Free radicals, anticonvulsants, and the neuronal ceroid-lipofuscinoses

Upregulation of ACSL, ND75, Vha26 and sesB genes by antiepileptic drugs resulted in genotoxicity in drosophila

Clobazam (CLB) and Vigabatrin (VGB) are commonly used antiepileptic drugs (AEDs) in the treatment of epilepsy. Here, we have examined the genotoxic effect of these AEDs in Drosophila melanogaster. The Drosophila larvae were exposed to different concentrations of CLB and VGB containing food media. The assessment encompassed oxidative stress, DNA damage, protein levels, and gene expression profiles. In the CLB-treated group, a reduction in reactive oxygen species (ROS) and lipid peroxidation (LPO) levels was observed, alongside increased levels of superoxide dismutase (SOD), catalase (CAT), and nitric oxide (NO). Conversely, the VGB-treated group displayed contrasting results, with increased ROS and LPO and decreased SOD, CAT, and NO levels. However, both CLB and VGB induced DNA damage in Drosophila. Proteomic analysis (SDS-PAGE and OHRLCMS) in the CLB and VGB groups identified numerous proteins, including Acyl-CoA synthetase long-chain, NADH-ubiquinone oxidoreductase 75 kDa subunit, V-type proton ATPase subunit E, ADP/ATP carrier protein, malic enzyme, and DNA-binding protein modulo. These proteins were found to be associated with pathways like growth promotion, notch signaling, Wnt signaling, neuromuscular junction (NMJ) signaling, bone morphogenetic protein (BMP) signaling, and other GABAergic mechanisms. Furthermore, mRNA levels of ACSL, ND75, Vha26, sesB, and Men genes were upregulated in both CLB and VGB-treated groups. These findings suggest that CLB and VGB could have the potential to induce genotoxicity and post-transcriptional modifications in humans, highlighting the importance of monitoring their effects when used as AEDs.

Application of Anticonvulsants, Antiepileptic Drugs, and Vitamin C in the Treatment and Analysis of Batten Disease

Batten disease is a rare group of neurological diseases, specifically called neuronal ceroid lipofuscinosis. This is a genetic disorder and usually manifests during childhood. Batten disease is fatal and there is currently no proven cure. However, there are certain treatment methods that show potential in mitigating the aftermath of the disease. This review will explore the application and effectiveness of antiepileptic drugs, anticonvulsants, and vitamin C in multiple scenarios to treat Batten disease. Anticonvulsants are a broad group of medications that are used to treat epileptic seizures. Epileptic seizures are a big indicator of Batten disease, making anticonvulsants a potential treatment for Batten disease patients. Antiepileptic drugs also work to stop seizures by decreasing neurological excitation, thus for the same reason are often grouped alongside anticonvulsants and are being investigated as a promising way to help Batten disease patients. Vitamin C helps maintain the integrity of several intracellular processes in the central nervous system, which makes it a possible candidate for treating Batten disease. The known effects of anticonvulsants, antiepileptic drugs, and vitamin C on Batten disease are very limited and should be considered more often by healthcare professionals because of their potential effects on patients with Batten disease.

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.

Lowered quality of life in mood disorders is associated with increased neuro-oxidative stress and basal thyroid-stimulating hormone levels and use of anticonvulsant mood stabilizers

RATIONALE, AIMS

Major affective disorders including bipolar disorder (BD) and major depressive disorder (MDD) are associated with impaired health-related quality of life (HRQoL). Oxidative stress and subtle thyroid abnormalities may play a pathophysiological role in both disorders. Thus, the current study was performed to examine whether neuro-oxidative biomarkers and thyroid-stimulating hormone (TSH) levels could predict HRQoL in BD and MDD.

METHODS

This cross-sectional study enrolled 68 BD and 37 MDD patients and 66 healthy controls. The World Health Organization (WHO) QoL-BREF scale was used to assess 4 QoL subdomains. Peripheral blood malondialdehyde (MDA), advanced oxidation protein products, paraoxonaxe/CMPAase activity, a composite index of nitro-oxidative stress, and basal TSH were measured.

RESULTS

In the total WHOQoL score, 17.3% of the variance was explained by increased advanced oxidation protein products and TSH levels and lowered CMPAase activity and male gender. Physical HRQoL (14.4%) was associated with increased MDA and TSH levels and lowered CMPAase activity. Social relations HRQoL (17.4%) was predicted by higher nitro-oxidative index and TSH values, while mental and environment HRQoL were independently predicted by CMPAase activity. Finally, 73.0% of the variance in total HRQoL was explained by severity of depressive symptoms, use of anticonvulsants, lower income, early lifetime emotional neglect, MDA levels, the presence of mood disorders, and suicidal ideation.

CONCLUSIONS

These data show that lowered HRQoL in major affective disorders could at least in part result from the effects of lipid peroxidation, protein oxidation, lowered antioxidant enzyme activities, and higher levels of TSH.

Evaluation of the Influence of Antiepileptic Therapy on Antioxidant Enzyme Activity and Lipid Peroxidation in Erythrocytes of Children With Epilepsy

The aim of this study was to evaluate the influence of antiepileptic therapy on antioxidant enzyme activity and lipid peroxidation in the erythrocytes of children with epilepsy. For this purpose, the activity of superoxide dismutase, glutathione peroxidase, and glutathione reductase and the malondialdehyde concentration in 61 healthy children and 90 children with epilepsy were measured. The activities of all of these enzymes were insignificantly higher, whereas the malondialdehyde concentration was significantly lower in the patients treated with carbamazepine monotherapy. In patients treated with valproate monotherapy, the activities of all enzymes were insignificantly lower, whereas the malondialdehyde concentration was insignificantly higher. In patients treated with polytherapy, the activity of superoxide dismutase was insignificantly lower, whereas the activity of glutathione peroxidase and glutathione reductase was insignificantly higher and the malondialdehyde concentration was lower. There were differences in glutathione reductase activity between the valproate monotherapy group and both the carbamazepine monotherapy and polytherapy groups and in malondialdehyde concentrations between the carbamazepine and valproate groups. The results indicate that the oxidant-antioxidant balance in children with epilepsy is modified by antiepileptic therapy. (J Child Neurol 2006;21:558–562; DOI 10.2310/7010.2006.00115).

