Ameliorative effects of L-theanine on dextran sulfate sodium induced colitis in C57BL/6J mice are associated with the inhibition of inflammatory responses and attenuation of intestinal barrier disruption

Dongxu Wang; Min Cai; Taotao Wang; Tiantian Liu; Jinbao Huang; Yijun Wang; Daniel Granato

doi:10.1016/j.foodres.2020.109409

Ameliorative effects of L-theanine on dextran sulfate sodium induced colitis in C57BL/6J mice are associated with the inhibition of inflammatory responses and attenuation of intestinal barrier disruption

Food Res Int. 2020 Nov:137:109409. doi: 10.1016/j.foodres.2020.109409. Epub 2020 Jun 9.

Authors

Dongxu Wang¹, Min Cai², Taotao Wang³, Tiantian Liu², Jinbao Huang², Yijun Wang², Daniel Granato⁴

Affiliations

¹ School of Grain Science and Technology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212004, China; School of Tea and Food Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, China. Electronic address: justwdx@163.com.
² School of Tea and Food Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, China.
³ Department of Clinical Nutrition, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212000, China.
⁴ Food Processing and Quality, Production Systems Unit - Natural Resources Institute Finland (Luke) - Tietotie 2, FI-02150 Espoo, Finland. Electronic address: daniel.granato@luke.fi.

PMID: 33233096
DOI: 10.1016/j.foodres.2020.109409

Abstract

This study investigated the effects of L-theanine supplementation on the colonic mucosa injury in C57BL/6J male mice treated with dextran sulfate sodium (DSS)-induced colitis. Treatment with L-theanine significantly decreased the disease activity index and ameliorated the inflammation-associated pathological damage in colon length, as well as the histopathological features of DSS-induced colitis. L-Theanine administration also inhibited DSS-induced changes in the colonic tissue that included myeloperoxidase by 4.5-fold and malondialdehyde by 2.3-fold in comparison to the DSS group. In addition, GSH was increased by 85% and lipopolysaccharides level was decreased by 55% in comparison to the DSS group. Proinflammatory cytokines expression, including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α, at the both protein and mRNA levels were also decreased significantly. Notably, the increase in serum content of lipopolysaccharides and colonic expressions of inducible nitric oxide synthase, cyclooxygenase-2, toll like receptor (TLR)-2, TLR-4, TLR-6, and TLR-9 induced by DSS were also significantly inhibited by L-theanine administration. In addition, L-theanine also attenuated the reduction of serum contents of diamine oxidase and the production of short-chain fatty acids in the colonic tissue, and gene expression of mucosal barrier zonula occludens-1 and claudin-1 in DSS-induced colitis. Furthermore, 16S rRNA phylogenetic sequencing revealed a shift in microbial community composition induced by DSS, but no significant difference was observed following L-theanine supplementation. Overall, our findings demonstrated that L-theanine inhibits intestinal inflammation and protects against intestinal barrier disruption in mice with DSS-induced colitis. Further clinical trials should be considered to assess the effects of L-theanine supplementation on oxidative and inflammatory responses in humans.

Keywords: Amino acids; Camellia sinensis; Chronic inflammation; Functional foods; Gut microflora; Oxidative stress.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Colitis* / chemically induced
Colitis* / drug therapy
Dextran Sulfate
Disease Models, Animal
Glutamates
Male
Mice
Mice, Inbred C57BL
Phylogeny
RNA, Ribosomal, 16S

Substances

Glutamates
RNA, Ribosomal, 16S
theanine
Dextran Sulfate