Proanthocyanidins alleviate pentylenetetrazole-induced epileptic seizures in mice via the antioxidant activity

Acute anticonvulsant effects of dapsone on PTZ- and MES-induced seizures in mice: NLRP3 inflammasome inhibition and Nrf2/HO-1 pathway preservation

BACKGROUND

Epilepsy, a neurological disorder characterized by recurrent seizures, presents considerable difficulties in treatment, particularly when dealing with drug-resistant cases. Dapsone, recognized for its anti-inflammatory properties, holds promise as a potential therapeutic option. However, its effectiveness in epilepsy requires further investigation. The aim of this study is to explore the effects of dapsone on seizure activity and neuroinflammation, particularly through the nuclear factor erythroid-2-related factor (Nrf2)/ Heme Oxygenase 1 (HO-1) and NOD-like receptor family pyrin domain-containing 3 (NLRP3) pathways, to better understand its therapeutic potential.

METHODS

To evaluate the effects of dapsone, two seizure models were utilized in mice: pentylenetetrazole (PTZ)-induced clonic seizures and maximal electroshock (MES)-induced generalized tonic-clonic seizures (GTCS) in mice. The impact of dapsone on neuroinflammatory markers and oxidative stress pathways, specifically Nrf2/HO-1 and NLRP3, as well as interleukin-1β (IL-1β), IL-8, and IL-18, was assessed using Western blotting and ELISA techniques.

RESULTS

In this study, dapsone (2, 5, 10, and 20 mg/kg, ip) showcased a significant increase in clonic seizure threshold following intravenous infusion of PTZ. Notably, doses of 5, 10, and 20 mg/kg exhibited increased latency and decreased the number of seizures. Additionally, dapsone at 10 and 20 mg/kg prevented the incidence of GTCS and subsequent mortality in the MES model. Furthermore, Dapsone demonstrated modulation of Nrf2/ HO-1 and NLRP3 IL-1 β/IL-18 pathways.

CONCLUSION

This study highlights the therapeutic potential of dapsone in epilepsy, emphasizing the involvement of Nrf2/HO-1 and NLRP3 pathways. These findings provide a foundation for future clinical research aimed at developing dapsone-based therapies for drug-resistant epilepsy.

Regulating the NMDA/NR2B signaling pathway mediates anticonvulsant, antineuroinflammation, and anti-oxidative stress effects of 1,3,benzothiazole derivative 1M in pentylenetetrazole-induced kindling in mice

Periodic epileptic episodes are the hallmark of epilepsy, a prevalent neurological disorder. Research suggests a significant correlation between neuroinflammation and oxidative stress in a variety of neurological diseases, such as epilepsy. A substantial amount of evidence supports the role of N-methyl-D-aspartate receptors (NMDARs) in the progression of epilepsy. Although several lines of research have disclosed numerous biochemical effects of early seizures, its connection with disturbed NMDAR/NR2B subunit expression remains unclear. 2-Mercaptobenzothiazole (MBT) is a vital scaffold with several biological activities, and its various substitutes show promising anti-inflammatory potential. The current study aimed to investigate the newly synthesized 1,3-(benzothiazole-2-sulfanyl)-1-(morpholine-4-yl)ethan-1-one (1 M), a substituted MBT, for its neuroprotective potential in a mice model of pentylenetetrazole-induced epilepsy (PTZ), by modulating NMDA/NR2B pathway. The compound was tested for docking and simulation analysis, demonstrating a solid and stable bond with the NR2B subunit of NMDA. To ascertain the effects of 1 M, as well as to further illustrate its mechanism of neuroprotection via NMDA/NR2B in PTZ-induced kindling model, mice of either sex were given two doses of test compound, 1 M (10 mg/kg and 20 mg/kg). The behavioral assessments were evaluated using open-field, Y-maze, and elevated-plus maze tests, which indicated improved behavioral alterations caused by PTZ after 1 M treatment. The antioxidant profiling was done by estimating glutathione-S-transferase (GST), catalase (CAT), reduced glutathione (GSH), and LPO (lipid peroxidation) in hippocampal tissues, where the test compound 1 M significantly restored the depleted antioxidants, showcasing its antioxidant potential. Moreover, the cellular morphological damages induced by PTZ were detected by H&E staining, which was rescued after 1 M administration. Furthermore, the activation of the inflammatory pathway was confirmed by quantitative analysis of inflammatory mediators tumor necrotic factor (TNF-α), nuclear factor kappa B (NF-κB), and cylooxegenase2 (COX-2) by enzyme-linked immunosorbent assay (ELISA), where 1 M administration significantly ameliorated their expression. Furthermore, to demonstrate the involvement of the NR2B pathway, NR2B-antagonist ifenprodil was employed, and results were further confirmed through RT-PCR analysis. Our results, when considered collectively, indicate that 1 M may act by inhibiting the NR2B subunit of the NMDA receptor, subsequently mitigating downstream oxidative stress and inflammatory mediators through various pathways.

