Protective effects of L-theanine on rats with dextran sulfate sodium-induced inflammatory bowel disease

Arch Pharm Res. 2020 Aug;43(8):821-862. doi: 10.1007/s12272-020-01248-9. Epub 2020 Jul 28.

Abstract

The aim of this study is to evaluate the anti-inflammatory and protective effects of L-theanine in inflammatory bowel disease (IBD) and to identify the underlying molecular mechanisms. Rats were pre-treated with L-theanine at 0, 50, 200, or 800 mg/kg/day. IBD was induced in rats using dextran sulfate sodium (DSS). Histopathological analysis suggests that L-theanine can suppress DSS-induced IBD with significant inhibition of inflammation in large and small intestinal tissues. Moreover, the 200 mg/kg/day L-theanine-treated DSS group had higher body and small intestine weights, a lower disease activity index and expression of inflammatory factors than the DSS group without pre-treatment. In RNA sequencing and tandem mass tag labeling analyses, large number of mRNAs and proteins expression level differed when compared with the DSS-induced rats with and without 200 mg/kg/day L-theanine pre-treatment. Moreover, Kyoto Encyclopedia of Genes and Genomes pathway analysis indicates the anti-inflammatory activities of L-theanine in DSS-induced IBD, with a high representation of genes in "Cholesterol metabolism" and "Retinol metabolism" pathways. Analysis of protein-protein interaction networks further indicates the involvement of these two pathways. These studies suggest that medium-dose L-theanine pre-treatment could ameliorate DSS-induced IBD through molecular mechanisms involving cholesterol and retinol metabolism.

Keywords: Anti-inflammatory; Dextran sulfate sodium; Inflammatory bowel disease; L-Theanine; Protective effects.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / administration & dosage
  • Anti-Inflammatory Agents / pharmacology*
  • Cholesterol / metabolism
  • Dextran Sulfate
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Glutamates / administration & dosage
  • Glutamates / pharmacology*
  • Inflammation / drug therapy*
  • Inflammation / pathology
  • Inflammatory Bowel Diseases / drug therapy*
  • Inflammatory Bowel Diseases / physiopathology
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Vitamin A / metabolism

Substances

  • Anti-Inflammatory Agents
  • Glutamates
  • Vitamin A
  • theanine
  • Dextran Sulfate
  • Cholesterol