Effect of the dietary polyphenolic fraction of chicory root, peel, seed and leaf extracts on caecal fermentation and blood parameters in rats fed diets containing prebiotic fructans

Abstract

The aim of this 28 d experiment was to examine the physiological response of growing rats to a dietary combination of prebiotic chicory fructans, with polyphenols originating from different parts of the chicory plant, i.e. roots, root peels, seeds and leaves. A total of forty rats were assigned to groups fed the following diets characterised by a similar content of oligofructose and inulin: control, with 10 % of a root extract (a low level of dietary polyphenols, 0·05 %), with 6·5 % of a root peel extract (a medium level of dietary polyphenols, 0·107 %), with a combination of 8 % of a peel extract and 0·8 % of a seed extract (a high level of dietary polyphenols, 0·208 %) and with 2·5 % of a leaf extract (a medium level of dietary polyphenols, 0·106 %, with chicoric acid constituting half of them). Chicory seeds are the richest source of polyphenols, especially abundant in dicaffeoylquinic acids. When applied as a dietary supplement, the mixture of monocaffeoylquinic and dicaffeoylquinic acids, from the extracts made of roots, root peels and seeds, elicited more favourable changes in parameters of the antioxidative status of the body and in the activity of bacterial b-glucuronidase in the faeces and caecal digesta. In turn, the extract from chicory leaves, containing considerable quantities of chicoric acid and polyphenolic glycosides, apart from chlorogenic acids, also triggered desirable changes in the lipid profile of the blood serum. The high concentration of polyphenols in the extracts examined enables their application as dietary supplements to be administered in low doses.Key words: Chicory: Polyphenols: Fructans: Caecum: RatsIn the last two decades, an increasing interest has been observed in the health-promoting properties of particular food constituents, including dietary fibre-polyphenolic complexes. Chicory belongs to plants of the Compositae family, accumulating energy in the form of the fructan inulin, the physiological (i.e. prebiotic) properties of which have been described in numerous studies. The available literature lacks comprehensive reports on the contents of individual active substances in the leaves and roots of chicory, particularly polyphenolic compounds. In the case of artichoke (Cynara scolymus L.), the leaves of which contain a similar array of biologically active substances as in chicory, the data are more compendious and more easily available (1) . The main components of chicory roots and leaves belonging to a group of phenolic compounds include monocaffeoylquinic acids (MCQA, e.g. chlorogenic acid being an ester of quinic and caffeic acids), dicaffeoylquinic acids (DCQA, e.g. cynarine, i.e. 1,5-DCQA) and chicoric acid. It has been reported that a high percentage of dietary chlorogenic and caffeic acids is not absorbed from the gastrointestinal tract of humans and may exhibit a variety of intestinal effects (2) . In vitro investigations have demonstrated that chlorogenic acid inhibits the process of DNA damage and the synthesis of mutagenic and carcinogenic N-nitroso compoun...

Physiological Properties of Dietary Ellagitannin-Rich Preparations Obtained from Strawberry Pomace Using Different Extraction Methods

“…Many authors have proposed that the beneficial activity of polyphenolic compounds present in fruit preparations is also linked with physiological effects of dietary fibre constituting the fibre-polyphenols complexes [Larrauri et al, 1996;Juśkiewicz et al, 2011]. Some of them have even postulated the necessity of characterising parameters of the antioxidant status of the body at dietary supplementation with different dietary fibres [Larrauri et al, 1996].…”

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Effect of diets varying in the type of dietary fibre and its combination with polyphenols on gut function, microbial activity and antioxidant status in rats

“…Carbohydrate determinations in CHIC were performed using a HPLC (Knauer Smartline with an RI K-2301 Knauer detector; Berlin, Germany), an Animex HPX 87C (300 × 7.8 mm) column and water as a mobile phase (flow rate of 0.5 ml · min -1 at 85 °C), as described previously by Juśkiewicz et al (2011).…”

Effect of a Fermented Brown Rice Extract on the Gastrointestinal Function in Methotrexate-Treated Rats

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