Mitochondria and oxidative stress in epilepsy: advances in antioxidant therapy

Epilepsy, affecting approximately 50 million individuals worldwide, is a neurological disorder characterized by recurrent seizures. Mitochondrial dysfunction and oxidative stress are critical factors in its pathophysiology, leading to neuronal hyperexcitability and cell death. Because of the multiple mitochondrial pathways that can be involved in epilepsy and mitochondrial dysfunction, it is optimal to treat epilepsy with multiple antioxidants in combination. Recent advancements highlight the potential of antioxidant therapy as a novel treatment strategy. This approach involves tailoring antioxidant interventions-such as melatonin, idebenone, and plant-derived compounds-based on individual mitochondrial health, including mitochondrial DNA mutations and haplogroups that influence oxidative stress susceptibility and treatment response. By combining antioxidants that target multiple pathways, reducing oxidative stress, modulating neurotransmitter systems, and attenuating neuroinflammation, synergistic effects can be achieved, enhancing therapeutic efficacy beyond that of a single antioxidant on its own. Future directions include conducting clinical trials to evaluate these combination therapies, and to translate preclinical successes into effective clinical interventions. Targeting oxidative stress and mitochondrial dysfunction through combination antioxidant therapy represents a promising adjunctive strategy to modify disease progression and improve outcomes for individuals living with epilepsy.

Pirfenidone regulates seizures through the HMGB1/TLR4 axis to improve cognitive functions and modulate oxidative stress and neurotransmitters in PTZ-induced kindling in mice

Background

Epilepsy is a neurological disorder characterized by recurrent seizures due to abnormal electrical activity in the brain. Pirfenidone, an antifibrotic drug, has shown anti-inflammatory and antioxidant properties in various disease models, including neurological conditions. However, its potential anticonvulsant effects have not been thoroughly explored. This study aims to evaluate the anticonvulsant potential of pirfenidone in a pentylenetetrazol-induced kindling model of epilepsy, focusing on its effect on seizure activity, cognition, antioxidant profiles, inflammatory markers, neurotransmitter balance, liver enzyme levels, and histopathological changes.

Methods

Healthy male Swiss albino mice were subjected to an acute Increasing Current Electroshock test and chronic pentylenetetrazol-kindling model. Pirfenidone was administered at doses of 100, 200, and 300 mg/kg, orally, with sodium valproate as a standard drug. Seizure severity and cognitive function were assessed in the pentylenetetrazol-kindling model, along with biochemical assays that evaluated antioxidant enzymes, inflammatory markers, neurotransmitter levels, and liver enzyme levels. Histopathological changes were also assessed in the hippocampus and cortex of experimental mice.

