Effect of curcumin on passive avoidance learning disorders induced by seizure activity under chronic restraint stress in rats

Abstract

Objective: As a major pigment of the rhizome of the curcuma longa, curcumin has several physiologic effects. It is known that repeated stress increases seizure probability in epileptic patients resulting in cognitive disorders. We have been reported the effect of chronic (for fourteen consecutive days) or acute intraperitoneal administration of 20 mg/kg body weight on pentylenetetrazole (PTZ)-seizure in male rats, which were hold under restraint stress two h per day for fourteen days. Methods: Investigating passive avoidance learning, 24 hours later, animals were tested in shuttle-box apparatus, and their step through latencies (STL) were recorded. Results: PTZ induced seizure or exposure to the stress per se, resulted in passive avoidance learning deficit. Stress also decreased the STL of PTZ treated animals significantly (P<0.05). Daily chronic prescription of curcumin, regardless presence or absence of stress, significantly reduced the seizure severity and improved learning ability (p<0.05). However, acute application of curcumin had no any significant effect. Conclusion: The results show that only chronic application of the curcumin can effectively inhibit resulting learning disorders under chronic stress situation.