Anti-seizure effects of medicinal plants in Malawi on pentylenetetrazole-induced seizures in zebrafish larvae

Neuroprotective potential of pyrazole benzenesulfonamide derivative T1 in targeted intervention against PTZ-induced epilepsy-like condition in in vivo zebrafish model

Epilepsy is a chronic neurological disease characterized by a persistent susceptibility to seizures. Pharmaco-resistant epilepsies, impacting around 30 % of patients, highlight the urgent need for improved treatments. Neuroinflammation, prevalent in epileptogenic brain regions, is a key player in epilepsy, prompting the search for new mechanistic therapies. Hence, in this study, we explored the anti-inflammatory potential of pyrazole benzenesulfonamide derivative (T1) against pentylenetetrazole (PTZ) induced epilepsy-like conditions in in-vivo zebrafish model. The results from the survival assay showed 79.97 ± 6.65 % at 150 µM of T1 compared to PTZ-group. The results from reactive oxygen species (ROS), apoptosis and histology analysis showed that T1 significantly reduces cellular damage due to oxidative stress in PTZ-exposed zebrafish. The gene expression analysis and neutral red assay results demonstrated a notable reduction in the inflammatory response in zebrafish pre-treated with T1. Subsequently, the open field test unveiled the anti-convulsant activity of T1, particularly at a concentration of 150 μM. Moreover, both RT-PCR and immunohistochemistry findings indicated a concentration-dependent potential of T1, which inhibited COX-2 in zebrafish exposed to PTZ. In summary, T1 protected zebrafish against PTZ-induced neuronal damage, and behavioural changes by mitigating the inflammatory response through the inhibition of COX-2.

In silico molecular docking and dynamic simulation of anti-cholinesterase compounds from the extract of Catunaregam spinosa for possible treatment of Alzheimer's disease

Alzheimer's disease (AD), is characterized by a progressive loss of cognitive abilities as well as behavioral symptoms including disorientation, trouble solving problems, personality and mood changes. Acetylcholinesterase (AChE) is a promising target for symptomatic improvement in AD due to its consistent and early cholinergic deficit. This research has investigated the potential compounds from Catunaregam spinosa as AChE inhibitors as a treatment option for AD, aiming to enhance cholinergic neurotransmission and alleviate cognitive decline. Tacrine, the FDA's first approved treatment for AD, is no longer in use due to its hepatotoxicity. Box-Behnken design (BBD) modelling was used to optimise the ultrasonic extraction of alkaloids from the dried fruits of C. spinosa. GC-MS analysis revealed the presence of ninety phytoconstituents in the extract. Among them, eighty-nine new phytoconstituents are reported in this plant fruit for the first time. Out of ninety phytoconstituents, eight phytoconstituents showed the best binding affinity against the AChE enzyme, i.e., PDB IDs 1GQR, 1QTI and 4PQE of AD targets using iGEMDOCK. The lead hits were tested for their drug-like properties and atomistic binding mechanisms using in silico ADMET prediction, LigPlot analysis, and molecular dynamics simulation. The results suggest four compounds such as 1,4,7,10,13,16-hexaoxacyclooctadecane; butanoic acid, 3-methyl-2-[(phenylmethoxy)imino]-, trime; butane-1,2,3,4-tetraol; and D-(+)-ribonic acid.gamma-lactone as potent inhibitors of AChE for the possible treatment of AD.

Medicinal plants for epileptic seizures: Phytoconstituents, pharmacology and mechanisms revisited

ETHNOPHARMACOLOGICAL RELEVANCE

Epilepsy is a neurological disorder that presents with recurring and spontaneous seizures. It is prevalent worldwide, affecting up to 65 million people, with 80% of cases found in lower-income countries. Medicinal plants are commonly employed for managing and treating epilepsy and convulsions due to their unique therapeutic properties. With increasing research and clinical application, medicinal plants are gaining attention globally due to their potent therapeutic effects and fewer side effects. The development of new plant-based antiepileptic/anticonvulsant agents has become a major focus in the pharmaceutical industry.

AIM OF THE REVIEW

This article summarizes recent research on medicinal plants with reported antiepileptic/anticonvulsant effects. It provides pharmacological and molecular mechanism of action information for the crude extracts and related active constituents evaluated in preclinical research for the treatment of epilepsy and convulsions, and offers a reference for the development of future related studies in this area.