Antiepileptic drugs affect lipid oxidative markers- neuroprostanes and F2-dihomo-isoprostanes- in patients with epilepsy: differences among first-, second-, and third-generation drugs by UHPLC-QqQ-MS/MS

This work show that treatment with new-generation AEDs reduces the excretion of NeuroPs/F₂-dihomo-IsoPs to values similar to those in the control group, indicating a positive effect of these AEDs on the antioxidant status of epileptic patients.

Edaravone ameliorates the adverse effects of valproic acid toxicity in small intestine

Valproic acid (VPA) is a drug used for the treatment of epilepsy, bipolar psychiatric disorders, and migraine. Previous studies have reported an increased generation of reactive oxygen species and oxidative stress in the toxic mechanism of VPA. Edaravone, a free radical scavenger for clinical use, can quench free radical reaction by trapping a variety of free radical species. In this study, effect of edaravone on some small intestine biochemical parameters in VPA-induced toxicity was investigated. Thirty seven Sprague Dawley female rats were randomly divided into four groups. The groups include control group, edaravone (30 mg–1 kg–1 day–1) given group, VPA (0.5 g–1 kg–1 day–1) given group, VPA + edaravone (in same dose) given group. Edaravone and VPA were given intraperitoneally for 7 days. Biochemical parameters such as malondialdehyde, as an index of lipid peroxidation(LPO), sialic acid (SA), glutathione levels and glutathione peroxidase, glutathione- S-transferase, superoxide dismutase, catalase, myeloperoxidase, alkaline phosphatase (ALP), and tissue factor (TF) activities were determined in small intestine samples by colorimetric methods. Decreased small intestine antioxidant enzyme activities, increased LPO and SA levels, and increased activities of ALP and TF were detected in the VPA group. Based on our results edaravone may be suggested to reverse the oxidative stress and inflammation due to VPA-induced small intestine toxicity.

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.

Oxidative injury in epilepsy: potential for antioxidant therapy?

Biological ill effects of oxidative injury from excess free radical production are implicated in many human conditions. Epilepsy is a chronic, dynamic neurological disorder associated with ongoing neuronal damage, particularly when uncontrolled. Oxidative injury may play a role in the initiation and progression of epilepsy, and therapies aimed at reducing oxidative stress may ameliorate tissue damage and favorably alter the clinical course. There is abundant in vivo evidence of oxidative injury in animal models of epilepsy and for efficacy of antioxidant therapy in reducing this injury in animal models of epileptogenesis. However, there is sparse direct clinical data on the use of antioxidants in human epilepsy. This review examines the evidence for the role of oxidative injury in epilepsy, the rationale for use of antioxidant therapy in epilepsy and appraises the current clinical performance of the studies of antioxidant therapies.

Anticonvulsant activity of Aloe vera leaf extract in acute and chronic models of epilepsy in mice

Objectives

The effect of Aloe vera in epilepsy has not yet been explored. This study was done to explore the effect of aqueous extract of Aloe vera leaf powder on three acute and one chronic model of epilepsy.

Methods

In acute study, aqueous extract of Aloe vera leaf (extract) powder was administered in doses 100, 200 and 400 mg/kg p.o. Dose of 400 mg/kg of Aloe vera leaf extract was chosen for chronic administration. Oxidative stress parameters viz. malondialdehyde (MDA) and reduced glutathione (GSH) were also estimated in brain of kindled animals.

Key findings

In acute study, Aloe vera leaf (extract) powder in a dose-dependent manner significantly decreased duration of tonic hind limb extension in maximal electroshock seizure model, increased seizure threshold current in increasing current electroshock seizure model, and increased latency to onset and decreased duration of clonic convulsion in pentylenetetrazole (PTZ) model as compared with control group. In chronic study, Aloe vera leaf (extract) powder prevented progression of kindling in PTZ-kindled mice. Aloe vera leaf (extract) powder 400 mg/kg p.o. also reduced brain levels of MDA and increased GSH levels as compared to the PTZ-kindled non-treated group.

Conclusions

The results of study showed that Aloe vera leaf (extract) powder possessed significant anticonvulsant and anti-oxidant activity.

Valproic acid modulates superoxide dismutase, uric acid-independent FRAP and zinc in blood of adult epileptic patients

We aimed to evaluate changes in antioxidant status in blood during valproate (VPA) monotherapy of adult patients with epilepsy. Antioxidant enzymes [plasma superoxide dismutase (pSOD), erythrocyte superoxide dismutase (eSOD)] and non-enzymatic indices [concentration of trace elements in serum: selenium, copper, zinc (sZn) and uric acid (UA), as well as the ferric reducing ability of plasma (FRAP) and UA-independent FRAP (UAiFRAP)] were evaluated in 21 adult patients with epilepsy and 21 healthy controls. Significant differences between the study group and controls were found for pSOD (p = 0.002) and UAiFRAP (p = 0.003). pSOD was higher, whilst UAiFRAP was lower in patients compared to controls. The activity of eSOD was higher in patients treated with VPA for a longer period (7-14 years) in comparison to controls (p = 0.001) and patients with a short period of VPA treatment (p < 0.001). Patients with uncontrolled epilepsy exhibited higher sZn than seizure-free patients (p = 0.041). Standard diet and moderate use of alcohol and/or nicotine did not exert significant effects on redox balance. We conclude that the antioxidant status of epileptic patients is modified by valproate monotherapy. The frequency of seizures and duration of VPA therapy are associated with changes of oxidative/antioxidative balance. The most sensitive and relevant parameters for antioxidative defence mechanism are pSOD, UAiFRAP and sZn.