Results

Pirfenidone at 200 mg/kg and 300 mg/kg significantly increased Seizure Threshold Current in the Increasing Current Electroshock test, indicating a protective effect against seizures. In the pentylenetetrazol-kindling model, pirfenidone delayed seizure onset and reduced severity, with the 300 mg/kg dose showing the strongest impact. Pirfenidone also demonstrated significant improvements in cognitive function, as evidenced by enhanced performance in passive avoidance and elevated plus maze tests. Antioxidant profiles showed increased levels of superoxide dismutase, catalase, and reduced glutathione, with a corresponding reduction in malondialdehyde and acetylcholinesterase levels. Pirfenidone significantly reduced pro-inflammatory cytokines including interleukin-6, interleukin-1β, transforming growth factor-β, tumor necrosis factor- α, high-mobility group box-1, and toll-like receptor-4, elevated gamma-aminobutyric acid, decreased glutamate levels, modulated aspartate aminotransferase and alanine aminotransferase levels. Histopathological analysis revealed that pirfenidone ameliorated cellular disintegration and neuronal damage in the hippocampus and cortex.

Conclusion

Pirfenidone shows potential as an anticonvulsant, anti-inflammatory, hepatoprotective, and neuroprotective agent, with additional benefits in improving cognition and oxidative stress profiles in epilepsy treatment. Further studies are required to explore its long-term safety and efficacy.

Effects of grape seed proanthocyanidin extract on cholesterol metabolism and antioxidant status in finishing pigs

Grape seed proanthocyanidin extract (GSPE) is a natural polyphenolic compound, which plays an important role in anti-inflammatory and antioxidant. The present study aimed to investigate the effects of GSPE supplementation on the cholesterol metabolism and antioxidant status of finishing pigs. In longissimus dorse (LD) muscle, the data showed that GSPE significantly decreased the contents of total cholesterol (T-CHO) and triglyceride (TG), and decreased the mRNA expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoAR) and Fatty acid synthase (FAS), while increased the mRNA expression of carnitine palmitoyl transferase-1b (CPT1b), peroxisome proliferator-activated receptors (PPARα) and peroxisome proliferator activated receptor-γ coactivator-1α (PGC-1α). GSPE also reduced the enzyme activities of HMG-CoAR and FAS, and meanwhile amplified the activity of CPT1b in LD muscle of finishing pigs. Furthermore, dietary GSPE supplementation increased the serum catalase (CAT) and total antioxidant capacity (T-AOC), serum and liver total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) levels, while reduced serum and liver malondialdehyde (MDA) level in finishing pigs. In the liver, Superoxide Dismutase 1 (SOD1), catalase (CAT), glutathione peroxidase 1 (GPX1), Nuclear Factor erythroid 2-Related Factor 2 (NRF2) mRNA levels were increased by GSPE. In conclusion, this study showed that GSPE might be an effective dietary supplement for improving cholesterol metabolism and antioxidant status in finishing pigs.

Diet-derived circulating antioxidants and risk of epilepsy: a Mendelian randomization study

Background

Previous studies suggest a link between diet-derived circulating antioxidants and epilepsy, but the causal relationship is unclear. This study aims to investigate the causal effect of these antioxidants on epilepsy.

Methods

To assess the causal link between dietary antioxidants and epilepsy risk, we conducted a two-sample Mendelian randomization (MR) analysis. This involved examining antioxidants such as zinc, selenium, α- and γ-tocopherol, vitamin A (retinol), vitamin C (ascorbate), and vitamin E (α-tocopherol). We utilized instrumental variables (IVs) which were genetic variations highly associated with these commonly used antioxidants. Exposure data were sourced from a comprehensive genome-wide association study (GWAS). We aggregated data from the International League Against Epilepsy (ILAE) Consortium sample, which included various types of epilepsy, as an outcome variable. Finally, we applied the inverse variance weighting method and conducted sensitivity analyses for further validation.

Results

Based on the primary MR estimates and subsequent sensitivity analyses, the inverse variance weighting (IVW) method revealed that a genetically predicted increase in zinc per standard deviation was positively associated with three types of epilepsy. This includes all types of epilepsy (OR = 1.06, 95% CI: 1.02-1.11, p = 0.008), generalized epilepsy (OR = 1.13, 95% CI: 1.01-1.25, p = 0.030), and focal epilepsy (documented hippocampal sclerosis) (OR = 1.01, 95% CI: 1.00-1.02, p = 0.025). However, there is no evidence indicating that other antioxidants obtained from the diet affect the increase of epilepsy either positively or negatively.

