Protective effect of curcumin against seizures and cognitive impairment in a pentylenetetrazole-kindled epileptic rat model

Anticonvulsant effect of anacardic acid in murine models: Putative role of GABAergic and antioxidant mechanisms

Epilepsy is a neurological disease affecting people of all ages worldwide. Side effects of antiepileptic drugs and their association with oxidative stress stimulate the search for new drugs, which would be more affordable with fewer adverse effects. Accordingly, the aim of the present work is to evaluate the anticonvulsant effect of anacardic acid (AA), a natural compound extracted from cashew liquid (Anacardium occidentalis), in murine models, as well as its antioxidant actions in Saccharomyces cerevisiae. AA (>90% purity) was tested, in vivo, in male Swiss mice (25-30 g) with four convulsive models, (1) pentylenetetrazole, (2) pilocarpine, (3) electroshock, and (4) kainic acid, at doses of 25, 50, and 100 mg/kg, body weight (B.W.) Additionally, the effective dose, toxic dose, and protective index studies were also performed. Results revealed that AA exhibits anticonvulsive effects in models 1, 3, and 4, with a mean effective dose (ED₅₀) of 39.64 (model 1) >100 mg/kg, B.W. (model 2), and 38.36 (model 3); furthermore, AA displays a protection index of 1.49 (model 1), <0.6 (model 2, and 1.54 (model 3). In addition, AA showed antioxidant activities in S. cerevisiae mutated for superoxide dismutases (SOD). In conclusion, these results show that AA exhibits significant anticonvulsant and antioxidant activities and may be used as a promising natural product for the treatment of epilepsy.

Curcumin in epilepsy disorders

Curcumin, a principal curcuminoid present in turmeric, has an antioxidant, anti-inflammatory and neuroprotective properties. Preclinical studies have indicated its beneficial effect for the treatment of epilepsy disorders. The molecule has an anti-seizure potential in preclinical studies, including chemical and electrical models of acute and chronic epilepsy. Curcumin also possesses an anti-epileptogenic activity as it reduces spontaneous recurrent seizures severity in a kainate model of temporal lobe epilepsy. The antioxidant and anti-inflammatory nature of curcumin might be responsible for its observed anti-seizure effects; nevertheless, the exact mechanism is not yet clear. The poor availability of curcumin to the brain limits its use in clinics. The application of nanoliposome and liposome technologies has been tested to enhance its brain availability and penetrability. Unfortunately, there are no randomized, double-blinded controlled clinical trials validating the use of curcumin in epilepsy. The present article analyzes different preclinical evidence illustrating the effect of curcumin in seizure models. The review encourages carrying out clinical trials in this important area of research. In conclusion, curcumin might be beneficial in patients with epilepsy disorders, if its bioavailability issues are resolved.

Protective effect of Fructus corni polysaccharide on hippocampal tissues and its relevant mechanism in epileptic rats induced by lithium chloride-pilocarpine

The aim of the present study was to investigate the potential effect of Fructus corni polysaccharide (PFC) on the hippocampus tissues in epileptic rats induced by lithium chloride-pilocarpine, and to explore the underlying mechanism. The epileptic rat models were established using lithium chloride-pilocarpine treatment. According to the dosage of PFC, the rat models were divided into three groups: The low-dose (100 mg/kg/day), middle-dose (200 mg/kg/day) and high-dose (300 mg/kg/day) groups. The intervention for rat models lasted for 24 days. Subsequently, the production levels of reactive oxygen species (ROS) and malondialdehyde (MDA), the activity of superoxide dismutase (SOD), the mitochondrial membrane potential and the expressions of mitogen-activated protein kinase [P-38, Janus kinase (JNK) and extracellular signal-regulated kinase 1/2], cytochrome-C and caspase-3 in hippocampal tissues were detected. In addition, the structure of the CA-1 region of the hippocampus was also observed. Compared with the control group, the production levels of ROS were increased and the mitochondrial membrane potential was decreased in the hippocampus tissues of rats in the model group. In addition, in the model group, it was observed that MDA content was increased, SOD activity was decreased, and the expressions of phosphorylated (p)-p38, p-JNK, cytochrome-c and caspase-3 were increased, compared with the control group. Furthermore, those abnormal variations of the indicators were reversed by the intervention of PFC. These findings suggest that PFC can ameliorate the secondary damage to the hippocampi of epileptic rats, and that the anti-oxidation and -apoptosis effects of PFC may be associated with the mechanism that provides a protective effect for hippocampal tissues.

Protective effect of Terminalia chebula against seizures, seizure-induced cognitive impairment and oxidative stress in experimental models of seizures in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Teminalia chebula (TC) has been traditionally used in the Ayurvedic system of medicine primarily for gastrointestinal disorders. Its fruit extract has also been used to treat epilepsy and other CNS disorders.

AIM OF THE STUDY

To evaluate the effect of hydroalcoholic fruit extract of Terminalia chebula (HETC) on experimental models of seizures, seizure-induced cognitive impairment and oxidative stress in rats.

MATERIALS AND METHODS

In vitro antioxidant activity of HETC was evaluated by using ABTS, NO and DPPH radical scavenging assay. For in-vivo study, seizures were induced in Wistar rats (200-225g) by pentylenetetrazole (PTZ) and maximal-electroshock. (MES). The anticonvulsant effect of the HETC (250, 500, and 1000mg/kg, orally) was evaluated in seizure models. The therapeutic and sub-therapeutic dose of valproate and phenytoin were also assayed. The potential effect of co-administration of HETC (500mg/kg) with sub-therapeutic dose of valproate and phenytoin were also evaluated in PTZ and MES seizures model respectively. Effect on cognition was assessed using elevated plus maze (EPM) and passive avoidance test (PA). The in- vivo oxidative stress parameters (malondialdehyde and glutathione) were assessed in the cerebral cortex and hippocampus part of rat brain.

RESULTS

The IC50 value of HETC in in vitro antioxidant assays i.e. ABTS, DPPH and NO radical scavenging assay was found to be 2.27μg/ml, 6.04μg/ml and 4.37μg/ml respectively. In experimental study, PTZ and MES treated groups exhibited 100% seizures with increased oxidative stress (p < 0.001) and cognitive deficits (p < 0.01) as compared to control group. HETC at highest dose (1000mg/kg) showed 83.33% (5/6) protection in MES induced seizures while 66.66% (4/6) protection in PTZ induced seizures. However, HETC (1000mg/kg) and co-administration of sub-therapeutic dose of HETC with valproate and phenytoin showed complete protection. In addition, it also attenuated the seizure induced oxidative stress and cognitive impairment as indicated by significant (p < 0.01) improvement in the transfer latencies in EPM and PA as compared to PTZ and MES treated group.

