A Review: Natural Compounds as Anti-Alzheimer's Disease Agents

Background: Alzheimer's Disease (AD) is the most common form of dementia and age related neurodegenerative incurable disease, distinguished by loss of memory and cognitive impairments. The etiology of this disease is still not well defined. However, the typical pathological features that affect AD patients are amyloid plaques (Aβ), increased oxidative stress, neurofibrillary tangles (NFT) in neurons; another very important feature is a deficit of acetylcholine due to hydrolysis by acetylcholinesterase (AChE). Since the past two decades, patients have been treated by AChE inhibitors only, but it is also important to consider the other features that are related to the onset of AD. Methods: In this context, the development of multitargeted drugs for AD is a challenge for many research groups. Exploring natural products (for example polyphenols, alkaloids and cannabinoid) that have shown antioxidative, anti-inflammatory, anti-amyloidogenic and anti-apoptotic activities is very important in the drug discovery to treat the AD. Results: Herein, the review demonstrated the summary of articles mainly, related to natural products that showed the inhibition activity for therapeutic targets and summarized the reported results from many research groups with structural illustration and influence of functional groups on inhibition studies. Conclusion: Hence, an updated review in this area could provide useful information for researchers working on this area, to develop potential novel drugs to treat the AD.