Vitamin C antioxidant effects in hippocampus of adult Wistar rats after seizures and status epilepticus induced by pilocarpine

Oxidative stress in rat brain during experimental status epilepticus: effect of antioxidants

Antioxidants have been proposed as a treatment for diseases of the central nervous system. However, few studies actually studied their effects in the brain. To test central actions of antioxidants, we used the lithium-pilocarpine (Li-Pilo) model of status epilepticus (SE) in the rat in which seizures are accompanied by significant oxidative stress. We used in vivo microdialysis to determine isoprostane levels during SE in real time and brain homogenates for other measures of oxidative stress. Six different antioxidants were tested in acute and preventive experiments (vitamin C, vitamin E, ebselen, resveratrol, n-tert-butyl-α-phenylnitrone and coenzyme Q10). None of the antioxidants had an effect when given acutely during SE. In contrast, when antioxidants were given for 3 days prior to seizure induction, vitamins C and E reduced isoprostane formation by 58% and 65%, respectively. Pretreatment with the other antioxidants was ineffective. In brain homogenates prepared after 90 min of seizures, SE decreased the ratio of reduced vs. oxidized glutathione (GSH/GSSG ratio) from 60.8 to 7.50 and caused a twofold increase of 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels and protein carbonyls. Pretreatment with vitamin C or vitamin E mitigated these effects and increased the GSH/GSSG ratio to 23.9 and 28.3, respectively. Again, the other antioxidants were not effective. We conclude that preventive treatment with vitamin C or vitamin E ameliorates seizure-induced oxidative damage in the brain. Several well-studied antioxidants were inactive, possibly due to limited brain permeability or a lack of chain-breaking antioxidant activity in hydrophilic compounds.

Oxidative Stress and Neurodegeneration in Animal Models of Seizures and Epilepsy

Free radicals are generated in the brain, as well as in other organs, and their production is proportional to the brain activity. Due to its low antioxidant capacity, the brain is particularly sensitive to free radical damage, which may affect lipids, nucleic acids, and proteins. The available evidence clearly points to a role for oxidative stress in neuronal death and pathophysiology of epileptogenesis and epilepsy. The present review is devoted to the generation of free radicals in some animal models of seizures and epilepsy and the consequences of oxidative stress, such as DNA or mitochondrial damage leading to neurodegeneration. Additionally, antioxidant properties of antiepileptic (antiseizure) drugs and a possible use of antioxidant drugs or compounds in patients with epilepsy are reviewed. In numerous seizure models, the brain concentration of free radicals was significantly elevated. Some antiepileptic drugs may inhibit these effects; for example, valproate reduced the increase in brain malondialdehyde (a marker of lipid peroxidation) concentration induced by electroconvulsions. In the pentylenetetrazol model, valproate prevented the reduced glutathione concentration and an increase in brain lipid peroxidation products. The scarce clinical data indicate that some antioxidants (melatonin, selenium, vitamin E) may be recommended as adjuvants for patients with drug-resistant epilepsy.

The New Challenge of Green Cosmetics: Natural Food Ingredients for Cosmetic Formulations

Nowadays, much attention is paid to issues such as ecology and sustainability. Many consumers choose “green cosmetics”, which are environmentally friendly creams, makeup, and beauty products, hoping that they are not harmful to health and reduce pollution. Moreover, the repeated mini-lock downs during the COVID-19 pandemic have fueled the awareness that body beauty is linked to well-being, both external and internal. As a result, consumer preferences for makeup have declined, while those for skincare products have increased. Nutricosmetics, which combines the benefits derived from food supplementation with the advantages of cosmetic treatments to improve the beauty of our body, respond to the new market demands. Food chemistry and cosmetic chemistry come together to promote both inside and outside well-being. A nutricosmetic optimizes the intake of nutritional microelements to meet the needs of the skin and skin appendages, improving their conditions and delaying aging, thus helping to protect the skin from the aging action of environmental factors. Numerous studies in the literature show a significant correlation between the adequate intake of these supplements, improved skin quality (both aesthetic and histological), and the acceleration of wound-healing. This review revised the main foods and bioactive molecules used in nutricosmetic formulations, their cosmetic effects, and the analytical techniques that allow the dosage of the active ingredients in the food.

Preharvest Treatment with Oxalic Acid Improves Postharvest Storage of Lemon Fruit by Stimulation of the Antioxidant System and Phenolic Content

Lemon trees (Citrus limon (L.) Burm. F) were treated monthly with oxalic acid (OA) at 0.1, 0.5, and 1 mM from initial fruit growth on the tree until harvest in2019. The experiment was repeated in 2020, with the application of OA 1 mM (according to the best results of 2019). In both years, fruit from OA-treated trees and the controls were stored for 35 days at 10 °C. Results showed that all treatments reduced weight loss (WL) and maintained higher firmness, total soluble solids (TSS), and total acidity (TA) than in the controls. Meanwhile, colour (hue angle) did not show significant differences. The activity of antioxidant enzymes, catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD) in the flavedo of the fruit from the OA-treated trees was higher than in the controls at harvest and after 35 days of storage. Similarly, the total phenolic content (TPC) in the flavedo and juice of the fruit from the OA-treated trees were higher than in the controls. The increase in the activity of the antioxidant enzymes and TPC started with the first preharvest OA treatment and were maintained during fruit development on the tree until harvest. Preharvest OA treatments enhanced the antioxidant system of the lemon fruits, reducing the postharvest incidence of decay. Thus, OA could be a useful tool to increase the quality and functional properties of lemon fruits.

Electrophysiological and neurochemical evaluation of the adverse effects of REM sleep deprivation and epileptic seizures on rat's brain

AIM

The current study aims to investigate the impact of paradoxical (REM) sleep deprivation and/or epileptic seizures on rat's cortical brain tissues.

MAIN METHODS

Animals were divided into four groups; control, epileptic, REM sleep deprived and epileptic subjected to REM sleep deprivation. Electrocorticogram (ECoG) signals were recorded and quantitatively analyzed for each group. Concentrations of amino acid neurotransmitters; proinflammatory cytokines; and oxidative stress parameters; and acetylcholinesterase activity were determined in the cortex of the animals in different groups.

KEY FINDINGS

Results showed significant variations in the spectral distribution of ECoG waves in the epilepsy model, 24- and 48-hours of REM sleep deprivation and their combined effects indicating a state of cortical hyperexcitability. Significant increases in NO and taurine and significant decrement in glutamine, GABA and glycine were determined. In REM sleep deprived rats significant elevation in glutamate, aspartate, glycine and taurine and a significant lowering in GABA were obtained. This was accompanied by significant reduction in AchE and IL-β. In the cortical tissue of epileptic rats deprived from REM sleep significant increases in lipid peroxidation, TNF-α, IL-1β, IL-6 and aspartate and a significant reduction in AchE were observed.

SIGNIFICANCE

The present data indicate that REM sleep deprivation induces an increase in lipid peroxidation and storming in proinflammatory cytokines in the cortex of rat model of epilepsy during SRS. These changes are associated with a decreased seizure threshold as inferred from the increase in alpha and Beta waves and a decrease in Delta waves of ECoG.

