Beneficial Effects of Ibuprofen on Pentylenetetrazol-induced Convulsion

The Anticonvulsant Effect of Nonsteroidal Anti-Inflammatory Drug, Fenoprofen, in Pentylenetetrazole-Induced Epileptic Rats: Behavioral, Histological, and Biochemical Evidence

This study aimed to evaluate the anticonvulsant properties of fenoprofen on the experimental model of pentylenetetrazole (PTZ)-induced epilepsy. Male Wistar rats were randomly grouped into five, and the kindling model was induced by intraperitoneal injection of PTZ 35 (mg/kg) every other day for 1 month. Aside from the control and PTZ groups, three groups received intraperitoneal injections of fenoprofen at doses of 10, 20, and 40 (mg/kg) before each PTZ injection. Rats were challenged with PTZ 70 (mg/kg) 1 week after kindling development. Then rats were subjected to deep anesthesia, and serum and brain samples were prepared. Oxidative stress (OS) markers (malondialdehyde, superoxide dismutase, and glutathione peroxidase) were measured in serum samples. Hippocampal tissue was used to investigate the relative expression of OS-related genes (nuclear factor [erythroid-derived 2]-like 2 (Nrf2)/heme oxygenase 1 (Hmox1)) and histological studies. Seizure behavior was assessed based on Lüttjohann's score. In treated groups, the number of myoclonic jerks and generalized tonic-clonic seizure (GTCS) duration decreased significantly, while myoclonic jerks and GTCS latency increased compared with the PTZ group. The biochemical evaluation revealed the antioxidative effects of fenoprofen. The decreased expression of Nrf2/HO-1 genes in the PTZ group was reversed after fenoprofen administration. The results of the histological study obtained from Nissl staining in the hippocampal tissue also confirmed the protective effect of fenoprofen. The anticonvulsant effects of fenoprofen seem to be through inhibition of OS-related markers, induction of protective effect in hippocampal tissue, and activation of the Nrf2/HO-1 signaling pathway.

Homocysteine decreases VEGF, EGF, and TrkB levels and increases CCL5/RANTES in the hippocampus: Neuroprotective effects of rivastigmine and ibuprofen

Homocysteine (Hcy) is produced through methionine transmethylation. Elevated Hcy levels are termed Hyperhomocysteinemia (HHcy) and represent a risk factor for neurodegenerative conditions such as Alzheimer's disease. This study aimed to explore the impact of mild HHcy and the neuroprotective effects of ibuprofen and rivastigmine via immunohistochemical analysis of glial markers (Iba-1 and GFAP). Additionally, we assessed levels of vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), chemokine ligand 5 (CCL5/RANTES), CX3C chemokine ligand 1 (CX3CL1), and the NGF/p75NTR/tropomyosin kinase B (TrkB) pathway in the hippocampus of adult rats. Mild chronic HHcy was induced chemically in Wistar rats by subcutaneous administration of Hcy (4 mg/kg body weight) twice daily for 30 days. Rivastigmine (0.5 mg/kg) and ibuprofen (40 mg/kg) were administered intraperitoneally once daily. Results revealed elevated levels of CCL5/RANTES and reduced levels of VEGF, EGF, and TrkB in the hippocampus of HHcy-exposed rats. Rivastigmine mitigated the neurotoxic effects of HHcy by increasing TrkB and VEGF levels. Conversely, ibuprofen attenuated CCL5/RANTES levels against the neurotoxicity of HHcy, significantly reducing this chemokine's levels. HHcy-induced neurochemical impairment in the hippocampus may jeopardize neurogenesis, synapse formation, axonal transport, and inflammatory balance, leading to neurodegeneration. Treatments with rivastigmine and ibuprofen alleviated some of these detrimental effects. Reversing HHcy-induced damage through these compounds could serve as a potential neuroprotective strategy against brain damage.

