Anticonvulsant effect of aqueous extract of Valeriana officinalis in amygdala-kindled rats: possible involvement of adenosine

Sesquiterpenoids and monoterpenoids from the water decoction of Valeriana officinalis L

Nine previously undescribed compounds including three sesquiterpenoids, three iridoids, two monoterpenoids and a furan fatty acid, along with seventeen known ones, were isolated from the water decoction of roots and rhizomes of Valeriana officinalis L. Structure elucidation of the twenty-six compounds were accomplished by analysis of the extensive spectroscopic data, and the absolute configurations of the nine previously undescribed ones were established by NOESY experiment and the electronic circular dichroism (ECD) simulations. Among them, β-patchoulene-8-O-β-D-glucopyranoside, 11-methoxyl-viburtinal, and protocatechuic acid showed anti-neuroinflammatory potentials by significantly inhibiting the secretion of nitric oxide (NO) on BV-2 cells upon LPS stimulation (p < 0.001) without affecting the cell viability.

The potential of Valeriana as a traditional Chinese medicine: traditional clinical applications, bioactivities, and phytochemistry

Valeriana plants are members of the Caprifoliaceae family, which include more than 200 species worldwide. We summarized previous reports on traditional clinical applications, bioactivities, and phytochemistry of Valeriana by searching electronic databases of Science Direct, Web of Science, PubMed, and some books. Some Valeriana species have been used as traditional medicines, demonstrating calming fright and tranquilizing mind, promoting Qi and blood, activating blood circulation and regulating menstruation, dispelling wind and eliminating dampness, regulating Qi-flowing to relieve pain, and promoting digestion and checking diarrhea, and treating diseases of the nervous, cardiovascular, and digestive systems, inflammation, gynecology, and others. Pharmacology studies revealed the effects of Valeriana, including sedative, hypnotic, antispasmodic, analgesic, antidepressant, anxiolytic, anticonvulsant, antiepileptic, neuroprotective, antibacterial, antiviral, cytotoxic, and antitumor effects as well as cardiovascular and cerebrovascular system improvements. More than 800 compounds have been isolated or identified from Valeriana, including iridoids, lignans, flavonoids, sesquiterpenoids, alkaloids, and essential oils. Constituents with neuroprotective, anti-inflammatory, cytotoxic, and sedative activities were also identified. However, at present, the developed drugs from Valeriana are far from sufficient. We further discussed the pharmacological effects, effective constituents, and mechanisms directly related to the traditional clinical applications of Valeriana, revealing that only several species and their essential oils were well developed to treat insomnia. To effectively promote the utilization of resources, more Valeriana species as well as their different medicinal parts should be the focus of future related studies. Clinical studies should be performed based on the traditional efficacies of Valeriana to facilitate their use in treating diseases of nervous, cardiovascular, and digestive systems, inflammation, and gynecology. Future studies should also focus on developing effective fractions or active compounds of Valeriana into new drugs to treat diseases associated with neurodegeneration, cardiovascular, and cerebrovascular, inflammation and tumors. Our review will promote the development and utilization of potential drugs in Valeriana and avoid wasting their medicinal resources.

Plant Species of Sub-Family Valerianaceae-A Review on Its Effect on the Central Nervous System

Valerianaceae, the sub-family of Caprifoliaceae, contains more than 300 species of annual and perennial herbs, worldwide distributed. Several species are used for their biological properties while some are used as food. Species from the genus Valeriana have been used for their antispasmodic, relaxing, and sedative properties, which have been mainly attributed to the presence of valepotriates, borneol derivatives, and isovalerenic acid. Among this genus, the most common and employed species is Valerianaofficinalis. Although valerian has been traditionally used as a mild sedative, research results are still controversial regarding the role of the different active compounds, the herbal preparations, and the dosage used. The present review is designed to summarize and critically describe the current knowledge on the different plant species belonging to Valerianaceae, their phytochemicals, their uses in the treatment of different diseases with particular emphasis on the effects on the central nervous system. The available information on this sub-family was collected from scientific databases up until year 2020. The following electronic databases were used: PubMed, Scopus, Sci Finder, Web of Science, Science Direct, NCBI, and Google Scholar. The search terms used for this review included Valerianaceae, Valeriana, Centranthus, Fedia, Patrinia, Nardostachys, Plectritis, and Valerianella, phytochemical composition, in vivo studies, Central Nervous System, neuroprotective, antidepressant, antinociceptive, anxiolytic, anxiety, preclinical and clinical studies.

