Protective effects of lamotrigine and vitamin B12 on pentylenetetrazole-induced epileptogenesis in rats

Benefits of Combining Antiepileptic Drugs with Vitamin B12 on Redox Balance: Penicillin-Induced Experimental Epilepsy Model

Purpose

A combination of antiepileptic drugs and antioxidants may be an effective treatment by restoring the disrupted redox balance and reducing oxidative stress exposure to neurons. This study aims to evaluate the effects of valproate and vitamin B12 on oxidative stress in an experimental epilepsy model induced by penicillin when administered alone or in combination.

Patients and Methods

35 male Wistar rats were used in this study. The rats were divided into five groups, which were saline group, 1 mg/kg, 2 mg/kg Vit B12 groups and Sodium valproate group Sodium valproate + Vit B12 group. The epileptic activity was induced by 500 IU of penicillin injection. Sodium valproate and Vitamin B12 were administered 30 min after penicillin administration. Electrocorticogram recordings were taken for 2 hours post-treatment and serum parameters were assessed for oxidative stress markers using spectrophotometric method.

Results

There is statistically significant difference between the groups in total antioxidant status, total oxidant status, and oxidative stress index value (p=0.013; p˂0.001; p˂0.001, respectively). The valproate+vitamin B12 group showed elevated total thiol and native thiol levels, along with reduced disulphide levels, resulting in the lowest OSI value.

Conclusion

These findings suggest the combined treatment effectively reduces oxidative stress. This study provides valuable insights into the antioxidant properties of valproate and vitamin B12, positioning them as potential agents for managing epilepsy. Understanding the efficacy and reliability of antioxidant strategies in epilepsy management could contribute significantly to advancements in epilepsy therapeutics.

Understanding Lamotrigine's Role in the CNS and Possible Future Evolution

The anti-epileptic drug lamotrigine (LTG) has been widely used to treat various neurological disorders, including epilepsy and bipolar disorder. However, its precise mechanism of action in the central nervous system (CNS) still needs to be determined. Recent studies have highlighted the involvement of LTG in modulating the activity of voltage-gated ion channels, particularly those related to the inhibition of neuronal excitability. Additionally, LTG has been found to have neuroprotective effects, potentially through the inhibition of glutamate release and the enhancement of GABAergic neurotransmission. LTG's unique mechanism of action compared to other anti-epileptic drugs has led to the investigation of its use in treating other CNS disorders, such as neuropathic pain, PTSD, and major depressive disorder. Furthermore, the drug has been combined with other anti-epileptic drugs and mood stabilizers, which may enhance its therapeutic effects. In conclusion, LTG's potential to modulate multiple neurotransmitters and ion channels in the CNS makes it a promising drug for treating various neurological disorders. As our understanding of its mechanism of action in the CNS continues to evolve, the potential for the drug to be used in new indications will also be explored.

The Effect of High-Dose Methyl Vitamin B12 Therapy on Epileptogenesis in Rats: An In Vivo Study