Mechanism of NLRP3 Inflammasome in Epilepsy and Related Therapeutic Agents

Epilepsy is one of the most widespread and complex diseases in the central nervous system (CNS), affecting approximately 65 million people globally, an important factor resulting in neurological disability-adjusted life year (DALY) and progressive cognitive dysfunction. Medication is the most essential treatment. The currently used drugs have shown drug resistance in some patients and only control symptoms; the development of novel and more efficacious pharmacotherapy is imminent. Increasing evidence suggests neuroinflammation is involved in the occurrence and development of epilepsy, and high expression of NLRP3 inflammasome has been observed in the temporal lobe epilepsy (TLE) brain tissue of patients and animal models. The inflammasome is a crucial cause of neuroinflammation by activating IL-1β and IL-18. Many preclinical studies have confirmed that regulating NLRP3 inflammasome pathway can prevent the development of epilepsy, reduce the severity of epilepsy, and play a neuroprotective role. Therefore, regulating NLRP3 inflammasome could be a potential target for epilepsy treatment. In summary, this review describes the priming and activation of inflammasome and its biological function in the progression of epilepsy. In addition, we reviewes the current pharmacological researches for epilepsy based on the regulation of NLRP3 inflammasome, aiming to provide a basis and reference for developing novel antiepileptic drugs.

Immunosuppressant Tacrolimus Treatment Delays Acute Seizure Occurrence, Reduces Elevated Oxidative Stress, and Reverses PGF2α Burst in the Brain of PTZ-Treated Rats

It is still an urgent need to find alternative and effective therapies to combat epileptic seizures. Tacrolimus as a potent immunosuppressant and calcineurin inhibitor is emerging as promising drug to suppress seizures. However, there are few reports applying tacrolimus to epilepsy and providing data for its antiseizure properties. In this study, we investigated the antiseizure effects of 5 and 10 mg/kg doses of tacrolimus treatment priorly to pentylenetetrazol (PTZ) induction of seizures in rats. As an experimental design, we establish two independent rat groups where we observe convulsive seizures following 70 mg/kg PTZ and sub-convulsive seizures detected by electroencephalography (EEG) following 35 mg/kg PTZ. Thereafter, we proceed with biochemical analyses of the brain including assessment of malondialdehyde level as an indicator of lipid peroxidation and detection of superoxide dismutase (SOD) enzyme activity and PGF2α. Tacrolimus pre-treatment dose-dependently resulted in lesser seizure severity according to Racine's scale, delayed start-up latency of the first myoclonic jerk and attenuated the spike percentages detected by EEG in seizure-induced rats. However, only the higher dose of tacrolimus was effective to restore lipid peroxidation. An increase in SOD activity was observed in the PTZ group, mediated by seizure activity per se, however, it was greater in the groups that received treatment with 5 and 10 mg/kg of Tacrolimus. PGF2α bursts following PTZ induction of seizures were reversed by tacrolimus pre-treatment in a dose-dependent manner as well. We report that the well-known immunosuppressant tacrolimus is a promising agent to suppress seizures. Comparative studies are necessary to determine the possible utilization of tacrolimus in clinical cases.

Aerobic exercise, alone or combined with an anti-inflammatory drug, reduces the severity of epileptic seizures and levels of central pro-inflammatory cytokines in an animal model of epileptic seizures

Epilepsy is a chronic neurological disorder and there is increasing evidence about the role of inflammation in epileptogenesis. These findings have spurred the search for new immunomodulatory approaches that can improve prognosis. Using an animal model of chemically-induced epileptic seizures, we tested exercise alone as non-pharmacological therapy, and exercise combined with an anti-inflammatory drug. Five groups were used: sedentary, diazepam, aerobic exercise alone, aerobic exercise combined with an anti-inflammatory drug, and naive control. Our goal was to compare the severity of the epileptic seizures between groups as well as seizure latency in a pentylenetetrazole-induced paradigm. Cytokine levels (IL-1β, TNF-α, and IL-10) were measured. Both exercise groups showed a reduction in seizure severity and lower levels of pro-inflammatory cytokines in the cortex, while the levels of cytokines in the hippocampus remained unaffected.

Age-Dependent Reduction in the Expression Levels of Genes Involved in Progressive Myoclonus Epilepsy Correlates with Increased Neuroinflammation and Seizure Susceptibility in Mouse Models

