The ginger component 6-shogaol prevents TNF-α-induced barrier loss via inhibition of PI3K/Akt and NF-κB signaling

• Published in: Molecular nutrition & food research 2016-12, Vol.60 (12), p.2576-2586
• Main Authors: Luettig, Julia, Rosenthal, Rita, Lee, In-Fah M., Krug, Susanne M., Schulzke, Jörg D.
• Format: Article
• Language: English
• Subjects: 6-Shogaol; Anti-Inflammatory Agents - pharmacology; B-Lymphocytes - metabolism; Caco-2 Cells; Catechols - pharmacology; Claudin-1 - genetics; Claudin-1 - metabolism; Claudins - genetics; Claudins - metabolism; Ginger; HT29 Cells; Humans; Intestinal barrier; Intestines - cytology; Intestines - drug effects; NF-kappa B - genetics; NF-kappa B - metabolism; Phosphatidylinositol 3-Kinases - genetics; Phosphatidylinositol 3-Kinases - metabolism; Signal Transduction - drug effects; Tight junction; Tight Junctions - drug effects; Tight Junctions - metabolism; TNF-α; Tumor Necrosis Factor-alpha - pharmacology; Up-Regulation; Zingiber officinale - chemistry
• ISSN: 1613-4125; 1613-4133
• DOI: 10.1002/mnfr.201600274

Scope Anti‐inflammatory properties of the ginger‐derived pungent component 6‐shogaol (6‐SG) have been studied intensively in recent years. Purpose of this study was to characterize the influence of 6‐SG on inflammation‐related intestinal barrier dysfunction, especially its paracellular component. Methods and results The effect of 6‐SG was studied in the human intestinal cell models HT‐29/B6 and Caco‐2 either under control conditions or challenged by the pro‐inflammatory cytokine tumor necrosis factor α (TNF‐α). Electrophysiological measurements, freeze‐fracture electron microscopy, and protein analyses were performed. 6‐SG partially prevented both, the TNF‐α‐induced decrease in transepithelial resistance and the rise in fluorescein permeability. By inhibiting phosphatidylinositol‐3‐kinase/Akt signaling 6‐SG prevented the TNF‐α‐induced increase in protein expression of claudin‐2, a channel‐forming tight junction protein. In addition, the TNF‐α‐induced disassembly of the sealing tight junction protein claudin‐1 was attenuated, the latter of which was due to TNF‐α‐triggered phosphorylation of nuclear factor kappa light chain enhancer of activated B cells (NF‐κB). Conclusion 6‐SG has barrier‐protective effects by affecting TNF‐α‐induced claudin‐2 upregulation and claudin‐1 disassembly via inhibition of phoshatidylinositol‐3‐kinase/Akt and nuclear factor kappa light chain enhancer of activated B‐cell signaling. Therefore, 6‐SG‐containing food might be beneficial for barrier preservation during intestinal inflammation. The study shows a protective role of the ginger‐derived pungent component 6‐shogaol (6‐SG) against barrier dysfunction in intestinal inflammation. 6‐SG blocks the TNF‐α‐induced barrier disturbance by preventing the increased expression of the channel‐forming tight junction protein claudin‐2 via inhibition of PI3K/Akt. Furthermore, 6‐SG inhibits the TNF‐α‐induced activation of NF‐κB signaling and by that stabilizes the barrier sealing tight junction protein claudin‐1 in the tight junction .