Coenzyme Q10 Insufficiency Contributes to the Duration and Frequency of Seizures in Epileptic Patients

Introduction:

Oxidative stress has recently emerged as a possible mechanism in the pathogenesis of epilepsy. Coenzyme Q10 (CoQ10) is a strong endogenous antioxidant that protects cells from lipid oxidation and Reactive Oxygen Species (ROS) production; however, the impact of CoQ10 on seizure characteristics in epileptic patients is unclear.

Methods:

The current study enrolled patients with Epileptic Seizure (ES) to evaluate their serum concentration of CoQ10 and to investigate whether a relationship exists between CoQ10 levels with the duration, frequency, and type of seizure.

Results:

A total of 39 patients with epileptic seizures and 35 healthy controls were included in the study. The levels of CoQ10 in ES patients were significantly lower in comparison with healthy controls (11.99±5.93 vs (ng/ml). 16.48±4.20 (ng/ml) P<0.001). We also found that the duration of epilepsy and seizure frequency was negatively correlated with serum CoQ10 levels.

Conclusion:

These findings indicate that CoQ10 deficiency might substantially contribute to the clinical signs of epileptic patients.

Seizure-Induced Oxidative Stress in Status Epilepticus: Is Antioxidant Beneficial?

Epilepsy is a common neurological disorder which affects patients physically and mentally and causes a real burden for the patient, family and society both medically and economically. Currently, more than one-third of epilepsy patients are still under unsatisfied control, even with new anticonvulsants. Other measures may be added to those with drug-resistant epilepsy. Excessive neuronal synchronization is the hallmark of epileptic activity and prolonged epileptic discharges such as in status epilepticus can lead to various cellular events and result in neuronal damage or death. Unbalanced oxidative status is one of the early cellular events and a critical factor to determine the fate of neurons in epilepsy. To counteract excessive oxidative damage through exogenous antioxidant supplements or induction of endogenous antioxidative capability may be a reasonable approach for current anticonvulsant therapy. In this article, we will introduce the critical roles of oxidative stress and further discuss the potential use of antioxidants in this devastating disease.

Salidroside shows anticonvulsant and neuroprotective effects by activating the Nrf2-ARE pathway in a pentylenetetrazol-kindling epileptic model

Evidence points towards oxidative stress and neuroinflammation being major processes associated with brain dysfunction in epilepsy. Salidroside reportedly possesses anti-oxidative activity and neuroprotective potential, in addition to exerting an anti-neuroinflammatory response. This study was designed to evaluate the anticonvulsant and neuroprotective role of salidroside in rats with pentylenetetrazole (PTZ) kindling and to explore the underlying mechanism. Male Wistar rats were administered a sub-convulsive dose of PTZ (35 mg/kg) every other day for 15 injections, and salidroside (50 mg/kg) was injected intraperitoneally along with alternate-day PTZ. The seizure degree, cognitive function, and number of hippocampal neurons were investigated. The expression of nuclear factor erythroid 2-related factor- antioxidant response element (Nrf2-ARE) signaling pathways, oxidative stress parameters and inflammatory cytokines were also observed. Our study showed that salidroside treatment suppressed the kindling acquisition process, ameliorated cognitive impairment, and rescued the number of pyramidal neurons in the CA3 regions. Salidroside treatment could activate the Nrf2-ARE signal pathway, and suppressed oxidative stress and neuroinflammation. Our findings demonstrated that salidroside exerted anticonvulsant and neuroprotective effects in epileptic rats by activating the Nrf2-ARE signal pathway.

Citrus limon (Lemon) Phenomenon-A Review of the Chemistry, Pharmacological Properties, Applications in the Modern Pharmaceutical, Food, and Cosmetics Industries, and Biotechnological Studies

This review presents important botanical, chemical and pharmacological characteristics of Citrus limon (lemon)—a species with valuable pharmaceutical, cosmetic and culinary (healthy food) properties. A short description of the genus Citrus is followed by information on the chemical composition, metabolomic studies and biological activities of the main raw materials obtained from C. limon (fruit extract, juice, essential oil). The valuable biological activity of C. limon is determined by its high content of phenolic compounds, mainly flavonoids (e.g., diosmin, hesperidin, limocitrin) and phenolic acids (e.g., ferulic, synapic, p-hydroxybenzoic acids). The essential oil is rich in bioactive monoterpenoids such as D-limonene, β-pinene, γ-terpinene. Recently scientifically proven therapeutic activities of C. limon include anti-inflammatory, antimicrobial, anticancer and antiparasitic activities. The review pays particular attention, with references to published scientific research, to the use of C. limon in the food industry and cosmetology. It also addresses the safety of use and potential phototoxicity of the raw materials. Lastly, the review emphasizes the significance of biotechnological studies on C. limon.

Reactive oxygen species in status epilepticus

There has been growing evidence for a critical role of oxidative stress in neurodegenerative disease, providing novel targets for disease modifying treatments. Although antioxidants have been suggested and tried in the treatment of epilepsy, it is only recently that the pivotal role of oxidative stress in the pathophysiology of status epilepticus has been recognized. Although conventionally thought to be generated by mitochondria, reactive oxygen species during status epilepticus and prolonged seizure are generated mainly by NADPH (nicotinamide adenine dinucleotide phosphate) oxidase (stimulated by NMDA receptor activation). Excessive production of reactive oxygen species results in lipid peroxidation, DNA damage, enzyme inhibition, and mitochondrial damage, culminating in neuronal death. Antioxidant therapy has been hampered by poor CNS penetration and rapid consumption by oxidants. However, alternative approaches such as inhibiting NADPH oxidase or increasing endogenous antioxidant defenses through activation of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) could avoid these problems. Small molecules that increase Nrf2 activation have proven to be not only effective neuroprotectants following status epilepticus, but also potently antiepileptogenic. There are "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".

Effects of Astaxanthin Supplementation on Oxidative Stress

A systematic review and meta-analysis was conducted in six databases from 1948 to 2015 to assess the antioxidant activity of astaxanthin in humans. Nine randomized controlled trials were included in the systematic review. Results of meta-analysis revealed a borderline significant antioxidant effect of astaxanthin between the intervention and control groups, with a malondialdehyde-lowering effect for lipid peroxidation (p = 0.050). However, the data included here are insufficient. When compared with the baseline in intervention groups, the meta-analysis suggested that astaxanthin supplements significantly decreased plasma malondialdehyde {Standard mean difference (SMD) -1.32 μmol/L [95% CI -1.92, -0.72]; p < 0.0001} and isoprostane (SMD -3.10 ng/mL [95% CI -4.69, -1.51]; p < 0.0001). However, they increased superoxide dismutase (SMD 1.57 U/mL [95% CI 0.57, 2.56]; p = 0.002) and total antioxidant capacity (SMD 0.77 mmol 95% CI [0.12, 1.43]; p = 0.018). For dosage subgroup analysis, high dose (≥20 mg/day) of astaxanthin showed significant antioxidant effect (on total antioxidant capacity, isoprostane, and superoxide dismutase, p < 0.05). However, low dose (<20 mg/day) showed no significant effect (p > 0.05). Further duration subgroup analysis indicated that astaxanthin showed antioxidant effect after a 3-week intervention (p < 0.001), whereas this effect was not observed after a 12-week or 3-month intervention (on isoprostane and superoxide dismutase, p > 0.05). This review suggested that the antioxidant effect of astaxanthin on humans is unclear.