Lipid peroxidation in women with epilepsy

Background:

Lipid peroxidation is an indicator of free radical metabolism and oxidative stress in human beings and other organisms. Malondialdehyde (MDA), an end product of lipid peroxidation, is a metabolite that can be readily estimated in serum samples. Excess oxidative stress may be a final common pathway through which anti epileptic drugs may exert their teratogenic potential in pregnant women with epilepsy. Our objective in this study was to ascertain the variations in malondialdehyde (MDA) in women with epilepsy.

Material and Methods:

This study was carried out in the Kerala Registry of Epilepsy and pregnancy after obtaining clearance from the Institutional Ethics Committee. Informed consent was obtained from all the subjects. The quantitative examination of MDA was performed according to standard procedures. The ideal plasma level of MDA is below 2 nmol/ml.

Results:

Fifteen women with confirmed epilepsy (mean age 26.9 ± 3.5) were included in the study. Two women were pregnant. MDA levels ranged from 1.7 to 2.8 nmol/ml (mean level = 2.13 ± 0.37 nmol/ml). Eight women (53 %) had MDA levels above the upper limit of normal. Three patients had levels above 2.5 nmol/ml, which corresponded to the 75 centile.

Conclusions:

This study had shown that the estimation of MDA levels in plasma is a convenient method to study lipid peroxidation and thereby oxidative stress in women with epilepsy. Over half of Women With Epilepsy (WWE) have excess oxidative stress as indicated by high levels of MDA in the plasma. Correlations between MDA level and characteristics of epilepsy, AED therapy, nutritional status and other medical conditions need to be observed in a larger cohort.

Modulation of pentylenetetrazole-induced kindling and oxidative stress by curcumin in mice

Epilepsy is a chronic neurological disorder affecting 1% population worldwide. A number of experimental studies have reported anticonvulsant, neuroprotective and antioxidant activity of certain natural products like curcumin, an active ingredient of turmeric. The present study was designed to explore the effect of acute administration of curcumin at doses 50, 100 and 200 mg/kg, orally (p.o.) pentylenetetrazole-induced kindling in mice. Further two oxidative stress markers viz., malondialdehyde (MDA) and glutathione were estimated in brain tissues of rodents. Curcumin (50, 100 and 200 mg/kg, p.o.) dose dependently suppressed the progression of kindling in mice. In addition, the increased levels of MDA and glutathione were also reduced by curcumin in kindled animals. These results suggest that curcumin appears to possess protective activity against kindling in mice.

Effect of carbamazepine and lamotrigine on cognitive function and oxidative stress in brain during chemical epileptogenesis in rats

The present study assessed the effect of carbamazepine and lamotrigine on cognitive function and oxidative stress in brain during chemically induced epileptogenesis in rats. Epileptogenesis was induced by administration of pentylenetetrazole (30 mg/kg, s.c.) on alternate days (three times/week) for 9-11 weeks or until stage 4 of seizure score was achieved. The neurobehavioural parameters used for cognitive assessment were step-down latency in continuous avoidance apparatus and transfer latency in elevated plus maze test paradigm. Carbamazepine and lamotrigine were administered intraperitoneally in doses of 60 mg/kg and 25 mg/kg, respectively, according to the groups, once a day for 11 weeks. Oxidative stress was assessed in isolated homogenized whole brain samples and estimated for the levels of malondialdehyde, reduced glutathione, catalase and superoxide dismutase. The results showed that lamotrigine did not produce any change in cognitive function, while carbamazepine produced cognitive dysfunction. Cognitive decline seen in the carbamazepine-treated pentylenetetrazole-kindled group was also associated with increased oxidative stress. Lamotrigine treatment had no effect on oxidative stress parameters alone, while it significantly decreased oxidative stress in the pentylenetetrazole-kindled group as compared to the pentylenetetrazole-kindled carbamazepine-treated group.

Anti-convulsant effect and mechanism of Astragalus mongholicus extract in vitro and in vivo: protection against oxidative damage and mitochondrial dysfunction

Astragalus mongholicus (AM) is a traditional medicinal herb used as a neuroprotective agent for its anxiolytic, antidepressant, antiamnestic, and antiaggresive effects. However, the mechanisms underlying its anti-convulsant properties are not well studied. In the present study, we examined the anticonvulsant effects on pentylenetetrazol (PTZ)-induced seizures in mice and the possible mechanisms of protection against oxidative damage and mitochondrial dysfunction in vitro. The behavioral studies showed that the root extract of AM had powerful anticonvulsant effects against seizures induced by PTZ and the biochemical studies showed that root extract of AM inhibited PTZ-induced increase in lipid peroxidation, protein oxidation and reactive oxygen species, and enhanced mitochondrial function. Electron spin resonance spectroscopy studies demonstrated that the extracts from the root and aerial parts of AM possess potent effects on scavenging hydroxyl and lipid free radicals. We found that AM extract significantly protected malondialdehyde-induced oxidative damage by ameliorating activities of the mitochondrial complexes I, II, malate dehydrogenase and mitochondrial membrane potential. These data suggest that the anti-convulsant effects of AM extract may be mediated by its protective actions against oxidative damage and amelioration of mitochondrial dysfunction.

