title: Anthocyanin-rich açaí (Euterpe oleracea Mart.) extract attenuates manganese-induced oxidative stress in rat primary astrocyte cultures.
abstract: Manganese (Mn) is an essential element for human health. However, at high concentrations Mn may be neurotoxic. Mn accumulates in astrocytes, affecting their redox status. In view of the high antioxidant and anti-inflammatory properties of the exotic Brazilian fruit açaí (Euterpe oleracea Mart.), its methanolic extract was obtained by solid-phase extraction (SPE). This açaí extract showed considerable anthocyanins content and direct antioxidant capacity. The açaí extract scavenged 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH•) with an EC₅₀ of 19.1 ppm, showing higher antioxidant activity compared to butylated hydroxytoluene (BHT), but lower than ascorbic acid and quercetin. This obtained açaí extract also attenuated Mn-induced oxidative stress in primary cultured astrocytes. Specifically, the açaí extract at an optimal and nutritionally relevant concentration of 0.1 μg/ml prevented Mn-induced oxidative stress by (1) restoring GSH/GSSG ratio and net glutamate uptake, (2) protecting astrocytic membranes from lipid peroxidation, and (3) decreasing Mn-induced expression of erythroid 2-related factor (Nrf2) protein. A larger quantity of açaí extract exacerbated the effects of Mn on these parameters except with respect to lipid peroxidation assessed by means of F₂-isoprostanes. These studies indicate that at nutritionally relevant concentration, anthocyanins obtained from açaí protect astrocytes against Mn neurotoxicity, but at high concentrations, the "pro-oxidant" effects of its constituents likely prevail. Future studies may be profitably directed at potential protective effects of açaí anthocyanins in nutraceutical formulations.
authors.affiliation: a Department of Pediatrics , Vanderbilt University Medical Center , Nashville , Tennessee , USA.
authors.forename: Vivian
authors.initials: V
authors.lastname: da Silva Santos
authors.forename: Emily
authors.initials: E
authors.lastname: Bisen-Hersh
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Yu
authors.forename: Ingridy Simone Ribeiro
authors.initials: IS
authors.lastname: Cabral
authors.forename: Viviani
authors.initials: V
authors.lastname: Nardini
authors.forename: Megan
authors.initials: M
authors.lastname: Culbreth
authors.forename: João Batista
authors.initials: JB
authors.lastname: Teixeira da Rocha
authors.forename: Fernando
authors.initials: F
authors.lastname: Barbosa
authors.forename: Michael
authors.initials: M
authors.lastname: Aschner
mesh_terms: D000818:Animals; D051381:Rats; D000831:Animals, Newborn; D000872:Anthocyanins / Q000009:adverse effects / Q000032:analysis / Q000378:metabolism; D028023:Arecaceae / Q000737:chemistry; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D001692:Biological Transport / Q000187:drug effects; D001938:Brazil; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D019587:Dietary Supplements / Q000009:adverse effects / Q000032:analysis; D005638:Fruit / Q000737:chemistry; D005786:Gene Expression Regulation / Q000187:drug effects; D018698:Glutamic Acid / Q000378:metabolism; D008345:Manganese / Q000009:adverse effects / Q000737:chemistry; D020149:Manganese Poisoning / Q000178:diet therapy / Q000517:prevention & control; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000378:metabolism; D018696:Neuroprotective Agents / Q000009:adverse effects / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D010936:Plant Extracts / Q000009:adverse effects / Q000737:chemistry / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D051267:NF-E2-Related Factor 2 / Q000096:biosynthesis / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D018698:Glutamic Acid; D008345:Manganese; D009419:Nerve Tissue Proteins; D018696:Neuroprotective Agents; D010936:Plant Extracts; D051267:NF-E2-Related Factor 2