CONCLUSIONS

The findings suggest that HETC exhibited significant anticonvulsant activity and also potentiated the subtherapeutic dose of phenytoin and valproate indicate its usefulness as an adjuvant to antiepileptic drugs with an advantage of preventing cognitive impairment and oxidative stress.

Neuroprotective effect of curcumin nanoparticles against rat model of status epilepticus induced by pilocarpine

Background

The present study aims to investigate the neuroprotective effect of curcumin nanoparticles (Cur-NP) on the rat model of status epilepticus (SE) induced by pilocarpine.

Methods

In the present study, animals were divided into three groups: control animals, rat model of SE induced by a single dose of pilocarpine (380 mg/kg) injected intraperitoneally, and rat model of SE that received a daily intraperitoneal injection of Cur-NP (50 mg/kg) for four consecutive days prior to pilocarpine administration.

Results

The present results revealed a state of oxidative stress in the cortex and hippocampus of rat model of SE as compared to control. This was evident from the significant increase in lipid peroxidation and the significant decrease in reduced glutathione and nitric oxide. In addition, a significant increase in the levels of tumor necrosis factor-alpha (TNF-α) and caspase-3 was detected in the two studied brain regions of rat model of SE. The activities of acetylcholinesterase (AchE) and Na+/K+-ATPase decreased significantly in the cortex and hippocampus of rat model of SE. Protection with Cur-NP prevented oxidative stress and improved the elevated level of caspase-3 in the hippocampus and cortex and the hippocampal TNF-α to nonsignificant changes. Although Cur-NP prevented the decrease in AchE activity in the two studied brain regions, it failed to return Na+/K+-ATPase activity to its normal value.

Conclusions

It is clear from the present findings that Cur-NP could prevent the oxidative stress and neuroinflammation and cell death that were induced during SE. This in turn may help in ameliorating the subsequent cascades of events that follow SE and its development into epileptogenesis.

The anticonvulsant effect of a polysaccharide-rich extract from Genipa americana leaves is mediated by GABA receptor

BACKGROUND

This study aimed to chemically characterize a polysaccharide-rich extract (PRE) obtained from Genipa americana leaves and evaluate its neuroprotective effect in the brain morphology and oxidative markers using mice behavioral models.

METHODS

Dry powder (5 g) of G. americana leaves were submitted to depigmentation in methanol. PRE was obtained by extraction in NaOH and precipitation with absolute ethanol and characterized by infrared spectroscopy (FTIR) and nuclear magnetic resonance (¹H and ¹³C NMR). Swiss mice (25-35 g) received saline (0.9% NaCl) or PRE (1-27 mg/kg) by intraperitoneal (i.p.) route, 30 min before evaluation in behavioral models (open field, elevated plus maze, sleeping time, tail suspension, forced swimming, seizures induced by pentylenetetrazole-PTZ). Animal's brain were dissected and analyzed for histological alterations and oxidative stress.

RESULTS

FTIR spectrum showed bands around 3417 cm^-1 and 2928 cm^-1, relative to the vibrational stretching of OH and CH, respectively. ¹H NMR spectrum revealed signals at δ 3.85 (methoxyl groups) and δ 2.4 (acetyl) ppm. ¹³C NMR spectrum revealed signals at δ 108.0 and δ 61.5 ppm, corresponding to C1 and C5 of α-L-arabinofuranosyl residues. PRE presented central inhibitory effect, increasing the latency for PTZ-induced seizures by 63% (9 mg/kg) and 55% (27 mg/kg), and the latency to death by 73% (9 mg/kg) and 72% (27 mg/kg). Both effects were reversed by the association with flumazenil.

CONCLUSIONS

PRE, containing a heteropolysaccharide, presents antioxidant and anticonvulsant effect in the model of PTZ-induced seizures via gamma-aminobutyric acid (GABA), decreasing the number of hippocampal black neurons.

Anticonvulsant effects of Senna spectabilis on seizures induced by chemicals and maximal electroshock

Senna spectabilis (Fabaceae) is one of the medicinal plants used in Cameroon by traditional healers to treat epilepsy, constipation, insomnia, anxiety. The present study aimed to investigate the anticonvulsant effects of Senna spectabilis decoction on seizures induced by maximal electroshock (MES), pentylenetetrazole (PTZ), pilocarpine (PC) and its possible action mechanisms in animal models using flumazenil (FLU), methyl-ß-carboline-3-carboxylate (BC) and bicuculline (BIC). Senna spectabilis decoction (106.5 and 213.0mg/kg) antagonized completely tonic-clonic hind limbs of mice induced by MES. The lowest plant dose (42.6mg/kg) provided 100% of protection against seizures induced by PTZ (70mg/kg). Administration of different doses of the plant decoction antagonized seizures induced by PC up to 75%, causing a dose dependent protection and reduced significantly the mortality rate induced by this convulsant. Both FLU and BC antagonize strongly the anticonvulsant effects of this plant and are unable to reverse totally diazepam or the plant decoction effects on inhibiting seizures. The animals did not present any sign of acute toxicity even at higher doses of the plant decoction. In conclusion, Senna spectabilis possesses an anticonvulsant activity. We showed that its decoction protects significantly mice against seizures induced by chemicals and MES, delays the onset time and reduces mortality rate in seizures-induced. It also appears that the oral administration of the decoction of S. spectabilis is more active than the intraperitoneal administration of the ethanolic extract on inhibiting seizures induced by MES and PTZ. Moreover, the plant decoction could interact with GABA_A complex receptor probably on the GABA and benzodiazepines sites.

Curcumin-loaded chitosan-alginate-STPP nanoparticles ameliorate memory deficits and reduce glial activation in pentylenetetrazol-induced kindling model of epilepsy

Despite several beneficial effects of curcumin, its medical application has been hampered due to low water solubility. To improve the aqueous solubility of curcumin, it has been loaded on chitosan (CS)-alginate (ALG) - sodium tripolyphosphate (STPP) nanoparticles (NPs). Then, the effect of curcumin NPs on memory improvement and glial activation was investigated in pentylenetetrazol (PTZ)-induced kindling model. Male NMRI mice have received the daily injection of curcumin NPs at dose of 12.5 or 25mg/kg. All interventions were injected intraperitoneally (i.p), 10days before PTZ administration and the injections were continued until 1h before each PTZ injection. Spatial learning and memory was evaluated using Morris water maze test after the 7th PTZ injection. Animals have received 10 injections of PTZ and then, brain tissues were removed for histological evaluation. Nissl staining was used to determine the level of cell death in hippocampus and immunostaining method was performed against NeuN and GFAP/Iba1 for assessment of neuronal density and glial activation respectively. Behavioral results showed that curcumin NPs exhibit anticonvulsant activity and prevent cognitive impairment in fully kindled animals. The level of cell death and glial activation reduced in animals which have received curcumin NPs compared to those received free curcumin. To conclude, these findings suggest that curcumin NPs effectively ameliorate memory impairment and attenuate the level of activated glial cells in a mice model of chronic epilepsy.

