Khat (Catha edulis) and ethanol co-dependence modulate seizure expression in a pentylenetetrazol seizure model

A review on epilepsy, current treatments, and potential of medicinal plants as an alternative treatment

Epilepsy is considered common neurological diseases that threaten the lives of millions of people all around the world. Since ancient times, different forms of medications have been used to treat this condition. Adverse events associated with treatments and the residence time of available drugs caused to search for safer and more efficient therapies and drugs remain one of the major areas of research interest for scientists. As one of the therapeutics with fewer side effects, plants and their essential oils can be considered replacements for existing treatments. Medicinal plants have proven to be an effective natural source of antiepileptic drugs; most of them have their mechanism of action by affecting GABA receptors in different paths. Cannabis indica and Cymbopogon winterianus are well-known plant species with antiepileptic activities. The current review presenting a list of plants with antiepileptic effects aims to pave the way for finding alternative drugs with fewer side effects for scientists.

Evaluation of neurotoxicity and hepatotoxicity effects of acute and sub-acute oral administration of unripe ackee (Blighia sapida) fruit extract

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Acute oral dose of 2000 mg/kg of unripe B. sapida fruit extract (BSE) was toxic to mice.

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Repeated treatment with BSE impaired locomotor function, memory performance and shortened seizure latency in mice.

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Repeated treatment with BSE significantly up-regulate acetylcholinesterase enzyme activity in mice.

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Repeated treatment with BSE elevates oxidative stress in the brain and liver of mice.

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Repeated treatment with BSE showed histopathological evidences of toxicity in mice brain and liver.

Ackee (Blighia sapida) is a commonly eaten fruit that is indigenous to West Africa and Jamaica. Ackee poisoning in young children have been reported in parts of Nigeria due to consumption of the unripe fruits. This study was designed to identify potential mechanisms of acute and sub-acute toxicity of unripe B. sapida fruit extract (BSE).

Acute toxic effect was investigated in mice of either sex administered BSE 2000 mg/kg. The sub-acute toxicity effects were investigated in mice of either sex that received 28 days repeated administration of BSE (100 and 500 mg/kg, p.o.). Locomotor activity and memory performance were measured as well as seizure vulnerability in PTZ-induced model. Liver enzymes were assessed in the serum. Acetylcholinesterase, oxidative stress parameters and histopathological changes were assessed in the brain and liver tissues.

Signs and symptoms of toxicity such as urination, tremor, depressed locomotion and death were observed in acute toxicity test. Sub-acute dosing caused significant impairment in locomotor activity and memory performance in mice. Seizure threshold was shortened in BSE-treated compared to control mice. Brain acetylcholinesterase activity was significantly increased. Alkaline phosphatase (ALP) was significantly elevated in mice that received BSE (500 mg/kg). Furthermore, BSE caused significant increase in oxidative stress expressed in nitrite, malondialdehyde, reduced glutathione and catalase in the brain and liver tissues. Histological staining revealed neuronal damage of brain hippocampus and hepatocellular swelling and necrosis.

Blighia sapida unripe fruit extract increased susceptibility to seizure and impaired locomotor and memory function. The biochemical and histopathological findings revealed potential toxicity mechanisms related to neurotoxicity and hepatotoxicity.

Seizure vulnerability and anxiety responses following chronic co-administration and acute withdrawal of caffeine and ethanol in a rat model

BACKGROUND

Caffeine antagonizes the intoxicating effects of alcohol. Consequently, there has been a dramatic global increase in the consumption of caffeinated drinks together with alcohol, especially among young adults. We assessed the seizure vulnerability and anxiety responses following the chronic co-administration of, and withdrawal from, caffeine and ethanol in male rats.

