Neuroprotective Role of Natural Polyphenols

Abstract

Neurodegenerative diseases cause a progressive functional alteration of neuronal systems, resulting in a state of dementia which is considered one of the most common psychiatric disorders of the elderly. Dementia implies an irreversible impairment of intellect that increases with age causing alteration of memory, language and behavioral problems. The most common form, which occurs in more than half of all cases, is Alzheimer's disease, characterized by accumulation of amyloid plaques and neurofibrillary tangles. Neuroinflammation and oxidative stresses have been considered as a hallmark of Alzheimer disease, playing a crucial role in neurotoxicity. For this reason, an adequate antioxidant strategy may improve the treatment of neurodegenerative diseases and dementia. Several studies support the neuroprotective abilities of polyphenolic compounds resulting in neuronal protection against injury induced by neurotoxins, ability to suppress neuroinflammation and the potential to promote memory, learning and cognitive functions. We critically reviewed here the therapeutic potential of pure herbal compounds (e.g., green tea polyphenol (-)- epigallocatechin-3-gallate, resveratrol, curcumin, quercetin and others) and extracts enriched in polyphenols showing the most promising neuroprotective effects. We are also presenting data on the ability of an extract derived from elderberry, Sambucus nigra, possessing elevated polyphenolic content and antioxidant capacity to protect neuronal cells against oxidizing agents.

Protective Effects of Indian Spice Curcumin Against Amyloid-β in Alzheimer’s Disease

“…Physical exercise and healthy diets have been reported to have implications to delay disease progression of Alzheimer’s disease (AD) in elderly individuals and improved cognitive functions in subjects with mild cognitive impairment and early AD patients [3, 4]. There are a large number of natural products and herbs currently available, including curcumin, green tea and vitamin C, vitamin E, beta carotene, Gingko Biloba, Ginseng, Rosemary, Sage, and many others [1–3].…”

Comparison of the Neuroprotective and Anti‐Inflammatory Effects of the Anthocyanin Metabolites, Protocatechuic Acid and 4‐Hydroxybenzoic Acid

“…In this regard, polyphenols have emerged as promising therapeutic candidates due to their impressive antioxidant, antineuroinflammatory, and antiapoptotic effects (reviewed by [7]). In particular, anthocyanins, a unique class of flavonoid compounds, show significant potential as a treatment for neurodegenerative disease for these reasons in addition to the observation that they are among the most commonly consumed polyphenolic species around the world [8].…”

Chicoric acid supplementation prevents systemic inflammation‐induced memory impairment and amyloidogenesis via inhibition of NF‐κB

“…It has been reported that natural phytochemicals, such as resveratrol, curcumin, apigenin, and epigallocatechin gallate, could suppress LPS‐induced neuroinflammation and amyloidogenesis, and thus improve learning and memory impairment (11). Chicoric acid (CA), a caffeic acid derivative, existing extensively in echinacea (also known as purple coneflower; Echinacea purpurea ), chicory, lettuce, dandelion, and other edible plants and vegetables, has been regarded as a nutraceutical that has powerful antioxidant, anti‐HIV, and antiobesity activities (12, 13).…”