Identifying new antiepileptic drugs through genomics-based drug repurposing

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

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.

The role of nitric oxide in anticonvulsant effect of nanocurcumine on pentylenetetrazole-induced seizure in mice

A plant alkaloid obtained from Curcuma longa, curcumin possesses anti-oxidant and anti-inflammatory effects. Nanoformulations have been developed for preclinical studies which demonstrate enhanced therapeutic efficacy. Effect of acute intraperitoneal (i.p.) administration of curcumin C3 complex nanoparticles [1,5, 10, 20, 40, 80mg/kg, (i.p.)] 75min prior to PTZ, on clonic seizure thresholds induced by intravenous infusion of pentylenetetrazole (PTZ) 0.5% was investigated in comparison with curcumin (40 and 80mg/kg, i.p.) in male mice. Moreover, to clarify the probable role of NO in the anticonvulsant property of nanocurcumin, non-effective doses of l-arginine (l-Arg), a NO donor; 7-nitroindazole, 7-NI, a preferential neuronal NO synthase inhibitor; L-NAME, a non-selective NO synthase inhibitor and aminoguanidine (AG), a selective inducible NO synthase inhibitor (iNOS), in combination with nanocurcumin (80mg/kg, i.p.), 15-30min before it were employed.

RESULTS

While curcumin did not show any anticonvulsant effect, nanocurcumin revealed dose-dependent anticonvulsant property at the doses 20, 40 and 80mg/kg, P<0.01, P<0.01 and P<0.001, respectively. l-Arg (30 and 60mg/kg) dose-dependently reversed the anticonvulsant effect of the most effective nanocurcumin dose (80mg/kg), P<0.01 and P<0.001, respectively. On the other hand, L-NAME (3 and 10mg/kg, i.p.) markedly potentiated the sub effective dose of nanocurcumin (10mg/kg), P<0.01 and P<0.001, respectively. Similarly, AG (50 and 100mg/kg, i.p.) profoundly augmented the seizure thresholds of nanocurcumin (10mg/kg), P<0.01 and P<0.001, respectively. In addition, 7-NI (10, 30 and 60mg/kg, i.p.) failed to influence the responses.

CONCLUSION

These data may support excess of NO production following PTZ infusion probably resulting from iNOS source. Consequently, nanocurcumin probably down regulated NO. To conclude, nanocurcumin showed anticonvulsant effect. Furthermore, this effect was reversed following l-arginine as an external NO precursor. However, both the non-selective NOS inhibitor and selective iNOS inhibitor increased the thresholds. It is evident that nanocurcumin may influence the seizure thresholds at least in part through a decrease in NO.

Biological activities of curcuminoids, other biomolecules from turmeric and their derivatives - A review

In recent years, several drugs have been developed deriving from traditional products and current drug research is actively investigating the possible therapeutic roles of many Ayruvedic and Traditional Indian medicinal therapies. Among those being investigated is Turmeric. Its most important active ingredient is curcuminoids. Curcuminoids are phenolic compounds commonly used as a spice, pigment and additive also utilized as a therapeutic agent used in several foods. Comprehensive research over the last century has revealed several important functions of curcuminoids. Various preclinical cell culture and animals studies suggest that curcuminoids have extensive biological activity as an antioxidant, neuroprotective, antitumor, anti-inflammatory, anti-acidogenic, radioprotective and arthritis. Different clinical trials also suggest a potential therapeutic role for curcuminoids in numerous chronic diseases such as colon cancer, lung cancer, breast cancer, inflammatory bowel diseases. The aim of this review is to summarize the chemistry, analog, metal complex, formulations of curcuminoids and their biological activities.

Obestatin improves oxidative brain damage and memory dysfunction in rats induced with an epileptic seizure

Obestatin was shown to alleviate renal, gastrointestinal and haemorrhage-induced brain injury in rats. In order to investigate the neuroprotective effects of obestatin on seizure-induced oxidative brain injury, an epileptic seizure was induced with a single intraperitoneal (i.p.) dose of pentylenetetrazole (PTZ, 45mg/kg) in male Wistar rats. Thirty minutes before the PTZ injection, rats were treated with either saline or obestatin (1μg/kg, i.p.). Seizure was video-taped and then evaluated by using Racine's scoring (0-5). For the assessment of memory function, passive-avoidance test was performed before seizure induction, which was repeated on the 3rd day of seizure. The rats were decapitated at the 24th or 72nd hour of seizures and brain tissues were obtained for histopathological examination and for measuring levels of malondialdehyde (MDA), glutathione (GSH), reactive oxygen radicals and myeloperoxidase (MPO) activity. Obestatin treatment reduced the average seizure score, decreased the occurrence and duration of generalized tonic-clonic seizures, presenting with a shorter latency to their onset. Increased lipid peroxidation and enhanced generation of oxygen-derived radicals detected at the post-seizure 72nd h were suppressed by the consecutive treatments of obestatin, but no changes were observed by the single obestatin treatment in the 24-h seizure group. Neuronal damage and increased GFAP immunoreactivity, observed in the hippocampal areas and cortex of PTZ-induced rats were alleviated in 3-day obestatin-treated PTZ group. PTZ-induced memory dysfunction was significantly improved in obestatin-treated PTZ group as compared to saline-treated rats. The present data indicate that obestatin ameliorated the severity of PTZ-induced seizures, improved memory dysfunction and reduced neuronal damage by limiting oxidative damage.

Effects of ferulic acid on oxidative stress, heat shock protein 70, connexin 43, and monoamines in the hippocampus of pentylenetetrazole-kindled rats

The present study investigated the effects of ferulic acid (FA) on pentylenetetrazole (PTZ)-induced seizures, oxidative stress markers (malondialdehyde (MDA), catalase, and reduced glutathione (GSH)), connexin (Cx) 43, heat shock protein 70 (Hsp 70), and monoamines (serotonin (5-HT) and norepinephrine (NE)) levels in a rat model of PTZ-induced kindling. Sixty Sprague Dawley rats were divided into 5 equal groups: (a) normal group; (b) FA group: normal rats received FA at a dose of 40 mg/kg daily; (c) PTZ group: normal rats received PTZ at a dose of 50 mg/kg i.p. on alternate days for 15 days; (d) FA-before group: treatment was the same as for the PTZ group, except rats received FA; and (e) FA-after group: rats received FA from sixth dose of PTZ. PTZ caused a significant increase in MDA, Cx43, and Hsp70 along with a significant decrease in GSH, 5-HT, and NE levels and CAT activity in the hippocampus (p < 0.05). Pre- and post-treatment with FA caused significant improvement in behavioral parameters, MDA, CAT, GSH, 5-HT, NE, Cx43 expression, and Hsp70 expression in the hippocampal region (p < 0.05). We conclude that FA has neuroprotective effects in PTZ-induced epilepsy, which might be due to attenuation of oxidative stress and Cx43 expression and upregulation of neuroprotective Hsp70 and neurotransmitters (5-HT and NE).

