Table 1.

Differential expression of ECS components in human IBD compared to controls as described in the literature.

		IBD
ECS component		UC	CD	References
Receptors	CB1	No change, downregulation, or upregulation	Upregulation	[26–28]
	CB2	Upregulation		[27,30]
		Upregulation (protein) or no change (mRNA, protein)		[26,28]
Ligands	AEA	Upregulation		[10]
		Downregulation		[26]
	2-AG	No change		[10,26]
Synthesizing enzymes	NAPE-PLD	Downregulation or reduced activity		[26,27]
	DAGL	Upregulation		[27]
Degrading enzymes	FAAH	No change (epithelium) or upregulation (immune cells) or increased activity		[26,27]
	MGL	Upregulation		[27]

CB₁: cannabinoid receptor 1; CB₂: cannabinoid receptor 2; AEA: anandamide; 2-AG: 2-arachidonoylglycerol; ECS: endocannabinoid system; IBD: inflammatory bowel disease; NAPE-PLD: N-acyl phosphatidylethanolamine phospholipase D; DAGL: diacylglycerol lipase; FAAH: fatty acid amide hydrolase; MGL: monoacylglycerol lipase.