Abstract
BackgroundIntestinal epithelial barrier dysfunction predisposes to many gastrointestinal, metabolic, and psychological disorders. A flavonoid rich extract of Glycyrrhiza glabra (FREG) has previously been reported to possess anti-inflammatory, antioxidant, and antiulcer properties.AimTo investigate the effect of FREG (GutGard®) on restoring intestinal barrier function in tumor necrosis factor-alpha (TNF-α) stimulated human colonic adenocarcinoma cell monolayer (Caco-2) and 2,4,6-Trinitrobenzenesulfonic acid (TNBS) induced ulcerative colitis in rats.MethodsIn in vitro, human intestinal Caco-2 cell monolayers were treated with TNF-α in the presence or absence of FREG and the paracellular permeability to FITC-conjugated 4-kD dextran (FD4) was measured to evaluate protection against the barrier dysfunction. In in vivo, intestinal barrier dysfunction was induced in male albino Wistar rats via intrarectal instillation of TNBS. Subsequently, the rats were treated orally with either FREG at 6.25, 12.5, and 25 mg/kg body weight, or Mesacol (250 mg/kg) for 5 days. On day 5, intestinal epithelial permeability was assessed with FD4 leakage into the serum. Also, colonic inflammation, colon morphology, histology and macroscopic score, weight to length ratio were evaluated. The activity of myeloperoxidase (MPO), TNF- α, secretory IgA levels and tight junction proteins expression were evaluated in rat’s colon.ResultsFREG protected the intestinal epithelial barrier integrity in human intestinal Caco-2 cells in vitro. FREG administration significantly improved the intestinal epithelial barrier function as evident from significant reduction in FD4 leakage. The colon morphology, histology score, macroscopic score, colon weight to length ratio also indicates beneficial effects of FREG on barrier function. In addition, FREG regulated the tight junction proteins, and markedly decreased TNF-α, MPO levels and significantly increased the secretory IgA levels in TNBS induced colitis rats.ConclusionThe study findings support the protective action of FREG on intestinal epithelial barrier integrity indicating its potential in protecting from implications of leaky gut.
Highlights
The intestinal epithelium is constituted of a single layer of columnar epithelial cells (IECs) that forms a physical and functional barrier to prevent the entry of toxins, commensal and pathogenic microorganisms into the underlying mucosa and contacting with the immune cells
The results showed that the exposure of flavonoid rich extract of Glycyrrhiza glabra (FREG) at 2.5–20 μg/mL for 48 h had no significant effect on the viability of human intestinal epithelial cells (Fig. 1)
Effect of FREG in preventing and restoring the intestinal barrier dysfunction FREG attenuated the disruption of intestinal epithelial barrier function induced by Tumor necrosis factor-alpha (TNF-α) in Caco-2 cell monolayers
Summary
The intestinal epithelium is constituted of a single layer of columnar epithelial cells (IECs) that forms a physical and functional barrier to prevent the entry of toxins, commensal and pathogenic microorganisms into the underlying mucosa and contacting with the immune cells. The gut barrier integrity is frequently disrupted in a variety of acute or chronic intestinal diseases, such as ulcerative colitis, Crohn’s disease, irritable bowel syndrome (IBS), celiac disease and infectious diarrhoea [4,5,6,7,8]. These diseases induce the release of proinflammatory cytokines (TNF-α, INF-γ, IL-1β, IL-6, IL-13), increased the oxidative stress by release of ROS and contribute to the intestinal barrier dysfunction or leaky gut [9,10,11,12,13,14]. Aim: To investigate the effect of FREG (GutGard®) on restoring intestinal barrier function in tumor necrosis factoralpha (TNF-α) stimulated human colonic adenocarcinoma cell monolayer (Caco-2) and 2,4,6-Trinitrobenzenesulfonic acid (TNBS) induced ulcerative colitis in rats
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