Pilocarpine/ascorbic acid interaction in the immature brain: Electrophysiological and oxidative effects in well-nourished and malnourished rats

Ascorbic acid (AA) administration has been associated with neuroprotection against oxidative stress, although at high doses it can facilitate oxidation and acts like a proconvulsing drug. The pilocarpine-induced epilepsy model has been widely studied. However, less is known about the effects of sub-convulsive doses of pilocarpine on brain activity in immature animals under normal or deficient nutritional conditions. Herein, we investigated the effects of chronic pilocarpine administration in a sub-convulsive dose, with or without AA, on the excitability-related phenomenon denominated as cortical spreading depression (CSD) and levels of lipid peroxidation-induced malondialdehyde in well-nourished and malnourished rats. At postnatal days 7-28, rats received no gavage treatment (naïve group), saline (vehicle group), 45 mg/kg/d of pilocarpine and/or 120 mg/kg/d of AA. CSD propagation and malondialdehyde levels were analyzed at 34-40 days. The pilocarpine group presented with lower CSD velocities, while AA groups exhibited higher CSD velocities and augmented malondialdehyde levels compared with controls. The co-administration of AA partially antagonized the pilocarpine CSD effects, but did not revert it to control levels. Malnutrition increased CSD amplitude and velocity in comparison to the well-nourished condition. The electrocorticogram (ECoG) amplitude increased after CSD (ECoG potentiation) when compared with the baseline amplitude before CSD. However, no intergroup difference was observed in this CSD-related ECoG potentiation. The results support the hypothesis of a pilocarpine/ascorbic acid interaction in the immature rat brain and might help further the understanding of this interaction on neuronal electrical activity and oxidative stress.

Sub-chronic boldine treatment exerts anticonvulsant effects in mice

OBJECTIVES

Boldine is an aporphine alkaloid which is best known for its antioxidant, anti-inflammatory and cytoprotective characteristics. It seems that all these activities are related to boldine ability to scavenge reactive free radicals. As indicated by several pieces of evidence, free radicals generation are involved in initiation and propagation of epilepsy.

METHODS

In this study, we investigated the sub-chronic effects of boldine on intraperitoneal and intravenous pentylenetetrazole (PTZ) models and electroshock-induced seizure in mice. Mice in treatment groups received different doses of boldine (once in a day for 8 days, ip.) and control group received solvent. We also evaluated the role of antioxidant activity of boldine as a part of its anti-seizure activity.

RESULTS

The results demonstrated that sub-chronic administration of boldine increased time latencies to the onset of myoclonic and clonic seizure induced by intraperitoneal PTZ model and increased clonic seizure threshold in intravenous PTZ model. It also decreased tonic hind limb extension duration in the electroshock-induced seizure model. Co-administration of boldine with a non-effective dose of vitamin C induced the anticonvulsant activity of vitamin C. Superoxide dismutase (SOD) activity in the brain tissue of animals was increased following sub-chronic administration of boldine which all indicated antioxidant activity of boldine may be a part of its anticonvulsant activity.

DISCUSSION

The anticonvulsant effects of boldine in three different animal models of epilepsy have been indicated. We have also shown that the antioxidant role of boldine might be a part of its anticonvulsant effect.

Antiepileptogenic and Neuroprotective Effects of Pergularia daemia on Pilocarpine Model of Epilepsy

In this study, we investigated antiepileptogenic and neuroprotective effects of the aqueous extract of Pergularia daemia roots (PDR) using in vivo and in vitro experimental models. In in vivo studies, status epilepticus caused by pilocarpine injection triggers epileptogenesis which evolves during about 1–2 weeks. After 2 h of status epilepticus, mice were treated during the epileptogenesis period for 7 days with sodium valproate and vitamin C (standards which demonstrated to alter epileptogenesis), or Pergularia daemia. The animals were then, 1 week after status epilepticus, challenged with acute pentylenetetrazole (PTZ) administration to test behaviorally the susceptibility to a convulsant agent of animals treated or not with the plan extract. Memory was assessed after PTZ administration in the elevated plus maze and T-maze paradigms at 24 and 48 h. Antioxidant and acetylcholinesterase activities were determined in the hippocampus after sacrifice, in vitro studies were conducted using embryonic rat primary cortical cultures exposed to L-glutamate. Cell survival rate was measured and apoptotic and necrotic cell death determined. The results showed that chronic oral administration of PDR significantly and dose-dependently increased the latency to myoclonic jerks, clonic seizures and generalized tonic–clonic seizures, and the seizure score. In addition, PDR at all doses (from 4.9 to 49 mg/kg) significantly decreased the initial and retention transfer latencies in the elevated plus maze. Interestingly PDR at the same doses significantly increased the time spent and the number of entries in T-maze novel arm. PDR significantly increased the activities of acetylcholinesterase and antioxidant enzymes superoxide dismutase, catalase, and total glutathione and proteins, and decreased malondialdehyde level. Furthermore, PDR increased viability rate of primary cortical neurons after L-glutamate-induced excitotoxicity, in a dose dependent manner. Altogether these results suggest that PDR has antiepileptogenic and neuroprotective effects, which could be mediated by antioxidant and antiapoptotic activities.

Vitamin C attenuates methotrexate-induced oxidative stress in kidney and liver of rats

Like several other anticancer drugs, methotrexate (MTX) causes side effects, such as neuropathic pain, hepatotoxicity, and nephrotoxicity. Abnormal production of reactive oxygen species has been suspected in the pathophysiology of MTX-induced hepatorenal toxicity. Therefore, the aim of this study was to investigate the probable protective role of vitamin C (Vit C) on oxidative stress induced by MTX in the liver and kidney tissues of rats. A total of 32 rats were randomly and equally divided into four groups. The first group served as the control group. The second group received a single dose of 20 mg/kg of MTX intraperitoneally. To demonstrate our hypothesis, the third and the fourth groups received 250 mg/kg of Vit C for 3 days by oral gavage, with or without MTX treatment. At the end of the study, the liver and kidney tissues of the rats were collected and examined using histology. Both the tissues were assayed for malondialdehyde concentration and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities. In hepatic and renal tissues, lipid peroxidation levels were increased, whereas SOD, CAT, and GSH-Px levels were decreased by MTX. All parameters, including CAT levels in hepatic tissue, were significantly restored after the administration of Vit C for 3 days. Similar to the biochemical findings, evidence of oxidative damage was examined in both types of tissues by histopathological examination. From the results of this study, we were able to observe that Vit C administration modulates the antioxidant redox system and reduces the renal and hepatic oxidative stress induced by MTX. Vit C can ameliorate the toxic effect of MTX in liver and kidney tissues of rat.