Cognition and memory impairment attenuation via reduction of oxidative stress in acute and chronic mice models of epilepsy using antiepileptogenic Nux vomica

Ethnopharmacological relevance Processed Nux vomica seed extracts and homeopathic medicinal preparations (HMPs) are widely used in traditional Indian and Chinese medicine for respiratory, digestive, neurological and behavioral disorders. Antioxidant property of Nux vomica is well known and recent investigation has highlighted the anticonvulsant potential of its homeopathic formulation.

AIM OF THE STUDY

To explore the anticonvulsant and antiepileptogenic potential of Nux vomica HMPs (6CH, 12CH and 30CH potency) in pentylenetetrazole (PTZ) induced acute and chronic experimental seizure models in mice and investigate their effects on cognition, memory, motor activity and oxidative stress markers in kindled animals.

MATERIALS AND METHODS

Acute seizures were induced in the animals through 70 mg/kg (i.p.) administration of PTZ followed by the evaluation of latency and duration of Generalized tonic-clonic seizures (GTCS). Subconvulsive PTZ doses (35 mg/kg, i.p.) induced kindling in 29 days, which was followed by assessment of cognition, memory and motor impairment through validated behavioral techniques. The status of oxidative stress was estimated through measurement of MDA, GSH and SOD.

RESULTS

HMPs delayed the latency and reduced the duration of GTCS in acute model signifying possible regulation of GABAergic neurotransmission. Kindling was significantly hindered by the HMPs that justified the ameliorated cognition, memory and motor activity impairment. The HMPs attenuated lipid peroxidation by reducing MDA level and strengthened the antioxidant mechanism by enhancing the GSH and SOD levels in the kindled animals.

CONCLUSIONS

Nux vomica HMPs showed anticonvulsant and antiepileptogenic potency in acute and chronic models of epilepsy. The test drugs attenuated behavioral impairment and reduced the oxidative stress against PTZ induced kindling owing to which they can be further explored for their cellular and molecular mechanism(s).

Herbal Medicine in the Treatment of Epilepsy

Epilepsy is one of the most common disorders of the central nervous system. Although epilepsy is common worldwide, approximately 80% of epileptic patients live in the developing countries or those with low-middle income. Up until the second decade of the 20th century, epilepsy was treated mostly by traditional remedies. Today, antiepileptic drugs are used as a general treatment instead to prevent and control epileptic seizures. However, patient access to these drugs is hindered due to the healthcare systems of their countries and a number of other reasons, such as cultural, socio-demographic, and financial poverty. In addition, approximately 30-40%of epileptic patients suffer from refractory epilepsy, additionally, AEDs have adverse side-effects that can lead to treatment failure or reduce the patient's quality of life. Despite recent advances in the treatment of epilepsy, there is still a need for improving medical treatment with a particular focus on efficacy, safety, and accessibility. Since herbal medicines have been used for many centuries around the world for treating epilepsy, it is, therefore, plausible that a rigorous study on herbal medicine and phytochemical components within plants of various species and origin may lead to the discovery of novel AEDs. Nowadays, many medicinal plants used in different cultures and regions of the world have been identified. Most phytochemical components of these plants have been identified and, in some cases, their targets located. Therefore, it is possible that new, effective, and accessible anticonvulsants drugs can be obtained from a medicinal plant.

Anticonvulsant activity of Valeriana edulis roots and valepotriates on the pentylenetetrazole-induced seizures in rats

ETHNOPHARMACOLOGICAL RELEVANCE

For many centuries, Mexican Valerian (Valeriana edulis ssp. procera) has been an important plant in folk medicine. It has been considered useful to control epilepsy; however, electroencephalographic evidence of its anticonvulsant activity is missing in literature.

AIM OF THE STUDY

In the present study, in situ electroencephalographic (EEG) analysis was performed along with administration of a crude ethanol extract of V. edulis and its valepotriate fraction on the pentylenetetrazole (PTZ)-induced convulsive behavior in rats.

