Ayurveda and botanical drugs for epilepsy: Current evidence and future prospects

Natural product-derived therapies for treating drug-resistant epilepsies: From ethnopharmacology to evidence-based medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Epilepsy is one of the most prevalent neurological human diseases, affecting 1% of the population in all age groups. Despite the availability of over 25 anti-seizure medications (ASMs), which are approved in most industrialized countries, approximately 30% of epilepsy patients still experience seizures that are resistant to these drugs. Since ASMs target only limited number of neurochemical mechanisms, drug-resistant epilepsy (DRE) is not only an unmet medical need, but also a formidable challenge in drug discovery.

AIM

In this review, we examine recently approved epilepsy drugs based on natural product (NP) such as cannabidiol (CBD) and rapamycin, as well as NP-based epilepsy drug candidates still in clinical development, such as huperzine A. We also critically evaluate the therapeutic potential of botanical drugs as polytherapy or adjunct therapy specifically for DRE.

METHODS

Articles related to ethnopharmacological anti-epileptic medicines and NPs in treating all forms of epilepsy were collected from PubMed and Scopus using keywords related to epilepsy, DRE, herbal medicines, and NPs. The database clinicaltrials.gov was used to find ongoing, terminated and planned clinical trials using herbal medicines or NPs in epilepsy treatment.

RESULTS

A comprehensive review on anti-epileptic herbal drugs and natural products from the ethnomedical literature is provided. We discuss the ethnomedical context of recently approved drugs and drug candidates derived from NPs, including CBD, rapamycin, and huperzine A. Recently published studies on natural products with preclinical efficacy in animal models of DRE are summarized. Moreover, we highlight that natural products capable of pharmacologically activating the vagus nerve (VN), such as CBD, may be therapeutically useful to treat DRE.

CONCLUSIONS

The review highlights that herbal drugs utilized in traditional medicine offer a valuable source of potential anti-epileptic drug candidates with novel mechanisms of action, and with clinical promise for the treatment of drug-resistant epilepsy (DRE). Moreover, recently developed NP-based anti-seizure medications (ASMs) indicate the translational potential of metabolites of plant, microbial, fungal and animal origin.

In Vitro: The Effects of the Anticoccidial Activities of Calotropis procera Leaf Extracts on Eimeria stiedae Oocysts Isolated from Rabbits

Hepatic coccidiosis is an infectious and mortal disease that causes global economic losses in rabbits. The research aimed to assess the efficacy of Calotropis procure leaf extracts on the inhibition of Eimeria stiedae oocysts and to determine the optimal dosage for suppressing the parasite's infective phase. In this experiment, oocyst samples per milliliter were tested, and 6-well plates (2 mL) of 2.5% potassium dichromate solution containing 10² non-sporulated oocysts on Calotropis procera leaf extracts were exposed after 24, 48, 72, and 96 h, and the treatments were as follows: a nontreated control, 25%, 50%, 100%, and 150% of C. procera for oocyst activities. In addition, amprolium was utilized as a reference drug. The Calotropis procera was analyzed by GC-Mass, and results showed that the botanical extract contained 9 chemical components that were able to inhibit the oocysts of E. stiedae at 100% and 150% concentrations by about 78% and 93%, respectively. In general, an increase in the incubation period and a greater dose resulted in a decrease in the inhibition rate. The results showed that C. procera has an effective ability, inhibitory potential, and protective effect on the coccidian oocyst sporulation of E. stiedae. It can be used in the disinfection and sterilization of poultry and rabbit houses to get rid of Eimeria oocysts.

Acteoside Isolated from Colebrookea oppositifolia Smith Attenuates Epilepsy in Mice Via Modulation of Gamma-Aminobutyric Acid Pathways

The present study was aimed to evaluate the anticonvulsant activity of acteoside and explore its mechanism of action. Initially, the acteoside was evaluated in maximal electroshock (MES) and pentylenetetrazole (PTZ)-induced convulsions, and later it was evaluated against N-methyl-D-aspartic acid (NMDA)-induced mortality in Swiss albino mice. Based on the response in these models, further evaluations were performed to explore the mechanism of action. In the results, the acteoside (10, 25, and 50 mg/kg) has shown significant anticonvulsant activity in the PTZ model (p < 0.01 for all doses); however, there was no protection observed in MES and NMDA models. Therefore, further mechanism-based studies were performed on the PTZ model, and the outcomes have revealed that there was a significant reduction in GABA (p < 0.01 for both regions) and elevation of glutamate (p < 0.01 for both regions) in the cortex and hippocampus regions of PTZ-treated animals. Further, the antioxidant levels (SOD, catalase, GPx, GR, GSH, LPO) were altered significantly (p < 0.01 for all parameters), with reduced GABA_A mRNA levels (p < 0.01) in the PTZ control compared with the normal control. Interestingly, co-administration of acteoside (25 mg/kg) (p < 0.01 for all parameters) has restored all the PTZ-induced alterations compared to PTZ-control. Moreover, the anti-PTZ action of acteoside was completely blocked in the presence of flumazenil, and thus confirmed the GABAergic mechanism behind the anticonvulsant activity of acteoside. Besides, actophotometer and rotarod tests have confirmed that the acteoside is free from central side effects like motor incoordination and locomotor deficits.

