Effect of Royal Jelly (Rj) on Learning and Memory in Rats After Intracerebroventricular Injection of Streptozotocin (Icv-Stz)



Zamani Z¹ ; Reisi P² ; Alaei H³ ; Pilehvarian AA¹ ; Zamani Z¹ Show Affiliations
Source: Journal of Isfahan Medical School Published:2011

Abstract

Background: Alzheimer’s disease (AD) is a progressive and irreversible neuropsychiatric disorder of the brain. It is the leading cause of senile dementia, characterized by neuronal degeneration and cognitive deteriorations, especially in the elderly. Intracerebroventricular streptozotocin (ICV-STZ) injection in rats’ brain provides a relevant model to sporadic dementia of Alzheimer type. Royal Jelly is a viscous substance produced by the young worker honey bees of the species, Apis mellifera. Earlier studies showed that RJ induces neurogenesis and neuronal differentiation. There are no reports so far showing if RJ has good effects on Alzheimer disease; thus in this study, we examined effect of RJ on learning and memory in rats after intracerebroventricular injection of streptozotocin. Methods: Forty eight male Wistar rats, each weighing 300-350 g, were used in the present study. The animals were divided in to four equal groups: sham, sham-royal jelly, streptozotocin, and streptozotocin- royal jelly. STZ and STZ–RJ groups received a bilateral ICV injection of STZ (1.5 mg/kg). Two other groups underwent the same surgical procedures, but same volume of saline was injected instead of STZ. Groups of sham-RJ and STZ-RJ was feed RJ-food (3% w/w) (lyophilized royal jelly mixed with powdered regular food) for a period of 10 days and groups of sham and streptozotocin was feed regular rats food in the same time. Learning and memory was analyzed by Morris water maze test and passive avoidance learning test. Finding: The results comes from passive avoidance learning test showed that learning and memory indices were significantly impaired in streptozotocin group respect to sham group, but there was not any significant difference between sham and streptozotocin-royal jelly groups. Although royal jelly improved learning and memory indices in sham-RJ group, but these changes were not significant. Conclusion: Intracerebroventricular injection of streptozotocin (icv-STZ) was determined to cause adverse effects on learning and memory in rat. The administration of royal jelly to these animals alleviated the adverse effects of streptozotocin. The results of this research suggest that Royal Jelly may have good effect on prevent and attenuation of Alzheimer’s disease. © 2011, Isfahan University of Medical Sciences(IUMS). All rights reserved.