Antioxidant Activity of Inulin and Its Role in the Prevention of Human Colonic Muscle Cell Impairment Induced by Lipopolysaccharide Mucosal Exposure

Abstract

BackgroundFructans, such as inulin, are dietary fibers which stimulate gastro-intestinal (GI) function acting as prebiotics. Lipopolysaccharide (LPS) impairs GI motility, through production of reactive oxygen species. The antioxidant activity of various fructans was tested and the protective effect of inulin on colonic smooth muscle cell (SMC) impairment, induced by exposure of human mucosa to LPS, was assessed in an ex vivo experimental model.MethodsThe antioxidant capacity of fructans was measured in an in vitro system that simulates cooking and digestion processes. Human colonic mucosa and submucosa, obtained from disease-free margins of resected segments for cancer, were sealed between two chambers, with the mucosal side facing upwards with Krebs solution with or without purified LPS from a pathogenic strain of Escherichia coli (O111:B4) and inulin (Frutafit IQ), and the submucosal side facing downwards into Krebs solution. The solutions on the submucosal side were collected following mucosal exposure to Krebs in the absence (N-undernatant) or presence of LPS (LPS-undernatant) or LPS+inulin (LPS+INU-undernatant). Undernatants were tested for their antioxidant activity and the effects on SMCs contractility. Inulin protective effects on mucosa and submucosa layers were assessed measuring the protein oxidation level in the experimental conditions analyzed.ResultsAntioxidant activity of inulin, which was significantly higher compared to simple sugars, remained unaltered despite cooking and digestion processes. Inulin protected the mucosal and submucosal layers against protein oxidation. Following exposure to LPS-undernatant, a significant decrease in maximal acetylcholine (Ach)-induced contraction was observed when compared to the contraction induced in cells incubated with the N-undernatant (4±1% vs 25±5% respectively, P<0.005) and this effect was completely prevented by pre-incubation of LPS with Inulin (35±5%).ConclusionsInulin protects the human colon mucosa from LPS-induced damage and this effect appears to be related to the protective effect of inulin against LPS-induced oxidative stress.

The Role of Soluble, Insoluble Fibers and Their Bioactive Compounds in Cancer: A Mini Review

“…Inulin increases absorption of vitamins and minerals; especially calcium and magnesium, protects body from translocation of bacteria and proliferation of pathogens, regulates intestinal epithelial cell growth, contributes to immune functions, and reduces triglycedaemia in hyperlipidaemic and hyperinsulemia individuals [80]. Inulin protected the mucosal and submucosal membranes against protein oxidation, reducing the oxidative stress, by protecting colon from lipopolysaccharides (LPS)-induced damage [81]. LPS are produced by gram-negative bacteria that impair intestinal smooth muscle contractibility, and increase inflammation [81].…”

“…Inulin protected the mucosal and submucosal membranes against protein oxidation, reducing the oxidative stress, by protecting colon from lipopolysaccharides (LPS)-induced damage [81]. LPS are produced by gram-negative bacteria that impair intestinal smooth muscle contractibility, and increase inflammation [81]. It has been hypothesized that hyperinsulemia could be a key factor in tumor development, Inulin by decreasing serum glucose could inhibit tumor growth; moreover, the prebiotic bacteria growth complements the lactic acid, which is shown to have antigenotoxic and anticarcinogenic properties [11] [82].…”

A Combination Supplement of Fructo- and Xylo-Oligosaccharides Significantly Abrogates Oxidative Impairments and Neurotoxicity in Maternal/Fetal Milieu Following Gestational Exposure to Acrylamide in Rat

“…Additionally, several studies have convincingly shown [56] suggesting that they may play an antioxidant role in vivo. Interestingly, in a recent study, the potential protective effect of inulin, to alleviate LPS induced oxidative stress was reported [57]. This evidence indicates that the protective effect of prebiotics may be at least in part mediated by antioxidative mechanism/s.…”

Effect of Inulin on Proteome Changes Induced by Pathogenic Lipopolysaccharide in Human Colon

“…This allows the prebiotic to reach the colon intact and undergo fermentation by a limited number of bacteria genera/species. Interestingly, we have recently demonstrated that inulin preserves its antioxidant capability following cooking and simulated digestion processes [2]. …”