Curcumin has anticonvulsant activity on increasing current electroshock seizures in mice

Epilepsy is one of the most common serious disorders of the brain. Several experimental studies have reported neuroprotective and antioxidant activity of certain natural products like curcumin, an active ingredient of turmeric. The present study was designed to explore the effect of acute administration of curcumin at doses 50, 100 and 200 mg/kg, orally (p.o.) and its chronic (x 21 days) administration in 100 mg/kg, p.o. on increasing current electroshock (ICES) test, elevated plus maze and actophotometer in mice. Curcumin in a dose of 100 mg/kg significantly increased the seizure threshold in ICES test on both acute and chronic administration. The same dose of 100 mg/kg on acute administration showed anxiogenic effect on elevated plus maze and actophotometer test. However, this anxiogenic effect of curcumin disappeared on chronic administration. These results suggest that curcumin appears to possess anticonvulsant activity in mice.

Dose dependent effects of ghrelin on pentylenetetrazole-induced oxidative stress in a rat seizure model

It has been suggested that free oxygen radicals play a role in the genesis of epilepsy and in post-seizure neuronal death. The aim of this study was to investigate the dose dependent effect of ghrelin on pentylenetetrazole (PTZ)-induced oxidative stress in a rat seizure model. For this purpose, the ghrelin groups were treated with intraperitoneal injections of ghrelin at doses of 20, 40, 60 and 80 microg/kg before the PTZ injection. Superoxide dismutase (SOD) and catalase (CAT) activities, and reduced glutathione (GSH) and thiobarbituric acid-reactive substance (TBARS) levels were measured in erythrocytes, liver and brain tissue. TBARS, the indicator of lipid peroxidation, was significantly increased in erythrocytes, liver and brain tissue, while antioxidant enzyme activities and glutathione levels were significantly decreased in PTZ injected rats. Ghrelin pretreatment prevented lipid peroxidation and the reduction in antioxidant enzyme activities and GSH levels against PTZ-induced oxidative stress in a dose dependent manner. The present data indicates that PTZ at a convulsive dose induces an oxidative stress response by depleting the antioxidant defense systems and increasing lipid peroxidation in the erythrocytes, liver and brain of rats. Ghrelin pretreatment diminished oxidative stress and prevented the decrease in antioxidant enzyme activities, and thus may reduce neuronal death in the brain during seizures. However, further studies are needed in order to confirm our hypothesis.

Selenium and intractable epilepsy: is there any correlation?

Oxidative stress and generation of reactive oxygen species are strongly implicated in a number of neuronal and neuromuscular disorders, including epilepsy. The functions of selenium as an antioxidant trace element are believed to be carried out by selenoproteins that possess antioxidant activities and the ability to promote neuronal cell survival. Because of this protective role of selenium against oxidative damage, a case-control study was designed to compare its serum level between intractable epileptic patients and normal subjects. Eighty patients who met the criteria of intractable epilepsy were compared with a normal control group of the same age, socioeconomic level, and place of living. Serum selenium level was measured with an atomic absorption spectrophotometer. The mean (+/- S.D.) of serum selenium were 68.88 (+/-17.58) ng/mL and 85.93 (+/-13.93) ng/mL in the patient and control groups respectively. Independent sample t test with P < 0.05 indicated a significant lower mean of serum selenium in the patient group compared with that of the normal control group. However, there was no association between serum selenium and some suggested predictive factors of intractable seizures, including age at the onset of seizures, neonatal seizure, neurologic impairment, and etiology of epilepsy. Measurement of serum selenium in patients with intractable epilepsy should be considered.

The effects of carbamazepine, valproic acid and phenobarbital on the oxidative and antioxidative balance in epileptic children

BACKGROUND

Oxidative stress has been related in a wide variety of ways with nervous tissue. We studied the effect of antiepileptic monotherapy on serum level of total antioxidant capacity, lipid hydroperoxide, total peroxide, oxidative stress index, and individual serum antioxidants such as albumin, bilirubin and uric acid.

PATIENTS AND METHODS

We studied 122 subjects including healthy controls, untreated epileptic patients and epileptic patients treated with valproic acid, carbamazepine or phenobarbital. Serum total antioxidant capacity was measured as an index of antioxidants, and total peroxide was measured as index of oxidative stress. The serum concentrations of uric acid, albumin, bilirubin and lipid hydroperoxide were monitored simultaneously.

RESULTS

We found that serum total antioxidant capacity levels were significantly decreased in the untreated group compared with the controls. Serum total peroxide levels were markedly increased in the untreated and carbamazepine-treated groups compared to in the controls; and lipid hydroperoxide and oxidative stress index levels were significantly higher in the phenobarbital-treated group than in the controls. Uric acid concentrations were significantly lower in the valproic-acid-treated group than in the untreated group, and total bilirubin concentrations were higher in the untreated group than in the controls.

CONCLUSION

Epileptic children exposed to oxidative stress and conventional antiepileptic drugs change the oxidative/antioxidative balance. The serum oxidant and antioxidant status of epileptic children with valproic acid monotherapy are better regulated compared with children with carbamazepine and phenobarbital monotherapy.

Evaluation of the influence of antiepileptic therapy on antioxidant enzyme activity and lipid peroxidation in erythrocytes of children with epilepsy

The aim of this study was to evaluate the influence of antiepileptic therapy on antioxidant enzyme activity and lipid peroxidation in the erythrocytes of children with epilepsy. For this purpose, the activity of superoxide dismutase, glutathione peroxidase, and glutathione reductase and the malondialdehyde concentration in 61 healthy children and 90 children with epilepsy were measured. The activities of all of these enzymes were insignificantly higher, whereas the malondialdehyde concentration was significantly lower in the patients treated with carbamazepine monotherapy. In patients treated with valproate monotherapy, the activities of all enzymes were insignificantly lower, whereas the malondialdehyde concentration was insignificantly higher. In patients treated with polytherapy, the activity of superoxide dismutase was insignificantly lower, whereas the activity of glutathione peroxidase and glutathione reductase was insignificantly higher and the malondialdehyde concentration was lower. There were differences in glutathione reductase activity between the valproate monotherapy group and both the carbamazepine monotherapy and polytherapy groups and in malondialdehyde concentrations between the carbamazepine and valproate groups. The results indicate that the oxidant-antioxidant balance in children with epilepsy is modified by antiepileptic therapy.

