In the study, published online ahead of print in the Journal of Agriculture and Food Chemistry, researchers pre-treated mouse BV-2 microglial cells (a type of immune cell in the brain that protects neurons from oxidative stress and inflammation) with açai pulp fractions.
Under a highly activated state caused by stressors such as lipopolysaccharide (LPS), said the authors, “these cells produce inflammatory molecules such as cytokines, superoxide, and nitric oxide, ultimately leading to a cascade of pro-inflammatory proteins, in turn leading to the death of neurons.”
Pre-treatment of microglial cells with açai pulp had significant effect on pro-inflammatory markers
But pre-treatment with the açai pulp fractions “significantly attenuated” the lipopolysaccharide (LPS)-induced production of these inflammatory molecules, they found.
“The results from the current study suggest that pretreatment of BV-2 microglial cells with the individual açai pulp fractions was protective against LPS-induced NO release, iNOS production, COX-2 expression, NF-κB phosphorylation, TNFα release, and p38-MAPK activation.”
They added: “Pretreatment of microglial cells with acai pulp significantly attenuated the production of reactive nitrogen species as well as expression of proinflammatory mediator proteins.”
The results suggest that consumption of açai pulp “may contribute to ‘health span’ in aging, as it is able to combat some of the inflammatory and oxidative mediators of aging at the cellular level”, they concluded.
However, in order to determine if açai fruit is able to reverse or allay age-related motor or cognitive deficits, experiments were being planned to feed aged rats açai-supplemented diets.
In the study, which was supported by the US Department of Agriculture (USDA) Intramural grants and contract research organization AIBMR Life Sciences, the researchers used pasteurized, freeze-dried açai pulp. Polyphenols from the pulp were then fractionated with solvents.
BV-2 murine microglial cells, which were plated on 12-well plates for immunohistochemical analysis, were then pre-treated with either açai extract diluted in media or control media for four hours and then stimulated with lipopolysaccharide (LPS) at 100ng/mL overnight.
With the appearance of a purple grape and taste of a tropical berry, Açai berries (pronounced ah-sigh-ee) have been shown to have powerful antioxidant properties thanks to a high level of anthocyanins, pigments that are also present in red wine.
In vitro studies have showed that açai extracts, as well as individual flavonoids of açai, exhibit potent anti-inflammatory, anti-carcinogenic, antioxidant, and certain neuro-protective properties.
Human studies have also suggested the fruit can increase cellular protection from reactive oxygen species and address joint pain perception
However, this is the first time their effect on brain cells and the signaling mechanisms involved in inter-neuronal communications has been examined.
Source: Journal of Agriculture and Food Chemistry, 2012 Jan 5, published online ahead of print
‘Anthocyanin-rich açai (Euterpe oleracea Mart.) fruit pulp fractions attenuate inflammatory stress signaling in mouse brain BV-2 microglial cells.’
Authors: Poulose SM, Fisher DR, Larson JA, Bielinski DF, Rimando AM, Carey AN, Schauss AG, Shukitt-Hale B.