatin (1 or 10 mg/kg/day) or fluoxetine treatment also prevented LPS-induced increase in TNF-α and reduction of BDNF levels in the hippocampus and prefrontal cortex. Treatment with atorvastatin (1 or 10 mg/kg/day) or fluoxetine prevented LPS-induced increase in lipid peroxidation and the reduction of glutathione levels in the hippocampus and prefrontal cortex. The present study suggests that atorvastatin treatment exerted neuroprotective effects against LPS-induced depressive-like behaviour which may be related to reduction of TNF-α release, oxidative stress and modulation of BDNF expression.

Intranasally administered pitavastatin ameliorates pentylenetetrazol-induced neuroinflammation, oxidative stress and cognitive dysfunction

AIM

The present study aimed to evaluate the neuroprotective potential of intranasally administered pitavastatin in the PTZ-induced kindling model.

MATERIALS AND METHODS

Subconvulsant dose of PTZ (35 mg/kg, i.p) was administered on an alternate day until the development of kindling. Behavioural test, biochemical tests and inflammatory cytokines were estimated. Comparative molecular docking study of sodium valproate (VPA) and pitavastatin was performed to predict the binding affinity with GABA_A and GABA transaminase. Intranasally administered pitavastatin (0.5 mg/kg and 1 mg/kg) and VPA (200 mg/kg) were used to investigate its protective effect.

KEY FINDINGS

Comparative in-silico study showed docking score of -4.56 and -2.86 against GABA_A receptor whereas -5.56 and -1.86, against GABA transaminase. Root mean square deviation (RMSD) of 0.39A and 0.55A was found for pitavastatin and VPA, respectively. The present study showed the dose-dependent protective effect of intranasally administered pitavastatin and oral VPA against PTZ-induced seizure, cognitive impairment, oxidative stress, and neuroinflammation.

SIGNIFICANCE

Our findings suggest that the intranasally administered pitavastatin is potential therapeutic approach to managing PTZ-induced kindling and associated comorbid conditions via its antioxidant, anti-inflammatory, and anticonvulsant potential. Further, pitavastatin can modulate GABA_A receptor and GABA transaminase enzyme to ameliorate seizure. Meanwhile, more extensive studies are required to establish the molecular mechanism underlying the neuroprotective effect of pitavastatin.