Effect of pentylenetetrazol-induced epileptic seizure on the antioxidant enzyme activities, glutathione and lipid peroxidation levels in rat erythrocytes and liver tissues

OBJECTIVES

In order to clarify whether oxidative stress accompanies epilepsy, we examined the effects of pentylenetetrazol (PTZ)-induced epilepsy on the lipid peroxidation and antioxidant enzyme activities in erythrocytes and liver tissues of adult Wistar rats.

MATERIALS AND METHODS

The activities of antioxidative enzymes (glucose-6-phosphate dehydrogenase (G-6-PD)), copper, zinc-superoxide dismutase (Cu,Zn-SOD), catalase (CAT), selenium-dependent glutathione peroxidase (Se-GSH-Px) and the levels of reduced glutathione (GSH) and thiobarbituric acid-reactive substances (TBARS) were measured in erythrocytes and liver tissues of pentylenetetrazol (PTZ)-induced epileptic adult Wistar rats.

RESULTS

Single PTZ treatment in a convulsive dose of 50 mg/kg significantly reduced the erythrocyte Cu,Zn-SOD, CAT enzyme activities and GSH levels compared to controls (P < 0.001, P < 0.001, P < 0.05, respectively). Erythrocyte and liver tissue TBARS levels in the epileptic group were significantly higher than controls (P < 0.0001). There was a significant decrease in liver tissue Cu,Zn-SOD activity and GSH levels in the epileptic group (P < 0.0001), whereas significantly higher activities of G-6-PD and Se-GSH-Px were found in the epileptic group.

CONCLUSIONS

Our results demonstrate a generalized diminished antioxidant activity and increased TBARS level indicating enhanced oxidative stress in the liver and erythrocytes of epileptic rats. Increased oxidative stress in the liver of epileptic rats might be due to the activation of the recently found glutamate receptors in the liver. These findings suggest that the use of antioxidants with antiepileptic drugs and new drugs such as type-5 metabotropic glutamate receptor (mGlu5) antagonist (MPEP) might protect erythrocytes and liver tissue against anoxic damage and oxidative stress.

A randomized, double-blind, placebo controlled trial of melatonin add-on therapy in epileptic children on valproate monotherapy: effect on glutathione peroxidase and glutathione reductase enzymes

AIMS

To compare the effect of add-on melatonin with placebo on the antioxidant enzymes (glutathione peroxidase and glutathione reductase) in epileptic children on valproate monotherapy.

METHODS

In a double-blind, randomized, placebo controlled trial, the effect of add-on melatonin administration on the antioxidant enzymes in epileptic children on valproate (VPA) monotherapy was assessed. A total of 31 patients met the entry criteria. 16 patients were randomly allocated to receive add-on melatonin, and 15 to receive add-on placebo. Blood samples (5 ml) were collected just before the morning dose of valproate for baseline values of glutathione peroxidase and glutathione reductase enzymes, and then after 14 days of add-on melatonin/placebo. Blood was then centrifuged at 3500 r.p.m., serum separated and stored in deep freezer at -20 degrees C until assay of glutathione reductase. Heparinized blood was collected and stored at -20 degrees C in eppendorfs in the deep freezer for assay of glutathione peroxidase. All activity assays were performed on the Ames (Technicon) RA 50 chemistry analyser.

RESULTS

Fifteen patients in the add-on melatonin group and 14 patients in the add-on placebo group were finally assessed. There was an increase in the activity of antioxidant enzymes, glutathione peroxidase (GSH-Px) and glutathione reductase (GSSG-Rd), in the add-on melatonin (MEL) group as compared with a reduction in the same in the add-on placebo group (P). After the addition of melatonin/placebo in the respective groups, there was a 7.5% decrease in GSH-Px in the valproate + placebo group, whereas a 11.9% increase in the valproate + melatonin group was observed, the difference between the groups being not statistically significant (P = 0.29). On administration of melatonin/placebo, the post-treatment concentrations of GSSG-Rd in the valproate + placebo group decreased from 92.0 U l(-1) to 67.0 U l(-1) and increased from 82.0 U l(-1) to 113.0 U l(-1), in the valproate + melatonin group, respectively, the difference between them being statistically significant (P = 0.05). The percentage change in the values of GSSG-Rd in the two groups was statistically significant (P = 0.005).

CONCLUSIONS

Melatonin exerts neuroprotection due to its antioxidant, antiexcitotoxic and free radical scavenging properties within the central nervous system. Melatonin, thus, as an adjunct, can be a putative neuroprotector in conditions involving oxidative stress like epilepsies.

Add-on melatonin improves quality of life in epileptic children on valproate monotherapy: a randomized, double-blind, placebo-controlled trial

This randomized, double-blind, placebo-controlled study in epileptic children aged 3-12 years evaluated the effects of add-on melatonin administration on the quality of life of these children on sodium valproate (VPA) monotherapy using a parental questionnaire. Quality of Life in Childhood Epilepsy is a questionnaire designed to assess a variety of age-relevant domains such as physical function, emotional well-being, cognitive function, social function, behavior, and general health. Of the 31 patients, 16 randomly received add-on melatonin (MEL), whereas 15 received add-on placebo (P). The questionnaire had good internal consistency reliability, because for most of the multi-item scales Cronbach's alpha reliability exceeded 0.5 (range: 0.59-0.94). To our knowledge, this is the first study assessing quality of life in epileptic children with add-on melatonin administration in the form of a randomized, double-blind, placebo-controlled trial. The study suggests a potential use of melatonin as an adjunct to antiepileptic therapy due to its diverse spectrum of action as an antioxidant, neuroprotector, and free radical scavenger, thus offering the advantage of reducing oxidant stress and subsequent damage. The beneficial effects of melatonin on sleep, its wide safety window, and its ability to cross the blood-brain barrier have the potential to improve quality of life in pediatric epilepsy.

