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.

Açaí is a fruit from the Brazilian Amazon region, with an exotic flavor, possessing high antioxidant and anti-inflammatory properties. Based on these properties, the fruit is classified as one of the new “super fruits.” The mean daily consumption of açai pulp may reach 300 ml in several Brazilian regions. Further, this fruit is also gaining popularity in Europe and North America. In this context, the aim of this study was to assess the levels of some essential minerals in freeze-dried açaí pulp obtained in different Brazilian locations. It was found that açaí pulp is rich in essential minerals (Ca, Fe, Mg, Zn), but the levels of copper (Cu) and especially manganese (Mn) are surprisingly markedly higher than the traditional sources of these elements in the human diet. A daily consumption of 300 ml açaí pulp leads to a Mn daily intake exceeding at least sixfold (14.6 mg on average) the reference daily intake for an adult. Consequently, Mn intake may surpass the permitted daily maximum intake of 11 mg, which leads to a special concern, particularly for children, vegetarians, and individuals with anemia, since iron (Fe) absorption is impaired by Mn. Our findings demonstrate that this fruit is a potential source of several nutrients and a good dietary supplement to resolve malnutrition problems. However, due to the expressive levels of Mn, further studies are necessary to evaluate potential adverse effects associated with açaí consumption.