Intestinal Absorption and Antioxidant Activity of Grape Pomace Polyphenols

Abstract

The absorption and antioxidant activity of polyphenols from grape pomace (GP) are important aspects of its valorization as a feed additive in the diet of weaned piglets. This study aimed to evaluate the presence of polyphenols from GP both in vitro in IPEC cells and in vivo in the duodenum and colon of piglets fed with diets containing or not 5% GP and also to compare and correlate the aspects of their in vitro and in vivo absorption. Total polyphenolic content (TPC) and antioxidant status (TAS, CAT, SOD and GPx enzyme activity, and lipid peroxidation-TBARS level) were assessed in duodenum and colon of piglets fed or not a diet with 5% GP. The results of UV-Vis spectroscopy demonstrated that in cellular and extracellular medium the GP polyphenols were oxidized (between λmax = 276 nm and λmax = 627.0 nm) with the formation of o-quinones and dimers. LC-MS analysis indicated a procyanidin trimer possibly C2, and a procyanidin dimer as the major polyphenols identified in GP, 12.8% of the procyanidin trimer and 23% of the procyanidin dimer respectively being also found in the compound feed. Procyanidin trimer C2 is the compound accumulated in duodenum, 73% of it being found in the colon of control piglets, and 62.5% in the colon of GP piglets. Correlations exist between the in vitro and in vivo investigations regarding the qualitative evaluation of GP polyphenols in the cells (λmax at 287.1 nm) and in the gut (λmax at 287.5 nm), as oxidated metabolic products. Beside the presence of polyphenols metabolites this study shows also the presence of the unmetabolized procyanidin trimers in duodenum and colon tissue, an important point in evaluating the benefic actions of these molecules at intestinal level. Moreover the in vivo study shows that a 5% GP in piglet’s diet increased the total antioxidant status (TAS) and decreased lipid peroxidantion (TBARS) in both duodenum and colon, and increased SOD activity in duodenum and CAT and GPx activity in colon. These parameters are modulated by the different polyphenols absorbed, mainly by the procyanidin trimers and catechin on one side and the polyphenols metabolites on the other side.

Chemical–nutritional quality and oxidative stability of milk and dairy products obtained from Friesian cows fed with a dietary supplementation of dried grape pomace

“…This aspect could be easily explained since grape composition is influenced by edaphoclimatic conditions and viticultural practices, as well as variety, maturity and sanitary conditions. The considerable phenolic content and antioxidant activity are instead in agreement with the results obtained by other authors . Studies carried out with the aim of assessing the amount of phenolic compounds naturally occurring in cow milk demonstrated the presence of low concentrations of these bioactive phytochemicals, most of which derive from feed while a small fraction could be the product of the catabolism of some amino acids by rumen bacteria .…”

“…DI C18:1 cis-9/(C18:0 + C18:1 cis-9) 0.62 ± 0.02 0.63 ± 0.01 n. and antioxidant activity are instead in agreement with the results obtained by other authors. 36 Studies carried out with the aim of assessing the amount of phenolic compounds naturally occurring in cow milk demonstrated the presence of low concentrations of these bioactive phytochemicals, most of which derive from feed while a small fraction could be the product of the catabolism of some amino acids by rumen bacteria. 37 In addition, polyphenols of bovine origin can be formed by the action of gut bacterial flora on plant phenolic compounds, and secondary metabolites, such as equol, can be found in dairy cow milk.…”

RNA Sequencing-Based Whole-Transcriptome Analysis of Friesian Cattle Fed with Grape Pomace-Supplemented Diet

“…On one hand, the most important limitation of the use of GPO as ruminant feed is the presence of a high amount of lignified fibers and tannins, with potentially negative effects on digestive nutrient utilization. On the other hand, these latter derivatives may improve the ruminal metabolism by increasing protein supply to the small intestine, accompanied by a decreased ruminal degradability and a decreased methanogenesis [ 28 ]. Several reports described the beneficial effects of GPO on animal product quality.…”

Effects of dietary grape seed polyphenols supplementation during late gestation and lactation on antioxidant status in serum and immunoglobulin content in colostrum of multiparous sows1

“…Grape seed polyphenols (GSP) have been widely used as a human food supplement for health promotion and disease prevention. The polyphenols in grape pomace can increase the total antioxidant status and decrease lipid peroxidation in duodenum and colon, and increase SOD activity in duodenum and CAT and GSH-Px activity in the colon of piglets (Chedea et al, 2018). Feeding polyphenol-rich plant products (grape seed or grape pomace meal extract) has been shown to decrease expression of various proinflammatory genes in duodenum, ileum, and colon of growing pigs (Fiesel et al, 2014).…”