METHODS

The rats were randomly assigned to six groups consisting of 10 animals each: 10 mg/kg of caffeine, 20 mg/kg of caffeine, 4 g/kg of 20% ethanol, combined caffeine (20 mg/kg) and ethanol (4 g/kg of 20%), 4 mL/kg distilled water, and an untreated control group. The test substances were administered intragastrically twice daily for 29 days. On day 29, the rats were tested on the elevated plus maze to assess anxiety-related responses. On day 30, pentylenetetrazol (PTZ), a chemoconvulsant, was administered intraperitoneally at a dose of 40 mg/kg to the animals. Seizure responses and mortality up to 72 h were recorded.

RESULTS

Compared with the control group, the rats that received chronic treatment with low-dose caffeine, ethanol alone, and combined caffeine and ethanol exhibited significant anxiogenic-like effects, unlike with high-dose caffeine. Both low- and high-dose caffeine significantly increased PTZ seizure latency. Ethanol alone and combined caffeine and ethanol both lowered PTZ seizure latency. No significant difference occurred between the controls and the untreated group for either anxiety or seizure expression. Combined caffeine and ethanol increased the seizure-induced mortality from withdrawal effects at 72 h.

CONCLUSIONS

These findings suggest that the chronic co-administration of caffeine and ethanol and the acute withdrawal from these drugs lead to anxiogenic effects and increased seizure vulnerability.

Pharmacological and Toxicological Effects of Catha edulis F. (Khat)

Khat chewing is deeply rooted in the culture and tradition of communities in khat belt countries, and its consumption is spread to other countries through the suitcase trade. The aim of this article is to review current knowledge on the chemistry, social, pharmacology and toxicology of khat and its use. Khat produces effect invariably in every system, which is harmful or beneficial in some instances. Harmful effects are observed in heavy users, although firm evidence is lacking. Chewing khat acutely elicits states of euphoria, which is followed by low mood. Khat contains alkaloids with psychostimulant properties, but the effect cannot be totally explained by these alkaloids. It is also not clear whether the effect produced in some organs like liver could be attributed to khat or pesticides sprayed during farming. Although the evidence indicates that khat has adverse effects in most organs, our understanding of the complex interaction between use and effect is incomplete, and causal relationships have not yet been described. Moreover, khat has positioned itself well in the social, economic and political arena. Thus, a multidisciplinary research is required to understand the different dimensions and come up with ways that maximize the benefit while minimizing the risk. Copyright © 2017 John Wiley & Sons, Ltd.

Projection neurons in the cortex and hippocampus: differential effects of chronic khat and ethanol exposure in adult male rats

BACKGROUND

Recent evidence suggests that many individuals who chew khat recreationally also drink ethanol to offset the stimulating effect of khat. The objective of this study was to describe the separate and interactive effects of chronic ethanol and khat exposure on key projection neurons in the cortex and hippocampus of young adult male rats.

METHODS

Young adult male Sprague Dawley rats were divided into six treatment groups: 2 g/kg khat, 4 g/kg khat, 4 g/kg ethanol, combined khat and ethanol (4 g/kg each), a normal saline control, and an untreated group. Treatments were administered orally for 28 continuous days; brains were then harvested, sectioned, and routine hematoxylin-eosin staining was done. Following photomicrography, ImageJ® software captured data regarding neuron number and size.

RESULTS

No differences occurred in counts of both granular and pyramidal projection neurons in the motor cortex and all four subfields of the hippocampal formation. Khat dose-dependently increased pyramidal neuron size in the motor cortex and the CA3 region, but had different effects on granular neuron size in the dentate gyrus and the motor cortex. Mean pyramidal neuron size for the ethanol-only treatment was larger than that for the 2 g/kg khat group, and the saline control group, in CA3 and in the motor cortex. Concomitant khat and ethanol increased granular neuron size in the motor cortex, compared to the 2 g/kg khat group, the 4 g/kg khat group, and the 4 g/kg ethanol group. In the CA3 region, the 4 g/kg ethanol group showed a larger mean pyramidal neuron size than the combined khat and ethanol group.