MATERIALS AND METHODS

Experiments were performed using male Wistar rats with nail-shaped electrodes implanted in the frontal and parietal cortices for EEG recording. All animals received a single dose of PTZ (35 mg/kg, i.p.) to test the anticonvulsant activity of V. edulis crude extract and valepotriate fraction (100 mg/kg, i.p.) 15 and/or 30 min after administration. EEG recordings were obtained from the cortices and were evaluated to assess ictal behavior over 60-75 min. Chromatographic analysis of the valepotriate fraction and in silico predictions of pharmacodynamic properties were also explored. The latency, frequency and duration of seizures evaluated using EEG recordings from the frontal and parietal cortices of rats showed significant changes demonstrating the inhibition of paroxystic activity.

RESULTS

The spectral analysis confirmed the reduction of excitatory activity induced by V. edulis extract, which was improved in the presence of the valepotriate fraction as compared to that induced by ethosuximide (a reference anticonvulsant drug). The presence of valepotriates such as: isodihydrovaltrate (18.99%), homovaltrate (13.51%), 10-acetoxy-valtrathydrin (4%) and valtrate (1.34%) was identified by chromatographic analysis. Whereas, not only GABA_A receptor participation but also the cannabinoid CB2 receptor was found to be likely involved in the anticonvulsant mechanism of action after in silico prediction.

CONCLUSIONS

Our data support the anticonvulsant properties attributed to this plant in folk medicine, due to the presence of valepotriates.

Valeriana officinalis Counteracts Rotenone Effects on Spreading Depression in the Rat Brain in vivo and Protects Against Rotenone Cytotoxicity Toward Rat Glioma C6 Cells in vitro

Astrocytes can protect neurons against oxidative stress and excitability-dependent disorders, such as epilepsy. Valeriana officinalis has been used as anticonvulsant and can exert an antioxidant effect, which may underlie its opposing action against the toxic effects of the pesticide rotenone. We investigated the V. officinalis/rotenone interaction in the cortical spreading depression (CSD), a phenomenon that depends upon brain excitability (in vivo model). In addition, we analyzed the protective action of V. officinalis against the cytotoxic effects of rotenone in cultures of rat C6 glioma cells (in vitro model). For the CSD study, Wistar rats received either V. officinalis (250 mg/kg/day via gavage for 15 days; n = 8) or 10 mg/kg/day rotenone via subcutaneous injections for 7 days (n = 7), or they received both substances (n = 5). Two control groups received either saline (vehicle for V. officinalis; n = 8) or 1% Tween-80 aqueous solution (vehicle for rotenone; n = 9). After treatment, CSD was recorded for 4 h. The rotenone- and V. officinalis-treated groups presented, respectively, with lower (2.96 ± 0.14 mm/min), and higher CSD propagation velocity (3.81 ± 0.10 mm/min) when compared with the controls (Tween-80, 3.37 ± 0.06 mm/min and saline, 3.35 ± 0.08 mm/min; p < 0.05). The rotenone plus V. officinalis-treated group displayed a CSD velocity (3.38 ± 0.07 mm/min) that was similar to controls. In line with these results, in vitro experiments on rat glioma C6 cells revealed a protective effect (MTT assay) of V. officinalis against rotenone-induced cytotoxicity. These results suggest the therapeutic potential of V. officinalis for treating neurological diseases involving redox imbalance and astrocyte dysfunction.

Iridoids of Valeriana fauriei contribute to alleviating hepatic steatosis in obese mice by lipophagy

