Table 4.

Lignans explored in the context of inflammatory bowel diseases (IBDs)

Subgroups	Compounds	Dietary/Exogenous sources	Mechanisms of action (Preclinical models)	Studies in humans (including observational and intervention studies	References
Lignans	Flaxseed and Secoisolariciresinol diglucoside	Flaxseed and flaxseed oil	Reduces mortality and colonic ulcers, while aqueous-methanolic crude extracts (Fs.Cr) enhance mucin content and exhibit anti-inflammatory, antispasmodic, and antibacterial effecs. Phenolic compounds from flaxseed and SGD also reduce inflammation and improve mucosal repair in colitis models	Human studies on flaxseed oil found that flaxseed supplementation benefits UC patients. In a 12-week trial with 75 UC patients, both 30 g/day of grounded flaxseed (GF) and 10 g/day of flaxseed oil (FO) significantly reduced inflammatory markers, disease severity, blood pressure, and waist circumference compared to placebo. Additional trials showed improvements in metabolic syndrome parameters, inflammatory markers, and quality of life. However, long-term studies are needed for definitive conclusions	449-461
	Sesame seeds, sesamin, and sesamol	Sesame seeds, sesamin, and sesamol	Have shown notables benefits in treating IBD in preclinical models. Sesame oil and sesame cake reduce inflammation, fibrosis, and oxidative stress, while sesamin and sesamol specially mitigate UC symptoms by modulating inflammatory and oxidative pathways, enhancing gut barrier function, and improving both physical and mental health in affected animals	-	462-472
	Schisandrin	Schisandra chinesis	Show promise in treating UC. SCH treatments alleviate colitis severity, improve gut microbiota, and modulate inflammatory pathways, including SGK1/NLRP3 and NLRP3 inflammasome. Specifically, Schinsandrin B reduces pro-inflammatory cytokines and enhances epithelial barrier protection, while Schisandrin c improves intestinal permeability and Deoxyschinsandrin offers cytoprotection against oxidative stress-induced cell apoptosis	-	474-480
	Magnolol and Honokiol	Magnolia officinalis	Magnolol reduces pro-inflammatory cytokines and improves colitis symptoms by modulating MAPK and NF-κB pathways, while honokiol enhances epithelial barrier integrity, reduces cytokines, and inhibits NLRP3 inflammasome activation	-	482-492
	Magnolin	Magnolia genus	Animal studies showed that MGL treatment alleviates weight loss, colon shortening, disease activity, and inflammation in colitis models. MGL also enhances intestinal barrier functions by preserving tight junction proteins and preventing epithelial cells apoptosis	-	491-493
	Arctigenin	Arctium lappa	Alleviates colitis by reducing body weight loss, disease activity index, and colon histological damage. It promotes intestinal epithelial cell recovery, decreases immune cell infiltration and suppresses inflammation and oxidative stress by inhibiting MAPK and NF-κB pathways	-	494-496
	Enterolactone and enterodiol	Resulting from the metabolism of other lignans by the gut microbiota	Mitigates inflammation-induced loss of intestinal epithelial barrier integrity and oxidative stress in vitro	-	497,498
	Koreanaside A	Forsythia koreana	Alleviates inflammatory response by downregulating AP-1, NF-κB, and JAK/STAT signaling in LPS-induced macrophages and DSS-induced colitis mice	-	499
	Fargesin	Flos magnoliae	Anti-inflammatory effects on chemically induced IBD through NF-κB, signaling suppression	-	499