The Interaction of Dietary Pectin, Inulin, and Psyllium with Copper Nanoparticle Induced Changes to the Cardiovascular System

Abstract

We aimed to analyze how supplementation with a standard (recommended, 6.5 mg/kg) or enhanced (two-times higher, 13 mg/kg) dose of copper (Cu), in the form of nanoparticles (NPs) along with dietary intervention via the implementation of diverse types of fiber, affects the cardiovascular system in rats. Nine-week-old male Wistar Han rats (n/group = 10) received, for an additional 6 weeks, a controlled diet with cellulose as dietary fiber and ionic Cu (in the form of carbonate salt). The experimental groups received cellulose, pectin, inulin, and psyllium as dietary fiber, together with CuNPs (6.5 or 13 mg/kg diet). After the experimental feeding, samples of blood, hearts, and thoracic arteries were collected for further analysis. Compared to pectin, and under a standard dose of CuNPs, inulin and psyllium beneficially increased the antioxidant capacity of lipid- and water-soluble compounds in the blood, and decreased heart malondialdehyde. Moreover, pectin decreased heart catalase (CAT) and cyclooxygenase (COX)-2 in the aortic rings compared to inulin and psyllium under standard and enhanced doses of copper. When the dose of CuNPs was enhanced, inulin and psyllium potentiated vasodilation to acetylcholine by up-regulation of COX-2-derived vasodilator prostanoids compared to both cellulose and pectin, and this was modulated with selective inducible nitric oxide synthase (iNOS) inhibitor for psyllium only. Moreover, inulin decreased heart CAT compared to psyllium. Our results suggest that supplementation with dietary fiber may protect the vascular system against potentially harmful metal NPs by modulating the antioxidant mechanisms.

The Effect of an Elevated Dietary Copper Level on the Vascular Contractility and Oxidative Stress in Middle-Aged Rats

“…The solvent concentration was of less than 0.01% ( v / v ). These solutions were stored at −20 °C, and appropriate dilutions were made in Krebs–Henseleit solution (KH in mM: NaCl 115; CaCl 2 2.5; KCl 4.6; KH 2 PO 4 1.2; MgSO 4 1.2; NaHCO 3 25; glucose 11.1) on the day of the experiment [ 13 ]. Copper carbonate of ≥99% purity was obtained from Poch (Gliwice, Poland).…”

“…Aortic rings were mounted in 5 mL chambers (Graz, Barcelona, Spain) under a pre-load tension of 1 g (FT20, TAM-A, Hugo Sachs Elektronik, March, Germany) as previously described [ 13 ]. High KCl (75 mM) and acetylcholine (10 µM) were used to check the functional integrity of aortic rings.…”

“…Further, aortic rings were preincubated for 30 min with either the EP and DP receptor antagonist (AH-6809, 30 µM), the selective FP receptor antagonist (AL-8810, 10 µM), the selective cyclooxygenase-2 (COX-2) inhibitor (NS-398, 10 µM), the prostacyclin (PGI 2 ) synthesis inhibitor (tranylcypromine, 10 µM) and contracted with noradrenaline (0.1 µM). The cumulative concentrations (CCs) of acetylcholine (0.1 nM–10 µM) were added into the incubation chambers to analyze vasodilatory response [ 13 ].…”

“…The Langendorff system with the ISOHEART software 73-0161 (Hugo Sachs Elektronik, March, Germany) was used for isolated heart studies as previously described [ 13 ].…”

“…For additional 8 weeks, rats were supplemented with diet A (Group A) and diet B (Group B). † —refers to 35 g of mineral mixture, ‡ —refers to 630 mg/kg of micro mineral mixture, * Mineral mixture composition, ** Micro mineral mixture composition.The rats were housed as previously described [ 13 ]. Food and tap water (from 20 years old plumbing with 0.35 mg copper/L) were given ad libitum.…”