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. (November 2020)

• Record Type: Journal Article
• Authors: Wang, Dongxu; Cai, Min; Wang, Taotao; Liu, Tiantian; Huang, Jinbao; Wang, Yijun; Granato, Daniel
• Is Part Of: Food research international. Volume 137(2020)
• Publication Date: 2020-11
• Subjects: Chronic inflammation -- Camellia sinensis -- Amino acids -- Oxidative stress -- Gut microflora -- Functional foods; AA acetic acid -- ALT alanine aminotransferase -- AST aspartate aminotransferase -- BA butyric acid -- BB berberrubine -- BUN urea nitrogen -- CAT catalase -- COX cyclooxygenase -- Cr creatinine -- DAI disease activity index -- DAO diamine oxidase -- DSS dextran sulfate sodium -- ELISA enzyme-linked immunosorbent assay -- GPx glutathione peroxidase -- GTPs green tea polyphenols -- H&E hematoxylin and eosin -- IBD inflammatory bowel disease -- IL interleukin -- iNOS inducible nitric oxide synthase -- LA lactic acid -- LPS lipopolysaccharides -- MCP monocyte chemotactic protein -- MDA malondialdehyde -- MPO myeloperoxidase -- PA propionic acid -- PBS phosphate-buffered saline -- SCFAs short-chain fatty acids -- TJ tight junction -- TLR toll like receptor -- TNF tumor necrosis factor -- T-SOD total superoxide dismutase -- ZO zonula occludens; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2020.109409
• Languages: English
• ISSNs: 0963-9969

Abstract

Graphical abstract: Highlights: Effects of L-theanine on the colonic injury in DSS induced-colitis mice were investigated. L-theanine ameliorated the inflammation-associated damage in DSS induced-colitis mice. Nitric oxide synthase, cyclooxygenase-2, TLR-2, TLR-4, TLR-6, and TLR-9 were inhibited by L-theanine. L-theanine reduced lipopolysaccharides and increased the production of short-chain fatty acids. 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.