Uraemic toxin‐induced inflammation and oxidative stress in human endothelial cells: protective effect of polyphenol‐rich extract from açaí

Abstract

New Findings What is the central question of this study?Does a polyphenol‐rich extract from açaí have a potential role in preventing uraemic toxin‐induced endothelial cell dysfunction? What is the main finding and its importance?Polyphenols from açaí prevented cell death, restored migratory capacity, protected from inflammation and contributed to the restoration of the antioxidant response in endothelial cells exposed to uraemic toxins. The protective role of açaí against toxic effects exerted by uraemic toxins presents a potential new therapeutic target in endothelial cells. Abstract In chronic kidney disease (CKD), progressive loss of kidney function results in the accumulation of protein‐bound uraemic toxins such as p‐cresyl sulfate (pCS) and indoxyl sulfate (IS). Among strategies to ameliorate the harmful actions of uraemic toxins, phenolic compounds have been extensively studied. The main goal of this work was to evaluate the antioxidant and anti‐inflammatory actions of phenolic‐rich açaí seed extract (ASE) in response to endothelial dysfunction induced by IS and pCS, in human umbilical vein endothelial cells (HUVECs). Cells were treated with ASE (10 µg ml−1) in the presence or absence of IS (61 µg ml−1) and pCS (40 µg ml−1). Cell viability, cell death, cell migratory capacity and inflammatory biomarker expression were evaluated. Cellular antioxidant response was measured through the activity and expression of antioxidant enzymes, and oxidative damage was evaluated. IS and pCS lowered cell viability, triggered cell death and lowered the migratory capacity in endothelial cells (P < 0.05). ASE prevented cell death and restored the migratory capacity in cells exposed to IS. Both toxins up‐regulated pro‐inflammatory cytokine expression, and ASE was able to beneficially counteract this effect. Tumour necrosis factor‐α secretion was greater in uraemic toxin‐treated cells and ASE reversed this phenomenon in cells treated with both toxins concomitantly (P < 0.05). With regard to the antioxidant response, superoxide dismutase expression was strikingly lower in cells treated with both toxins, and ASE inhibited this harmful effect (P < 0.05). From the results, we conclude that ASE exerted protective effects on inflammation and oxidative stress caused by uraemic toxins (particularly by IS) in human endothelial cells.

Açaí (Euterpe oleracea Mart.) Seed Extracts from Different Varieties: A Source of Proanthocyanidins and Eco-Friendly Corrosion Inhibition Activity

“…The potential health benefits attributed to açaí seed extracts [ 29 , 30 , 31 ] highlight how critical comprehensive chemical characterization is. Research on the seed extract’s new biological effects is associated with its composition, thus adding value to this residue.…”

“…The HPLC (Perkin-Elmer Flexar) was equipped with a LC column oven, LC autosampler, quaternary LC pump, solvent manager, PDA, FLD detectors, and Chromera-Flexar software. A previously published protocol was followed [ 31 ], where samples were prepared by dissolving 1.0 mg of crude extract in acetonitrile/water 1:1 to 1.0 mg/mL and filtering through 0.22 µm PTFE filters. Aliquots of 10 µL were injected in a Merck LiChrospher ® 100 diol column (250 × 4.6 mm, 5 µm) with a LiChroCART guard column of the same material.…”

Diabetic kidney disease in type 2 diabetes: a review of pathogenic mechanisms, patient-related factors and therapeutic options

“…Hyperglycaemia impairs NO production and bioavailability in renal ECs, resulting in increased oxidative stress, promoting endothelial dysfunction and injury (Alpert et al, 2005). Consequently, the injured ECs may act as active signal transducers of inflammatory (IL-1, TNF-α), metabolic and hemodynamic factors (TGF-β) that modify the morphology and function of the vessel walls, potentially activating proliferative and inflammatory responses in DKD (Monteiro et al, 2020;Nakagawa et al, 2004). There are studies evaluating the potential for regenerative medicine as a strategy for EC regenerative therapy in DKD, however further research is required to determine the efficacy and safety in humans (Bassi et al, 2012;Ikarashi et al, 2005).…”

Curcumin enhances p-cresyl sulfate-induced cytotoxic effects on renal tubular cells

“…Indoxyl sulfate (IS) and p-cresyl sulfate (PCS), protein-bound organic compounds, are the most well-known uremic toxins in the world and both of them are not removed efficiently by hemodialysis [4,5]. The uremic toxins can induce oxidative stress and inflammation resulting in cell senescence and death on renal tubular epithelial cells [6][7][8]. However, the mechanisms of uremic toxins-induced cytotoxicity and the different cytotoxic effects of IS and PCS remain to be studied.…”