Bioactivities of açaي (Euterpe precatoria Mart.) fruit pulp, superior antioxidant and anti-inflammatory properties to Euterpe oleracea Mart.

There are two predominant palm tree species producing edible fruit known as “açaí” found widely dispersed through the Amazon: Euterpe oleracea Mart. and Euterpe precatoria Mart. They differ from each other in terms of how the plants grow and their phytochemical composition. E. oleracea (EO) has received considerable attention as a “super fruit” because of its high antioxidant capacity, while studies on E. precatoria (EP) remain rare. In this study, the antioxidant and anti-inflammatory activities of EP fruit pulps were evaluated by different assays including a series of oxygen radical absorbance capacity (ORAC) based assays, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, the cell-based antioxidant protection in erythrocyte (CAP-e) assay, as well as the nuclear factor-kappa B (NF-κB) secreted embryonic alkaline phosphatase (SEAP) assay. Total phenolics were also measured as an indication of the total phenol content. For comparative purposes, the EO fruit pulp was included. The antioxidant capacity of the EP fruit pulp was determined to be superior to the EO fruit pulp in every chemical based assay. In the cell-based CAP-e assay, the EP fruit pulp showed a dose-dependent inhibition against oxidative damage with an IC50 of 0.167 g/l. In the SEAP reporter assay, the EP fruit pulp polyphenol-rich extracts inhibited lipopolysaccharide (LPS)-induced NF-κB activation by 23% (p < 0.05) at 20 μg/ml, whereas the extract of the EO fruit pulp did not show a significant inhibitory effect at comparable doses. In addition, carotenoids were quantified for the first time in EP, since EP has high scavenging capacity against singlet oxygen.