Anticonvulsant effects of antiaris toxicaria aqueous extract: investigation using animal models of temporal lobe epilepsy

BACKGROUND

Antiaris toxicaria has previously shown anticonvulsant activity in acute animal models of epilepsy. The aqueous extract (AAE) was further investigated for activity in kindling with pentylenetetrazole and administration of pilocarpine and kainic acid which mimic temporal lobe epilepsy in various animal species.

RESULTS

ICR mice and Sprague-Dawley rats were pre-treated with AAE (200-800 mg kg^-1) and convulsive episodes induced using pentylenetetrazole, pilocarpine and kainic acid. The potential of AAE to prevent or delay onset and alter duration of seizures were measured. In addition, damage to hippocampal cells was assessed in kainic acid-induced status epilepticus test. 800 mg kg^-1 of the extract suppressed the kindled seizure significantly (P < 0.05) as did diazepam. AAE also produced significant effect (P < 0.01) on latency to first myoclonic jerks and on total duration of seizures. The latency to onset of wet dog shakes was increased significantly (P < 0.05) by AAE on kainic acid administration. Carbamazepine and Nifedipine (30 mg kg^-1) also delayed the onset. Histopathological examination of brain sections showed no protective effect on hippocampal cells by AAE and nifedipine. Carbamazepine offered better preservation of hippocampal cells in the CA1, CA2 and CA3 regions.

CONCLUSION

Antiaris toxicaria may be effective in controlling temporal lobe seizures in rodents.

Dual Role of Vitamin C on the Neuroinflammation Mediated Neurodegeneration and Memory Impairments in Colchicine Induced Rat Model of Alzheimer Disease

The neurodegeneration in colchicine induced AD rats (cAD) is mediated by cox-2 linked neuroinflammation. The importance of ROS in the inflammatory process in cAD has not been identified, which may be deciphered by blocking oxidative stress in this model by a well-known anti-oxidant vitamin C. Therefore, the present study was designed to investigate the role of vitamin C on colchicine induced oxidative stress linked neuroinflammation mediated neurodegeneration and memory impairments along with peripheral immune responses in cAD. The impairments of working and reference memory were associated with neuroinflammation and neurodegeneration in the hippocampus of cAD. Administration of vitamin C (200 and 400 mg/kg BW) in cAD resulted in recovery of memory impairments, with prevention of neurodegeneration and neuroinflammation in the hippocampus. The neuroinflammation in the hippocampus also influenced the peripheral immune responses and inflammation in the serum of cAD and all of these parameters were also recovered at 200 and 400 mg dose of vitamin C. However, cAD treated with 600 mg dose did not recover but resulted in increase of memory impairments, neurodegeneration and neuroinflammation in hippocampus along with alteration of peripheral immune responses in comparison to cAD of the present study. Therefore, the present study showed that ROS played an important role in the colchicine induced neuroinflammation linked neurodegeneration and memory impairments along with alteration of peripheral immune responses. It also appears from the results that vitamin C at lower doses showed anti-oxidant effect and at higher dose resulted in pro-oxidant effects in cAD.

Anticonvulsant effect of argan oil on pilocarpine model induced status epilepticus in wistar rats

Argan oil (AO) is rich in oleic and linoleic acids, polyphenols, sterols, and tocopherols. This composition gives it numerous beneficial pharmacological effects such as hypolipemiant, hypotensive, and antiproliferative. Oxidative stress is a mechanism of cell death induced by seizures and status epilepticus (SE). This study aims at investigating AO effects on (i) latency to first seizure, seizure severity, weight loss, mortality rate, (ii) lipid peroxidation level, nitrite level, and catalase activity in the hippocampus after SE induced by pilocarpine (PC). Wistar rats (1-month old) were daily administered by oral gavage with AO (1 ml/100 g/day) or with NaCl 0.9% during 2 months before receiving PC (400 mg/kg). After the PC injection, all groups were observed for 24 h. The catalase activity, the lipid peroxidation, and nitrite concentrations were measured using spectrophotometric methods. AO pretreatment increased the latency to first seizures, decreased the weight loss, and reduced mortality rate after SE. AO pretreatment produces significant decrease of the lipid peroxidation and nitrite levels. On the contrary, AO increased the catalase activity in rat hippocampus after seizures. For the first time, our results suggest that AO pretreatment is capable of attenuating seizure severity and oxidative stress in the hippocampus of Wistar rats. This indicates that AO may exhibit a neuroprotection against the temporal lobe epilepsy. Further investigations are in progress to confirm this pharmacological property.

Status epilepticus: Using antioxidant agents as alternative therapies

The epileptic state, or status epilepticus (SE), is the most serious situation manifested by individuals with epilepsy, and SE events can lead to neuronal damage. An understanding of the molecular, biochemical and physiopathological mechanisms involved in this type of neurological disease will enable the identification of specific central targets, through which novel agents may act and be useful as SE therapies. Currently, studies have focused on the association between oxidative stress and SE, the most severe epileptic condition. A number of these studies have suggested the use of antioxidant compounds as alternative therapies or adjuvant treatments for the epileptic state.

Expression pattern of NMDA receptors reveals antiepileptic potential of apigenin 8-C-glucoside and chlorogenic acid in pilocarpine induced epileptic mice

The present study was aimed to evaluate the effect of apigenin 8-C-glucoside (Vitexin) and chlorogenic acid on epileptic mice induced by pilocarpine and explored its possible mechanisms. Intraperitonial administration of pilocarpine (85mg/kg) induced seizure in mice was assessed by behavior observations, which is significantly (p>0.05) reduced by apigenin 8-C-glucoside (AP8CG) (10mg/kg) and chlorogenic acid (CA) (5mg/kg), similar to diazepam. Seizure was accompanied by an imbalance in the levels of Gamma-aminobutyric acid (GABA) and glutamate in the pilocarpine administered group. Moreover, convulsion along with reduced acetylcholinesterase, increased monoamine oxidase and oxidative stress was observed in epileptic mice brain. AP8CG and CA significantly restored back to normal levels even at lower doses. Further, increased lipid peroxidation and nitrite content was also significantly attenuated by AP8CG and CA. However, CA was found to be more effective when compared to AP8CG. In addition, the mRNA expression of N-methyl-d-aspartate receptor (NMDAR), mGluR1 and mGlu5 was significantly (P≤0.05) inhibited by AP8CG and CA in a lower dose. The mRNA expression of GRIK1 did not differ significantly in any of the group and showed a similar pattern of expression. Our result shows that AP8CG and CA selectively inhibit NMDAR, mGluR1 and mGlu5 expression. Modification in the provoked NMDAR calcium response coupled with neuronal death. Hence, these findings underline that the polyphenolics, AP8CG and CA have exerted antiepileptic and neuroprotective activity by suppressing glutamate receptors.

