The Role of Selected Bioactive Compounds in the Prevention of Alzheimer’s Disease

Abstract

Neurodegeneration is a feature of many debilitating, incurable age-dependent diseases that affect the nervous system and represent a major threat to the health of elderly persons. Because of the ongoing process of aging experienced by modern societies, the increasing prevalence of neurodegenerative diseases is becoming a global public health concern. A major cause of age-related dementia is Alzheimer’s disease (AD). Currently, there are no effective therapies to slow, stop, or reverse the progression of this disease. However, many studies have suggested that modification of lifestyle factors, such as the introduction of an appropriate diet, can delay or prevent the onset of this disorder. Diet is currently considered to be a crucial factor in controlling health and protecting oneself against oxidative stress and chronic inflammation, and thus against chronic degenerative diseases. A large number of bioactive food compounds may influence the pathological mechanisms underlying AD. Among them, phenolic compounds, omega-3 fatty acids, fat-soluble vitamins, isothiocyanates, and carotenoids seem to be promising. They act not only as antioxidant and anti-inflammatory agents, but also as active modulators of the pathological molecular mechanisms that play a role in AD development, including the formation of amyloid plaques and tau tangles, the main hallmarks of AD pathology. In vivo animal model studies as well as clinical and epidemiological research suggest that nutritional intervention has a positive effect on the health of older people and may prevent age-related cognitive decline, especially when the diet contains more than one bioactive nutrient. The Mediterranean diet and in particular its combination with Dietary Approaches to Stop Hypertension, which is called the MIND diet, are nutritional patterns based on many products rich in bioactive compounds that appear to be the most effective in preventing neurodegeneration. The present review gathers evidence that supports the neuroprotective effect of bioactive substances.

The Sorbus spp.—Underutilised Plants for Foods and Nutraceuticals: Review on Polyphenolic Phytochemicals and Antioxidant Potential

“…It is evident that among phytochemicals and other nutrients, polyphenolic compounds and ascorbic acid may be considered as the most valuable health beneficial constituents, which have been reported in various anatomical parts of Sorbus spp. The polyphenolics, which may influence the colour and flavour, have demonstrated antioxidant [54,81], antidiabetic [11,82] anti-hyperlipidemic [83], anti-inflammatory [84], antimicrobial [85], anticancer [86,87] antiviral [67], antifungal [79], antitumoral [88], anti-periodontal [89], and anti-osteoarthritis [90] effects, as well as vasoprotective [84], neuroprotective [26,91,92], cardioprotective [36], hepatoprotective [7], properties and COX-2 (cyclooxygenase-2) inhibitory [93] activities. Many of these activities are correlated to antioxidant capacity of bioactive compounds, which at cellular level may neutralize excessive reactive oxygen species, and thereby protect important biomolecules in the conditions of oxidative stress, which can cause cellular injury and development of chronic diseases.…”

Biomaterials in Neurodegenerative Disorders: A Promising Therapeutic Approach

“…It consists in the accumulation of amyloid beta (Aβ) due to genetic defects (i.e., APP, presenilin 1, presenilin 2), environmental factors, and other stressors. These senile plaques induce an immune response, leading to inflammation, tau hyperphosphorylation, and its aggregation in tangles [12] that lead to neuron degeneration and death, and impairing neurotransmission in many brain regions [13].…”

Functional Foods: An Approach to Modulate Molecular Mechanisms of Alzheimer’s Disease

“…Observational studies, indirectly confirming the neuroprotective effects of olive oil, showed that MD is linked to a reduced risk of AD [178,188], independently from other factors such as sex, education or APOE gene allele. This diet has been promoted by researchers, clinicians and institutions as a model for healthy eating mainly because it provides a significant source of antioxidants [189].…”

“…Again by virtue of its antioxidant properties, it has neuroprotective potential; indeed it protects from neurodegenerative diseases such as AD and, more generally, dementias and Parkinson's disease, especially in combination with other active ingredients, such as lutein, astaxanthin and zeaxanthin [177]. Many studies show that free radical level and amyloid-induced mitochondrial dysfunction lowered [178] after LYC treatment. Recently, a study demonstrated that 8 weeks of LYC treatment reversed MDA increase and glutathione peroxidase decrease in serum of tau transgenic mice expressing P301L mutation [179][180][181].…”