Recent Progress in Research on Mechanisms of Action of Natural Products against Alzheimer’s Disease: Dietary Plant Polyphenols

Abstract

Alzheimer’s disease (AD) is an incurable degenerative disease of the central nervous system and the most common type of dementia in the elderly. Despite years of extensive research efforts, our understanding of the etiology and pathogenesis of AD is still highly limited. Nevertheless, several hypotheses related to risk factors for AD have been proposed. Moreover, plant-derived dietary polyphenols were also shown to exert protective effects against neurodegenerative diseases such as AD. In this review, we summarize the regulatory effects of the most well-known plant-derived dietary polyphenols on several AD-related molecular mechanisms, such as amelioration of oxidative stress injury, inhibition of aberrant glial cell activation to alleviate neuroinflammation, inhibition of the generation and promotion of the clearance of toxic amyloid-β (Aβ) plaques, inhibition of cholinesterase enzyme activity, and increase in acetylcholine levels in the brain. We also discuss the issue of bioavailability and the potential for improvement in this regard. This review is expected to encourage further research on the role of natural dietary plant polyphenols in the treatment of AD.

Proanthocyanidins-Rich Fraction of Tamarindus Indica Maintained Redox Status of Environmental Toxicant-Induced Genotoxicity in Drosophila Melanogaster

“…However, pretreatment of the flies with proanthocyanidins-rich fraction did not stop the upregulation of AChE gene due to exposure to a noxious environment. This contradicts findings reported by [14], where phenolics such as curcumin appeared to upregulate the expression level of AChE in fruit flies. The variation in our findings may be due to genetic diversity and other factors, such as nutritional and environmental factors [15,16] within the fruit flies' population that could influence gene expression.…”

Editorial: The role of natural products in neurological disorders

“…These mainly plant-based diets are rich in polyphenols, commonly found in extra virgin olive oil (EVOO), vegetables, and fruits such as grapes, blueberries, and apples, in addition to tea and red wine. Polyphenols have diverse and complex structures and are mostly found in glycosidic forms in plants ( 7 ). The main food group in Medi is EVOO.…”