Effects of Hyssopus Officinalis Hydroalcoholic Extract on Pentylenetetrazol-Induced Convulsive Seizures in Rat.

Hyssopus officinalis L. is one of the most important medicinal plants in traditional medicine used to treat seizures. In this study, we assessed the effects of H. officinalis hydroalcoholic extract against pentylenetetrazol (PTZ)-induced seizures in rat. The anti-seizure activity of the extract was assessed in three doses of 25, 50, and 100 mg/kg. Kindling was induced by intraperitoneal injection of PTZ (35 mg/kg) every 48 h, and H. officinalis extract was administered daily and behavioral tests performed. The possible involvement of GABA receptors in the extract activity was investigated using flumazenil. Tonic seizure threshold and mortality rate were measured following intraperitoneal injection of 60 mg/kg PTZ on the 14th day, following 14 days administration of H. officinalis hydroalcoholic extract. Blood and hippocampus samples were prepared to measure brain and serum antioxidant capacity, malondialdehyde (MDA), and nitric oxide (NO). Finally, the expression of GABA receptor gene in brain tissue was investigated. H. officinalis extract increased tonic seizure threshold and decreased mortality due to PTZ. Flumazenil, as a GABA receptor antagonist, reduced the tonic seizure threshold. Extract treatment significantly improved memory and learning, increased brain antioxidant capacity, decreased brain MDA and NO in kindled rats. It also increased GABA receptor gene expression in pre-treated groups compared to the negative control group. H. officinalis extract probably exerts potential antiepileptic effects through the GABAergic system. Also, H. officinalis extract has a supportive effect against hippocampal neuronal damage and improves memory and learning in kindled rats. [ABSTRACT FROM AUTHOR]