Inhibition of interleukin-8 release in the human colonic epithelial cell line HT-29 by cannabinoids

Abstract

We have investigated the effects of cannabinoid agonists and antagonists on tumour necrosis factor-α (TNF-α)-induced secretion of interleukin-8 from the colonic epithelial cell line, HT-29. The cannabinoid receptor agonists {(−)-3-[2-hydroxy-4-(1,1-dimethyl-heptyl)-phenyl]4-[3-hydroxypropyl]cyclo-hexan-1-ol} (CP55,940); Δ-9-tetrahydrocannabinol; [ R(+)-[2,3-dihydro-5-methyl-3-[(morpholinyl) methyl] pyrrolo[1,2,3-de]1,4-benzoxazin-6-yl](1-naphthyl) methanone mesylate} (WIN55,212-2) and 1-propyl-2-methyl-3-naphthoyl-indole (JWH 015) inhibited TNF-α induced release of interleukin-8 in a concentration-dependent manner. The less active enantiomer of WIN55212-2, [ S(−)-[2,3-dihydro-5-methyl-3-[(morpholinyl)methyl]pyrrolo[1,2,3-de]1,4-benzoxazin-6-yl](1-naphthyl) methanone mesylate (WIN55212-3), and the cannabinoid CB 1 receptor agonist arachidonoyl-2-chloroethylamide (ACEA) had no significant effect on TNF-α-induced release of interleukin-8. The cannabinoid CB 1 receptor antagonist N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1,4-pyrazole-3-carboxamide hydrochloride (SR141716A; 10 −6 M) antagonised the inhibitory effect of CP55,940 (pA 2=8.3±0.2, n=6) but did not antagonise the inhibitory effects of WIN55212-2 and JWH 015. The cannabinoid CB 2 receptor antagonist N-(1,S)-endo1,3,3-trimethylbicyclo(2,2,1)heptan-2-yl)-5(4-chloro-3-methyl-phenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR144528; 10 −6 M) antagonised the inhibitory effects of CP55,940 (pA 2=8.2±0.8, n=6), WIN55212-2 (pA 2=7.1±0.3, n=6) and JWH 015 (pA 2=7.6±0.3, n=6) , respectively. Western immunoblotting of HT-29 cell lysates revealed a protein with a size that is consistent with the presence of cannabinoid CB 2 receptors. We conclude that in HT-29 cells, TNF-α-induced interleukin-8 release is inhibited by cannabinoids through activation of cannabinoid CB 2 receptors.