en Nervous system (others) Others Experimental research article Experimental research article Introduction: Olive leaf contains anti-inflammatory and COX-2 inhibitor compounds. Considering the role of the COX enzyme in seizures, this research was performed to assess the effects of this extract in treatment of seizures induced by PTZ. Methods: In this research, male Wistar rats (200±20 g) were injected intra-cerebroventricularly with 1 μl saline or olive leaf extract (125 μg, 250 μg and 500 μg), before the intraperitoneal administration of PTZ (80 mg/kg) for induction of seizure. Then, seizure score and onset times of every stage of seizure were recorded during 20 minutes after PTZ administration. The data was analyzed by one-way analysis of variance (ANOVA) and non parametric tests. Results: Result of this research showed that the injection of 125, 250 and 500 μg of olive leaf extract had no effect on the onset time of seizure stages 1, 2 and 3 compared to the control group (P>0.05). However, they significantly decreased the onset time of seizure stages 4 and 5 compared to the control group (P<0.05). On the other hand, olive leaf extract decreased onset time of generalized (tonic-clonic) seizures, but had no effect on partial seizures. Different doses of olive leaf extract had no effect on seizure scores. Conclusion: Olive leaf extract has convulsive property and this effect is time and dose dependent. Key words: Epilepsy, Olive-leaf extract, PTZ 108 115 http://ppj.phypha.ir/browse.php?a_code=A-10-304-4&slc_lang=en&sid=1 Morteza Zendehdel zendedel@ut.ac.ir 320031947532846008898 320031947532846008898 Yes Division of Physiology, Department of Basic Sciences, Faculty of Veterinary Medicine, Univercity of Tehran, Tehran, Iran Keyvan Keramati 320031947532846008899 320031947532846008899 No Department of Biology, Faculty of Basic Sciences, Islamic Azad University, Damghan Branch, Damghan, Iran Sedigheh Garavand 320031947532846008900 320031947532846008900 No Master Science of Physiology