Metal chelation, radical scavenging and inhibition of Aβ42 fibrillation by food constituents in relation to Alzheimer's disease. (15th May 2016)

• Record Type: Journal Article
• Authors: Chan, Stephen; Kantham, Srinivas; Rao, Venkatesan M.; Palanivelu, Manoj Kumar; Pham, Hoang L.; Shaw, P. Nicholas; McGeary, Ross P.; Ross, Benjamin P.
• Is Part Of: Food chemistry. Volume 199(2016)
• Page Start: 185
• Page End: 194
• Publication Date: 2016-05-15
• Subjects: l-Ascorbic acid (PubChem CID: 54670067) -- Caffeic acid (PubChem CID: 689043) -- Caffeine (PubChem CID: 2519) -- Curcumin (PubChem CID: 969516) -- (−)-Epigallocatechin gallate (PubChem CID: 65064) -- Gallamide (PubChem CID: 69256) -- Gallic acid (PubChem CID: 370) -- Propyl gallate (PubChem CID: 4947) -- Resveratrol (PubChem CID: 445154) -- α-Tocopherol (PubChem CID: 14985); Polyphenols -- Vitamins -- Metal chelators -- Antioxidants -- Amyloid-beta peptide; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2015.11.118
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Studied 9 compounds as chelators, antioxidants, and Aβ fibrillation inhibitors. Developed an assay using 5-Br-PAPS to examine the complexation of Zn(II) and Cu(II). SPLET is the prevailing mechanism of radical scavenging by the polyphenols. Gallic acid, EGCG, and curcumin are multifunctional agents. l -Ascorbic acid and α-tocopherol are potent antioxidants but not multifunctional. Abstract: 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 antioxidantsl -ascorbic acid and α-tocopherol, with better brain uptake, deserve further investigation for specifically addressing oxidative stress within the AD brain.