Trimetazidine potentiates the antiepileptic activity and ameliorates the metabolic changes associated with pentylenetetrazole kindling in rats treated with valproic acid

Oxidative stress is implicated in epileptogenesis as well as in the metabolic changes associated with increased risk of atherosclerotic vascular disease in epilepsy. The present work investigated the impact of the antioxidant trimetazidine (TMZ) on the antiepileptic activity of valproic acid (VPA) and on the metabolic and histological changes in hippocampal, aortic, and hepatic tissues associated with epilepsy and (or) VPA. Rats were divided into non-pentylenetetrazole (non-PTZ) group subdivided into control and VPA-treated groups, and PTZ-treated group subdivided into PTZ, PTZ/VPA, PTZ/TMZ, and PTZ/VPA + TMZ groups. VPA treatment in PTZ rats resulted in an antioxidant effect with improvement in oxidative stress, metabolic and histopathological changes induced by PTZ in hippocampus, aortic, and hepatic tissues. TMZ exhibited anticonvulsant activity and potentiated the anticonvulsant effect of VPA. Combination of TMZ with VPA induced a greater reduction in oxidative stress, improvement in the metabolic and histopathological changes compared to VPA treatment. In contrast, VPA administration in non-PTZ-treated rats induced a pro-oxidative effect, associated with metabolic and histopathological changes in aortic and hepatic tissues. These findings suggest that co-administration of TMZ with VPA in epilepsy might antagonize not only the oxidative stress associated with epilepsy but might also counteract a potential pro-oxidative effect of VPA.

Ferulic acid exhibits antiepileptogenic effect and prevents oxidative stress and cognitive impairment in the kindling model of epilepsy

AIMS

Some conventional antiepileptic drugs induce oxidative stress and cognitive impairment which may limit their clinical applications. Ferulic acid is a phenolic phytochemical with antioxidant and neuroprotective properties that prompted us to evaluate its therapeutic potential in epilepsy which is usually associated with oxidative stress and cognitive decline.

MATERIALS AND METHODS

Male Wistar rats received 30mg/kg of pentylenetetrazole (PTZ) intraperitoneally (i.p.) once every alternate day until the development of kindling. The locomotor activity, elevated plus maze, and passive avoidance tests were performed. Oxidative stress was evaluated by the determination of brain malondialdehyde and reduced glutathione. The effects of pre-treatment with ferulic acid (25, 50, 75, and 100mg/kg, i.p.) against PTZ-kindled seizures, cognitive impairment, and oxidative stress were investigated.

KEY FINDINGS

Kindling was developed 34.18±1.54days after PTZ treatment which was associated with generalized tonic-clonic seizures (GTCS), myoclonic jerks, cognitive deficit, and oxidative stress. Ferulic acid at doses of 75 and 100mg/kg significantly reduced the seizure score, number of myoclonic jerks, cognitive decline and oxidative stress. Spontaneous locomotor activity did not significantly differ between the groups.

SIGNIFICANCE

Ferulic acid exhibits antiepileptogenic effect and prevents oxidative stress and cognitive impairment induced by PTZ kindling. Therefore, this phenolic phytochemical appears as a promising adjuvant for antiepileptic drugs. Meanwhile, further experimental and clinical studies are required to provide insights into the cellular/molecular mechanism(s) underlying the action of ferulic acid.

Anticonvulsant effects of iridoid glycosides fraction purified from Feretia apodanthera Del. (Rubiaceae) in experimental mice models of generalized tonic-clonic seizures

Background

Despite the increasing number and variety of antiepileptic drugs, nearly 30 % of epileptic patients who receive appropriate medical attention have persisting seizures. Anticonvulsant activity has been demonstrated for different iridoid glycoside-rich plant extracts. This study was designed to investigate the anticonvulsant effects of iridoid glycosides purified from Feretia apodanthera and to explore the possible mechanisms involved in antiepileptic activity.

Methods

The anticonvulsant effects of iridoid glycosides extracts were investigated against 2.7 mg/kg bicuculline- and 70 mg/kg pentylenetetrazole-induced convulsions. The behavioural and electroencephalographic manifestations of 50 mg/kg pentylenetetrazole-induced seizures in mice as a model of generalized tonic-clonic seizures were also evaluated. Finally, the extracts were tested on the course of kindling development, kindled-seizures and oxidative stress markers in 30 mg/kg pentylenetetrazole-kindled mice. Their effects on brain GABA content were also determined.

Results

The iridoid glycosides (30–90 mg/kg) protected mice against bicuculline-induced motor seizures in all pre-treated animals. Behavioural seizures- and mortality-induced by 70 mg/kg pentylenetetrazole were strongly antagonized by the extracts (60–90 mg/kg). The number of crisis (n/20 min), the cumulative duration of crisis (sec/20 min), and the mean duration of crisis (sec) recorded in 50 mg/kg pentylenetetrazole-treated mice were significantly decreased in all pre-treated mice with the extracts (60–90 mg/kg). Administration of the extracts (30–90 mg/kg) significantly increased the latency to myoclonic jerks, clonic seizures as well as generalized tonic-clonic seizures, improved the seizure mean stage and decreased the number of myoclonic jerks in 30 mg/kg pentylenetetrazole-kindled mice. Pentylenetetrazole kindling induced significant oxidative stress and brain GABA content alteration that was reversed by pretreatment with the extracts in a dose-dependent manner.

Conclusions

The results indicate that pretreatment with the iridoid glycosides extracts of Feretia apodenthera improves generalized tonic-clonic seizures-induced by chemo-convulsants, protects mice against kindling development and oxidative stress, and improves brain GABA content in pentylenetetrazole-kindled mice.

Protective effect on phenytoin-induced cognition deficit in pentylenetetrazol kindled mice: A repertoire of Glycyrrhiza glabra flavonoid antioxidants

CONTEXT

Glycyrrhiza glabra L. (Febaceae) has been widely used in traditional medicine and scientifically explored for its anticonvulsant and memory improving potential.

OBJECTIVE

The objective of this study is to investigate the effect of flavonoid rich fraction of G. glabra root extract against phenytoin-induced cognition deficit in pentylenetetrazol (PTZ) kindled mice.

MATERIALS AND METHODS

The ethyl acetate fraction was initially screened in different in vitro free radical scavenging assays. For in vivo studies, the kindled mice in different groups were given 15 d post-treatment with phenytoin (25 mg/kg; p.o.) per se or in combination with varying doses of the fraction (5, 10, and 15 mg/kg; p.o.). Seizure severity score and cognitive functions were accessed using Racine's scale and passive shock avoidance paradigm, respectively on every 5th d after a PTZ challenge dose (35 mg/kg; i.p.). At the end of study, the animals were scarified for cerebral biochemistry.

