Polyphenol-rich Blackcurrant Pomace Counteracts Impaired Antioxidant Status and Serum Lipid Profile in Rabbits Fed a Diet High in Unsaturated Fat

Julia Jarosaawska,Paulius Matusevicius

doi:10.4172/2155-9600.1000531

Abstract

Blackcurrant pomace, a by-product of juice fabrication with promising health benefits, is currently an unutilized nutritional resource. In the presented study an influence of dietary supplementation with blackcurrant pomace, constituting a source of antioxidant phytochemicals and fiber, on selected metabolic biomarkers of rabbits was evaluated. A 28-d experiment carried out on 34-d old rabbits addressed the analysis of physiological properties of two types of diet, standard chow and with additional 10% of lard, each supplemented with unprocessed blackcurrant pomace rich in polyphenols or a processed one, partly deprived of polyphenolic fraction. Twenty rabbits were allocated to four groups fed the following diets: Standard chow +15% of either unprocessed or processed blackcurrant pomace or lard-enriched diet +15% of either unprocessed or processed blackcurrant pomace. Irrespectively of the diet type, inclusion of unprocessed, compared to processed blackcurrant pomace, significantly improved antioxidant status of rabbits expressed by lower level of substances reacting with thiobarbituric acid (TBARS) in the liver and kidneys, as well as higher level of serum total antioxidant status (TAS), integral antioxidant capacities of hydrophilic (ACW) and lipophilic (ACL) substances. Upon lard-enriched diet, unprocessed blackcurrant abundant in polyphenols affected more beneficially serum triacylglycerides (TAG), total cholesterol (TC) and insulin levels. The antioxidant, hypolipidemic and hypoinsulinemic action of the blackcurrant supplement should be ascribed to the polyphenolic constituents present in the pomace.

Highlights

Many authors have proposed that the beneficial activity of polyphenolic compounds present in unrefined diet is linked, to a great extent, with physiological effects of dietary fiber constituting the fiberpolyphenols complexes [1,2]
Our study showed that the addition of the polyphenolic fraction from chicory root to diets containing prebiotic fructans did not diminish the positive effect of inulin and oligofructose on the ecosystem of the gastrointestinal tract, and triggered positive changes in the blood lipid profile as well as deceleration of pro-oxidative processes in selected tissues [5]
Hepatic steatosis associated with excessive fat accumulation in hepatocytes, is a condition often present in pathological states related to altered metabolism of the whole organism, which itself may contribute to other illnesses

Summary

Introduction

Many authors have proposed that the beneficial activity of polyphenolic compounds present in unrefined diet is linked, to a great extent, with physiological effects of dietary fiber constituting the fiberpolyphenols complexes [1,2]. The fiber-antioxidants complex seems to be a natural route of delivering components with antioxidative properties to colonic microbiota, protecting antioxidants against degradation in the stomach [3,4]. These studies point to potential advantages of diet supplementation with natural preparations containing both functional polysaccharides and polyphenolic compounds, which enables utilizing the physiological properties of both groups of these compounds locally in the gut as well as in internal tissues. Our study showed that the addition of the polyphenolic fraction from chicory root to diets containing prebiotic fructans did not diminish the positive effect of inulin and oligofructose on the ecosystem of the gastrointestinal tract, and triggered positive changes in the blood lipid profile as well as deceleration of pro-oxidative processes in selected tissues [5]

Methods

Results

Conclusion