Epilepsy is one of the most common serious neurological conditions. In contemporary society, the frequency and importance of epilepsy can hardly be overstated from the epidemiologic studies. However, in most studies, the overall incidence of epilepsy in developed societies has been found to be around 50 cases per 100,000 persons per year, and rises steeply in older age [1, 2]. The current therapeutic treatment of epilepsy with modern antiepileptic drugs (AEDs) is associated with side-effects, dose-related and chronic toxicity, and teratogenic effects, and approximately 30% of the patients continue to have seizures with current AEDs therapy [1, 3].
Natural products from folk remedies have contributed significantly in the discovery of modern drugs and can be an alternative source for the discovery of AEDs with novel structures and better safety and efficacy profiles . Now, various phytochemical and pharmacological studies have been carried out on these anticonvulsant plants . Moreover, the number of patients and medical practitioners in the industrialized world which use herbal medicines as a supplement to or substitute for prescription drugs are increased. Herbal medicines are often considered to be a gentle and safe alternative to synthetic drugs. More than half of the medically important pharmaceutical drugs are either natural products or derivatives of natural products [6–8]. In recent years, some experimental studies have indeed evaluated Medieval Iranian medical remedies using modern scientific methods. These studies raised the possibility of revival of traditional treatments on the basis of evidence-based medicine .
In Iran, several herbs have been used for anticonvulsant effects from ancient times . In Iran P. incarnata is prepared by Iran Darouk Pharmaceutical Co. as the form of tablet and drop with the name of Pasipay and is used in the case of nervous disorder, anxiety, insomnia, muscular tension.
The genus Passiflora consists of 500 species that are mostly found in warm and tropical regions. Passiflora comes from Latin word "Passio" that was first time discovered by Spanish discoverers in 1529 and was described as a symbol for "passion of Christ" [11, 12]. This plant was used widely in traditional medicine in West India, Mexico, Netherland, South America, Italia and Argentina for treatment of bronchitis, asthma, whooping cough, pneumonia and insomnia. It also has antianxiety, sedative, antispasmodic and mild anti-microbial effects that are known since long time . One of species of this genus named as Passiflora incarnata is more popular than its other species in Europe and in homeopathic medicine; it is used to treat insomnia and anxiety. Passiflora contains several compounds including alkaloids, phenols, glycosyl flavonoids and cyanogenic compounds . In the some experiments, it has potential effects for treatment of some diseases like as anxiety, insomnia, attention- deficit hyperactivity disorder, hypertension and cancer [13–18]. Also, recent study showed that leaves of it had anticonvulsant effects .
The effectiveness of Pasipay has been established in treating the physical symptoms of opioid withdrawal in human . But there was no report about the role of opioid system for CNS depressant effects of Passiflora species. Also, there were controversial reports about the role of GABAergic system for CNS effects of it [21, 22]. In this study we examined anticonvulsant effects of Pasipay using pentylenetetrazole (PTZ) induced seizure as petit mal epilepsy model in mice. It was predicted that Pasipay would show anticonvulsive effects in PTZ model, which may be due to several mechanism. Thus, we elucidated the possible mechanisms underlying the actions of Pasipay on the CNS and assessed the probable involvement of GABAergic and opioid system.