RESULTS

The fraction showed marked antioxidant activity indicated by low IC50 values in DPPH (20.9 µg/mL), nitric oxide radical scavenging (195.2 µg/mL), and capacity of hydrogen peroxide scavenging (3.4 µg/mL) assays. Treatment with phenytoin per se and along with the flavonoid rich fraction showed significant reduction in seizure severity score as compared to vehicle control. The combined-treated groups also showed improved cognitive functions indicated by reduced number of mistakes and increased step-down latency in passive shock avoidance paradigm.

CONCLUSION

From the results, it can be concluded that the flavonoid rich fraction in combination with phenytoin reduces seizure severity and improve cognitive functions in PTZ-kindled mice.

Neurochemical modulation involved in the beneficial effect of liraglutide, GLP-1 agonist on PTZ kindling epilepsy-induced comorbidities in mice

Epilepsy is a neurological disorder which occurs due to excessive firing of excitatory neurons in specific region of brain and associated with cognitive impairment and depression. GLP-1 has been reported to maintain hyperexcitability of neurons. Therefore, this study was designed to investigate the neuroprotective effect of liraglutide, GLP-1 analogue in PTZ kindling epilepsy-induced comorbidities and neurochemical alteration in mice. Male albino mice were administered PTZ (35 mg/kg) on every alternate day up to 29th days and challenge test was performed on 33rd day. From 1st day liraglutide (75 and 150 µg/kg) and diazepam (3 mg/kg) were administered up to 33rd day, 30 min prior to PTZ treatment. On 30th day animals were trained on elevated plus maze and passive shock avoidance paradigm and retention was recorded on 31st and 33rd day. On 32nd day tail suspension test was performed. Animals were sacrificed on 34th day for biochemical (LPO, GSH, and nitrite) and neurotransmitters (GABA, glutamate, DA, NE, 5-HT and their metabolites) estimation. Chronic treatment with PTZ developed generalized tonic-clonic seizures, reduced cognitive skills, increased oxidative stress and alteration in the level of neurotransmitters. Pre-treatment with liraglutide (75 and 150 μg/kg) significantly prevented the seizure severity, restored behavioural activity, oxidative defence enzymes, and altered level of neurochemicals in mice brain. The protective effect of liraglutide is attributed to restoration of altered level of GABA, glutamate, DA, NE, and 5-HT by the up-regulation of GLP-1Rs in mice brain.

Anticonvulsant activity of the cyclooxygenase-2 (COX-2) inhibitor etoricoxib in pentylenetetrazole-kindled rats is associated with memory impairment

PURPOSE

Various selective and nonselective cyclooxygenase (COX) inhibitors are known to have effects on development and progression of seizures. In the present study, the effect of the selective COX-2 inhibitor etoricoxib on seizures, oxidative stress, and learning and memory was studied.

METHOD

Male Wistar rats were kindled using subconvulsant dose of pentylenetetrazole (PTZ) (30mg/kg, i.p.), on alternating days until animals were fully kindled. After a one-week PTZ-free period, kindled rats were challenged with PTZ 30mg/kg, and the latency, duration, and severity of seizures were recorded. Etoricoxib was then administered intraperitoneally at 1mg/kg and 10mg/kg in kindled rats for nine days (days 6-14). On the ninth day of etoricoxib treatment, PTZ challenge (30mg/kg) was given, and seizure parameters were noted. On day 15, behavioral assessment was carried out. The Morris water maze (MWM) apparatus and the passive avoidance (PA) apparatus were used for studying cognitive impairment. The rats were then sacrificed, and malondialdehyde (MDA) and glutathione (GSH), markers of oxidative stress, were estimated in the brain samples.

RESULTS

Etoricoxib at lower dose (1mg/kg) had an anticonvulsant effect which was reduced or reversed at higher dose (10mg/kg). Etoricoxib also impaired the learning and memory in rats as tested by passive avoidance and Morris water maze tests.

CONCLUSION

The results of the present study suggest that use of etoricoxib, especially at low dose, in patients with epilepsy may not be detrimental with regard to seizure control. However, attention should be paid to cognitive parameters.

Effects of a lyophilized aqueous extract of Feretia apodanthera Del. (Rubiaceae) on pentylenetetrazole-induced kindling, oxidative stress, and cognitive impairment in mice

Feretia apodanthera Del. (Rubiaceae) is extensively used in ethnomedicine in Cameroon and Nigeria for epilepsy, febrile convulsions, and rheumatic pains and for enhancing cognitive performance. The aim of the present study was to examine the effects of a lyophilized aqueous extract of F. apodanthera on the course of kindling development, kindling-induced learning deficit, oxidative stress markers, and cholinesterase activity in pentylenetetrazole (PTZ)-kindled mice. Pentylenetetrazole, 30mg/kg, induced kindling in mice after 30.00±1.67days. The aqueous extract of F. apodanthera showed dose-dependent antiseizure effects. Feretia apodanthera (150-200mg/kg) significantly increased the latency to myoclonic jerks, clonic seizures, and generalized tonic-clonic seizures. The extract also improved the seizure score and decreased the number of myoclonic jerks. Pentylenetetrazole kindling induced significant oxidative stress and cognitive impairment which were reversed by pretreatment with F. apodanthera in a dose-dependent manner. The significant decrease in cholinesterase activity observed in the PTZ-kindled mice was reversed by pretreatment with the F. apodanthera extract. The results indicated that pretreatment with the aqueous extract of F. apodanthera antagonizes seizures, oxidative stress, and cognitive impairment in PTZ-kindled mice. The aqueous extract of F. apodanthera also showed anxiolytic activities, but the inhibition of memory impairment was not attributed to the anxiolytic activities of the plant. These results thus suggest the potential of F. apodanthera as an adjuvant in epilepsy both to prevent seizures as well as to protect against seizure-induced oxidative stress and memory impairment.