Introduction Epileptogenesis has been considered one of the most prevalent diseases affecting significant numbers of individuals worldwide. Since vitamin B12 has been reported to possess antiepileptic effects, this supports that vitamin B12 deficiency is correlated to seizure occurrence. Hence, this study aimed to evaluate the neuroprotective effects of vitamin B12 injection on pentylenetetrazole (PTZ)-induced rats. Methods The study was performed using 40 adult female Sprague-Dawley rats (~250 g). A 45 mg/kg PTZ was intraperitoneally injected into rat models to induce seizure effects. Different groups of rat models received methyl vitamin B12 therapy at different dosages, a low dosage of 45 µg/kg and a high dosage of 85 µg/kg, at different pre-treatment periods, one day and two weeks prior to PTZ injection. A control group, which received only PTZ injection, served as a reference. The seizure latency, seizure intensity, and differences in the quality of seizures and their characteristics, from simple twitches to complete seizures, were observed after 30 minutes of PTZ injection. Results In general, the latency to convulsion significantly increased when vitamin B12 pre-treatment was employed. The longest latency time (LT) of 520.63±73.83 seconds was observed when a high dosage of vitamin B12 at 85 µg/kg was injected one day prior to PTZ inoculation, which was significantly higher than that of the control group at 176.88±62.67 seconds (P<0.001). Moreover, the duration of convulsion significantly decreased in which the lowest duration time (DT) of 7.00±4.68 seconds was observed when a high dosage of vitamin B12 at 85 µg/kg was injected two weeks prior to PTZ inoculation, which was significantly lower than that of the control group at 257.75±41.93 seconds (P<0.001). Lastly, the percentage of the population with PTZ-induced convulsion generally decreased after vitamin B12 pre-treatment in which majority showed more of simple less aggressive twitches rather than tonic-clonic seizures. Conclusion The results showed that vitamin B12 pre-treatment alleviates the seizure occurrence among PTZ-kindled rat models. These findings then suggest that vitamin B12 is a potential strategy and treatment for epilepsy and other related epileptogenesis activities.

The protective effect of inhibiting mitochondrial fission on the juvenile rat brain following PTZ kindling through inhibiting the BCL2L13/LC3 mitophagy pathway

Maintaining the balance of mitochondrial fission and mitochondrial autophagy on seizures is helpful to find a solution to control seizures and reduce brain injuries. The present study is to investigate the protective effect of inhibiting mitochondrial fission on brain injury in juvenile rat epilepsy induced by pentatetrazol (PTZ) by inhibiting the BCL2L13/LC3-mediated mitophagy pathway. PTZ was injected (40 mg/kg) to induce kindling once every other day, for a total of 15 times. In the PTZ + DMSO (DMSO), PTZ + Mdivi-1 (Mdivi-1), and PTZ + WY14643 (WY14643) groups, rats were pretreated with DMSO, Mdivi-1 and WY14643 for half an hour prior to PTZ injection. The seizure attacks of young rats were observed for 30 min after model establishment. The Morris water maze (MWM) was used to test the cognition of experimental rats. After the test, the numbers of NeuN(+) neurons and GFAP(+) astrocytes were observed and counted by immunofluorescence (IF). The protein expression levels of Drp1, BCL2L13, LC3 and caspase 3 in the hippocampus of young rats were detected by immunohistochemistry (IHC) and Western blotting (WB). Compared with the PTZ and DMSO groups, the seizure latency in the Mdivi-1 group was longer (P < 0.01), and the severity degree and frequency of seizures were lower (P < 0.01). The MWM test showed that the incubation periods of crossing the platform in the Mdivi-1 group was significantly shorter. The number of platform crossings, the platform stay time, and the ratio of residence time/total stay time were significantly increased in the Mdivi-1 group (P < 0.01). The IF results showed that the number of NeuN(+) neurons in the Mdivi-1 group was greater, while the number of GFAP(+) astrocytes was lower. IHC and WB showed that the average optical density (AOD) and relative protein expression levels of Drp1, BCL2L13, LC3 and caspase 3 in the hippocampi of rats in the Mdivi-1 group were higher (P < 0.05). The above results in the WY14643 group were opposite to those in the Mdivi-1 group. Inhibition of mitochondrial fission could reduce seizure attacks, protect injured neurons, and improve cognition following PTZ-induced epilepsy by inhibiting mitochondrial autophagy mediated by the BCL2L13/LC3 mitophagy pathway.

Thiamine alleviates cognitive impairment and epileptogenesis by relieving brain inflammation in PTZ-induced kindling rat model

OBJECTIVE

Epileptogenesis, the process by which the brain becomes epileptic, is related to neuroinflammation, hyperexcitability cognitive deficits. Evidence suggests that improving brain inflammation can inhibit the epileptogenesis process and help the emergence of new drugs for the treatment of epilepsy. Therefore, the PTZ kindling model of epilepsy was utilized to assess the neuroprotective role of thiamine in epileptogenesis.

