Estimation of the Chelating Ability of an Extract from Aronia melanocarpa L. Berries and Its Main Polyphenolic Ingredients Towards Ions of Zinc and Copper

Abstract

Previously, we have revealed that prolonged administration of a polyphenol-rich 0.1% extract from the berries of Aronia melanocarpa L. (chokeberries) alone and under chronic exposure to cadmium influences the body status of zinc (Zn) and copper (Cu). The aim of this study was to evaluate, in an in vitro model, the chelating properties of the extract (0.05% and 0.1%) and its main polyphenolic ingredients (cyanidin 3-O-β-galactoside, chlorogenic acid, neochlorogenic acid, (+)-catechin, (−)-epicatechin, quercetin, and kaempferol) regarding divalent ions of Zn (Zn2+) and Cu (Cu2+) at pH reflecting physiological conditions at the gastrointestinal tract such as 2 (empty stomach), 5.5 (full stomach), and 8 (duodenum). The study has revealed that the extract from Aronia berries, as well as cyanidin 3-O-β-galactoside and quercetin, can bind Zn2+ and Cu2+, but only at pH 5.5. Moreover, kaempferol was able to chelate Zn2+ at pH 5.5; however, this ability was weaker than those of cyanidin 3-O-β-galactoside and quercetin. The ability of the chokeberry extract to chelate Zn2+ and Cu2+ may be explained, at least partially, by the presence of polyphenols such as anthocyanin derivatives of cyanidin and quercetin. The findings seem to suggest that Aronia products, used as supplements of a diet, should be consumed before meals, and particular attention should be paid to adequate intake of Zn and Cu under prolonged consumption of these products to avoid deficiency of both bioelements in the body due to their complexation by chokeberry ingredients in the lumen of the gastrointestinal tract.

The Impact of a Polyphenol-Rich Extract from the Berries of Aronia melanocarpa L. on Collagen Metabolism in the Liver: A Study in an In Vivo Model of Human Environmental Exposure to Cadmium

“…The independent action of AE may result from its high antioxidative potential and the ability to combat oxidative stress [3,12,13]; as a result, it prevents oxidative-mediated alteration in collagen expression and the concentrations of MMPs and TIMPs. The interactive action of the extract and Cd was mediated by the chelating properties of its ingredients [3,4,17]. Chelation of Cd 2+ by, first of all, polyphenols, as well as fiber (including pectins), decreases the absorption from the digestive tract and retention in the body of this element as well as, thereby, its accumulation in the liver [3,4,17].…”

“…The interactive action of the extract and Cd was mediated by the chelating properties of its ingredients [3,4,17]. Chelation of Cd 2+ by, first of all, polyphenols, as well as fiber (including pectins), decreases the absorption from the digestive tract and retention in the body of this element as well as, thereby, its accumulation in the liver [3,4,17]. Indeed, Cd concentration in this organ in the rats supplemented with AE during the treatment with this toxic metal was lower by 10-37% compared to those that only received Cd (Table S7).…”

“…Polyphenols are a wide group of natural compounds present in numerous food and medicinal plants [ 1 , 2 ]. These compounds are characterized by proven beneficial actions in organisms, such as antioxidative, anti-inflammatory, antiatherogenic, antidiabetic, and chelating properties [ 1 , 2 , 3 , 4 , 5 , 6 ]. Owing to this fact, the consumption of polyphenol-rich products is widely recommended, not only by nutritionists.…”

Evaluation of Antioxidant and Anti-Inflammatory Activity of Anthocyanin-Rich Water-Soluble Aronia Dry Extracts

“…In this work, we have prepared and studied the new water-soluble extract from chokeberry fruit pomace. Currently, manufacturers of plant extracts try to standardize the herbal products to the fixed concentrations of selected compounds [ 12 , 13 , 14 , 15 ]. The commonly accepted content of berry fruit extracts in the standardized products is equal to 25% of anthocyanins [ 12 ].…”

“…The cardioprotective, antidiabetic, anti-inflammatory, immunomodulatory, antibacterial, and anticancer properties of the chokeberry extracts have been also intensively studied [ 6 , 7 , 8 , 9 , 14 , 18 , 23 , 24 ]. Most of the health-promoting activities of aronia berries is owed to their high antioxidant activity.…”