CONCLUSION

These results suggest that concomitant khat and ethanol exposure changes granular and pyramidal projection neuron sizes differentially in the motor cortex and hippocampus, compared to the effects of chronic exposure to these two drugs separately.

Anticonvulsant and anxiolytic activity of the leaf aqueous and ethanolic extracts of Melanthera scandens in a rat model

Modern drug therapy of epilepsy is complicated by the inability of drugs to control seizures in some patients and side effects that range in severity from minimal impairment of the central nervous system to death from aplastic anemia or hepatic failure. Medicinal plants used in traditional medicine for the treatment of epilepsy have been scientifically shown to possess promising anticonvulsant activities in animal models for screening for anticonvulsant activity and can be a source of newer anticonvulsants. The aim of this study was to investigate the preliminary phytochemical properties, anticonvulsant and anxiolytic activities of Melanthera scandens aqueous and ethanolic extracts. Phytochemicals from the aqueous and ethanolic extracts were screened by standard methods. Anticonvulsant activity was evaluated against pentylenetetrazol (PTZ)-induced seizure model in rats. The effect of the extract at oral dose levels of 250, 500 and 1000 mg/kg was evaluated in an experimental rat model, using diazepam (5 mg/kg) as positive control. Anxiolytic activity was performed using elevated plus maze method. Phytochemical screening revealed that M. scandens extracts contain carbohydrates, flavonoids, saponins, glycosides, tannins, terpenoids, phenols and phytosterols. The aqueous extract at a dose of 500 mg/kg significantly increased seizure latency (P=0.0023), while the ethanolic extract did not have a significant effect on seizure latency. Both extracts significantly reduced the seizure severity (P= 0.0155), and provided up to 100% protection against PTZ induced death at 1000 mg/kg. Both extracts had no significant effect on the duration of PTZ induced seizures. Both extracts were found to increase the number of entries and the time spent in the open arms of the maze at a dose of 250 mg/kg, indicating anxiolytic activity, which was not seen at higher doses (500 and 1000 mg/kg). The total numbers of entries into the closed arm were significantly reduced at 500 and 1000 mg/kg oral doses of both extracts, indicating a reduction in locomotor activity of the rats. The results obtained in this study suggest that both the aqueous and ethanolic extracts of M. scandens possess anticonvulsant and anxiolytic activities in a rat model.

Khat (Catha edulis Forsk.) Dependence Potential and Pattern of Use in Saudi Arabia

Background. Catha edulis Forsk. (Khat) is used for its psychoactive effects among people in Africa and the Arabian Peninsula, although its utilization is illegal in some countries such as Saudi Arabia. This study examined the pattern of Khat use and assessed the applicability of the Drug Abuse Screening Test-10 (DAST-10) to measure Khat dependence. Methods. A pretested questionnaire was used to gather data from 603 respondents. Variables included demographic characteristics, pattern of use, reasons for Khat chewing, and DAST-10. Stepwise-logistic regression was used to explore predictors of Khat dependence. Results. The majority of the respondents were married, had a secondary school level of education, were employed, were younger than 35 years old, and were living in rural areas. Many chewers gave more than one reason for using Khat. It was mainly used to increase mental capacity, physical strength, and social entertainment, as well as enhance cheerfulness and orgasms. Statistical modeling of Khat dependence suggested that the most significant predictors were residence (OR = 1.67, P < 0.02), frequency of Khat chewing (OR = 4.8, P < 0.01), age of starting Khat chewing (OR = 1.15, P < 0.01), and time of Khat effect (OR = 1.15, P < 0.04). Conclusion. Our study provides important information on the pattern of Khat use and its potential to cause dependence.