MATERIALS AND METHODS

Articles related to ethnopharmacological and antiepileptic studies on plants or natural products from 2018 to 2023 were collected from PubMed, Web of Science and Scopus, etc. using keywords related to epilepsy, medicinal plants, and natural products, etc. RESULTS: Eighty plant species are commonly used to treat epilepsy and convulsions in African and Asian countries. Sixty natural products showing potential for antiepileptic/anticonvulsant effects have been identified from these medicinal plants. These products can be broadly classified as alkaloids, coumarins, flavonoids, saponins, terpenoids and other compounds. The antiepileptic action of plant extracts and their active ingredients can be classified according to their abilities to modulate the GABAergic and glutamatergic systems, act as antioxidants, exhibit anti-neuroinflammatory effects, and provide neuroprotection. In addition, we highlight that some medicinal plants capable of pharmacologically relieving epilepsy and cognition may be therapeutically useful in the treatment of refractory epilepsy.

CONCLUSIONS

The review highlights the fact that herbal medicinal products used in traditional medicine are a valuable source of potential candidates for antiepileptic drugs. This confirms and encourages the antiepileptic/anticonvulsant activity of certain medicinal plants, which could serve as inspiration for further development. However, the aspects of structural modification and optimization, metabolism, toxicology, mechanisms, and clinical trials are not fully understood and need to be further explored.

Chemically-induced epileptic seizures in zebrafish: A systematic review

The use of zebrafish as a model organism is gaining evidence in the field of epilepsy as it may help to understand the mechanisms underlying epileptic seizures. As zebrafish assays became popular, the heterogeneity between protocols increased, making it hard to choose a standard protocol to conduct research while also impairing the comparison of results between studies. We conducted a systematic review to comprehensively profile the chemically-induced seizure models in zebrafish. Literature searches were performed in PubMed, Scopus, and Web of Science, followed by a two-step screening process based on inclusion/exclusion criteria. Qualitative data were extracted, and a sample of 100 studies was randomly selected for risk of bias assessment. Out of the 1058 studies identified after removing duplicates, 201 met the inclusion criteria. We found that the most common chemoconvulsants used in the reviewed studies were pentylenetetrazole (n = 180), kainic acid (n = 11), and pilocarpine (n = 10), which increase seizure severity in a dose-dependent manner. The main outcomes assessed were seizure scores and locomotion. Significant variability between the protocols was observed for administration route, duration of exposure, and dose/concentration. Of the studies subjected to risk of bias assessment, most were rated as low risk of bias for selective reporting (94%), baseline characteristics of the animals (67%), and blinded outcome assessment (54%). Randomization procedures and incomplete data were rated unclear in 81% and 68% of the studies, respectively. None of the studies reported the sample size calculation. Overall, these findings underscore the need for improved methodological and reporting practices to enhance the reproducibility and reliability of zebrafish models for studying epilepsy. Our study offers a comprehensive overview of the current state of chemically-induced seizure models in zebrafish, highlighting the common chemoconvulsants used and the variability in protocol parameters. This may be particularly valuable to researchers interested in understanding the underlying mechanisms of epileptic seizures and screening potential drug candidates in zebrafish models.

Medicinal plants utilized in the management of epilepsy in Ethiopia: ethnobotany, pharmacology and phytochemistry

Epilepsy is a common central nervous system (CNS) disorder that affects 50 million people worldwide. Patients with status epilepticus (SE) suffer from devastating comorbidities and a high incidence of mortalities. Antiepileptic drugs (AEDs) are the mainstream treatment options for the symptomatic relief of epilepsy. The incidence of refractory epilepsy and the dose-dependent neurotoxicity of AEDs such as fatigue, cognitive impairment, dizziness, attention-deficit behavior, and other side effects are the major bottlenecks in epilepsy treatment. In low- and middle-income countries (LMICs), epilepsy patients failed to adhere to the AEDs regimens and consider other options such as complementary and alternative medicines (CAMs) to relieve pain due to status epilepticus (SE). Plant-based CAMs are widely employed for the treatment of epilepsy across the globe including Ethiopia. The current review documented around 96 plant species (PS) that are often used for the treatment of epilepsy in Ethiopia. It also described the in vivo anticonvulsant activities and toxicity profiles of the antiepileptic medicinal plants (MPs). Moreover, the phytochemical constituents of MPs with profound anticonvulsant effects were also assessed. The result reiterated that a lot has to be done to show the association between herbal-based epilepsy treatment and in vivo pharmacological activities of MPs regarding their mechanism of action (MOA), toxicity profiles, and bioactive constituents so that they can advance into the clinics and serve as a treatment option for epilepsy.