Nonalcoholic fatty liver disease (NAFLD) is a common risk factor for metabolic syndrome that increases the risk of future cardiovascular disease, stroke, and diabetes. Recently, autophagy has been proposed as a means to prevent NAFLD. We investigated whether substances with autophagy-inducing activity alleviate NAFLD. The Valeriana fauriei (V. fauriei) was selected as a potential autophagy inducer among various natural materials using a Cyto-ID autophagy detection kit. V. fauriei 70 % ethanol extract (VFE) increased LC3II levels in the presence of the lysosomal inhibitor and reduced the GFP/mCherry puncta ratio, suggesting that VFE enhanced autophagy. VFE reduced oleic acid (OA)-induced lipid accumulation and increased the number of autophagosome in hepatocytes. Autophagy induction by VFE is due to inhibition of mTORC1 activity. VFE supplementation reduced fatty liver by downregulating lipogenesis-related genes and increased the autophagy, as revealed by TEM and IHC analysis in the fatty liver. We identified iridoids as main compounds of VFE; didrovaltrate (DI), valeriotriate B (VAL B), valeriotetrate C (VAL C), valtrate (VAL), and valechlorine (VC) were shown to enhance autophagy. These compounds also reduced OA-induced lipid accumulation in an Atg5-dependent manner. Taken together, VFE and its iridoids might be effective in alleviating fatty liver by acting as autophagy enhancers to break down LDs.

Awareness and current knowledge of epilepsy

Epilepsy is a severe neural disorder that affects approximately fifty million individuals globally. Despite the fact that for most of the people with epilepsy, convulsions are better controlled by current accessible antiepileptic medicines, yet there are more than 30% of individuals affected with medically intractable epilepsy and around 30-40% of all patients with epilepsy affected by many adverse reactions and convulsion resistance to the present antiepileptic drugs. Consequently, various scientists attempt to develop new strategies to treat epilepsy, for instance, to find out novel antiepileptic ingredients from traditional medicines. This work aims to present a complete summary of natural medicines prescribed as antiepileptic agents all over the world by ethnic groups and different tribes. We undertook an extensive bibliographic analysis by searching peer reviewed papers and classical textbooks and further consulting well accepted worldwide scientific databases. We carried out PubMed, EMbase and CENTRAL searches by means of terms such as "antiepileptic" and "anti-convulsant" activity of plants. Medicinal plants have been prescribed to treat epilepsy and have been recognized as antiepileptic medicines. In this review, a variety of herbs have been reviewed for thorough studies such as Cuminum cyminum, Butea monosperma, Solanum americanum, Anacyclus pyrethrum, Leonotis leonurus, Elaeocarpus ganitrus and Angelica archangelica. This paper shows that it was high time experimental studies are increased to obtain novel potential active principles from medicinal plants. Plant extracts and their chemical constituents should be further evaluated to clarify their mechanisms of action. This paper provides a solid base upon which to further investigate the clinical efficacy of medicinal plants that are both currently prescribed by physicians as traditional antiepileptic agents, but also could be effective as an antiepileptic drug with further research and study.

Herbal medicine for epilepsy seizures in Asia, Africa and Latin America: A systematic review

RELEVANCE

More than 70 million people suffer epilepsy worldwide. Low availability of anti-epileptic drugs, side-effects and drug-resistant epilepsy affect the quality of life of persons with epilepsy in countries with a poorly developed health system. Herbal medicine is frequently used for this neurological condition.

OBJECTIVES

The main objective was to provide a detailed analysis of Herbal Medicine used for neurological conditions related with epilepsy in Asia, Africa and Latin America. More broadly, this study aims to highlight species with assessed efficacy (cross-cultural use, pharmacological effects on models of epileptic seizures) and safety (toxicological data in laboratory) information, in order to point out species of interest for further studies. A critical assessment of models used in pharmacological evaluations was done.

MATERIALS AND METHODS

The systematic search for Herbal Medicine treatments for epilepsy was performed considering all the articles published until February 2017 through three scientific databases. It was made with MeSH terms and free text defining the epilepsy seizures and plant species. We included studies carried out in Asia, Africa and Latin America. All articles reporting the use of Herbal Medicine to treat epilepsy seizures and/or their pharmacological evaluation were retained for further analysis.

RESULTS

The search yielded 1886 articles, from 30 countries. Hundred and six articles published between 1982 and 2017 were included, corresponding to a total of 497 use reports for 351 plant species belonging to 106 families. Three hundred and seventy seven use reports corresponding to 264 species in ethnopharmacological surveys and 120 evaluation reports corresponding to 107 species were noted. Twenty-nine reports, for 29 species, combined both ethnopharmacological and pharmacological evaluation. Fifty eight studies originated from Africa, 35 studies from Asia and 18 from Latin America. Highest use report was noted for rhizomes of Acorus calamus L. (12 use report in 1 country) and leaves of Bacopa monnieri (L.) Wettst. (8 use report in 2 countries). Therefore these species display the highest use convergence. Regarding pharmacological evaluation most studied species were: Leonotis leonurus (L.) R.Br. (4 evaluation reports in 1 country), Uncaria rhynchophylla (Miq.) Miq. ex Havil. (3 evaluation reports in 2 countries) and Calotropis gigantea (L.) Dryand. (3 evaluation reports in 1 country). In vivo models of chronic epilepsy were more relevant than in vitro models or chemical models inducing acute seizures for pharmacological assessment.

