Phytochemical Profiling of Processed Açaí Pulp (Euterpe oleracea) Through Mass Spectrometry and Its Protective Effects Against Oxidative Stress in Cardiomyocytes and Rats

Abstract

The antioxidant capacity and modulation of oxidative stress by industrially processed açaí pulp extract from the Amazon (APEA) and its major anthocyanins, cyanidin 3-glucoside (C3G) and cyanidin-3-O-rutinoside (C3R), were evaluated as potential strategies for preventing cardiovascular diseases. The APEA was chemically characterized using ultrafast liquid chromatography-mass spectrometry (UFLC-MS), which revealed six main phenolic compounds. Notably, 9-(2,3-dihydroxypropoxy)-9-oxononanoic acid, acanthoside B, roseoside, cinchonine, and nonanedioate were identified for the first time in açaí extracts. In vitro antioxidant assays demonstrated that APEA exhibited strong DPPH- and ABTS-radical-scavenging activities (up to 80% inhibition and 65 mmol TE/100g DW, respectively) and showed ferrous- and copper-ion-chelating activities comparable to those of EDTA-Na₂ at higher concentrations (up to 95% inhibition). Hydroxyl and superoxide radical scavenging activities reached 80% inhibition, similar to that of ascorbic acid. In H₂O₂-treated H9c2 cardiomyocytes, APEA significantly reduced the intracellular ROS levels by 46.9%, comparable to the effect of N-acetylcysteine. APEA also attenuated menadione-induced oxidative stress in H9c2 cells, as shown by a significant reduction in CellROX fluorescence (p < 0.05). In vivo, APEA (100 mg/kg) significantly reduced CCl-induced hepatic lipid peroxidation (MDA levels), restored glutathione (GSH), and increased the antioxidant enzymes CAT, GPx, and SOD, demonstrating superior effects to C3G and C3R, especially after 21 days of treatment (p < 0.001). These findings suggest that Amazonian açaí pulp (APEA) retains potent antioxidant activity after industrial processing, with protective effects against oxidative damage in cardiomyocytes and hepatic tissue, highlighting its potential as a functional food ingredient with cardioprotective and hepatoprotective properties.

Keywords: Amazon (Brazil); Euterpe oleracea Mart.; antioxidant properties; açaí pulp; cardiovascular diseases; oxidative stress.

Figure 1

LC–MS/MS fingerprint of açaí pulp extract from the Amazon (APEA) in positive mode. (A) total ion chromatogram. (B) phytochemical profile of APEA. The comparison between library GNPS and query spectra of phytocomponents identified in Açai Pulp via LC-MS/MS analyses can be visualized in the Supplementary Materials.

Figure 2

LC–MS/MS fingerprint of açaí pulp extract from the Amazon (APEA) in negative mode. (A) total ion chromatogram. (B) phytochemical profile of APEA. The comparison between library GNPS and query spectra of phytocomponents identified in açai pulp via LC-MS/MS analyses can be visualized in Supplementary Materials.

Figure 3

Antioxidant capacity of açaí pulp extract from the Amazon (APEA), cyanidin 3-glucoside (C3G), and cyandin-3-O-rutenoside (C3R). DPPH-free-radical scavenging activity (A); ABTS-scavenging activity (B); ferrous-ion-chelating activity (C); copper-ion-chelating activity (D); hydroxyl-radical-scavenging activity (E); and superoxide-radical-scavenging activity (F). Data represent the mean ± S.E.M. from three independent experiments. One-way ANOVA followed by the post hoc Tukey’s test. * p < 0.05 between the concentrations of samples [25, 50, and 100 μg/mL vs. 5 and 10 μg/mL]; ** p < 0.05 vs. the control group (EDTA-Na2 and ascorbic acid as an standards).

Figure 4

Cytotoxic effects of açaí pulp extract from the Amazon (APEA), cyanidin 3-glucoside (C3G), and cyandin-3-O-rutenoside (C3R) on the H9c2 cardiomyocyte cells line. Cell viability measured via MTT and Alamar Blue assays. DMEM culture medium was used as a negative control for cytotoxicity.

Figure 5

Micrograph of H9c2 cardiomyocyte cells treated with açaí pulp extract from the Amazon (APEA), cyanidin 3-glucoside (C3G), and cyandin-3-O-rutenoside (C3R). H9c2 cardiomyocyte cells were incubated with 100 µg/mL APEA, C3G, and C3R 24 h and labeled with DAPI to show the nuclear morphology. Control H9c2 cardiomyocyte cells without samples [negative control] (A,B); H9c2 cardiomyocyte cells showing no nuclear morphological changes, such as pyknosis and fragmentation, treated with APEA (C,D); H9c2 cardiomyocyte cells treated with C3G showing few signs of nuclear morphological changes (arrows) (E,F); H9c2 cardiomyocyte cells treated with C3R showing few signs of nuclear morphological changes (arrows) (G,H). (A,C,E,G) are micrographs seen with a 20× objective lens; (B,D,F,H) are micrographs seen with a 40× objective lens.

Figure 6

Intracellular reactive oxygen species (ROS) generation in the H₂O₂ and/or açaí pulp extract from the Amazon (APEA), cyanidin 3-glucoside (C3G), and cy-andin-3-O-rutenoside (C3R)-treated H9c2 cardiomyocyte cells. Data represent the mean ± S.E.M. from three independent experiments. One-way ANOVA followed by the post hoc Tukey’s test. * Difference between hydrogen peroxide and untreated group; ** difference between N-acetylcysteine and hydrogen peroxide; *** difference between samples and hydrogen peroxide.

Figure 7

K3-induced oxidative stress in H9c2 cardiomyocyts cells with the CellROX^TM fluorescence assay. Açaí pulp extract from the Amazon (APEA), cyanidin 3-glucoside (C3G), and cyandin-3-O-rutenoside (C3R). Data represent the mean ± S.E.M. from three independent experiments. One-way ANOVA followed by the post hoc Tukey’s test. * Difference between K3 and untreated group, ** difference between N-acetylcysteine and K3, and *** difference between samples and K3.