Table 3.

Effect of TCTB exposure on intestinal barrier function.

Toxin	Animal species	Concentration and duration of exposure	Effects on barrier function	References
In vivo approach
DON	Mouse	acute exposure 25 mg/kg bw (one gavage)	Increase in 4 kDa dextran permeability Effect on the distribution pattern of claudin 1, 3 and 3 tight junction proteins in small intestine	[70]
	Rat	chronic exposure 2 mg/kg feed 28 days	Decrease in transepithelial electrical resistance (TEER) Increase in 4 kDa dextran permeability	[50]
In vitro approach: intestinal epithelial cell lines
DON	Human HT-29 cell line	2 to 50 µM 24 h 10 µM 0–24 h	Dose dependent inhibition of cell viability (IC50 = 10 µmol/L) Time dependent: Increase in total DNA damage Increase in p53 protein level Increase in caspase-3 activity	[68]
	Human Caco-2 cell line	84 µM 24 h	Decreased survival rate of 40%	[64]
	Human HT-29 cell line	0.13 to 0.7 µM 6 to 15 d	Decrease in brush border enzyme activity Decrease in protein content Decrease in transepithelial electrical resistance (TEER) Increase in lucifer yellow permeability	[62]
	Human Caco-2 cell line	30 µM 48 h	Decrease in TEER Decrease in claudin-4 tight junction proteins Increase in 4 kDa dextran permeability	[71]
	Human Caco-2 cell line	10 µM 12 h	Increase in E coli K12 translocation	[72]
	Human Caco-2 cell line	1.7 to 17 µM 24 h	Decrease in claudin-4 tight junction proteins	[73]
DON	Porcine IPEC-1 cell line	10 to 50 µM 48 h	Decrease in TEER Decrease in claudin-3 and 4 tight junction proteins Increase in 4 kDa dextran permeability Increase in E coli 28C translocation	[71]
DON 3-ADON 15-ADON	Porcine IPEC-1 cell line	10 to 30 µM	Decrease in TEER and increase in 4 kDa dextran permeability 15-ADON >> DON > 3-ADON	[51]
		24 to 48 h	Decrease in claudin-3 and -4 tight junction proteins expression 15-ADON >> DON = 3-ADON
DON	Porcine IPEC-J2 cell line	2.5 to 10 µM 24 h	Decrease in cell viability Increase of lactate dehydrogenase release Decrease in ATP content	[67]
Ex vivo approaches
DON	Porcine tissue (Ussing chamber)	20 to 50 µM 2 h	Increase in 4 kDa dextran permeability	[71]
	Porcine tissue (jejunal explants)	1 to 10 µM 4 h	Shortened and coalescent villi, lysis of enterocytes, edema	[48]