CONCLUSION

Species with the highest use report were not those with pharmacological evaluation. It will be pertinent to assess the pharmacological effects and safety of medicinal plants used mostly by traditional healers on predictive models of seizures.

Investigating owner use of dietary supplements in dogs with idiopathic epilepsy

Epilepsy is the most common chronic neurological disorder in dogs. Some diets have been shown to have a positive impact upon the seizure activity in dogs with idiopathic epilepsy (IE), while other diets and dietary supplements (DS), although marketed as providing health benefits, lack conclusive scientific evidence on their actual beneficial effects. A web-based owner questionnaire was designed to assess how and why owners of dogs with IE use different dietary regimes and DS. The study cohort, with 297 valid responses, consisted mainly of pure-breed (82.5%) male neutered (52.9%) dogs. Over two-thirds of owners (67.7%) changed their dog's diet after their dog received a diagnosis of IE. Nearly half of the owners (45.8%) reported giving DS, the most common being coconut oil or derived medium-chain triglyceride oil (71.3%). Some owner justifications of DS use included improvement of seizure frequency (88.2%), seizure severity (61.8%) and protection from potential drug side effects (62.5%). Many owners give DS to their dog with IE. The pharmacokinetic properties of anti-epileptic drugs, such as efficacy, absorption and clearance can be influenced by other medications, diets and possibly by DS. We propose that use of DS should be considered and monitored by veterinary surgeons in epilepsy management.

Chemical comparison of the underground parts of Valeriana officinalis and Valeriana turkestanica from Poland and Kazakhstan

The volatile constituents from the n-hexane extracts of the roots and rhizomes of Valeriana officinalis (VO) and Valeriana turkestanica (VT) were investigated by GC-MS analysis. Two VO samples were obtained from cultivation, one from commercially available material, while VT was collected in a mountain of Kazakhstan. The most characteristic components present in all of the analysed samples were sesquiterpenoids. The three investigated samples of VO produced mainly valerenane and kessane sesquiterpenoids. Acetoxyvalerenic acid (33.94%), valerenic acid (15.05%), valerenal (11.93%), valeric acid 2,6-dimethylnon-1-en-3-yn-5-yl ester (5.24%), valerenol (3.31%), elemol (3.19%) and (E)-valerenyl isovalerate (2.53%), were the common components identified in the n-hexane extract from the roots of VT. In comparison to VO this species does not produce kessane sesquiterpenoids and polyunsaturated fatty acids. This study shows that the roots of VT possess compounds of high biological significance, since they have the appropriate contents of valerenic acid and its derivatives, thus VT can be considered as a substitute for VO.

Effect of Valeriana fauriei extract on the offspring of adult rats exposed to prenatal stress

Exposing a pregnant female to stress is a risk factor for the development of psychiatric disorders in the offspring. In the present study, we examined the effects of an extract of Valeriana fauriei (VF) root (100 mg/kg/day, administered on postnatal days 35-56) on behavioral patterns as well as protein expression in the prefrontal cortex of the offspring of prenatally-stressed rats. Modified behavioral tests, including the forced swim test, the open field test, a social interaction test and the prepulse inhibition test were performed and many of the parameters were found to decrease in the offspring of the rats exposed to PNS compared with the offspring of the non-stressed rats. Western blot and immunohistochemical analyses of the prefrontal cortex revealed that the downregulation of several neurodevelopmental proteins in the offspring of rats dams exposed to PNS was reversed after treatment with VF extract. These findings demonstrate that the downregulation of several proteins in the prefrontal cortex of the offspring of prenatally‑stressed rats may be associated with subsequent behavioral changes, and that these phenomena recovered following VF treatment. Our results suggest that VF decreases the incidence of prenatal stress related-psychiatric disorders, such as depression and schizophrenia.

