The effect of phytocannabinoids on airway hyper-responsiveness, airway inflammation, and cough.

Cannabis has been demonstrated to have bronchodilator, anti-inflammatory, and antitussive activity in the airways, but information on the active cannabinoids, their receptors, and the mechanisms for these effects is limited. We compared the effects of Δ(9)-tetrahydrocannabinol, cannabidiol, cannabigerol, cannabichromene, cannabidiolic acid, and tetrahydrocannabivarin on contractions of the guinea pig-isolated trachea and bronchoconstriction induced by nerve stimulation or methacholine in anesthetized guinea pigs following exposure to saline or the proinflammatory cytokine, tumor necrosis factor α (TNF-α). CP55940 (2-[(1R,2R,5R)-5-hydroxy-2-(3-hydroxypropyl) cyclohexyl]-5-(2-methyloctan-2-yl)phenol), a synthetic cannabinoid agonist, was also investigated in vitro. The cannabinoids were also evaluated on TNF-α- and lipopolysaccharide-induced leukocyte infiltration into the lungs and citric acid-induced cough responses in guinea pigs. TNF-α, but not saline, augmented tracheal contractility and bronchoconstriction induced by nerve stimulation, but not methacholine. Δ(9)-Tetrahydrocannabinol and CP55940 reduced TNF-α-enhanced nerve-evoked contractions in vitro to the magnitude of saline-incubated trachea. This effect was antagonized by the cannabinoid 1 (CB(1)) and CB(2) receptor antagonists AM251 [N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-caroxamide] and JTE907 [N-(1,3-benzodioxol-5-ylmethyl)-1,2-dihydro-7-methoxy-2-oxo-8-(pentyloxy)-3-quinolinecarboxamide], respectively. Tetrahydrocannabivarin partially inhibited the TNF-α-enhanced nerve-evoked contractions, whereas the other cannabinoids were without effect. The effect of cannabidiol and Δ(9)-tetrahydrocannabinol together did not differ from that of the latter alone. Only Δ(9)-tetrahydrocannabinol inhibited TNF-α-enhanced vagal-induced bronchoconstriction, neutrophil recruitment to the airways, and citric acid-induced cough responses. TNF-α potentiated contractions of airway smooth muscle in response to nerve stimulation by enhancing postganglionic acetylcholine release. Δ(9)-Tetrahydrocannabinol and CP55940 inhibited the TNF-α-enhanced acetylcholine release, and hence contraction and bronchoconstriction, through activation of presynaptic CB(1) and CB(2) receptors. The other cannabinoids did not influence cholinergic transmission, and only Δ(9)-THC demonstrated effects on airway hyper-responsiveness, anti-inflammatory activity, and antitussive activity in the airways.

Fucosylated chondroitin sulfates from the body wall of the sea cucumber Holothuria forskali: conformation, selectin binding, and biological activity.

Fucosylated chondroitin sulfate (fCS) extracted from the sea cucumber Holothuria forskali is composed of the following repeating trisaccharide unit: → 3)GalNAcß4,6S(1 → 4) [FucαX(1 → 3)]GlcAß(1 →, where X stands for different sulfation patterns of fucose (X = 3,4S (46%), 2,4S (39%), and 4S (15%)). As revealed by NMR and molecular dynamics simulations, the fCS repeating unit adopts a conformation similar to that of the Le(x) blood group determinant, bringing several sulfate groups into close proximity and creating large negative patches distributed along the helical skeleton of the CS backbone. This may explain the high affinity of fCS oligosaccharides for L- and P-selectins as determined by microarray binding of fCS oligosaccharides prepared by Cu(2+)-catalyzed Fenton-type and photochemical depolymerization. No binding to E-selectin was observed. fCS poly- and oligosaccharides display low cytotoxicity in vitro, inhibit human neutrophil elastase activity, and inhibit the migration of neutrophils through an endothelial cell layer in vitro. Although the polysaccharide showed some anti-coagulant activity, small oligosaccharide fCS fragments had much reduced anticoagulant properties, with activity mainly via heparin cofactor II. The fCS polysaccharides showed prekallikrein activation comparable with dextran sulfate, whereas the fCS oligosaccharides caused almost no effect. The H. forskali fCS oligosaccharides were also tested in a mouse peritoneal inflammation model, where they caused a reduction in neutrophil infiltration. Overall, the data presented support the action of fCS as an inhibitor of selectin interactions, which play vital roles in inflammation and metastasis progression. Future studies of fCS-selectin interaction using fCS fragments or their mimetics may open new avenues for therapeutic intervention.