PROTECTIVE EFFECTS OF ELLAGITANNINS-RICH STRAWBERRY EXTRACTS ON BIOCHEMICAL AND METABOLIC BIOMARKERS OF RATS FED A DIET HIGH IN FRUCTOSE

Abstract

The study compared the effects of two dietary strawberry extracts rich in monomeric (ME) or dimeric (DE) ellagitannins (ET) on blood and tissue biomarkers in rats fed high-fructose diets. The extract rich in monomeric ET contained 94.9% polyphenols and 67% ME in it, the extract rich in dimeric ET 95.9% polyphenols, and 78.0% DE in it. Although both strawberry extracts beneficially affected antioxidant status and lipid profile of the liver and blood serum, the ME extract showed a higher ability to inhibit lipid peroxidation in liver, more effectively decreased serum and liver triglycerides, and exerted greater anti-inflammatory effect in blood serum in comparison to the DE extract. The above mentioned changes in some metabolic biomarkers were connected to the fact that monomeric ET were more prone to intestinal breakdown than dimeric ET. The total caecal and urinal content of ET metabolites was significantly higher in the ME groups vs. DE groups, regardless of diet type. To sum up, the biochemical action of the monomeric ET-rich extract from strawberry in the normalization of fructose-induced disturbances was more distinct than those of dimeric ET-rich preparation. The study was supported by the National Science Centre Poland (grant DEC-2012/05/B/NZ9/03402).