Central analgesic effect of valproate in patients with epilepsy

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.

Ventrolateral Periaqueductal Gray Matter Neurochemical Lesion Facilitates Epileptogenesis and Enhances Pain Sensitivity in Epileptic Rats

The ventrolateral periaqueductal gray matter (vlPAG) plays a critical role in the pathogenesis of migraine and few studies have shown that vlPAG might be involved in the pathophysiology of epilepsy. But its roles in epileptogenesis and comorbid relationship between migraine and epilepsy have never been reported. In this study, the impairments of vlPAG neuronal network during spontaneous recurrent seizure (SRS) development after status epilepticus (SE) were investigated, and the pain sensitivity as well as the SRS investigated after neurochemical lesion to vlPAG to determine the role of vlPAG in epileptogenesis and in migraine comorbidity with epilepsy. Neuronal loss and alterations of excitatory and inhibitory neural transmission within vlPAG accompanied the development of epileptogenesis induced by SE. On the other hand, neurochemical lesion to vlPAG enhanced frequency and duration of spontaneous seizure event and frequency of epileptiform inter-ictal spike discharges in electroencephalography (EEG), but decreased pain threshold in epileptic rats. This indicates an involvement of the pain regulating structure, vlPAG, in the pathogenesis of epilepsy. This may imply that vlPAG network alterations could be a possible underlying mechanism of the interactive comorbid relationship between epilepsy and migraine.

Alterations in pain responsiveness and serum biomarkers in juvenile myoclonic epilepsy: an age- and gender-matched controlled pilot study

Introduction: Serum levels of several biomarkers along with sensory responsiveness were investigated in juvenile myoclonic epilepsy patients in comparison with healthy controls. Methods: Ten epileptic patients (36.1 ± 3.4 years) and ten gender- and age-matched healthy controls were recruited. Mechanical sensitivity, cold pressor tolerance and serum levels of BDNF, CGRP, PGE2, S100B and TNF-α were investigated. Results: Mechanical sensitivity to pinprick was lower in patients (p < 0.05) while cold pain tolerance threshold was higher. Serum level of BDNF was higher in patients compared with controls (p < 0.01). The same pattern was evident for CGRP (p < 0.05). Serum level of PGE2 was lower in patients (p < 0.01). Conclusion: Juvenile myoclonic epilepsy patients had an altered serum biomarker pattern and sensory perception in comparison with controls.

Antinociceptive activity of sodium valproate in mice after chronic treatment

1. Mice were given sodium valproate (0.71%) in the drinking fluid for 21 days. The antinociceptive activity, locomotor activity and body temperature changes were recorded at 7, 14 and 21 days. The possible carryover antinociceptive effects were also determined after valproate withdrawal for up to 3 days after 7-, 14- and 21-day treatment. 2. The antinociceptive activity was present only on days 7, 14 and 21 and, on withdrawal of the drug, the antinociceptive activity disappeared. 3. Thus, with this regimen of valproate administration, there was no persistent antinociceptive activity (carryover effect). There were essentially no effects of valproate on the locomotor activity and body temperature of mice. The antinociceptive effects were due to the presence of the drug and disappeared on valproate's withdrawal.