K(+) channel blocker-induced neuroinflammatory response and neurological disorders: immunomodulatory effects of astaxanthin

OBJECTIVE

Channelopathies due to the brain ion channel dysfunction is considered to be an important mechanism involved in various neurodegenerative diseases. In this study, we evaluated the ability of kaliotoxin (KTX) as K(+) channel blocker to induce neuro-inflammatory response and neurodegenerative alteration. We also investigate the effects of astaxanthin (ATX) against KTX disorders.

MATERIAL AND TREATMENT

NMRI mice were injected with KTX (1 pg/kg, by i.c.v route) with or without pretreatment using ATX (80 mg/kg, o.p route).

RESULTS

Results showed that KTX was detected in cerebral cortex area due to its binding to the specific receptors (immunofluorescence analysis). It induced an activation of inflammatory cascade characterized by an increase of IL-6, TNFα, NO, MDA levels and NF-κB expression associated to a decrease of GSH level. The neuroinflammatory response is accompanied with cerebral alterations and blood-brain barrier (BBB) disruption. The use of ATX prior to the KTX exerts a preventive effect not only on the neuroinflammation but also on altered tissues and the BBB disruption.

CONCLUSIONS

Kaliotoxin is able to induce neurological disorders by blocking the K(+) ion channel, and ATX suppresses this alterations with down regulation of IL-6, TNF-α and NF-κB expression in the brain.

Combined Low-Intensity Exercise and Ascorbic Acid Attenuates Kainic Acid-Induced Seizure and Oxidative Stress in Mice

Physical exercise and vitamins such as ascorbic acid (ASC) have been recognized as an effective strategy in neuroprotection and neurorehabilitatioin. However, there is a need to find an efficient treatment regimen that includes ASC and low-intensity exercise to diminish the risk of overtraining and nutritional treatment by attenuating oxidative stress. In the present study, we investigated the combined effect of low-intensity physical exercise (EX) and ASC on kainic acid (KA)-induced seizure activity and oxidative stress in mice. The mice were randomly assigned into groups as follows: "KA only" (n = 11), "ASC + KA" (n = 11), "Ex + KA" (n = 11), "ASC + Ex + KA" (n = 11). In the present study, low intensity of swimming training period lasted 8 weeks and consisted of 30-min sessions daily (three times per week) without tail weighting. Although no preventive effect of low-intensity exercise or ASC on KA seizure occurrence was evident, there was a decrease of seizure activity, seizure development (latency to first seizures), and mortality in "ASC + Ex + KA" compared to "ASC + KA", "Ex + KA", and "KA only" group. In addition, a preventive synergistic coordination of low-intensity exercise and ASC was evident in glutathione peroxidase and superoxide dismutase activity compared to separate treatment. These results suggest that low-intensity exercise and ASC treatment have preventive effects on seizure activity and development with alternation of oxidative status.

Astaxanthin rescues neuron loss and attenuates oxidative stress induced by amygdala kindling in adult rat hippocampus

Oxidative stress plays an important role in the neuronal damage induced by epilepsy. The present study assessed the possible neuroprotective effects of astaxanthin (ATX) on neuronal damage, in hippocampal CA3 neurons following amygdala kindling. Male Sprague-Dawley rats were chronically kindled in the amygdala and ATX or equal volume of vehicle was given by intraperitoneally. Twenty-four hours after the last stimulation, the rats were sacrificed by decapitation. Histopathological changes and the levels of reactive oxygen species (ROS), malondialdehyde (MDA) and reduced glutathione (GSH) were measured, cytosolic cytochrome c (CytC) and caspase-3 activities in the hippocampus were also recorded. We found extensive neuronal damage in the CA3 region in the kindling group, which was preceded by increases of ROS level and MDA concentration and was followed by caspase-3 activation and an increase in cytosolic CytC. Treatment with ATX markedly attenuated the neuronal damage. In addition, ATX significantly decreased ROS and MDA concentrations and increased GSH levels. Moreover, ATX suppressed the translation of CytC release and caspase-3 activation in hippocampus. Together, these results suggest that ATX protects against neuronal loss due to epilepsy in the rat hippocampus by attenuating oxidative damage, lipid peroxidation and inhibiting the mitochondrion-related apoptotic pathway.

Effect of intrahippocampal administration of vitamin C and progesterone on learning in a model of multiple sclerosis in rats

PURPOSE

The purpose of this study was to evaluate the effect of intrahippocampal injection of vitamin C and progesterone, alone or in combination, on passive avoidance learning (PAL) in multiple sclerosis.

METHODS

Sixty- three male wistar rats were divided into nine groups (n=7) as following: control (saline), lesion, vitamin C (0.2, 1, 5 mg/kg), progesterone (0.01, 0.1, 1 µg/µl) and combination therapy. Lesion was induced by intrahippocampal injection of ethidium bromide. In combination therapy, animals were treated with vitamin C (5 mg/kg) plus progesterone (0.01 mg/kg). Animals in experimental groups received different treatments for 7 days, and then all groups were tested for step through latency (STL).

RESULTS

Our results showed that intrahippocampal injection of ethidium bromide destroys PAL significantly (p<0.001). Treatment with vitamin C (5mg/kg) significantly (p<0.05) improved PAL. Lower doses of progesterone did not affect latency but dose of 1 µg/µl significantly (p<0.05) increased STL. In combination therapy group STL was significantly (p<0.05) more than in the lesion group, although it was not significantly different from the vitamin C group.

CONCLUSION

Based on our results, we concluded that intrahippocampal injection of vitamin C improves memory for PAL, but progesterone alone or in combination with vitamin C had no improving effects on memory.

Evaluation of p-cymene, a natural antioxidant

CONTEXT

Several studies have demonstrated that essential oils and their major components have antioxidant activity. p-Cymene is a monoterpene and a major constituent of essential oils of various species of plants.

OBJECTIVE

This paper evaluated the antioxidant potential of p-cymene in the hippocampus of mice by determining the levels of thiobarbituric acid reactive substances (TBARS), nitrite content, and activity of catalase (CAT) and superoxide dismutase (SOD).

MATERIALS AND METHODS

Swiss mice were intraperitoneally treated with 0.05% Tween 80 dissolved in 0.9% saline solution, ascorbic acid 250 mg/kg, and p-cymene at doses of 50, 100, and 150 mg/kg, respectively. After treatment, all groups were observed for 24 h, afterwards, the groups were euthanized for removal of the brain and dissection of the hippocampus.

RESULTS

The results of treatment with p-cymene were a significant decrease in lipid peroxidation and nitrite content at a dose of CYM 50: 65.54%, CYM 100: 73.29%, CYM 150: 89.83%, and CYM 50: 71.21%; CYM 100: 68.61% and CYM 150:67%, respectively, when compared with the control group. The results showed that at all tested doses, p-cymene produces an increase in SOD and catalase activity significantly at a dose of CYM 50: 22.7%, CYM 100: 33.9%, CYM 150: 63.1%, and CYM 50: 119.25%, CYM 100: 151.83% and CYM 150: 182.70%, respectively, when compared with the vehicle-treated group.

