Roles of Dietary Amino Acids and Their Metabolites in Pathogenesis of Inflammatory Bowel Disease

Table 1

Studies on dietary nutrients supplementation for the management of IBD.

Nutrients	Primary components	Chemical structure	Functions	Ref.
Corabion	A mixture of vitamin C, vitamin E, 3-PUFAs (EPA and DHA), and Arg		Reduction of DAI, neutrophil recruitment, oxidative stress, proinflammatory cytokines, and E-cadherin internalization; attenuation of colon shortening and tissue damage	[23]
Pomegranate extract	Ellagic acid		Reduction of MPO activity, TNF-α levels, (COX-2), iNOS overexpression, and MAPKs phosphorylation; preventing NF-B translocation	[24, 25]
Krill oil	3-PUFAs and phospholipids		Reduction of DAI, HCS, colon length, and protein oxidation markers; improvement of Pparg1 and (PG)E3 expression	[26]
Tetradecylthioacetic acid	An artificial 16-carbon fatty acid with a sulphur-substitution in the -position		Reduction of colonic oxidative damage and colon wall thickness; improvement of expression of Pparg1α; inhibition of the production of inflammatory cytokines (TNF-, IL-1, and IL-6)	[27]
Fibre	Nonstarch polysaccharides, resistant oligosaccharides, analogous carbohydrates, and lignin		Maintain remission and reduce lesions of the intestinal mucosa	[28, 29]
Anthocyanins	Natural agents derived from strawberry, blueberry, barberry, and other plants		Cytoprotection; remission of oxidative stress and inflammatory cytokines; suppression of cellular signaling pathways of inflammatory processes	[30]
α-Linolenic acid	3-PUFA: plant-derived oil		Inhibition of the production of IL-6 and TNF-; reduction of cell apoptosis, intestinal permeability, and bacterial translocation; improving histological repair	[31, 32]
FAAH inhibitors	PF-3845		Possess anti-inflammatory effect in TNBS-induced colitis in mice; alter the levels of endocannabinoids	[33]
	FAAH-II		Inhibition of inflammatory miRNAs and cytokines; reduction of the number of activated T cells, the frequency of macrophages, and neutrophils in the colon	[34]

EPA, eicosapentaenoic acid; DHA, docosahexaenoic acid; (COX-2), cyclooxygenase-2; iNOS, inducible nitric oxide synthase; MAPKs, mitogen-activated protein kinases; MPO, myeloperoxidase; NF-κB, nuclear transcription factor kappa B; PUFAs, polyunsaturated fatty acids; DAI, disease activity index; HCS, histological combined score; Pparg1a, PPAR-g coactivator 1α; (PG)E3, prostaglandin-E3; IL-1β, interleukin-1β; PUFA, polyunsaturated fatty acids; FAAH, fatty acid amide hydrolase.