Penicillin-Induced Epileptiform ECoG Activity in Gerbils: Effects of Physical Exercise and a Diospyros kaki Extract

Fruits for Seizures? A Systematic Review on the Potential Anti-Convulsant Effects of Fruits and their Phytochemicals

Epilepsy is a devastating neurological disorder. Current anti-convulsant drugs are only effective in about 70% of patients, while the rest remain drug-resistant. Thus, alternative methods have been explored to control seizures in these drug-resistant patients. One such method may be through the utilization of fruit phytochemicals. These phytochemicals have been reported to have beneficial properties such as anti-convulsant, anti-oxidant, and anti-inflammatory activities. However, some fruits may also elicit harmful effects. This review aims to summarize and elucidate the anti- or pro-convulsant effects of fruits used in relation to seizures in hopes of providing a good therapeutic reference to epileptic patients and their carers. Three databases, SCOPUS, ScienceDirect, and PubMed, were utilized for the literature search. Based on the PRISMA guidelines, a total of 40 articles were selected for critical appraisal in this review. Overall, the extracts and phytochemicals of fruits managed to effectively reduce seizure activities in various preclinical seizure models, acting mainly through the activation of the inhibitory neurotransmission and blocking the excitatory neurotransmission. Only star fruit has been identified as a pro-convulsant fruit due to its caramboxin and oxalate compounds. Future studies should focus more on utilizing these fruits as possible treatment strategies for epilepsy.

The Potential Role of Previous Physical Exercise Program to Reduce Seizure Susceptibility: A Systematic Review and Meta-Analysis of Animal Studies

Background: Clinical and pre-clinical studies indicate a reduction in seizure frequency as well as a decrease in susceptibility to subsequently evoked seizures after physical exercise programs. In contrast to the influence of exercise after epilepsy previously established, various studies have been conducted attempting to investigate whether physical activity reduces brain susceptibility to seizures or prevents epilepsy. We report a systematic review and meta-analysis of different animal models that addressed the impact of previous physical exercise programs to reduce seizure susceptibility.

Methods: We included animal model (rats and mice) studies before brain insult that reported physical exercise programs compared with other interventions (sham, control, or naïve). We excluded studies that investigated animal models after brain insult, associated with supplement nutrition or drugs, that did not address epilepsy or seizure susceptibility, ex vivo studies, in vitro studies, studies in humans, or in silico studies. Electronic searches were performed in the MEDLINE (PubMed), Web of Science (WOS), Scopus, PsycINFO, Scientific Electronic Library Online (SciELO) databases, and gray literature, without restrictions to the year or language of publication. We used SYRCLE's risk of bias tool and CAMARADES checklist for study quality. We performed a synthesis of results for different types of exercise and susceptibility to seizures by random-effects meta-analysis.

Results: Fifteen studies were included in the final analysis (543 animals), 13 of them used male animals, and Wistar rats were the most commonly studied species used in the studies (355 animals). The chemoconvulsants used in the selected studies were pentylenetetrazol, penicillin, kainic acid, pilocarpine, and homocysteine. We assessed the impact of study design characteristics and the reporting of mitigations to reduce the risk of bias. We calculated a standardized mean difference effect size for each comparison and performed a random-effects meta-analysis. The meta-analysis included behavioral analysis (latency to seizure onset, n = 6 and intensity of motor signals, n = 3) and electrophysiological analysis (spikes/min, n = 4, and amplitude, n = 6). The overall effect size observed in physical exercise compared to controls for latency to seizure onset was −130.98 [95% CI: −203.47, −58.49] (seconds) and the intensity of motor signals was −0.40 [95% CI: −1.19, 0.40] (on a scale from 0 to 5). The largest effects were observed in electrophysiological analysis for spikes/min with −26.96 [95% CI: −39.56, −14.36], and for spike amplitude (μV) with −282.64 [95% CI: −466.81, −98.47].

