Intensified convulsions induced through intravenous infusion of PTZ by Nepeta menthoides hydroalcoholic extract in mice

Background and Objective: Repeated application of Ustukhuddoos has been recommended for a long time in Iranian traditional medicine for some of nervous disorders like epilepsy. In Iran, both imported Lavandula officinalis and endemic Nepeta menthoides are commonly known as Ustukhuddoos. Despite of some reports about antiepileptic and antioxidant effects of Lavandula officinalis, there is no available report for this effect of Nepeta menthoides. Therefore, this study was designed to investigate the anti-epileptic and antioxidant activity of Nepeta menthoides extract on timed intravenous pentylenetetrazol infusion seizure in mice model.

Materials and Methods: A convulsive model that utilizes timed intravenous infusions of pentylenetetrazol (PTZ) was developed to study anticonvulsant and antioxidant effect of ten days Nepeta menthoides pretreatment in mice. PTZ was infused through an indwelling tail vein catheter, and the threshold dose of PTZ was determined from the time needed to produce clonic convulsions, the body weight of the animal, and the rate of infusion of PTZ. Diazepam (Diaz), a major antiepileptic drug, was also tested for comparison.

Results: Versus diazepam, Nepeta menthoides did not show antiepileptic properties because of not only it did not increase threshold dose of PTZ but also significantly decreased it at some doses (p < 0.05). It means Nepeta menthoides significantly increased susceptibility to seizures. Nepeta menthoides also significantly increased brain nitric oxide (NO) level in comparison with control group (p < 0.05) and it was ineffective on MDA level.

Conclusion: This study reported that Nepeta menthoides not only did not prevent seizures, but also increased susceptibility to seizures. Also, due to an increase in NO by Nepeta, nitric oxide may be a progenitor agent for epilepsy.