In Vitro Digestion of Chestnut and Quebracho Tannin Extracts: Antimicrobial Effect, Antioxidant Capacity and Cytomodulatory Activity in Swine Intestinal IPEC-J2 Cells

Abstract

Quebracho (Qu) and chestnut (Ch) are natural sources of tannins and they are currently used in animal nutrition as feed ingredients. However, to date the bio-accessibility, antimicrobial, antioxidant, and intestinal epithelial cell stimulatory doses of Qu and Ch have not been determined. Our study investigates the antioxidant and E. coli F4+ and F18+ growth inhibitory activity of Qu, Ch, and their combinations after solubilization in water (to evaluate the already bio-accessible molecules) and after simulated gastro-intestinal digestion in vitro. The effect of an in vitro digested Ch and Qu combination was also tested on intestinal epithelial IPEC-J2 cells experimentally stressed with hydrogen peroxide (H2O2) and Dextran Sodium Sulfate (DSS). The results showed that undigested Qu and Ch alone, and in combination, exerted a valuable antioxidant capacity and E. coli F4+ and F18+ growth inhibitory activity. The concentration of 1200 µg/mL exhibited the highest E. coli growth inhibitory activity for all the samples tested. In addition, after in vitro digestion, Qu and Qu50%–Ch50% maintained E. coli growth inhibitory activity and a modest antioxidant capacity. Three hours pre-treatment with in vitro digested Qu50%–Ch50% counteracted the H2O2 and DSS experimentally-induced stress in the intestinal IPEC-J2 cells. Ch and Qu tannin extracts, particularly when combined, may exert E. coli F4+ and F18+ growth inhibitory activity and valuable antioxidant and cell viability modulation activities.

Evaluation of Dietary Administration of Chestnut and Quebracho Tannins on Growth, Serum Metabolites and Fecal Parameters of Weaned Piglets

“…In fact, the combined effect of Ch/Qu tannins could be exacerbated during stressful conditions, such as experimental bacterial infections [ 24 , 28 ]. According to Reggi et al [ 16 ], beneficial effects were reported when Ch/Qu digesta were administered to experimentally stressed intestinal swine cells, suggesting that it might have a trophic effect at the intestinal epithelium, and an increased viability of cells was observed after tannin treatment. In present study, animals were reared in a conventional herd farm.…”

“…The Ctrl and Ch/Qu diets adopted in the in vivo trial were in vitro digested using the protocol reported by Reggi et al [ 16 ]. The in vitro digestion was performed according to the protocol described by Regmi et al [ 38 ] with minor adaptations previously reported by our group [ 39 ].…”

“…Due to such restrictions, alternatives to antibiotics and alternatives to zinc oxide are urgently needed to guarantee animal production in line with health principles [ 11 , 12 ]. In this scenario, plant extracts can represent a valuable alternative as a natural source of functional compounds, such as polyphenolic compounds [ 13 , 14 , 15 , 16 , 17 ]. Among polyphenols, tannins derived from plant extracts are the largest class which can be classified into hydrolysable (HTs) or condensed (CTs) subgroups [ 18 ].…”

“…are a source of CTs or proanthocyanidins [ 21 ]. Tannins extracted from these plants have been applied in intensive swine farms due to their antioxidant, anti-inflammatory, and antibacterial activities [ 16 , 21 ].…”

By-Products of Agri-Food Industry as Tannin-Rich Sources: A Review of Tannins’ Biological Activities and Their Potential for Valorization

“…On the other hand, a crude extract of chestnut had stronger antibacterial properties than purified vescalagin and castalagin, probably due to the synergy exerted by the molecules contained in the extract [ 42 ]. Finally, C. sativa extracts have been reported to inhibit E. coli and Clostridium perfringens growth when applied at 1200 µg/mL and 3–150 µg/mL, respectively [ 43 , 93 ].…”