Blood Levels of Trace Elements, Electrolytes, and Oxidative Stress/Antioxidant Systems in Epileptic Patients

Epileptic patients exhibited variably altered status of trace elements, electrolytes, and free radical scavenging enzyme activities. We investigated the effect of epilepsy and long-term antiepileptic drug therapy on the serum level of some trace elements (zinc, selenium, and copper), electrolytes (calcium, magnesium, sodium, and potassium), and antioxidants (glutathione peroxidase, and uric acid) and plasma levels of lipid peroxidation index (malondialdehyde), total antioxidant capacity, and ceruloplasmin. Seventy epileptic patients and fourteen controls were recruited in this study. In the treated group (particularly with valproate), we reported increases in the levels of zinc, calcium, sodium, malondialdehyde, and glutathione peroxidase and decreases in the levels of copper, total antioxidant capacity, and ceruloplasmin with no difference in selenium, magnesium, and potassium. However among untreated epileptics, uric acid level was increased and total antioxidant capacity was markedly lowered. We conclude that the above parameters balance differs in epileptics comparable to controls and hence their correlation to seizures pathophysiology and their degree of control or resistance to antiepileptic drug therapy. Better regulation of the lipid peroxidation and antioxidants and fewer disturbances in mineral metabolism were observed in monotherapy versus polytherapy and with carbamazepine versus valproate therapy.

Trace Elements and Electrolytes Homeostasis and Their Relation to Antioxidant Enzyme Activity in Brain Hyperexcitability of Epileptic Patients

Epileptogenesis is a big challenge. Various experimental and human studies suggested that the homeostasis of trace elements, electrolytes, membrane lipid peroxidation, and antioxidants is crucial for brain function, and they were directly or indirectly implicated as taking part in the pathophysiology of neuronal excitability, neuronal excitotoxicity, and seizure recurrence and its resistance to treatment with antiepileptic drugs (AEDs). In addition, AEDs can also alter the homeostasis of trace elements, electrolytes, and seriously increase membrane lipid peroxidation at the expense of protective antioxidants, leading to an increase in seizure recurrence and an idiosyncratic drug effect. Differential effects were detected among different AEDs treatments in which carbamazepine (CBZ) was found to be better anticonvulsant for the control of free radical related seizures and the level of trace elements were better regulated with CBZ than with valproate (VPA) and phenytoin (PHT) therapies. It is concluded that adequate trace elements and antioxidants supply is important for brain functions and prevention of neurological diseases and further elucidation of the pathological actions of such substances in the brain should result in new therapeutic approaches. Trace elements and antioxidant might have neuroprotective biological targeted benefits when used in epileptic patients.

Antioxidant and anticonvulsant effect of a modified formula of chaihu-longu-muli-tang

Antiepileptic drug therapy in individuals with epilepsy can induce free radical generation and profound lipid peroxidation. Some Chinese herbs with antiepileptic potential show antioxidant effects. We performed an open add-on study of TW970, a modified formula of the Chinese medicine "chaihu-longu-muli-tang", on 20 patients with refractory epilepsy and a seizure frequency of at least four fits per month, and another 20 patients with benign epilepsy and a seizure frequency of less than four fits per month. The control group consisted of 20 age-matched healthy adults. Seizure frequency, serum malondialdehyde (MDA), glutathione (GSH) and copper-zinc superoxide dismutase (Cu,Zn-SOD) were investigated in patients with refractory and benign epilepsy before and after four months add-on treatment of TW970. There was a decrease in seizure frequency in refractory epileptics from 13.4 +/- 3.4 to 10.7 +/- 2.5/per month, although the p value was 0.084. Before TW970 add-on treatment, a significant enhancement of lipid peroxidation with increased MDA and Cu,Zn-SOD activities together with decreased GSH were seen in refractory epileptics compared with normal controls. After TW970 add-on treatment of refractory epileptics for four months, normalization of MDA and Cu,Zn-SOD levels was achieved. Before and after TW970 add-on treatment, there were no statistically significant changes of the above-mentioned parameters in the patients with benign epilepsy. These results suggest that TW970 can reduce the seizure frequency in patients with refractory epilepsy and this may be due to the antioxidant effects of the modified formula of chaihu-longu-muli-tang.

Enhanced lipid peroxidation in epileptics with null genotype of glutathione S-transferase M1 and intractable seizure

Null genotype of glutathione S-transferase class me (GSTM1(-)) and the plasma level of malondialdehyde (MDA) were determined in normal subjects, epileptics with good seizure control and epileptics with intractable seizure. The frequency of GSTM1(-) of the epileptics with intractable seizure was significantly higher than that of the group with good seizure control and that of the normal subjects. The average plasma level of MDA of the patients with GSTM1(-) genotype was higher than that of the subjects with GSTM1(+) in either the normal or epileptic group. Thus, the GSTM1(-) genotype may be one of the genetic factors involved in the response to anticonvulsant therapy.

