Exploring the effects of phenolic compounds to reduce intestinal damage and improve the intestinal barrier integrity: A systematic review of in vivo animal studies

Abstract

Background & aims: The integrity of the intestinal barrier in the diseased is key to prevent further complications and disease such as sepsis and death, whereas, the role of food bioactive molecules (i. e. phenolic compounds (PCs) on the intestinal barrier, is still unknown. The current aim was to explore the benefits of the oral PC administration on the intestinal barrier integrity in animals. Methods: The effects of PCs on the intestinal barrier integrity in in vivo animal models of intestinal inflammation were assessed up-to August 2020 from the PubMed, SCOPUS, and Cochrane Library databases under the PRISMA methodology. The risk of bias was assessed from ARRAY and SCYRCLE tools. Results: From 1241 articles, 14 studies were included. In animals, oral resveratrol (n ¼ 6) improves the intestinal barrier integrity and reduces intestinal damage. Additionally, grape seed extract (n ¼ 2), curcumin (n ¼ 1), genistein (n ¼ 1), chlorogenic acid (n ¼ 1), grape pomace (n ¼ 1), olive leaf (n ¼ 1) or cranberry extract (n ¼ 1) improve the intestinal barrier integrity downregulating various inflammatory molecules (TNF-a, and other interleukins), and increasing the antioxidant enzymes in animals. Furthermore, resveratrol, quercetin, epigallocatechin, and other PCs improve the epithelial barrier integrity and pro-inflammatory molecule expression in the intestinal epithelia. Conclusions: The oral PC administration in animals improves the intestinal barrier integrity and function from three main mechanisms: 1) The reduction of pro-inflammatory molecules, 2) the improvement in tight-junction protein expression, and 3) the improvement of the antioxidant intracellular activity suggesting the potential use of PCs in the management of intestinal injury in humans, particularly for resveratrol, the most studied PC.

Supplementation With Chinese Medicinal Plant Extracts From Lonicera hypoglauca and Scutellaria baicalensis Mitigates Colonic Inflammation by Regulating Oxidative Stress and Gut Microbiota in a Colitis Mouse Model

“…IL-10 is a necessary inflammatory factor for inducement and maintenance of regulatory T (Treg) cells against colitis ( Sivaprakasam et al, 2016 ). Numerous plant-extracted polyphenols can decrease the levels of inflammatory cytokines to attenuate inflammation responses ( Sandoval-Ramirez et al, 2021 ). For example, caffeic acid, tea polyphenols, salvianolic acid, and sesamol could ameliorate colitis by reducing the levels of IL-1β, IL-6, TNF-α, and other pro-inflammatory cytokines in DSS-induced models ( Ye et al, 2009 ; Wang et al, 2018 ; Liu et al, 2020b ; Zhao et al, 2020 ).…”

Caffeic Acid Supplement Alleviates Colonic Inflammation and Oxidative Stress Potentially Through Improved Gut Microbiota Community in Mice

“…Inflammatory response plays a key role in activating the production of mature IL-6, IL-1β, and TNF-α in UC patients and colitis mice ( Marafini et al, 2019 ). Numerous phenolic acids can inhibit the inflammatory responses to improve colitis ( Sandoval-Ramirez et al, 2021 ). For example, caffeic acid, tea polyphenols, salvianolic acid, and sesamol could ameliorate colitis by reducing the levels of IL-1β, IL-6, TNF-α, and other pro-inflammatory cytokines in DSS-induced colitis mice ( Ye et al, 2009 ; Wang et al, 2018 ; Liu Y. et al, 2020 ; Zhao et al, 2020 ).…”

The Gut Microbiota-Bile Acids-TGR5 Axis Mediates Eucommia ulmoides Leaf Extract Alleviation of Injury to Colonic Epithelium Integrity

“…Furthermore, we found that ELE significantly improved DSS-induced colon epithelial injury and reduced the mRNA expression of TLR4 and IL-6, which might attribute to the enriched phenolic acids, flavonoid, and polysaccharide contents in ELE. Previously, studies have shown that the phenolic acid, total flavonoids, and polysaccharides alleviate IBD by relieving inflammation and oxidative stress ( Zhao et al, 2019 ; Hussain et al, 2020 ; Sandoval-Ramirez et al, 2020 ). Chlorogenic acid, the main component of ELE, showed beneficial effect on ameliorating LPS-induced inflammation in different cell types (i.e., macrophages, hepatocytes, and intestinal cells) by suppressing the TLR4 signaling pathway ( Shi et al, 2013 ; Ruan et al, 2014 ; Ruifeng et al, 2014 ).…”