Melatonin alters amino acid metabolism and inflammatory responses in colitis mice

Abstract

Inflammatory bowel disease is a chronic inflammatory dysfunction of the gastrointestinal tract. This study explored the hypothesis that melatonin has beneficial functions in the mouse model of colitis induced by dextran sodium sulfate (DSS), with a specific focus on the expression of intestinal inflammatory cytokines and the serum levels of amino acids. The results revealed that mice with melatonin supplementation had a reduction in weight loss and disease index induced by DSS treatment. Melatonin stifled the expression of colonic IL-17 in mice with DSS-induced colitis. Melatonin also lowered the serum levels of Asp, Ser, Met, and Leu (p < 0.05), but increased those of Glu and Cys (p < 0.05). Thus, melatonin treatment is promising and may function as a potential adjuvant therapy to alleviate the clinical symptoms of patients with inflammatory bowel disease.

Alterations in melatonin and 5‐HT signalling in the colonic mucosa of mice with dextran‐sodium sulfate‐induced colitis

“…However, with most of these studies, melatonin was given before the onset of the disease (Cuzzocrea et al, 2001;Liu et al, 2017;Trivedi and Jena, 2013;Zielińska et al, 2016), which likely accounts for the differences observed when compared with our results where treatment was given once symptoms were present. However, with most of these studies, melatonin was given before the onset of the disease (Cuzzocrea et al, 2001;Liu et al, 2017;Trivedi and Jena, 2013;Zielińska et al, 2016), which likely accounts for the differences observed when compared with our results where treatment was given once symptoms were present.…”

“…Our study is at odds with other studies that have seen improvements in either TNBS-or DSS-induced colitis when treated with melatonin. However, with most of these studies, melatonin was given before the onset of the disease (Cuzzocrea et al, 2001;Liu et al, 2017;Trivedi and Jena, 2013;Zielińska et al, 2016), which likely accounts for the differences observed when compared with our results where treatment was given once symptoms were present. In these studies phenotypic changes, such as shortening of the colon, were also observed to an extent greater that DSS alone (Zielińska et al, 2016), which from our observations is highly correlated with a worsening of colitis.…”

Melatonin Improves Laying Performance by Enhancing Intestinal Amino Acids Transport in Hens

“…Similarly, intestinal B 0 AT and EAAT3 mRNAs expression in young chicken could be elevated by MEL (1–10 μg/d) injection ( 7 ). MEL (0.2 mg/mL) could also restore DSS-induced decrease of Glu and Cys in mice serum ( 15 ). These results indicate that lower dosage of MEL feeding in laying hens could increase the AA levels in serum by enhancing transcription of PepT1, B 0 AT, b 0, + AT , and EAAT3 mRNA in the small intestine.…”

“…Arg-silicate-inositol complex supplementation increased egg production, egg weight, shell weight, and shell thickness during the laying peak period ( 14 ). Interestingly, MEL could restore dextran sodium sulfate (DSS)-induced decreasing of Glu and Cys in mice serum ( 15 ). However, whether it was AA transported by enterocytes that mediated the MEL effect on egg laying and egg quality remained unknown.…”

Regulation of Immune Function by Polyphenols

“…Ferulic acid inhibits the production of tumour necrosis factor- (TNF-) α in RAW264.7 cells stimulated with lipopolysaccharide (LPS) [ 19 , 20 ]. Immunological studies have shown that phenyl ethyl caffeate strongly and significantly inhibits the expression of interferon gamma-induced protein- (IP-) 10 in response to TNF, as well as the production of lymphoid factors and activation of nuclear factor- (NF-) κ B [ 21 – 23 ].…”