Investigation of the neuroprotective and healing effect of kaempferol treatment in rats with Alzheimer disease model

Alzheimer's disease is the most common type of dementia worldwide. There is no known cure for this neurodegenerative disease whose prevalence continues to increase every year. The main factors that form the pathology of Alzheimer's disease can be listed as senile plaques, neurofibrillary tangles and neuroinflammation. Oxidative stress is one of the main factors involved in the formation and progression of these pathologies. Many treatment initiatives aim to alleviate the neuropathogenesis of the disease and increase cognitive function. For this purpose, many herbal products and their active ingredients are used by researchers. Kaempferol is a flavonoid with anti-inflammatory and antioxidant properties produced as a secondary metabolite in many plants. Kaempferol's ability to reduce oxidative stress makes this molecule important in Alzheimer's disease studies. In this thesis study, firstly, streptozotocin (STZ) was injected intracerebroventricularly to Long-Evans male rats for modelling Alzheimer's disease. Kaempferol, an anti-neuroinflammatory agent, was administered intraperitoneally to the rats. At the end of the treatment, the neuroprotective effect of kaempferol was examined by conducting behavioral and molecular experiments. While kaempferol did not show a significant difference in the learning and memory test performed in the morris water maze, it made a significant difference between the groups in the passive avoidance test measuring fear-conditioned memory. However, while STZ injection did not show a significant change in PSEN level, it caused an increase in BACE and phosphorylated TAU levels. Interestingly, Kaempherol had no significant curative effect at the molecular level. These results show that kaempferol treatment has positive effects on memory loss which is one of the phenotypic features of Alzheimer's disease. For this reason, this study guides the future studies in terms of examining in detail the molecular bases of the healing effect of kaempherol in order to be a candidate molecule in the treatment of Alzheimer's disease. Keywords: Alzheimer's Disease, kaempferol, STZ, BACE1, p-TAU, PSEN