Reversal of pentylenetetrazole-altered swimming and neural activity-regulated gene expression in zebrafish larvae by valproic acid and valerian extract

RATIONALE

Ethnopharmacology has documented hundreds of psychoactive plants awaiting exploitation for drug discovery. A robust and inexpensive in vivo system allowing systematic screening would be critical to exploiting this knowledge.

OBJECTIVE

The objective of this study was to establish a cheap and accurate screening method which can be used for testing psychoactive efficacy of complex mixtures of unknown composition, like plant crude extracts.

METHODS

We used automated recording of zebrafish larval swimming behavior during light vs. dark periods which we reproducibly altered with an anxiogenic compound, pentylenetetrazole (PTZ). First, we reversed this PTZ-altered swimming by co-treatment with a well-defined synthetic anxiolytic drug, valproic acid (VPA). Next, we aimed at reversing it by adding crude root extracts of Valeriana officinalis (Val) from which VPA was originally derived. Finally, we assessed how expression of neural activity-regulated genes (c-fos, npas4a, and bdnf) known to be upregulated by PTZ treatment was affected in the presence of Val.

RESULTS

Both VPA and Val significantly reversed the PTZ-altered swimming behaviors. Noticeably, Val at higher doses was affecting swimming independently of the presence of PTZ. A strong regulation of all three neural-activity genes was observed in Val-treated larvae which fully supported the behavioral results.

CONCLUSIONS

We demonstrated in a combined behavioral-molecular approach the strong psychoactivity of a natural extract of unknown composition made from V. officinalis. Our results highlight the efficacy and sensitivity of such an approach, therefore offering a novel in vivo screening system amenable to high-throughput testing of promising ethnobotanical candidates.

A pharmacological basis of herbal medicines for epilepsy

Epilepsy is the most common chronic neurological disease, affecting about 1% of the world's population during their lifetime. Most people with epilepsy can attain a seizure-free life upon treatment with antiepileptic drugs (AEDs). Unfortunately, seizures in up to 30% do not respond to treatment. It is estimated that 90% of people with epilepsy live in developing countries, and most of them receive no drug treatment for the disease. This treatment gap has motivated investigations into the effects of plants that have been used by traditional healers all over the world to treat seizures. Extracts of hundreds of plants have been shown to exhibit anticonvulsant activity in phenotypic screens performed in experimental animals. Some of those extracts appear to exhibit anticonvulsant efficacy similar to that of synthetic AEDs. Dozens of plant-derived chemical compounds have similarly been shown to act as anticonvulsants in various in vivo and in vitro assays. To a significant degree, anticonvulsant effects of plant extracts can be attributed to widely distributed flavonoids, (furano)coumarins, phenylpropanoids, and terpenoids. Flavonoids and coumarins have been shown to interact with the benzodiazepine site of the GABAA receptor and various voltage-gated ion channels, which are targets of synthetic AEDs. Modulation of the activity of ligand-gated and voltage-gated ion channels provides an explanatory basis of the anticonvulsant effects of plant secondary metabolites. Many complex extracts and single plant-derived compounds exhibit antiinflammatory, neuroprotective, and cognition-enhancing activities that may be beneficial in the treatment of epilepsy. Thus, botanicals provide a base for target-oriented antiepileptic drug discovery and development. In the future, preclinical work should focus on the characterization of the effects of plant extracts and plant-derived compounds on well-defined targets rather than on phenotypic screening using in vivo animal models of acute seizures. At the same time, available data provide ample justification for clinical studies with selected standardized botanical extracts and plant-derived compounds. This article is part of a Special Issue entitled "Botanicals for Epilepsy".

Valerenic acid and Valeriana officinalis extracts delay onset of Pentylenetetrazole (PTZ)-Induced seizures in adult Danio rerio (Zebrafish)

Background

Anticonvulsant properties have been attributed to extracts of the herbal medicine Valeriana officinalis. Our aims were to examine the anticonvulsant properties of valerenic acid and valerian extracts and to determine whether valerian preparations interact with the activity of other anti-epileptic drugs (phenytoin or clonazepam). To achieve these goals, we validated the adult zebrafish, Danio rerio, as an animal model for studying anticonvulsant drugs.

