N-Palmitoyl-D-Glucosamine Inhibits TLR-4/NLRP3 and Improves DNBS-Induced Colon Inflammation through a PPAR-α-Dependent Mechanism

Biomolecules. 2022 Aug 22;12(8):1163. doi: 10.3390/biom12081163.

Abstract

Similar to canine inflammatory enteropathy, inflammatory bowel disease (IBD) is a chronic idiopathic condition characterized by remission periods and recurrent flares in which diarrhea, visceral pain, rectal bleeding/bloody stools, and weight loss are the main clinical symptoms. Intestinal barrier function alterations often persist in the remission phase of the disease without ongoing inflammatory processes. However, current therapies include mainly anti-inflammatory compounds that fail to promote functional symptoms-free disease remission, urging new drug discoveries to handle patients during this step of the disease. ALIAmides (ALIA, autacoid local injury antagonism) are bioactive fatty acid amides that recently gained attention because of their involvement in the control of inflammatory response, prompting the use of these molecules as plausible therapeutic strategies in the treatment of several chronic inflammatory conditions. N-palmitoyl-D-glucosamine (PGA), an under-researched ALIAmide, resulted in being safe and effective in preclinical models of inflammation and pain, suggesting its potential engagement in the treatment of IBD. In our study, we demonstrated that micronized PGA significantly and dose-dependently reduces colitis severity, improves intestinal mucosa integrity by increasing the tight junction proteins expression, and downregulates the TLR-4/NLRP3/iNOS pathway via PPAR-α receptors signaling in DNBS-treated mice. The possibility of clinically exploiting micronized PGA as support for the treatment and prevention of inflammation-related changes in IBD patients would represent an innovative, effective, and safe strategy.

Keywords: IBD; NLRP3; PPARs; intestinal barrier; intestinal inflammation; micronized N-palmitoyl-D-glucosamine; toll-like receptors; ulcerative colitis.

MeSH terms

  • Animals
  • Colitis* / chemically induced
  • Colitis* / drug therapy
  • Dinitrofluorobenzene / analogs & derivatives
  • Dogs
  • Glucosamine
  • Inflammation / drug therapy
  • Inflammatory Bowel Diseases* / drug therapy
  • Mice
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • PPAR alpha
  • Toll-Like Receptor 4

Substances

  • 2,4-dinitrofluorobenzene sulfonic acid
  • Dinitrofluorobenzene
  • Glucosamine
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Nlrp3 protein, mouse
  • PPAR alpha
  • Toll-Like Receptor 4

Grants and funding

This research received no external funding.