Lipid peroxidation and antioxidative enzyme activities in childhood epilepsy

This study aimed to investigate the relationship among lipid peroxidation, subsequent activation of scavenger enzymes (superoxide dismutase and glutathione peroxidase), and the presence of structural abnormality in 52 epileptic children receiving monotherapy (medically responsive) or polytherapy (medically intractable). Plasma lipid peroxidation in epileptic patients with abnormal magnetic resonance imaging (MRI) findings significantly increased as compared with that of 16 healthy children (P < .05), whereas antioxidant enzymes were not significantly affected. Both medically controlled and intractable children with normal MRI had higher activities of superoxide dismutase than those of controls (P < .05). The activity of superoxide dismutase in epileptic patients with structural abnormality did not significantly change as compared with controls. Activity of glutathione peroxidase in all of the epileptic children was not significantly different from controls. The activity of antioxidant enzymes or plasma malonyldialdehyde levels did not correlate with duration of epilepsy, frequency of seizures (> one seizure per month or not), and the presence or localization (focal, multifocal, or generalized) of electroencephalographic or MRI abnormalities. Increased plasma lipid peroxidation may be causally related to the presence of structural abnormality rather than ongoing epileptic activity or therapy status.

Oxidative stress in Rett syndrome

The investigation of parameters that might influence the neurological evolution of Rett syndrome might also yield new information about its pathogenic mechanisms. Oxidative stress caused by oxygen free radicals is involved in the neuropathology of several neurodegenerative disorders, as well as in stroke and seizures. To evaluate the free radical metabolism in Rett syndrome, we measured red blood cell antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase) and plasma malondialdehyde, as lipid peroxidation marker in a group of patients with Rett syndrome. No significant differences were observed in erythrocyte glutathione peroxidase, glutathione reductase and catalase activities, between the Rett syndrome patients and the control group. Erythrocyte superoxide dismutase activities were significantly decreased in Rett syndrome patients (P<0.001) compared with the control group. Plasma malondialdehyde concentrations were significantly increased in Rett syndrome patients (P<0.001). An unbalanced nutritional status in Rett syndrome might explain the reduced enzyme activity found in these patients. Our results suggest that free radicals generated from oxidation reactions might contribute to the pathogenesis of Rett syndrome. The high levels of malondialdehyde reflect peroxidative damage of biomembranes that may contribute to progressive dementia, impaired motor function, behavioural changes, and seizures, in Rett syndrome. We found a probable relationship between the degree of oxidative stress and the severity of symptoms, which should be further investigated with a larger number of patients in different disease stages.

Changes in the antioxidant system in epileptic children receiving antiepileptic drugs: two-year prospective studies

The aim of this study was to measure changes in the antioxidant systems of epileptic children who had been receiving either valproate or carbamazepine monotherapy for 2 years. For this purpose, levels of erythrocyte glutathione, glutathione peroxidase, superoxide dismutase, and serum lipid peroxidation in 25 healthy children and 27 children who had previously been diagnosed as having epilepsy but who had not, prior to the study, received antiepileptic drugs were tested. Of the 27 epileptic children, 14 were given valproate, and the remaining 13 were given carbamazepine; these tests were repeated in the 13th and 24th months of treatment. The results showed that, during valproate therapy, the lipid peroxidation levels of the epileptic children increased and the glutathione peroxidase levels decreased in comparison with those levels recorded in the control and pretreatment groups. In addition, the superoxide dismutase levels were found to be increased during the first year of valproate therapy when compared with those of the pretreatment group. However, during carbamazepine therapy, lipid peroxidation levels increased when compared with the control group only, not the pretreatment group. Furthermore, the results showed that during the second year of treatment, the superoxide dismutase levels of the children receiving carbamazapine monotherapy were found to be higher than those of both the control and pretreatment groups. From these results, it can be concluded that the antioxidant systems of the children who had been receiving valproate therapy during the 2 years were more significantly affected than those of the children who had been receiving carbamazepine.

Neuropsychological test battery in the follow-up of patients with juvenile neuronal ceroid lipofuscinosis

The aim of the present study was to develop a neuropsychological test battery for patients with juvenile neuronal ceroid lipofuscinosis (JNCL) and to study the development of cognitive functions during the first 5 years after diagnosis. Fourteen patients with JNCL entered the study. Nine patients were homozygous for the major mutation, whereas five were compound heterozygotes. All patients were studied annually with a special neuropsychological test battery (NEPSY) adapted from Luria's neuropsychological test, and modified for the visually handicapped; the Wechsler Intelligence Scale for Children - Revised (WISC-R) was also included. The neurological examinations were scored. Furthermore, 1.OT magnetic resonance imaging scan was performed at the beginning of follow-up and after a mean of 5 years. A decline in verbal IQ (WISC-R) during the follow-up period was found in all subjects except one compound heterozygous male. Short-term memory and digit memory span were already impaired at an early stage of the disease. Orientation to time was found to decline more than orientation to person and place. Motor speed usually became impaired after 10 years of age. Spatial orientation was impaired only in the patients homozygous for the major mutation. The test battery was found to be reliable and easy to use, and offered valuable information on the progress of the disease. It also provided important guidelines for rehabilitation.

Erythrocyte glutathione, glutathione peroxidase, superoxide dismutase and serum lipid peroxidation in epileptic children with valproate and carbamazepine monotherapy

This prospective study was carried out to determine changes in the antioxidant system in epileptic children receiving long term antiepileptic drugs (AEDs). Levels of erythrocyte glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and serum lipid peroxidation were determined in 25 healthy children and 30 epileptic children who had not yet received AEDs. Sixteen patients were treated with valproic acid (VPA) and 14 with carbamazepine (CBZ); 13 months later these parameters were retested. The results showed that SOD and lipid peroxidation levels were increased but the GSH-Px levels were decreased in epileptic children on VPA therapy compared with the control group and the results before treatment. No significant differences of these parameters were found in epileptic children on CBZ therapy compared with the control group and the results before treatment, except that lipid peroxidation level was slightly higher in epileptic patients before treatment. We conclude that antioxidant systems in epileptic children on CBZ therapy are better regulated in comparison with epileptic children on VPA therapy.

