Hypolipidemic and antioxidant effects of grape processing by-products ihigh-fat/cholesterol diet-induced hyperlipidemic hamsters

Abstract

Investigations have shown the presence of bioactive substances in agricultural by-products. As some of these compounds present hypolipidemic and antioxidant activities, they could be considered economical alternatives to be used as supplements. This study investigates the hypolipidemic and antioxidant properties of grape processing by-products, feeding them to hamsters for 28 days. Wine pomace flour and grape juice pomace flour proved to have substantial amounts of fibers and phenolic compounds, both recognized as hypolipidemic and antioxidant substances. Phenolic compounds were individually investigated, and their presence was confirmed in both flours. Hamsters receiving a hyperlipidemic diet exhibited increased plasma levels of triglycerides and cholesterol fractions, reduced activities of antioxidant enzymes and high levels of plasma transaminases indicating hepatic damages. In contrast, the groups receiving the same hyperlipidemic diet supplemented with grape processing by-products showed improved lipid profiles, increased activities of antioxidant enzymes, increased levels of cytosolic Nrf2 (transcription factor for antioxidant enzymes) and normal levels of plasma transaminases. Therefore, the use of these by-products demonstrated beneficial health effects at a very low cost.