Protective Effects of Ellagitannin-Rich Strawberry Extracts on Biochemical and Metabolic Disturbances in Rats Fed a Diet High in Fructose

Abstract

The present study compares the effects of two dietary strawberry extracts rich in monomeric (ME) or dimeric (DE) ellagitannins (ETs) on gastrointestinal, blood and tissue biomarkers in Wistar rats fed high-fructose diets. Both strawberry extracts beneficially affect the antioxidant status and lipid profile of the liver and serum. The ME extract shows a greater ability to inhibit lipid peroxidation in kidneys, more effectively decreases serum and liver triglycerides, and exerts greater anti-inflammatory effects in blood serum than the DE extract. The DE extract significantly reduces the activity of microbial enzymes in the cecum. These effects might be associated with higher cecum and urine levels of ET metabolites in rats fed with ME than in rats fed with DE. In conclusion, the diet-induced fructose-related disturbances observed in biochemical parameters are regulated by both extracts; nevertheless, the beneficial effects of the ME extract are mostly associated with systemic parameters, while those of the DE extracts are associated with local microbial activity.

Effects of Raw and Roasted Cocoa Bean Extracts Supplementation on Intestinal Enzyme Activity, Biochemical Parameters, and Antioxidant Status in Rats Fed a High-Fat Diet

“…Dietary supplementation of raw CBE significantly decreased the concentration of TBARS in heart of high-fat groups. Similar results were obtained in studies of other authors [64,65]. Many studies have shown that cocoa and cocoa products can exert strong antioxidant properties and improve resistance to oxidative stress [7].…”

“…D RT diet also significantly increased the release degree of β-galactosidase, compared to all other groups. The obtained results are confirmed by literature data indicating that supplementation with polyphenolic-rich extracts advantageously modulates the enzymatic activity of the cecum microbiota [63,64]. 67.9 ± 0.9 a 69.6 ± 1.4 a 64.9 ± 1.5 a 83.9 ± 1.4 b 0.008 β-glucuronidase Extracellular 1 13.…”

“…67.9 ± 0.9 a 69.6 ± 1.4 a 64.9 ± 1.5 a 83.9 ± 1.4 b 0.008 β-glucuronidase Extracellular 1 13. Fotschki et al [63,64] observed that the introduction to the diet of rats polyphenolic compounds belonging to the group of ellagotanins and flavan-3-ols, contributed to a significant reduction in β-glucuronidase activity, which is an indicator of adverse changes in the composition of the intestinal microflora, e.g., an increase in the population of pathogenic bacteria, including Escherichia coli, Pseudomonas aeruginosa, Staphylococcus, and Clostridia [54]. Moreover, this enzyme is responsible for the transformation of xenobiotics in the gastrointestinal tract into more toxic substances [61,65].…”

Concentrations of Blood Serum and Urinal Ellagitannin Metabolites Depend Largely on the Post-Intake Time and Duration of Strawberry Phenolics Ingestion in Rats

“…In the urine, the predominant metabolites were glucuronidated urolithin A and nasutin A. It has been reported that glucuronidation enhances the solubility of these molecules and facilitates their urinal excretion [Fotschki et al, 2018].…”

“…It should be noted that the chemical structure of ET and subsequently that of ET metabolites largely depends on the plant source [Landete, 2011;Karlińska et al, 2019]. The main strawberry ET is agrimoniin, a GOG-type dimer composed of two α-1-O-galloyl-2,3:4,6--bis-hexahydroxydiphenoyl-D-glucose units linked by a C-O-C bond between two gallic acid residues [Fotschki et al, 2018;Chiabrando et al, 2018;Nowicka et al, 2019]. The presence of sanguiin H-6 and lambertianin C, but as minor ET, has been also detected in strawberry fruit [Vrhovsek et al, 2012].…”