Methanol extract of Ficus platyphylla ameliorates seizure severity, cognitive deficit and neuronal cell loss in pentylenetetrazole-kindled mice

Decoctions of Ficus plathyphylla are used in Nigeria's folk medicine to manage epilepsy for many years and their efficacies are widely acclaimed among the rural communities of Northern Nigeria. In this study, we examined the ameliorative effects of the standardized methanol extract of Ficus platyphylla (FP) stem bark on seizure severity, cognitive deficit and neuronal cell loss in pentylenetetrazole-kindled mice. The (35)S-GTPγS, glutamate and γ-aminobutyric acid receptors binding properties of the extract were also evaluated. Male CD-1 mice were kindled with an initial subeffective dose of pentylenetetrazole (PTZ, 37.5mg/kg, i.p.) for a total of 13 convulsant injections and the treatment groups concurrently received FP (100 and 200mg/kg). Control animals received the same number of saline injections. Twenty-four h after kindling completion the animals' learning performance was tested in a two-way shuttle-box. The animals were challenged with another subeffective dose of PTZ (32.5mg/kg, i.p.) on day 7 after kindling completion. Animals were sacrificed a day after the challenged experiment and the brains were processed for histological investigation. FP ameliorates seizure severity, cognitive deficits and neuronal cell loss in PTZ kindled mice. Components of the extract showed affinity for GABAergic and glutamatergic receptors. Glutamate release was diminished and the (35)S-GTPγS binding assay revealed no intrinsic activity at glutamatergic receptors. Our results revealed that FP contains psychoactive secondary metabolites with anticonvulsant properties, thus supporting the isolation and development of the biologically active components of this medicinal plant as antiepileptic agents.

Ficus religiosa L. figs--a potential herbal adjuvant to phenytoin for improved management of epilepsy and associated behavioral comorbidities

Oxidative stress, together with mitochondrial dysfunction, has been reported to be involved in the pathogenesis of epileptogenesis and its associated comorbidities. Phytoflavonoids have shown numerous beneficial ameliorative effects on different neurological disorders by virtue of their antioxidant effect. The present study investigated the effect of flavonoid-rich ethyl acetate fraction of the crude fig extract of Ficus religiosa in combination with phenytoin on seizure severity, depressive behavior, and cognitive deficit in pentylenetetrazol (PTZ)-kindled mice. The flavonoid-rich ethyl acetate fraction of the crude fig extract was found to show significant antioxidant potential in various in vitro free radical scavenging assays. Combined treatment of this fraction (2.5, 5, and 10 mg/kg; i.p.) along with a subeffective dose of phenytoin (15 mg/kg; i.p.) in postkindled animals once daily for fifteen days showed a dose-dependent decrease in the seizure severity score, a decreased number of mistakes, increased step-down latency in passive shock avoidance paradigm, and decreased immobility time in the tail suspension test in comparison with the phenytoin only-treated group. Biochemical investigations of the brain tissue showed amelioration of thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) levels, and reduced catalase and acetylcholinesterase (AChE) activities, thereby indicating suppression of oxidative stress. In conclusion, the results of the present study showed the protective effect of the flavonoid-rich fraction of F. religiosa along with a subeffective dose of phenytoin in PTZ-kindling-associated cognitive deficit and depressive behavior with complete suppression of seizures through reduction of oxidative stress, supporting the the need for clinical evaluation of the supplementation of phytoflavonoids along with antiepileptic drugs (AEDs) for management of epilepsy and its psychiatric and cognitive comorbidities.

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.

The neuroprotective effect of cornus MAS on brain tissue of Wistar rats

Cornelian cherry (Cornus mas) is a valuable source of phenolic antioxidants. Flavonoid derivatives as nonenzymatic antioxidants are important in the pathophysiology of many diseases including neurological disorders (e.g., Alzheimer's disease) or heart disease. In this study, we examined the effect of an addition of freeze-dried fruit of cornelian cherry on three types of diets: control diet, fructose diet, and diet enriched in fats (high-fat diet). This effect was studied by determining the following antioxidant parameters in both brain tissue and plasma in rats: catalase, ferric reducing ability of plasma, paraoxonase, protein carbonyl groups, and free thiol groups. Results indicate that both fructose diet and high-fat diet affect the antioxidant capacity of the organism. Furthermore, an addition of cornelian cherry resulted in increased activity of catalase in brain tissue, while in plasma it caused the opposite effect. In turn, with regard to paraoxonase activity in both brain tissue and plasma, it had a stimulating effect. Adding cornelian cherry to the tested diets increased the activity of PON in both tested tissues. Moreover, protective effect of fruits of this plant was observed in the process of oxidation of proteins by decreasing levels of protein carbonyl groups and thiol groups in brain tissue as well as in plasma.

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

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

Effects of grape seed proanthocyanidin extract on pentylenetetrazole-induced kindling and associated cognitive impairment in rats

Numerous studies have demonstrated the antioxidant effects of grape seed proanthocyanidin extract (GSPE). The generation of free radicals and the ensuing apoptosis may contribute to the pathogenesis of epilepsy; therefore, in the present study, we examined the effects of GSPE on cognitive impairment and neuronal damage induced by chronic seizures in rats. Seizures were induced by a daily intraperitoneal (i.p.) injection of pentylenetetrazole (PTZ; 35 mg/kg/day, 36 days). Two other groups were treated with GSPE (100 or 200 mg/kg/day, orally) for 24 days and then for 36 days prior to each PTZ injection. After the final PTZ injection, hippocampus-dependent spatial learning was assessed using the Morris water maze (MWM). The rats were then sacrificed for the measurement of hippocampal malondialdehyde (MDA, a measure of lipid peroxidation) and glutathione (GSH, a measure of endogenous antioxidant capacity) levels, and for the expression of pro-apoptotic factors [cytochrome c (Cyt c), caspase‑9 and caspase‑3]. The mitochondrial generation of reactive oxygen species (ROS), degree of mitochondrial swelling, neuronal damage and mitochondrial ultrastructure were also examined. Performance in the MWM was markedly impaired by PTZ-induced seizures, as evidenced by longer escape latencies during training and fewer platform crossings during the probe trial. This cognitive decline was accompanied by oxidative stress (MDA accumulation, ROS generation, reduced GSH activity), an increased expression of pro-apoptotic proteins, as well as damage to CA1 pyramidal neurons and the mitochondria. Pre-treatment with GSPE dose‑dependently reversed PTZ-induced impaired performance in the MWM, oxidative stress, mitochondrial ROS generation, the expression of pro-apoptotic proteins and neuronal and mitochondrial damage. Thus, GSPE may reverse the hippocampal dysfunction induced by chronic seizures, by reducing oxidative stress and preserving mitochondrial function.

Phytochemical profiling of Curcuma kwangsiensis rhizome extract, and identification of labdane diterpenoids as positive GABAA receptor modulators

An ethyl acetate extract of Curcuma kwangsiensis S.G. Lee & C.F. Liang (Zingiberaceae) rhizomes (100 μg/ml) enhanced the GABA-induced chloride current (IGABA) through GABAA receptors of the α1β2γ2S subtype by 79.0±7.0%. Potentiation of IGABA was measured using the two-microelectrode voltage-clamp technique and Xenopus laevis oocytes. HPLC-based activity profiling of the crude extract led to the identification of 11 structurally related labdane diterpenoids, including four new compounds. Structure elucidation was achieved by comprehensive analysis of on-line (LC-PDA-ESI-TOF-MS) and off-line (microprobe 1D and 2D NMR) spectroscopic data. The absolute configuration of the compounds was established by comparison of experimental and calculated ECD spectra. Labdane diterpenes represent a new class of plant secondary metabolites eliciting positive GABAA receptor modulation. The highest efficiency was observed for zerumin A (maximum potentiation of IGABA by 309.4±35.6%, and EC50 of 24.9±8.8 μM).

