Title: Anthocyanin-rich açaí (Euterpe oleracea Mart.) extract attenuates manganese-induced oxidative stress in rat primary astrocyte cultures.
Authors: da Silva Santos, Vivian; Bisen-Hersh, Emily; Yu, Yingchun; Cabral, Ingridy Simone Ribeiro; Nardini, Viviani; Culbreth, Megan; Teixeira da Rocha, João Batista; Barbosa Jr, Fernando; Aschner, Michael
Published In J Toxicol Environ Health A, (2014)
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.
PubMed ID: 24617543
MeSH Terms: Animals; Animals, Newborn; Anthocyanins/adverse effects; Anthocyanins/analysis; Anthocyanins/metabolism; Arecaceae*/chemistry; Astrocytes*/cytology; Astrocytes*/drug effects; Astrocytes*/metabolism; Biological Transport/drug effects; Brazil; Cells, Cultured; Cerebral Cortex/cytology; Cerebral Cortex/drug effects; Cerebral Cortex/metabolism; Dietary Supplements*/adverse effects; Dietary Supplements*/analysis; Fruit/chemistry; Gene Expression Regulation/drug effects; Glutamic Acid/metabolism; Manganese Poisoning/diet therapy; Manganese Poisoning/prevention & control; Manganese*/adverse effects; Manganese*/chemistry; NF-E2-Related Factor 2/biosynthesis; NF-E2-Related Factor 2/metabolism; Nerve Tissue Proteins/biosynthesis; Nerve Tissue Proteins/metabolism; Neuroprotective Agents*/adverse effects; Neuroprotective Agents*/analysis; Neuroprotective Agents*/chemistry; Neuroprotective Agents*/metabolism; Oxidative Stress*/drug effects; Plant Extracts*/adverse effects; Plant Extracts*/chemistry; Plant Extracts*/metabolism; Rats; Rats, Sprague-Dawley