Plasma total glutathione concentrations in epileptic patients taking anticonvulsants

Glutathione plays an important role in protecting cells against oxidative damage as a free radical scavenger. Since several anticonvulsants have been associated with decreased intrahepatic glutathione levels, we investigated plasma concentrations of total glutathione (including reduced and oxidized forms, tGSH=GSH+GSSG) in 45 epileptic patients taking anticonvulsant drugs. Plasma tGSH concentrations were significantly lower than in controls in patients treated with carbamazepine or phenytoin monotherapy, or with multiple drugs. Plasma tGSH concentrations in patients treated with valproic acid and in patients treated with phenobarbital did not differ significantly from those in controls. In no patient group was a significant correlation evident between duration of treatment or drug concentration and plasma tGSH concentration. No significant differences in plasma total cysteine concentrations were found between any patient group and controls. We conclude that some anticonvulsant drugs can lower plasma tGSH levels, reflecting treatment-related oxidative stress.

Superoxide dismutase and glutathione peroxidase function in progressive myoclonus epilepsies

Progressive myoclonic epilepsies (EPM) are difficult to treat and refractory to most antiepileptic drugs. Besides epilepsy, EPMs also involve continuous neurological deterioration. Oxidative stress is thought to be an important factor in this process. We therefore analyzed a series of antioxidant enzymes in the blood of patients and compared with healthy age matched controls. In addition patients were given high doses of N-acetylcysteine (NAC), a glutathione percursor to determine if symptoms of EPM would improve. Five patients, four with EPM 1 (Unverricht-Lundborg disease) and one patient with EPM2 (Lafora body disease) were treated with 6 g/day of NAC. Before treatment, plasma samples were analyzed for glutathione peroxidase activity, catalase activity, extracellular superoxide dismutase (SOD) and CuZn-SOD and compared with the controls. Erythrocyte CuZn-SOD was significantly lower in the EPM patients compared to controls. NAC improved markedly and stabilized the neurological symptoms in patients with EPM 1 but had a doubtful effect in the patient with EPM 2.

Normal ascorbic acid in cerebrospinal fluid of patients with infantile neuronal ceroid-lipofuscinosis

Neuronal ceroid-lipofuscinoses (NCL) are a group of neurodegenerative disorders. There is much evidence for a role of peroxidation processes in the pathogenesis of NCL, although this would certainly be indirect. Reduced total antioxidant activity of cerebrospinal fluid (CSF) has been reported in NCL. Since ascorbic acid represents a major antioxidant in CSF, we have now determined this parameter in CSF of two patients with the infantile form of NCL (Santavuori-Haltia disease). However, the ascorbic acid values obtained (103.6 and 181.3 microM) are comparable with control values from the literature as well as with those measured in groups of children with neurologic/psychiatric diseases other than NCL (mean +/- standard deviation: 137.1+/-41.3 microM), with suspected (but excluded) meningitis (124.1+/-34.0 microM) and acute lymphoblastic leukemia (131.7+/-17.0 microM). Our results indicate that CSF ascorbic acid concentrations are not affected by peroxidation processes in infantile NCL, but reveal a sharply decreased ascorbic acid concentration in one of the non-NCL patients, possibly associated with his convulsions and/or his anticonvulsant therapy.

Antiepileptic effects of allopurinol on EL mice are associated with changes in SOD isoenzyme activities

We have investigated the potential antiepileptic action of superoxide dismutase (SOD) activities in the brain of the epileptic mutant EL mouse. EL mice which experienced frequent seizures (EL[s]) had abnormally low levels of SOD isoenzyme activity in the hippocampal area. Once epileptogenicity was established in these animals, activity of cyanide-sensitive Cu,Zn-SOD was maintained at significantly lower levels than in control mice. However, cyanide-insensitive Mn-SOD activity was not different from non-epileptic controls. In EL mice which had not experienced seizure provoking stimulations and exhibited no seizures (EL[ns]) there was moderately lower levels of SOD isoenzyme activities compared to controls. In spite of the low level of Cu,Zn-SOD activity in EL[s] mice, the Cu,Zn-SOD protein content was high in the hippocampus of these animals, suggesting that inactive Cu,Zn-SOD might be induced during development. After allopurinol (ALP) was given orally to EL[s] mice, Cu,Zn-SOD activities increased dramatically in the hippocampus and seizure activity was decreased. Even after 48 h, when antiepileptic action of ALP was lost, the SOD activity was maintained at the high level associated with initial ALP administration. EL[s] mice also showed DNA fragmentation in the hippocampal CA1 region and the parietal cortex, detected with in situ terminal transferase-mediated dUTP nick labeling with the aid of alkaliphosphatase or peroxidase. The degree of DNA fragmentation was less severe in EL[ns] mice. We propose that abnormalities in region specific Cu,Zn-SOD isoenzyme activity might produce free radicals, leading to DNA fragmentations and cell loss. This might contribute to hippocampal epileptogenesis in EL mice.

Oxidative injury in the nervous system

A free radical is a highly reactive chemical species that can react with organic macromolecules leading to cell and tissue damage and consequent functional disruption. Free radical or oxidative injury is increasingly recognized as an important factor in the pathophysiology of many human diseases, including those that affect the nervous system. This review summarizes important evidence implicating oxidative injury in the pathogenesis and progression of many important neurological disorders, including cerebrovascular disease, epilepsy, amyotrophic lateral sclerosis, and Huntington's disease. Results of controlled clinical trials of various antioxidant therapies in neurological disease performed to date are also highlighted.