Study on the anticonvusant activity of thymoquinone, the major constituent of Nigella Sativa L.seeds, through intracerebroventricular injection

ABSTRACT

Thymoquinone, the major constituent of Nigella sativa seeds, is a biologically active compound, which possesses several pharmacological effects. The aim of the present study was to evaluate the anticonvulsant effect of thymoquinone through intracerebroventricular [i.c.v.] injection. The anticonvulsant effects of thymoquinone, the major constituent of Nigella sativa seeds, were investigated using pentylenetetrazole [PTZ]-induced seizure model. In PTZ-induced epileptic seizures, the i.c.v. injection of thymoquinone [200 and 400 mol] prolonged the onset and reduced the duration of tonic-clonic seizures. The protective effect of thymoquinone against lethality was 45% and 50% in the mentioned doses, respectively. In this study, flumazenil [1 nmol, i.c.v.] reversed the anticonvulsant activity of thymoquinone. Also, pretreatment with naloxone [10 mol, i.c.v.] antagonized the prolongation of tonic-clonic seizure latency, as well as reduction in seizure duration both induced by thymoquinone [200 mol, i.c.v.]. These results indicate that thymoquinone may possess anticonvulsant activity probably through an opioid receptor-mediated increase in GABAergic tone