Khat (Catha edulis): A systematic review of evidence and literature pertaining to its harms to UK users and society

The use of khat ( Catha edulis) has been associated with a large number of physiological and societal harms, leading to calls for it to be controlled in the UK. The evidence of these harms is often equivocal, limited by confounding factors, or entirely anecdotal: high-powered, quality-controlled studies are lacking. Regardless, the body of relevant literature indicates that the once socially-regulated use of khat has been eroded. Some individuals have developed excessive consumption patterns, either using khat daily or in binge-sessions, though daily consumption is not necessarily problematic per se. The majority of users seem to use khat in moderation, where the associated harms appear low. For excessive users, harms associated with khat are greater, particularly relating to mental health. Social harms also seem to be largely related to excessive khat use rather than khat use itself. Even in cases of excessive khat use, however, causal relationships between chewing and harms have not been described. More research is required to establish the role of khat in liver disease, coronary problems, cancers of the digestive tract and incidents of domestic violence. Studies should consider the likeliness that certain users are more vulnerable to developing patterns of excessive khat use due to an interwoven set of factors such as social health determinants and pre- and post-migration experiences.

Chronic khat (Catha edulis) and alcohol marginally alter complete blood counts, clinical chemistry, and testosterone in male rats

INTRODUCTION

Khat (Catha edulis) is a recreational psychoactive drug with psychostimulant properties. While the use of this drug is widespread in eastern Africa, including the Horn of Africa, surveys and anecdotal data show that its use has become cosmopolitan, with users now living in Europe and North America as well. Recent data in Uganda suggest an increasing pattern of simultaneous khat and ethanol use particularly among young adults. However, the effects of this pattern of use remain largely unknown, even though long-term use of either drug alone is known to be harmful. The aim of this study was to examine the toxic effects of simultaneous chronic administration of khat and ethanol on hematological parameters, clinical chemistry, and testosterone in a rat model.

METHODS

Adult male Sprague-Dawley rats were randomly assigned to one of six dose groups: 2 g/kg khat; 4 g/kg khat; 4 g/kg ethanol; combined khat and ethanol (4 g/kg each); control; and an untreated group. Treatments were given by gavage twice daily for 28 days, followed by determination of hematological parameters, blood clinical chemistry, and testosterone.

RESULTS

Ethanol alone significantly reduced platelet counts compared to control-, untreated and low-dose khat-treated rats; conversely low-dose khat significantly increased both the hemoglobin and hematocrit values, while ethanol alone also significantly increased the hemoglobin value compared to controls. Simultaneous khat and ethanol administration per se did not produce more toxic consequences in chronic use than either drug alone.

CONCLUSION

Chronic short-term khat use and ethanol dependence individually produce note-worthy effects on the blood, but not on clinical chemistry or testosterone. Chronic short-term combined khat and ethanol use does not produce more toxic effects compared to use of either drug alone. This provides an opportunity for appropriate clinical interventions to avert the chronic long-term effects that result from use of these drugs of abuse.

Anticonvulsant effect of Marsilea quadrifolia Linn. on pentylenetetrazole induced seizure: a behavioral and EEG study in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Marsilea quadrifolia Linn (MQ) extract has been used traditionally as sedative and antiepileptic drug in India.

AIM OF THIS STUDY

To investigate the anticonvulsive potential of MQ extracts by using behavior and electroencephalographic (EEG) analysis on pentylenetetrazole (PTZ) induced seizure model in rats.

MATERIALS AND METHODS

For anticonvulsant effect, 60minutes after administration of MQ, behavior and EEG were analyzed during PTZ (60mg/kg) induced seizures. Changes of EEG power, latency of onset of seizure, seizure severity score, and duration of epileptic seizure were determined.

RESULTS

Both the water and ethanol extract of MQ increased the latency of seizure but also decreased duration of epileptic seizure and seizure severity score. This reduction of seizure severity was also observed in EEG recording and EEG power analysis. The effectiveness of MQ ethanol extract is better than MQ water extract.

CONCLUSION

Both water and ethanol extract of MQ were effective in reducing the severity of behavioral and EEG seizures induced by PTZ in rats. This study justifies the traditional use of this plant in epilepsy.