DISCUSSION AND CONCLUSION

The result of this study shows that p-cymene has an antioxidant potential in vivo and may act as a neuroprotective agent in the brain. This compound may present a new strategy in the development of treatment for many diseases in which oxidative stress plays an important pathophysiological role.

Seizure-induced oxidative stress in temporal lobe epilepsy

An insult to the brain (such as the first seizure) causes excitotoxicity, neuroinflammation, and production of reactive oxygen/nitrogen species (ROS/RNS). ROS and RNS produced during status epilepticus (SE) overwhelm the mitochondrial natural antioxidant defense mechanism. This leads to mitochondrial dysfunction and damage to the mitochondrial DNA. This in turn affects synthesis of various enzyme complexes that are involved in electron transport chain. Resultant effects that occur during epileptogenesis include lipid peroxidation, reactive gliosis, hippocampal neurodegeneration, reorganization of neural networks, and hypersynchronicity. These factors predispose the brain to spontaneous recurrent seizures (SRS), which ultimately establish into temporal lobe epilepsy (TLE). This review discusses some of these issues. Though antiepileptic drugs (AEDs) are beneficial to control/suppress seizures, their long term usage has been shown to increase ROS/RNS in animal models and human patients. In established TLE, ROS/RNS are shown to be harmful as they can increase the susceptibility to SRS. Further, in this paper, we review briefly the data from animal models and human TLE patients on the adverse effects of antiepileptic medications and the plausible ameliorating effects of antioxidants as an adjunct therapy.

Antioxidants as a preventive treatment for epileptic process: a review of the current status

Epilepsy is known as one of the most frequent neurological diseases, characterized by an enduring predisposition to generate epileptic seizures. Oxidative stress is believed to directly participate in pathways leading to neurodegeneration, which serves as the most important propagating factor, leading to the epileptic condition and cognitive decline. Moreover, there is also a growing body of evidence showing the disturbance of antioxidant system balance and consequently increased production of reactive species in patients with epilepsy. A meta-analysis, conducted in the present review confirms an association between epilepsy and increased lipid peroxidation. Furthermore, it was also shown that some of the antiepileptic drugs could potentially be responsible for additionally increased lipid peroxidation. Therefore, it is reasonable to propose that during the epileptic process neuroprotective treatment with antioxidants could lead to less sever structural damages, reduced epileptogenesis and milder cognitive deterioration. To evaluate this hypothesis studies investigating the neuroprotective therapeutic potential of various antioxidants in cells, animal seizure models and patients with epilepsy have been reviewed. Numerous beneficial effects of antioxidants on oxidative stress markers and in some cases also neuroprotective effects were observed in animal seizure models. However, despite these encouraging results, till now only a few antioxidants have been further applied to patients with epilepsy as an add-on therapy. Based on the several positive findings in animal models, a strong need for more carefully planned, randomized, double-blind, cross-over, placebo-controlled clinical trials for the evaluation of antioxidants efficacy in patients with epilepsy is warranted.

Low brain ascorbic acid increases susceptibility to seizures in mouse models of decreased brain ascorbic acid transport and Alzheimer's disease

Seizures are a known co-occurring symptom of Alzheimer's disease, and they can accelerate cognitive and neuropathological dysfunction. Sub-optimal vitamin C (ascorbic acid) deficiency, that is low levels that do not lead the sufferer to present with clinical signs of scurvy (e.g. lethargy, hemorrhage, hyperkeratosis), are easily obtainable with insufficient dietary intake, and may contribute to the oxidative stress environment of both Alzheimer's disease and epilepsy. The purpose of this study was to test whether mice that have diminished brain ascorbic acid in addition to carrying human Alzheimer's disease mutations in the amyloid precursor protein (APP) and presenilin 1 (PSEN1) genes, had altered electrical activity in the brain (electroencephalography; EEG), and were more susceptible to pharmacologically induced seizures. Brain ascorbic acid was decreased in APP/PSEN1 mice by crossing them with sodium vitamin C transporter 2 (SVCT2) heterozygous knockout mice. These mice have an approximately 30% decrease in brain ascorbic acid due to lower levels of SVCT2 that supplies the brain with ASC. SVCT2+/-APP/PSEN1 mice had decreased ascorbic acid and increased oxidative stress in brain, increased mortality, faster seizure onset latency following treatment with kainic acid (10 mg/kg i.p.), and more ictal events following pentylenetetrazol (50 mg/kg i.p.) treatment. Furthermore, we report the entirely novel phenomenon that ascorbic acid deficiency alone increased the severity of kainic acid- and pentylenetetrazol-induced seizures. These data suggest that avoiding ascorbic acid deficiency may be particularly important in populations at increased risk for epilepsy and seizures, such as Alzheimer's disease.

The effects of quinacrine, proglumide, and pentoxifylline on seizure activity, cognitive deficit, and oxidative stress in rat lithium-pilocarpine model of status epilepticus

The present data indicate that status epilepticus (SE) induced in adult rats is associated with cognitive dysfunctions and cerebral oxidative stress (OS). This has been demonstrated using lithium-pilocarpine (Li-Pc) model of SE. OS occurring in hippocampus and striatum of mature brain following SE is apparently due to both the increased free radicals production and the limited antioxidant defense. Pronounced alterations were noticed in the enzymatic, glutathione-S transferase (GST), catalase (CAT), and superoxide dismutase (SOD), as well as in the nonenzymatic; thiobarbituric acid (TBARS) and reduced glutathione (GST), indices of OS in the hippocampus and striatum of SE induced animals. Quinacrine (Qcn), proglumide (Pgm), and pentoxifylline (Ptx) administered to animals before inducing SE, were significantly effective in ameliorating the seizure activities, cognitive dysfunctions, and cerebral OS. The findings suggest that all the drugs were effective in the order of Ptx < Pgm < Qcn indicating that these drugs are potentially antiepileptic as well as antioxidant; however, further studies are needed to establish this fact. It can be assumed that these antiepileptic substances with antioxidant properties combined with conventional therapies might provide a beneficial effect in treatment of epilepsy through ameliorating the cerebral OS.

Low plasma antioxidant status in patients with epilepsy and the role of antiepileptic drugs on oxidative stress

BACKGROUND

Oxidative stress has been implicated in various disorders including epilepsy. We studied the antioxidant status in patients with epilepsy and aimed at determining whether there was any difference in the antioxidant levels between patients and controls, patients who are not on antiepileptic drugs (AEDs), and on treatment, between individual AEDs and patients on monotherapy and polytherapy.

MATERIALS AND METHODS

Antioxidant levels like catalase, glutathione peroxidase (GPx), vitamin E, glutathione (GSH), thiol group (SH), uric acid, and total antioxidant capacity (TAC) were compared between 100 patients with epilepsy and equal number of controls. Twenty-five patients who were not on AEDs were compared with patients on AEDs and the control group. Patients were divided into monotherapy and polytherapy group and antioxidant status was compared between the two groups and between individual drugs.