Discussion:Limitations of evidence. A higher number of animal models should be employed for analyzing the influence of exerciseon seizure susceptibility. The high heterogeneity in our meta-analysis is attributable to various factors, including the number of animals used in each study and the limited number of similar studies. Interpretation. Studies selected in this systematic review and meta-analysis suggest that previous physical exercise programs can reduce some of the main features related to seizure susceptibility [latency seizure onset, spikes/min, and spike amplitude (μV)] induced by the administration of different chemoconvulsants.

Systematic Review Registration: PROSPERO, identifier CRD42021251949; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=251949.

Physical exercise and 5-hydroxytryptophan, a precursor for serotonin synthesis, reduce penicillin-induced epileptiform activity

AIM

Previous studies have shown that 5- hydroxytryptophan (5-HTP) and exercise play an important role in the synthesis of serotonin independently. The effects of the treadmill exercise and 5- hydroxytryptophan (5-HTP) on seizure mechanisms created by epileptiform activity with penicillin model were investigated in rats.

METHOD

A total of 28 male albino Wistar rats were randomly divided into four groups: exercise (Ex), Control (Cnt), 5-hydroxytryptophan (5htp) and 5-hydroxytryptophan + exercise (5htpEx) groups. Treadmill exercise and gavage (25 mg/kg/day) were administered five days a week for ten weeks. Electrocorticogram data were recorded for 3 h at the end of the protocol using the Power-Lab data acquisition system. Spike frequency, amplitude, and latency time were analyzed offline. The significant differences among the groups were evaluated by one-way analysis of variance (ANOVA).

RESULTS

Spike frequency was observed at the highest level from the 20th minute in the Cnt group, and this continued until the end of the recording. The 5-HTP alone group did not affect epileptiform activity. At the 80th minute of penicillin injection, the epileptiform activity in the 5htpEx group decreased significantly compared with the Cnt, and this significance continued until the 110th minute. There was no statistical difference in the amplitude values of the groups. The 5htpEx group was significantly higher than both the Cnt and Ex group in the seizure latency times.

CONCLUSIONS

It was determined that exercise reduced the spike number and delayed seizure significantly by potentiating the effect of 5-HTP. Given that 5-HTP used in combination with exercise can perform useful actions such as reducing seizure sensitivity and consequently improving the quality of life for individuals with epilepsy, it may be a potential candidate for the treatment of epilepsy in nonpharmacological methods.

A new oxidative stress indicator: Effect of 5-hydroxytryptophan on thiol-disulfide homeostasis in exercise

OBJECTIVES

The aim of the present study was to evaluate the relationship between exercise and both 5-hydroxytryptophan and oxidative stress using thiol-disulfide homeostasis via what is likely a novel biomarker.

METHODS

Male albino Wistar rats (n = 32) were randomly divided into four groups as follows: control, exercise group, 5-hydroxytryptophan group (5H), and 5-HTP + exercise group (5Hex). Exercise and 5-HTP administration (25mg/kg per d) were performed 5d/wk for 10 wk. After completion of the experimental protocol, to determine oxidative stress parameters, serum total thiol and native thiol concentrations were measured. Dynamic disulfide status, reduced thiol, oxidized thiol (OT), and thiol oxidation reduction percentage ratios were compared between the groups. The methods used in the present study to measure dynamic thiol-disulfide homeostasis as calorimetric and duplex quantities were developed in 2014. These new methods are simple, reliable, and sensitive, with both high linearity and repeatability.

RESULTS

Compared with the control group, serum dynamic disulfide levels were significantly lower in the 5H group and highest in the control group. The lowest OT and the highest reduced thiol rates were determined to be in the 5H group. The highest OT value was found in the 5Hex group. Thiol oxidation reduction values were found to be highest in the 5H group and lowest in the 5Hex group.

CONCLUSIONS

Both 5-HTP and moderate exercise seem to be significantly effective in inhibiting oxidative damage. In addition, the new oxidative stress measurement method used in this study is a promising practical and useful method to evaluate and improve the performance of athletes.