Conclusion

Our research indicates that the risk of developing epilepsy may be directly linked to the genetic prediction of zinc, whereas no such association was found for other antioxidants.

(-)-α-bisabolol exerts neuroprotective effects against pentylenetetrazole-induced seizures in rats by targeting inflammation and oxidative stress

Epilepsy is the most common neurological disorder which is accompanied with behavioral and psychiatric alternations. Current evidences have shown that (-)-α-bisabolol (BSB) possess anti-inflammatory and antioxidative effects in several animal studies. Here, we conducted present study to evaluate its neuroprotective effects against pentylenetetrazole (PTZ)-induced seizures in rats. We used fifty male rats and they were randomly assigned into 5 groups control, BSB100, PTZ, BSB50 + PTZ, BSB100 + PTZ. The animals intraperitoneally received PTZ (45 mg/kg) for ten consecutive days to induce epilepsy model. BSB in doses of 50 and 100 mg/kg was administrated orally one hour before PTZ administration for ten days. The elevated plus maze (EPM) test was carried out to assess anxiety-like behavior. The seizure intensity was evaluated according to modifies Racine's convulsion scale (RCS). Y-maze and passive avoidance were utilized to assess working memory and aversive memory. The expression of pro-inflammatory cytokines and oxidative stress factors were measured using the enzyme-linked immunosorbent assay (ELISA). The neuronal cell loss in the hilar region was assessed using Nissl staining. Results showed that PTZ-treated rats had more seizure intensity, anxiety-like behavior, memory deficits, higher levels of TNF-α, IL-1β, and oxidative markers. Pre-treatment with BSB 100 significantly inhibited seizure intensity, anxiety-like behavior, and memory deficits; reduced levels of TNF-α, IL-1β, and MDA oxidative markers. Collectively, outcome of this work shows that BSB at the dose of 100 mg/kg may exert neuroprotective effects by mitigating seizures, oxidative stress, and neuroinflammation, and ameliorates memory and anxiety disorders in the PTZ-induced seizure rats.

Therapeutic Strategies to Ameliorate Neuronal Damage in Epilepsy by Regulating Oxidative Stress, Mitochondrial Dysfunction, and Neuroinflammation

Epilepsy is a central nervous system disorder involving spontaneous and recurring seizures that affects 50 million individuals globally. Because approximately one-third of patients with epilepsy do not respond to drug therapy, the development of new therapeutic strategies against epilepsy could be beneficial. Oxidative stress and mitochondrial dysfunction are frequently observed in epilepsy. Additionally, neuroinflammation is increasingly understood to contribute to the pathogenesis of epilepsy. Mitochondrial dysfunction is also recognized for its contributions to neuronal excitability and apoptosis, which can lead to neuronal loss in epilepsy. This review focuses on the roles of oxidative damage, mitochondrial dysfunction, NAPDH oxidase, the blood-brain barrier, excitotoxicity, and neuroinflammation in the development of epilepsy. We also review the therapies used to treat epilepsy and prevent seizures, including anti-seizure medications, anti-epileptic drugs, anti-inflammatory therapies, and antioxidant therapies. In addition, we review the use of neuromodulation and surgery in the treatment of epilepsy. Finally, we present the role of dietary and nutritional strategies in the management of epilepsy, including the ketogenic diet and the intake of vitamins, polyphenols, and flavonoids. By reviewing available interventions and research on the pathophysiology of epilepsy, this review points to areas of further development for therapies that can manage epilepsy.