RESULTS

Catalase, SH, vitamin E, and TAC were significantly low in patients with epilepsy than those in the control group (P < 0.001). GSH and uric acid did not show any difference; GPx in patients was significantly higher than those in the control group There were no differences in the antioxidant levels between the treated and the untreated groups; however, it was lower in untreated patients than controls (P < 0.001), suggesting that AEDs do not modify the oxidative stress. Patients on Valproate (VPA) showed higher catalase and GPx levels. Catalase was higher in the monotherapy than polytherapy group (P < 0.04).

CONCLUSION

Our study found significantly low levels of antioxidant in patients as compared to controls. AED did not influence the antioxidant status suggesting that seizures induce oxidative stress.

In vitro antioxidant and cytotoxic activity of some synthetic riparin-derived compounds

This study aimed to study the in vitro antioxidant activity and cytotoxicity on tumor cells lines of six synthetic substances derived from riparins. All the substances showed antioxidant activity and riparins C, D, E, F presented cell growth inhibition rates greater than 70%, suggesting that these molecules have antitumor properties. These substances also caused greater than 80% releases of cytoplasmic lactate dehydrogenase enzyme (LDH). Although the antioxidant and antitumor properties presented herein require further assessment, the outcomes indicate that these novel riparins are promising biologically active compounds.

Gas chromatography-mass spectrometry-based metabolic profiling of cerebrospinal fluid from epileptic dogs

Epilepsy is a common neurological disorder with seizures, but diagnostic approaches in veterinary clinics remain limited. Cerebrospinal fluid (CSF) is a body fluid used for diagnosis in veterinary medicine. In this study, we explored canine epilepsy diagnostic biomarkers using gas chromatography-mass spectrometry (GC-MS)-based metabolic profiling of CSF and multivariate data analysis. Profiles for subjects with idiopathic epilepsy differed significantly from those of healthy controls and subjects with symptomatic epilepsy. Among 60 identified metabolites, the levels of 20 differed significantly among the three groups. Glutamic acid was significantly increased in idiopathic epilepsy, and some metabolites including ascorbic acid were changed in both forms of epilepsy. These findings show that metabolic profiles of CSF differ between idiopathic and symptomatic epilepsy and that metabolites including glutamic acid and ascorbic acid in CSF may be useful for diagnosis of canine epilepsy.

Vitamin C: a new auxiliary treatment of epilepsy?

Although many approaches to the therapy of epilepsy exist, most of antiepileptic drugs, beside certain and unquestioned benefits, have convinced disadvantages. That is the reason for looking for new methods of treatment. Ascorbic acid, as an antioxidant and electron donor accumulated in central nervous system, seems to take part in diminishing reactions of oxidative stress in brain and cooperate with other antioxidants like alpha-tocoferol. Vitamin C, easily transported through the blood-brain barrier, is proved to reduce injury in the hippocampus during seizures. Depending on type of seizures, it has mostly inhibitory activity and even decreases mortality. Moreover, vitamin C acts as a neuroprotective factor by consolidating cell membranes and decreasing lipid peroxidation. A possible adjunctive role of vitamin C in epileptic patients needs to be considered.

Oxidative stress markers in the neocortex of drug-resistant epilepsy patients submitted to epilepsy surgery

PURPOSE

While there is solid experimental evidence of brain oxidative stress in animal models of epilepsy, it has not been thoroughly verified in epileptic human brain. Our purpose was to determine and to compare oxidative stress markers in the neocortex of epileptic and non-epileptic humans, with the final objective of confirming oxidative stress phenomena in human epileptic brain.

METHODS

Neocortical samples from drug-resistant epilepsy patients submitted to epilepsy surgery (n=20) and from control, non-epileptic cortex samples (n=11) obtained from brain bank donors without neurological disease, were studied for oxidative stress markers: levels of reactive oxygen species (ROS), such as superoxide anion (O2(-)); activity of antioxidant enzymes: superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and glutathione reductase (GR); and markers of damage to biomolecules (lipid peroxidation and DNA oxidation).

RESULTS

Compared with non-epileptic controls, the neocortex of epileptic patients displayed increased levels of superoxide anion (P≤0.001), catalase (P≤0.01), and DNA oxidation (P≤0.001); a decrease in GPx (P≤0.05), and no differences in SOD, GR and lipid peroxidation.

CONCLUSIONS

Our findings in humans are in agreement with those found in animal models, supporting oxidative stress as a relevant mechanism also in human epilepsy. The concurrent increase in catalase and decrease in GPx, together with unchanged SOD levels, suggests catalase as the main antioxidant enzyme in human epileptic neocortex. The substantial increase in the levels of O2(-) and 8-oxo-dG in epileptic patients supports a connection between chronic seizures and ROS-mediated neural damage.

Protective effects of curcumin against lithium-pilocarpine induced status epilepticus, cognitive dysfunction and oxidative stress in young rats

Status epilepticus (SE), one of the most severe forms of epilepsy is regarded a medical emergency with considerable morbidity and mortality. Due to the limited efficacy and enormous side effects of currently available drugs, a search for new safe and effective therapeutic agents is critical using experimentally induced SE in animals. The lithium-pilocarpine (Li-Pc) model of SE is most suitable and frequently used for pathophysiological and management strategies of SE. Recent studies have shown significant potential of pharmacological, prophylactic or therapeutic use of curcumin (Cur) in many beneficial activities in the body including neuroprotection in neurodegenerative diseases and antioxidant properties. The present study describes anticonvulsive effects of Cur in Li-Pc induced SE in young rats. The effect of Cur was examined on the intensity and frequency of SE, cognitive behavior in water maze as well as on oxidative stress related enzymes in the brain. Besides its anticonvulsant effect, Cur significantly ameliorates SE-induced cognitive dysfunction and oxidative damages in the hippocampus and striatum areas of the brain. Possible therapeutic application of Cur as an anticonvulsant and as an antioxidant for the treatment of SE has a great potential and warrants further studies.

The role of reactive species in epileptogenesis and influence of antiepileptic drug therapy on oxidative stress

Epilepsy is considered one of the most common neurological disorders. The focus of this review is the acquired form of epilepsy, with the development process consisting of three major phases, the acute injury phase, the latency epileptogenesis phase, and the phase of spontaneous recurrent seizures. Nowadays, an increasing attention is paid to the possible interrelationship between oxidative stress resulting in disturbance of physiological signalling roles of calcium and free radicals in neuronal cells and mitochondrial dysfunction, cell damage, and epilepsy. The positive stimulation of mitochondrial calcium signals by reactive oxygen species and increased reactive oxygen species generation resulting from increased mitochondrial calcium can lead to a positive feedback loop. We propose that calcium can pose both, physiological and pathological effects of mitochondrial function, which can lead in neuronal cell death and consequent epileptic seizures. Various antiepileptic drugs may impair the endogenous antioxidative ability to prevent oxidative stress. Therefore, some antiepileptic drugs, especially from the older generation, may trigger oxygen-dependent tissue injury. The prooxidative effects of these antiepileptic drugs might lead to enhancement of seizure activity, resulting in loss of their efficacy or apparent functional tolerance and undesired adverse effects. Additionally, various reactive metabolites of antiepileptic drugs are capable of covalent binding to macromolecules which may lead to deterioration of the epileptic seizures and systemic toxicity. Since neuronal loss seems to be one of the major neurobiological abnormalities in the epileptic brain, the ability of antioxidants to attenuate seizure generation and the accompanying changes in oxidative burden, further support an important role of antioxidants as having a putative antiepileptic potential.