Insights about multi-targeting and synergistic neuromodulators in Ayurvedic herbs against epilepsy: integrated computational studies on drug-target and protein-protein interaction networks

Epilepsy, that comprises a wide spectrum of neuronal disorders and accounts for about one percent of global disease burden affecting people of all age groups, is recognised as apasmara in the traditional medicinal system of Indian antiquity commonly known as Ayurveda. Towards exploring the molecular level complex regulatory mechanisms of 63 anti-epileptic Ayurvedic herbs and thoroughly examining the multi-targeting and synergistic potential of 349 drug-like phytochemicals (DPCs) found therein, in this study, we develop an integrated computational framework comprising of network pharmacology and molecular docking studies. Neuromodulatory prospects of anti-epileptic herbs are probed and, as a special case study, DPCs that can regulate metabotropic glutamate receptors (mGluRs) are inspected. A novel methodology to screen and systematically analyse the DPCs having similar neuromodulatory potential vis-à-vis DrugBank compounds (NeuMoDs) is developed and 11 NeuMoDs are reported. A repertoire of 74 DPCs having poly-pharmacological similarity with anti-epileptic DrugBank compounds and those under clinical trials is also reported. Further, high-confidence PPI-network specific to epileptic protein-targets is developed and the potential of DPCs to regulate its functional modules is investigated. We believe that the presented schema can open-up exhaustive explorations of indigenous herbs towards meticulous identification of clinically relevant DPCs against various diseases and disorders.

Recent Advances in Antiepileptic Herbal Medicine

BACKGROUND

Epilepsy is one of the most common neurological disorders worldwide, with about 80 percent of cases thought to be in developing nations where it is mostly linked to superstition. The limited supply, high cost as well as low efficacy and adverse side effects of antiepileptic drugs (AEDs) is a matter of major concern. Herbal medicine has always been traditionally part of treatment of epilepsy. Herbal medicines are generally well tolerated, with fewer side effects.

METHOD

To highlight some herbal extracts that have been studied for their anticonvulsant activity in animal models, literature search from PubMed and Science Direct, was performed. The keywords for the search consisted of combinations of the following terms: Herbal antiepileptic and/or anticonvulsant, botanicals + epilepsy. Literature published in the last five years was considered.

RESULTS

Eighteen (18) anticonvulsant herbal agents are reported and discussed. Experiments mostly consisted of phenotypic screens in rodents, with little diversity in screening methods. In most experiments, the tested extracts prolonged the time to onset of seizures and decreased their duration. Most experimenters implicate potentiation of GABAergic activity as the mode of action of the extracts, even though some experimenters did not fully characterise the bioactive chemical composition of their extracts.

CONCLUSION

Potential herbal remedies have shown positive results in animal models. It remains unclear how many make it into clinical trials and eventually making part of the AED list. More rigorous research, applying strict research methodology with uniform herbal combinations, as well as clinical studies are urgently needed.

Ancient Indian concepts about phenomenology, biology, and therapeutics of epilepsy

This article discusses etiology, pathogenesis, symptoms, and treatment of epilepsy, as described in Charaka Samhitā (translation: Charaka's Compendium) and Sushruta Samhitā, the two core texts of Ayurveda, an ancient system of medicine. Ayurveda emphasized amnesia and loss of consciousness as core features of epileptic seizures (Sanskrit: apasmar; translation: apa negation, smaran memory) and recognized that seizures occur due to a disturbance in brain function or flow of "humors" to the brain. Semiology of various seizure types was well described. Epilepsy was attributed to both internal and multiple exogenous factors. Treatment of epilepsy with formulations of naturally occurring substances, their compounding and use, is described in remarkable detail. Lifestyle modifications to protect people with epilepsy are also documented. Cognitive comorbidities of epilepsy were recognized. Although none of the Ayurveda formulations have any empirical evidence supporting their safety or efficacy in the treatment of epilepsy, studies are needed to generate relevant evidence, to recognize their hazards, and to integrate traditional and complementary systems of medicine with modern health care in an informed and safe manner.