Methods

All drug treatments were administered by immersion in water containing the drug. For assays of anticonvulsant activity, zebrafish were pretreated with: anti-epileptic drugs, valerenic acid, aqueous or ethanolic valerian extracts, or mixtures (phenytoin or clonazepam with valerenic acid or valerian extracts). Seizures were then induced with pentylenetetrazole (PTZ). A behavioral scale was developed for scoring PTZ-induced seizures in adult zebrafish. The seizure latency was evaluated for all pretreatments and control, untreated fish. Valerenic acid and both aqueous and ethanolic extracts of valerian root were also evaluated for their ability to improve survival after pentylenetetrazole-challenge. The assay was validated by comparison with well-studied anticonvulsant drugs (phenytoin, clonazepam, gabapentin and valproate). One-way ANOVA followed by Tukey post-hoc test was performed, using a p < 0.05 level of significance. All treatments were compared with the untreated animals and with the other pretreatments.

Results

After exposure to pentylenetetrazole, zebrafish exhibited a series of stereotypical behaviors prior to the appearance of clonic-like movements—convulsions. Both valerenic acid and valerian extracts (aqueous and ethanolic) significantly extended the latency period to the onset of seizure (convulsion) in adult zebrafish. The ethanolic valerian extract was a more potent anticonvulsant than the aqueous extract. Valerenic acid and both valerian extracts interacted synergistically with clonazepam to extended the latency period to the onset of seizure. Phenytoin showed interaction only with the ethanolic valerian extracts.

Conclusions

Valerenic acid and valerian extracts have anticonvulsant properties in adult zebrafish. Valerian extracts markedly enhanced the anticonvulsant effect of both clonazepam and phenytoin, and could contribute to therapy of epileptic patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-015-0731-3) contains supplementary material, which is available to authorized users.

Anticonvulsant effect of ferula assa-foetida oleo gum resin on chemical and amygdala-kindled rats

Background:

In Iranian traditional medicine, Ferula assa-foetida oleo gum resin (asafoetida) have been used as anti-convulsant agents.

Aims:

This study was designed to evaluate the anti-convulsant effect of asafoetida on chemical and amygdala -kindled rats.

Materials and Methods:

In chemical model, rats received orally asafoetida at dose of 50 and 100 mg/kg 90 minutes prior to Pentylenetetrazol injection in dose of 35 mg/kg intraperitoneally (i.p.) and control group received normal saline. Convulsive behavior was recorded for 30 minutes. For amygdala kindle model, bipolar stimulating and monopolar recording electrodes were implanted stereotaxically. After kindling, the effect of asafoetida (50 and 100mg/kg) on after discharge duration, duration of stage 5 seizure and latency to the onset of bilateral forelimb clonuses was measured.

Results:

Pretreatment animals with asafoetida significantly reduced the mean seizure stage during the 20 kindling injection of Pentylenetetrazol. Seizure parameters in amigdala kindle model improved in treatment animals at both dose 50 and 100 mg/kg. The number of stimulations in stage 3, 4, and 5 in asafoetida-treated rats at both doses significantly increased.

Conclusions:

These results showed that asafoetida could prevent seizure in both chemical and electrical kindling model and this effect may partially be related to the terpenoids compounds.

Adenosine receptors and epilepsy: current evidence and future potential

Adenosine receptors are a powerful therapeutic target for regulating epileptic seizures. As a homeostatic bioenergetic network regulator, adenosine is perfectly suited to establish or restore an ongoing balance between excitation and inhibition, and its anticonvulsant efficacy is well established. There is evidence for the involvement of multiple adenosine receptor subtypes in epilepsy, but in particular the adenosine A1 receptor subtype can powerfully and bidirectionally regulate seizure activity. Mechanisms that regulate adenosine itself are increasingly appreciated as targets to thus influence receptor activity and seizure propensity. Taken together, established evidence for the powerful potential of adenosine-based epilepsy therapies and new strategies to influence receptor activity can combine to capitalize on this endogenous homeostatic neuromodulator.