Brain aging is characterized by a gradual decline in cellular homeostatic processes, thereby losing the ability to respond to physiological stress. At the anatomical level, the aged brain is characterized by degenerating neurons, proteinaceous plaques and tangles, intracellular deposition of glycogen, and elevated neuroinflammation. Intriguingly, such age-associated changes are also seen in neurodegenerative disorders suggesting that an accelerated aging process could be one of the contributory factors for the disease phenotype. Amongst these, the genetic forms of progressive myoclonus epilepsy (PME), resulting from loss-of-function mutations in genes, manifest symptoms that are common to age-associated disorders, and genes mutated in PME are involved in the cellular homeostatic processes. Intriguingly, the incidence and/or onset of epileptic seizures are known to increase with age, suggesting that physiological changes in the aged brain might contribute to increased susceptibility to seizures. We, therefore, hypothesized that the expression level of genes implicated in PME might decrease with age, thereby leading to a compromised neuronal response towards physiological stress and hence neuroinflammation in the aging brain. Using mice models, we demonstrate here that the expression level of PME genes shows an inverse correlation with age, neuroinflammation, and compromised heat shock response. We further show that the pharmacological suppression of neuroinflammation ameliorates seizure susceptibility in aged animals as well as in animal models for a PME. Taken together, our results indicate a functional role for the PME genes in normal brain aging and that neuroinflammation could be a major contributory player in susceptibility to seizures.

Vitamin E Exerts Neuroprotective Effects in Pentylenetetrazole Kindling Epilepsy via Suppression of Ferroptosis

Epilepsy is one of the most common chronic neurological diseases. There is increasing evidence for ferroptosis playing an important role in the occurrence and development of epilepsy. Vitamin E is a common fat-soluble antioxidant that can regulate ferroptosis. The aim of this study was to investigate the effects of vitamin E on ferroptosis of hippocampal neurons in epileptic rats. Sixty-four male Sprague-Dawley (SD) rats were randomly divided into control, pentylenetetrazol (PTZ; 35 mg/kg), vitamin E (200 mg/kg) + PTZ, and Ferrostatin-1 (Fer-1; 2.5 μmol/kg) + PTZ groups, with drugs administered intraperitoneally 15 times every other day for 29 days. The behavioral manifestations (epileptic score, latency, and number of seizures in 30 min) and EEG changes were observed and recorded. Nissl staining and electrophysiological recording were used to assess neuronal damage and excitability in the hippocampal CA1 region, respectively. The levels of iron, glutathione (GSH), and malondialdehyde (MDA) in the hippocampus were assessed by spectrophotometry. Immunofluorescence staining was used to detect lipoxygenase 15 (15-LOX) expression. Western blot was used to determine glutathione peroxidase 4 (GPX4) and 15-LOX protein levels. Vitamin E treatment was associated with decreased epileptic grade, seizure latency, and number of seizures in the PTZ-kindled epileptic model. Vitamin E treatment also decreased 15-LOX expression, inhibited MDA and iron accumulation, and increased GPX4 and GSH expression. In conclusion, vitamin E can reduce neuronal ferroptosis and seizures by inhibiting 15-LOX expression.

The effect of sulfasalazine in pentylenetetrazole-induced seizures in rats

We aimed to reveal the anti-convulsant effects sulfasalazine and its mechanism in pentylenetetrazole (PTZ)-induced seizures in rats. Forty-eight male Wistar albino rats (200-250 g) were randomly divided into two groups: 24 for electroencephalography (EEG) recording (group A) and 24 for behavioral studies (group B). About 70 mg/kg PTZ was used for behavioral studies after sulfasalazine administration and 35 mg/kg PTZ was used for EEG recording after sulfasalazine administration. Electrodes were implanted on the dura mater over the left frontal cortex and the reference electrode was implanted over the cerebellum for EEG recording. Racine's convulsion scale, first myoclonic jerk onset time, spike percentages, brain malondialdehyde (MDA), superoxide dismutase (SOD), and prostaglandin F2α (PGF2α) levels were evaluated between the groups. First myoclonic jerk onset time was significantly shorter in the saline group than both 250 and 500 mg/kg sulfasalazine groups (P<0.05). Racine's convulsion scores were significantly lower in the 250 and 500 mg/kg sulfasalazine groups than the saline group (P<0.05, P<0.001). The two sulfasalazine groups had lower spike percentages than the saline group (P<0.05). Significantly lower MDA and PGF2α levels were observed in the 250 and 500 mg/kg sulfasalazine groups compared with the saline group (P<0.05, P<0.001, respectively). SOD increased significantly in both sulfasalazine groups compared with the PTZ+saline group (P<0.05). Our study demonstrated that sulfasalazine had protective effects on PTZ-induced convulsions by protecting against oxidative and inflammatory damage associated with PTZ.