Various food constituents have been proposed as disease-modifying agents for Alzheimer's disease (AD), due to epidemiological evidence of their beneficial effects, and for their ability to ameliorate factors linked to AD pathogenesis, namely by: chelating iron, copper and zinc; scavenging reactive oxygen species; and suppressing the fibrillation of amyloid-beta peptide (Aβ). In this study, nine different food constituents (l-ascorbic acid, caffeic acid, caffeine, curcumin, (-)-epigallocatechin gallate (EGCG), gallic acid, propyl gallate, resveratrol, and α-tocopherol) were investigated for their effects on the above factors, using metal chelation assays, antioxidant assays, and assays of Aβ42 fibrillation. An assay method was developed using 5-Br-PAPS to examine the complexation of Zn(II) and Cu(II). EGCG, gallic acid, and curcumin were identified as a multifunctional compounds, however their poor brain uptake might limit their therapeutic effects. The antioxidants l-ascorbic acid and α-tocopherol, with better brain uptake, deserve further investigation for specifically addressing oxidative stress within the AD brain.
Keywords: (−)-Epigallocatechin gallate (PubChem CID: 65064); Amyloid-beta peptide; Antioxidants; Caffeic acid (PubChem CID: 689043); Caffeine (PubChem CID: 2519); Curcumin (PubChem CID: 969516); Gallamide (PubChem CID: 69256); Gallic acid (PubChem CID: 370); Metal chelators; Polyphenols; Propyl gallate (PubChem CID: 4947); Resveratrol (PubChem CID: 445154); Vitamins; l-Ascorbic acid (PubChem CID: 54670067); α-Tocopherol (PubChem CID: 14985).
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