Evaluation of changes in interleukin 33 in Alzheimer's disease model and changes caused by propolis treatment on brain tissue of rats

Background: Alzheimer's disease is described as a structural and functional disorder of the human brain and its prevalence is increasing among middle-aged communities. Inflammation is one of the most important key factors in the development of Alzheimer's. IL-33, as a multifunctional cytokine, can play a significant role in Alzheimer's-induced inflammation. This study was performed to evaluate the anti-inflammatory properties of propolis On IL-33 gene expression. It is also designed to observe its effect on memory and learning in groups of laboratory rats. Methods To evaluate the learning and movement ability of the animals the passive avoidance learning, and locomotion tests were carried out after injection of scopolamine and propolis in third and fourth groups. Then, the morphologic changes and density of survival neurons counting have been assessed using histopathological analysis and following on, Real-Time PCR was applied to investigate the anti-inflammatory effect of propolis on the expression level of IL-33 mRNA in samples. Results Our study showed the treatment of animals using propolis led to an increase in learning and movement ability compared to the Alzheimer group. Besides, the histopathological evaluation demonstrated that the number of survival neurons were significantly more than Alzheimer group in hippocampal CA1 area, although the existing lesions was similar in both groups. The treatment of animals by propolis also resulted in a considerable increase in the expression of IL-33 in comparison with other groups. Conclusion In general, it seems that the application of propolis, as an anti-inflammatory compound, could be considered as a remarkable impact on Alzheimer improvement by both accelerations of IL-33 expression and learning ability. However further studies are needed to determine the exact mechanism and efficacy of this agent for the people suffer from Alzheimer.