Epilepsy in the Renaissance: a survey of remedies from 16th and 17th century German herbals

ETHNOPHARMACOLOGICAL RELEVANCE

Before modern anticonvulsive drugs were developed people in central Europe used herbal remedies to treat epilepsy. Hundreds of different plants for this indication can be found in German herbals of the 16th and 17th centuries. Here we compile these plants and discuss their use from a pharmacological perspective.

MATERIALS AND METHODS

Nine of the most important European herbals of the 16th and 17th century including Bock (1577), Fuchs (1543), Mattioli (1590), Lonicerus (1660, 1770), Brunfels (1532), Zwinger (1696), and Tabernaemontanus (1591, 1678) were searched for terms related to epilepsy, and plants and recipes described for its treatment were documented. We then searched scientific literature for pharmacological evidence of their effectiveness. Additionally the overlapping of these remedies with those in De Materia Medica by the Greek physician Dioscorides was studied.

RESULTS

Two hundred twenty one plants were identified in the herbals to be used in the context of epilepsy. In vitro and/or in vivo pharmacological data somehow related to the indication epilepsy was found for less than 5% of these plants. Less than 7% of epilepsy remedies are in common with De Materia Medica.

CONCLUSIONS

Numerous plants were used to treat epilepsy in the 16th and 17th centuries. However, few of these plants have been investigated with respect to pharmacological activity on epilepsy related targets.

Anticonvulsant and depressant effects of aqueous extracts of Carum copticum seeds in male rats

In this study, the effects of aqueous extracts of Carum copticum seeds (CCS) were evaluated in kindling models of epilepsy. Additionally, the sedative and anxiolytic effects of the extract were assessed. For pentylenetetrazole (PTZ) kindling, rats received a subconvulsant dose of PTZ (40 mg/kg, ip) every second day and seizure stages were recorded. CCS aqueous extract (200, 400, or 600 mg/kg, ip) was injected 30 minutes prior to each PTZ injection. In electrical kindling, bipolar stimulating and monopolar recording electrodes were implanted stereotaxically in the right basolateral amygdala of male Sprague-Dawley rats. After kindling, the effect of aqueous extracts of CCS (200, 400, or 600 mg/kg, ip) on afterdischarge duration, duration of rearing, forelimb clonus, and loss of equilibrium (stage 5 seizure), and latency to the onset of bilateral forelimb clonus were measured. The sedative and the anxiolytic effects of CCS extracts were evaluated in an open-field apparatus and elevated plus maze, respectively. The results indicate that aqueous extracts of CCS have a significant anticonvulsant effect. Different doses of extract significantly delayed the incidence of every seizure stage in the PTZ model of kindling. Moreover, CCS extract (400 and 600 mg/kg, ip) suppressed afterdischarge duration, latency to the onset of bilateral forelimb clonus, and stage 5 seizure in the electrical kindling model. These results suggest that CCS extract has remarkable antiepileptic and central depressant effects.

Evaluation of Behavioral and Pharmacological Effects of Hydroalcoholic Extract of Valeriana prionophylla Standl. from Guatemala

There are few studies on the pharmacological properties of Valeriana prionophylla Standl. (VP), known as "Valeriana del monte", and used in Mesoamerican folk medicine to treat sleep disorders. This study examines the pharmacological effects of the hydroalcoholic extract of the dry rhizome using the open field, rota rod, elevated plus-maze (EPM), forced swimming (FST), strychnine- and pentobarbital-induced sleeping time, PTZ-induced seizures, and the inhibitory avoidance tests. VP did not show any protective effect against PTZ-induced convulsions. In the EPM, exhibited an anxiolytic-like effect through the effective enhancement of the entries (38.5%) and time spent (44.7%) in the open arms, when compared with control group. Time spent and the numbers of entrances into the enclosed arms were decreased, similar to those effects observed with diazepam. In the FST, acute treatment with VP, produced a dose-dependent decrease in immobility time, similarly to imipramine. VP also produced a significant dose-dependent decrease in the latency of sleeping time, while producing an increase in total duration of sleep; influenced memory consolidation of the animals only at lower doses, unlike those that produced anti-depressant and anxiolytic effects. In summary, the results suggest that VP presents several psychopharmacological activities, including anxiolytic, antidepressant, and hypno-sedative effects.