METHODS

Male rats were exposed to PTZ-induced kindling and pretreated with low thiamine (25 mg/kg) or high thiamine (50 mg/kg). Cyclooxygenase (COX-1 and COX-2), interleukin 1-beta (IL-1β), tumor necrosis factor-alpha (TNF-α), and nuclear factor-κB (NF-κB) concentrations in the brain were analyzed using biochemical assays. Cognitive function was evaluated using the passive avoidance test.

RESULTS

Thiamine ameliorated epileptogenesis and enhanced the rats' performance in the passive avoidance test. Also, thiamine significantly decreased the level of neuroinflammatory mediators in the brain induced by PTZ.

CONCLUSION

These results provide evidence that thiamine alleviates PTZ-induced neuroinflammation and cognitive impairments.

The Role of Methyl Donors of the Methionine Cycle in Gastrointestinal Infection and Inflammation

Vitamin deficiency is well known to contribute to disease development in both humans and other animals. Nonetheless, truly understanding the role of vitamins in human biology requires more than identifying their deficiencies. Discerning the mechanisms by which vitamins participate in health is necessary to assess risk factors, diagnostics, and treatment options for deficiency in a clinical setting. For researchers, the absence of a vitamin may be used as a tool to understand the importance of the metabolic pathways in which it participates. This review aims to explore the current understanding of the complex relationship between the methyl donating vitamins folate and cobalamin (B12), the universal methyl donor S-adenosyl-L-methionine (SAM), and inflammatory processes in human disease. First, it outlines the process of single-carbon metabolism in the generation of first methionine and subsequently SAM. Following this, established relationships between folate, B12, and SAM in varying bodily tissues are discussed, with special attention given to their effects on gut inflammation.

Micellar buccal film for safe and effective control of seizures: Preparation, in vitro characterization, ex vivo permeation studies and in vivo assessment

The current research article focused on formulating an easily applied, water-based buccal film loaded with the antiepileptic drug, lamotrigine (LTG). The designed film can be comfortably administered by epileptic patients to ensure a controllable therapeutic efficacy against seizures. The solubility of LTG in water was significantly improved by micellar solubilization. Upon testing several surfactants, three of them (Synperonic PE/P84, Brij L23, and Brij 78) achieved maximum possible solubility for LTG and were characterized for their micellar size, cloud point, and % transmittance. Selected micellar systems were incorporated within a buccal film prepared using solvent casting method based on either gelatin or polyvinylpyrrolidone (3%w/v) with 1.5%w/v propylene glycol as a plasticizer. Different micellar films were characterized for their physicochemical characteristics, swelling index, folding endurance, drug content uniformity, and in vitro LTG release. From the tested formulations, one formulation; LTG-BF1 (in which Brij 78 was used for the micellar solubilization and gelatin as the matrix former), was selected as the optimum and extensively studied for mucoadhesion, ex vivo permeation studies by Franz diffusion cells and confocal laser scanning microscopy. Results showed superior enhanced permeation of micellar film. LTG-BF1 was evaluated for the in vivo performance using rats. Status epilepticus was induced in rats by injecting Pentylenetetrazol (PTZ) i.p. at an initial dose of 30 mg/kg, followed by 10 mg/kg every10 min till 60 min. A group of rats receiving the designed buccal formulation (20 mg/kg) was compared with a group receiving the same dose of the oral market product and the normal control and PTZ groups. Rats receiving LTG-BF1 recorded reduced seizure scores at all stages, longer latency time, and higher threshold PTZ dose compared to PTZ and market product groups. In addition, LTG-BF1 reduced brain concentrations of TNF-α and TGF-β with an elevation of EAAT2 and GABA brain contents compared to PTZ and market product groups and ameliorated neuronal damage. In conclusion, LTG-loaded buccal micellar film proved a superior antiepileptic effect in PTZ induced acute epileptic model.