Possible Interaction of Opioidergic and Nitrergic Pathways in the Anticonvulsant Effect of Ivermectin on Pentylenetetrazole-Induced Clonic Seizures in Mice

Ivermectin (IVM) is an antiparasitic drug that primarily works by the activation of GABAA receptors. The potential pharmacological pathways behind the anti-convulsant effect of IVM haven't yet been identified. In this study, intravenous injection of pentylenetetrazole (PTZ)-induced clonic seizure in mice was investigated in order to assess the possible influence of IVM on clonic seizure threshold (CST). We also look at the function of the Opioidergic and nitrergic pathways in IVM anticonvulsant action on clonic seizure threshold. IVM (0.5, 1, 5, and 10 mg/kg, i.p.) raised the PTZ-induced CST, according to our findings. Furthermore, the ineffective dose of nitric oxide synthase inhibitors (L-NAME 10 mg/kg, i.p.), and (7-NI 30 mg/kg, i.p.) or opioidergic system agonist (morphine 0.25 mg/kg, i.p.) were able to amplify the anticonvulsive action of IVM (0.2 mg/kg, i.p.). Moreover, the anticonvulsant effect of IVM was reversed by an opioid receptor antagonist (naltrexone 1 mg/kg, i.p.). Furthermore, the combination of the ineffective dose of morphine as an opioid receptor agonist with either L-NAME (2 mg/kg, i.p.) or 7-NI (10 mg/kg, i.p.) and with an ineffective dose of IVM (0.2 mg/kg, i.p.) had a significant anticonvulsant effect. Taken together, IVM has anticonvulsant activity against PTZ-induced clonic seizures in mice, which may be mediated at least in part through the interaction of the opioidergic system and the nitric oxide pathway.

Antibiotics modulate frequency and early generation of epileptic seizures in zebrafish

Antibiotics have been used for decades to treat various bacterial infections. Apart from bactericidal activities, their potential side effects have not been much studied or evaluated. Neurotoxicity is a major concern in the case of β-lactam and fluoroquinolone families, which can result in convulsions or seizures. Here, we proposed a hypothesis to check whether antibiotic treatment can conclusively enhance anxiety-like behaviours and how seizure behavioural profile gets modulated in pentylenetetrazole (PTZ)-treated zebrafish. Zebrafish were treated with selected antibiotics such as 25 mg/L Penicillin G (PG) and Ciprofloxacin (CPFX), for 7 days and thereafter exposed to PTZ (7.5 mM) for 20 min. The data indicate that PG and CPFX-treated groups exhibited anxiety-like or stressed behavioural phenotypes in the novel tank test (6 min), and also, they were found to promote hyperactivity. Early onset of PTZ-induced seizure-like behavioural scores, the heightened intensity of seizure and reduced latency in different scores were found in PG and CPFX-administered groups. This study substantiates that PG and CPFX as potential seizure modulators in zebrafish. The zebrafish is a well-established and still expanding model organism in many fields. Here, we again reinforce zebrafish as a prominent model to investigate seizure-like neuro-behavioural entities and confirm that chronic antibiotic use has negative consequences that can exacerbate the circumstances of vertebrate species exhibiting seizure-related reactions.

The Neuroprotective Effect Associated with Echinops spinosus in an Acute Seizure Model Induced by Pentylenetetrazole

Echinops spinosus (ES) is a medicinal plant with a wide range of pharmacological and biological effects. It is a medicinal herb having a variety of therapeutic characteristics, including antioxidant, anti-inflammatory, and antibacterial capabilities. The primary goal of this research is to investigate the neuroprotective and anticonvulsant characteristics of E. spinosa extract (ESE) against pentylenetetrazole (PTZ)-induced acute seizures. Negative control rats, ESE treatment rats, PTZ acute seizure model rats, ESE + PTZ rats, and Diazepam + PTZ rats were used in the study. The rats were given a 7-day treatment. ESE pretreatment elevated the latency to seizure onset and lowered seizure duration after PTZ injection. By reducing Bax levels and enhancing antiapoptotic Bcl-2 production, ESE prevented the release of interleukin-1β, tumor necrosis factor-α, and cyclooxygenase-2, as well as preventing hippocampal cell death after PTZ injection. ESE corrected the PTZ-induced imbalance in gamma-aminobutyric acid levels and increased the enzyme activity of Na⁺/K⁺-ATPase. Echinops spinosus is a potent neuromodulatory, antioxidant, antiinflammatory, and antiapoptotic plant that could be employed as a natural anticonvulsant in the future.