Characterization of anticonvulsant and antiepileptogenic potential of thymol in various experimental models

The present study was to investigate the anticonvulsant and antiepileptogenic potential of thymol. Anticonvulsant activity of thymol (5-100 mg/kg i.p.) was studied using maximal electroshock, pentylenetetrazole (PTZ), strychnine and 4-aminopyridine (4-AP) models. Thymol at the selected dose was also studied for its effect on locomotion. Antiepileptogenic property of thymol (5-25 mg/kg) was evaluated using PTZ-induced kindling model along with its effect on malondialdehyde and glutathione levels. Thymol (50 and 100 mg/kg, i.p.) showed anticonvulsant activity against maximal electroshock and pentylenetetrazole (66.66 and 83.33 % protection at 50 and 100 mg/kg, respectively) model but not against strychnine and 4-aminopyridine models. Thymol exhibited decreased locomotor activity in dose-dependent manner at the same dose range. Thymol at the dose of (25 mg/kg, i.p.) significantly decreased the seizure score, increased glutathione levels and decreased malondialdehyde levels in pentylenetetrazole-induced kindling model. Thymol exhibited significant anticonvulsant and antiepileptogenic property.

Dietary Strategy to Repair Plasma Membrane After Brain Trauma

Background. Damage to the plasma membrane is a prevalent but often neglected aspect of traumatic brain injury (TBI), which can impair neuronal signaling and hamper neurological recovery. Objective. This study was performed to assess a new noninvasive intervention to counteract peroxidative damage to the phospholipids in the membrane using the powerful action of foods. Although dietary docosahexaenoic acid (C22:6n-3; DHA) provides protection against TBI, the pervasive effects of TBI that cause phospholipid damage, including to DHA, raises concerns about how to preserve DHA in the brain for optimal functional recovery. Methods. Rats were maintained on curcumin and/or DHA-enriched diets for 2 weeks postinjury, and their brains were subjected to analyses. Results. Fluid percussion injury reduced DHA levels as well as levels of enzymes involved in the metabolism of DHA such as FADS2 and 17β-HSD4 and elevated levels of markers of lipid peroxidation such as 4-hydroxy-2-nonenal (4-HNE) and 4-hydroxy-2-hexenal (4-HHE). These effects were counteracted by DHA or curcumin, whereas the combination of curcumin and DHA had an enhanced effect on DHA and 4-HNE. The combination of curcumin and DHA was also efficient in counteracting reductions in the plasticity markers, brain-derived neurotrophic factor and its receptor p-trkB, and learning ability, which had been lessened after TBI. Conclusions. Curcumin complements the action of DHA on TBI pathology, and this property appears to be a viable strategy to counteract neuronal dysfunction after TBI and complement the application of rehabilitative interventions to foster functional recovery.

Lamotrigine positively affects the development of psychiatric comorbidity in epileptic animals, while psychiatric comorbidity aggravates seizures

Several clinical and preclinical studies have focused on the relationship between epilepsy and psychological disturbances. Although behavior in some experimental models of epilepsy has been studied, only few of them can be considered as models of epilepsy and mood disorder comorbidity. Since several models of epilepsy or psychiatric disorders are already available, we wondered whether a mixture of the two could experimentally represent a valid alternative to study such comorbidity. Here, we present a possible experimental protocol to study drug effects and physiopathogenesis of psychiatric comorbidity in epileptic animals. Pentylentetrazol-kindled animals were subjected to the chronic mild stress (CMS) procedure; furthermore, we tested the effects of chronic lamotrigine treatment on the development of comorbidity. We found that epileptic-depressed animals showed more pronounced behavioral alterations in comparison to other mice groups, indicating that kindled animals develop more pronounced CMS-induced behavioral alterations than nonepileptic mice; lamotrigine was able to prevent the development of comorbidities such as anxiety, depression-like behavior, and memory impairment.

Ameliorative effect of Curcumin on seizure severity, depression like behavior, learning and memory deficit in post-pentylenetetrazole-kindled mice

Epilepsy is a chronic neurological disorder and generally associated with certain psychiatric comorbidities. Among several comorbidities depressive behavior and cognitive impairment has been reported to be most debilitating comorbidity associated with epilepsy. This study was envisaged to evaluate the ameliorative effect of Curcumin on depression like behavior and cognitive impairment observed in pentylenetetrazole kindled animals. Male Swiss Albino mice were kindled with subconvulsive dose of pentylenetetrazole (35 mg/kg, i.p.). Successfully kindled animals were used in the study to observe the effect of different treatments. Treatment groups received phenytoin (30 mg/kg) and Curcumin (50, 100 and 200mg/kg) for 15 days. The animals were challenged with pentylenetetrazole (35 mg/kg, i.p.) on day 5, 10 and 15 and seizure severity score, immobility period, number of mistakes and step down latency were recorded. On 15th day, all the animals were sacrificed after behavioral evaluations and their brain was isolated and homogenized to estimate brain norepinephrine, serotonin, total nitrite level and acetylcholinesterase activity. Phenytoin treatment significantly improved the depressive like behavior along with its anticonvulsant effect, however was unable to improve memory impairment. Curcumin significantly attenuated seizure severity, depression like behavior and memory impairment in kindled animals, in dose dependent manner. These results were supported by the biochemical modulation of brain monoamine, nitrosative stress level and acetylcholinesterase activity. Thus present study concluded that Curcumin has the ameliorative effect on seizure severity, depression like behavior and memory impairment in pentylenetetrazole kindled mice, possibly via central monoaminergic modulation and inhibitory effect on nitrosative stress and acetylcholinesterase activity.

Selenium induced anticonvulsant effect: a potential role of prostaglandin E(1) receptor activation linked mechanism

PROJECT

Selenium deficiency has been associated with enhanced propensity of seizures in man and laboratory animals. Therefore, the present study has been designed to investigate the anti-convulsant effect of sodium selenite and seleno-dl-methionine on pentylenetetrazole induced seizures in mice and the role of prostaglandin receptor activation in the proposed anticonvulsant effect of sodium selenite.

PROCEDURE

Sodium selenite (1, 3 and 10 mg kg(-1), i.p.) and seleno-dl-methionine (0.3, 1 and 3 mg kg(-1), i.p.) was used to evaluate the potential effect on pentylenetetrazole induced seizures in mice. Pentylenetetrazole induced seizures were assessed in terms of onset time of straub's tail phenomenon, jerky movements of the whole body and convulsions. Additionally, an isobolographic study design was used to examine the interaction between sodium selenite and celecoxib (a cyclooxygenase-2 inhibitor). Sodium selenite and seleno-dl-methionine significantly attenuated pentylenetetrazole induced seizures in mice.