Anticonvulsant and related neuropharmacological effects of the whole plant extract of Synedrella nodiflora (L.) Gaertn (Asteraceae)

Purpose:

The plant Synedrella nodiflora (L) Gaertn is traditionally used by some Ghanaian communities to treat epilepsy. To determine if this use has merit, we studied the anticonvulsant and other neuropharmacological effects of a hydro-ethanolic extract of the whole plant using murine models.

Materials and Methods:

The anticonvulsant effect of the extract (10–1000 mg/kg) was tested on the pentylenetetrazole-, picrotoxin-, and pilocarpine-induced seizure models and PTZ-kindling in mice/rats. The effect of the extract was also tested on motor coordination using the rota-rod.

Results:

The results obtained revealed that the extract possesses anticonvulsant effects in all the experimental models of seizures tested as it significantly reduced the latencies to myoclonic jerks and seizures as well as seizure duration and the percentage severity. The extract was also found to cause motor incoordination at the higher dose of 1000 mg/kg.

Conclusions:

In summary, the hydro-ethanolic extract of the whole plant of S. nodiflora possesses anticonvulsant effects, possibly through an interaction with GABAergic transmission and antioxidant mechanisms and muscle relaxant effects. These findings thus provide scientific evidence in support of the traditional use of the plant in the management of epilepsy.

Effects of neuropeptide S on seizures and oxidative damage induced by pentylenetetrazole in mice

Neuropeptide S (NPS) and its receptor were recently discovered in the central nervous system. In rodents, NPS promotes hyperlocomotion, wakefulness, anxiolysis, anorexia, and analgesia and enhances memory when injected intracerebroventricularly (i.c.v.). Herein, NPS at different doses (0.01, 0.1 and 1nmol) was i.c.v. administered in mice challenged with pentylenetetrazole (PTZ; 60mg/kg) repeatedly injected. Aiming to assess behavioral alterations and oxidative damage to macromolecules in the brain, NPS was injected 5min prior to the last dose of PTZ. The administration of NPS only at 1nmol increased the duration of seizures evoked by PTZ, without modifying frequency and latency of seizures. Biochemical analysis revealed that NPS attenuated PTZ-induced oxidative damage to proteins and lipids in the hippocampus and cerebral cortex. In contrast, the administration of NPS to PTZ-treated mice increased DNA damage in the hippocampus, but not cerebral cortex. In conclusion, this is the first evidence of the potential proconvulsive effects of NPS in mice. The protective effects of NPS against lipid and protein oxidative damage in the mouse hippocampus and cerebral cortex evoked by PTZ-induced seizures are quite unexpected. The present findings were discussed analyzing the paradoxical effects of NPS: facilitation of convulsive behavior and protection against oxidative damage to lipids and proteins.

Pharmacological and biochemical analysis of interactions between N-acetylcysteine and some antiepileptic drugs on experimental seizures in mice

PURPOSE

In view of a putative role of oxidative stress in the pathophysiology of seizures, this study addressed the interactions between N-acetylcysteine (NAC), a potent antioxidant and two antiepileptic drugs sodium valproate (SVP) and phenytoin (PHT) on experimental seizures in mice.

METHODS

The interaction was studied at three fixed ratio combinations (i.e., 1:1, 1:3, and 3:1) in the mouse maximal electroshock (MES) test using isobolographic analysis. Markers of oxidative stress (reduced glutathione [GSH] and malondialdehyde [MDA]) were estimated in the cortex of mice pretreated with either of these drugs alone or their 3:1 ratio combinations at the experimentally determined ED(50) values (ED(50 exp) values). The grip strength and spontaneous alternation behavior (SAB) were also assessed. In addition, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and calcium levels were estimated.

RESULTS

We found an anticonvulsant action of NAC in the MES test. Further, the ED(50 exp) values for the combinations of PHT and NAC did not differ from the theoretically calculated ED(50) values indicating additive effects. In case of SVP and NAC, however, the ED(50 exp) values were lower than the theoretically calculated ED(50) values. The interaction of SVP with NAC at the fixed ratios of 1:3 and 3:1 was found to be synergistic. No significant changes were observed in the grip strength, SAB, cortical GSH and MDA levels, serum AST, ALT, ALP, or calcium levels.

CONCLUSION

Our results thus hold promise for the use of NAC as an adjunct to PHT and SVP therapy.

Analgesic, anticonvulsant and antioxidant activities of 3-[4-(3-trifluoromethyl-phenyl)-piperazin-1-yl]-dihydrofuran-2-one dihydrochloride in mice

Recently we have shown that 3-[4-(3-trifluoromethyl-phenyl)-piperazin-1-yl]-dihydrofuran-2-one dihydrochloride (LPP1) is an antinociceptive and local anesthetic agent in rodents. Below an extended study of the pharmacological activity of LPP1 is described. In vitro LPP1 has no affinity for GABA(A), opioidergic μ and serotonergic 5-HT(1A) receptors. The total antioxidant capacity of LPP1 (1-10mM) measured as ABTS radical cation-scavenging activity showed that LPP1 has dose-dependent antioxidant properties in vitro. Low plasma concentration of this compound detected by means of HPLC method 30min after its intraperitoneal administration suggests a rapid conversion to metabolite(s) which may be responsible for its analgesic and anticonvulsant activities in vivo. In vivo the compound's influence on the electroconvulsive threshold and its activity in the maximal electroshock seizure test (MES) were evaluated. The results demonstrated that LPP1 had an anticonvulsant activity in the MES model (ED(50)=112mg/kg) and at a dose of 50mg/kg was able to elevate the electroconvulsive threshold for 8mA as compared to the vehicle-treated mice. The analgesic activity of LPP1 was investigated in the acetic acid-induced writhing test in two groups of mice: animals with sensory C-fibers ablated, and mice with C-fibers unimpaired. It proved the potent activity of this compound in both groups (approximately 85% as compared to the vehicle-treated mice). The adverse effects of LPP1 were evaluated as acute toxicity (LD(50)=747.8mg/kg) and motor coordination impairments in the rotarod and chimney tests. The results from these tests show that LPP1 at doses higher than 100mg/kg is likely to impair the motor performance of experimental animals. Concluding, LPP1 is an analgesic and anticonvulsant compound which has antioxidant properties in vitro. Further studies are necessary to assess whether the antioxidant activity and the receptor profiling demonstrated in vitro can be confirmed for its metabolite(s) that are formed in vivo.