Essential Oils from Olea europaea and Cyperus esculentus Exhibit Promising Therapeutic Effect against Alzheimer's Disease in a Rat Model

Background: Alzheimer's disease poses a major challenge as a widespread and fatal neurodegenerative disorder, primarily affecting the elderly population worldwide. Objective: This study aimed to assess the potential protective and therapeutic effects of virgin olive oil and tiger nut essential oil on Alzheimer's dementia in male rats while also analyzing serum biomarker gene expression profiles in both Alzheimer's and control groups. Methods: Rats were fed basal diets supplemented with 5% virgin olive oil or tiger nut essential oil, along with high-fat meals containing trans fats, butter (25%), margarine (25%), and hydrogenated shorten oils (25%) to evaluate lipid profiles and serum biomarkers. Gene expression analysis revealed a significant upregulation of acetylcholinesterase, P53, BCL2, Mouse ICAM-1, PSEN, and BACE genes in the Alzheimer's disease group compared to controls. Real-time PCR analysis also identified inflammatory biomarkers and Alzheimer's disease-associated risk factors in high-fat diet-treated, virgin olive oil-treated, and control samples. Results: The study found significant correlations between serum biomarker levels, lipid profiles, and dietary treatments. The activities of acetylcholinesterase, glutathione, catalase, and superoxide dismutase differed notably between virgin olive oil and tiger nut essential oil treatments. High-fat dietary treatments resulted in substantial increases in serum lipid profiles due to trans-fat intake compared to the control group. Overall, both virgin olive oil and tiger nut essential oil demonstrated cognitive enhancement and potential therapeutic effects against Alzheimer's disease symptoms induced by trans-fat feeding, including inhibition of acetylcholines-terase activity, reduction of amyloid-beta accumulation, and mitigation of inflammation. Conclusion: The study suggests that serum biomarker gene expression profiles could serve as valuable indicators for differentiating between Alzheimer’s disease, virgin olive oil, and dietary treatments. Both virgin olive oil and tiger nut essential oil demonstrated protective effects, enhancing cognitive function and offering therapeutic potential against AD symptoms. These effects were achieved through the reduction of inflammation, the inhibition of AChE activity, and the reduction of amyloid-beta accumulation.