RESULTS

Prior administration of misoprostol (a selective agonist of prostaglandin E(1) receptors) markedly attenuated the anticonvulsant effect of sodium selenite as well as seleno-dl-methionine in mice. However, the administration of misoprostol per se did not produce any behavioral changes. Further, sodium selenite was observed to exert a synergistic interaction with celecoxib.

CONCLUSIONS

Selenium induced reduction in seizure like behavior might be ascribed to the activation of a prostaglandin E(1) receptor activation linked mechanism. It is further proposed that sodium selenite exerts a synergistic anti-convulsant effect with celecoxib indicating the therapeutic usefulness of combining the two agents to treat epilepsy.

Curcumin in inflammatory diseases

Curcumin (diferuloylmethane), a yellow coloring agent extracted from turmeric is also used as a remedy for the treatment and prevention of inflammatory diseases. Acute and chronic inflammation is a major factor in the progression of obesity, type II diabetes, arthritis, pancreatitis, cardiovascular, neurodegenerative and metabolic diseases, as well as certain types of cancer. Turmeric has a long history of use in Ayurvedic medicine for the treatment of inflammatory disorders. Recent studies on the efficacy and therapeutic applicability of turmeric have suggested that the active ingredient of tumeric is curcumin. Further, compelling evidence has shown that curcumin has the ability to inhibit inflammatory cell proliferation, invasion, and angiogenesis through multiple molecular targets and mechanisms of action. Curcumin is safe, non-toxic, and mediates its anti-inflammatory effects through the down-regulation of inflammatory transcription factors, cytokines, redox status, protein kinases, and enzymes that all promote inflammation. In addition, curcumin induces apoptosis through mitochondrial and receptor-mediated pathways, as well as activation of caspase cascades. In the current study, the anti-inflammatory effects of curcumin were evaluated relative to various chronic inflammatory diseases. Based on the available pharmacological data obtained from in vitro and in vivo research, as well as clinical trials, an opportunity exists to translate curcumin into clinics for the prevention of inflammatory diseases in the near future.

Effect of Anacyclus pyrethrum on pentylenetetrazole-induced kindling, spatial memory, oxidative stress and rho-kinase II expression in mice

Anacyclus pyrethrum (A. pyrethrum) has been reported to exhibit anticonvulsant activity. In the present study, the effect of hydro-alcoholic extract of A. pyrethrum root (HEAP) on pentylenetetrazole (PTZ) induced kindling, spatial memory, oxidative stress and rho kinase (ROCK II) was assessed. Male albino mice (25-30 g) were used in the study. PTZ (35 mg/kg, i.p. on alternate days) was injected to induce kindling and PTZ (70 mg/kg, i.p) challenge was given 7 days post-kindling. HEAP was administered orally daily in the doses of 100, 250 and 500 mg/kg along with PTZ injections during the kindling process and continued till PTZ challenge post kindling. Spatial memory was assessed using Morris water maze test. Oxidative stress parameters [malondialdehyde (MDA) and reduced glutathione (GSH)] and ROCK II expression were estimated in whole brain at the end of the study. Pre-treatment with HEAP (250 and 500 mg/kg) showed significant increase in the myoclonic jerk latency and delay in the development of kindling. A significant decrease in mortality was observed at higher doses of HEAP (250 and 500 mg/kg). Pre-treatment with HEAP significantly increased the number of platform crossings and decreased the escape latency, as opposed to the PTZ group, thus showing protection against memory deficit. HEAP pre-treatment also attenuated the oxidative stress induced by PTZ kindling. PTZ induced kindling increased the ROCK II expression whereas, HEAP pre-treatment attenuated the increase in ROCK II expression. To conclude, HEAP pre-treatment showed antiepileptic effect and also showed protection against cognitive impairment by decreasing oxidative stress and ROCK II expression in PTZ kindled mice.

Discovery of curcumin, a component of golden spice, and its miraculous biological activities

1. Curcumin is the active ingredient of the dietary spice turmeric and has been consumed for medicinal purposes for thousands of years. Modern science has shown that curcumin modulates various signalling molecules, including inflammatory molecules, transcription factors, enzymes, protein kinases, protein reductases, carrier proteins, cell survival proteins, drug resistance proteins, adhesion molecules, growth factors, receptors, cell cycle regulatory proteins, chemokines, DNA, RNA and metal ions. 2. Because of this polyphenol's potential to modulate multiple signalling molecules, it has been reported to possess pleiotropic activities. First demonstrated to have antibacterial activity in 1949, curcumin has since been shown to have anti-inflammatory, anti-oxidant, pro-apoptotic, chemopreventive, chemotherapeutic, antiproliferative, wound healing, antinociceptive, antiparasitic and antimalarial properties as well. Animal studies have suggested that curcumin may be active against a wide range of human diseases, including diabetes, obesity, neurological and psychiatric disorders and cancer, as well as chronic illnesses affecting the eyes, lungs, liver, kidneys and gastrointestinal and cardiovascular systems. 3. Although many clinical trials evaluating the safety and efficacy of curcumin against human ailments have already been completed, others are still ongoing. Moreover, curcumin is used as a supplement in several countries, including India, Japan, the US, Thailand, China, Korea, Turkey, South Africa, Nepal and Pakistan. Although inexpensive, apparently well tolerated and potentially active, curcumin has not been approved for the treatment of any human disease. 4. In the present article, we discuss the discovery and key biological activities of curcumin, with a particular emphasis on its activities at the molecular and cellular levels, as well as in animals and humans.

Evaluation of the antiepileptic effect of curcumin and Nigella sativa oil in the pilocarpine model of epilepsy in comparison with valproate

The present study aimed to investigate the effect of curcumin and Nigella sativa oil (NSO) on amino acid neurotransmitter alterations and the histological changes induced by pilocarpine in the hippocampus and cortex of rats. Epilepsy was induced by i.p. injection of pilocarpine, and the animals were left for 22 days to establish spontaneous recurrent seizures. They were then treated with curcumin, NSO or valproate for 21 days. Pilocarpine induced a significant increase in hippocampal aspartate and a significant decrease in glycine and taurine levels. In the cortex, a significant increase in aspartate, glutamate, GABA, glycine, and taurine levels was obtained after pilocarpine injection. Treatment of pilocarpinized rats with curcumin and valproate ameliorated most of the changes in amino acid concentrations and reduced the histopathological abnormalities induced by pilocarpine. N. sativa oil failed to improve the pilocarpine-induced abnormalities. This may explain the antiepileptic effect of curcumin and suggest its use as an anticonvulsant.