The cannabinoid TRPA1 agonist cannabichromene inhibits nitric oxide production in macrophages and ameliorates murine colitis

Abstract

BACKGROUND AND PURPOSEThe non-psychotropic cannabinoid cannabichromene is known to activate the transient receptor potential ankyrin-type1 (TRPA1) and to inhibit endocannabinoid inactivation, both of which are involved in inflammatory processes. We examined here the effects of this phytocannabinoid on peritoneal macrophages and its efficacy in an experimental model of colitis. EXPERIMENTAL APPROACHMurine peritoneal macrophages were activated in vitro by LPS. Nitrite levels were measured using a fluorescent assay; inducible nitric oxide (iNOS), cyclooxygenase-2 (COX-2) and cannabinoid (CB1 and CB2) receptors were analysed by RT-PCR (and/or Western blot analysis); colitis was induced by dinitrobenzene sulphonic acid (DNBS). Endocannabinoid (anandamide and 2-arachidonoylglycerol), palmitoylethanolamide and oleoylethanolamide levels were measured by liquid chromatographymass spectrometry. Colonic inflammation was assessed by evaluating the myeloperoxidase activity as well as by histology and immunohistochemistry. KEY RESULTSLPS caused a significant production of nitrites, associated to up-regulation of anandamide, iNOS, COX-2, CB1 receptors and down-regulation of CB2 receptors mRNA expression. Cannabichromene significantly reduced LPS-stimulated nitrite levels, and its effect was mimicked by cannabinoid receptor and TRPA1 agonists (carvacrol and cinnamaldehyde) and enhanced by CB1 receptor antagonists. LPS-induced anandamide, iNOS, COX-2 and cannabinoid receptor changes were not significantly modified by cannabichromene, which, however, increased oleoylethanolamide levels. In vivo, cannabichromene ameliorated DNBS-induced colonic inflammation, as revealed by histology, immunohistochemistry and myeloperoxidase activity. CONCLUSION AND IMPLICATIONSCannabichromene exerts anti-inflammatory actions in activated macrophages -with tonic CB1 cannabinoid signalling being negatively coupled to this effect -and ameliorates experimental murine colitis. BJP

Harnessing the anti-inflammatory potential of palmitoylethanolamide

“…The same effect was observed following activation of a7 nicotinic receptors in neurons in primary culture, whereas activation of muscarinic receptors increased PEA, but not AEA levels [29]. Activation of RAW264.7 macrophages in culture with LPS led to decreased PEA levels and increased AEA levels [18], whereas in peritoneal macrophages, AEA levels increased with no change in PEA levels [30]. Taken together, these observations suggest that, although these two NAEs share the same metabolic pathways, different biosynthetic pathways have a predominant role for each of them.…”

From Phytocannabinoids to Cannabinoid Receptors and Endocannabinoids: Pleiotropic Physiological and Pathological Roles Through Complex Pharmacology

“…CBC dose-dependently decreases LPS-induced inflammation in paw edema assay with a noncannabinoid receptor mechanism of action (198). It inhibits nitric oxide production, IL-10, and IFN-␥ levels in LPS-activated macrophages (740), reduces inflammation-induced gut hypermotility in vivo in mice (384), and produces antidepressant-like activity in rodents (236). CBC is analgesic by stimulating the descending pathway of antinociception in the ventrolateral periaqueductal grey, through activation of TRPA1, inhibition of endocannabinoid inactivation, and subsequent elevation of local endocannabinoid levels, and potentiation of adenosine signaling (519).…”

The safety, efficacy and neuromotor effects of the neurosteroid anaesthetic alfaxalone in rats

“…This study described panic responses produced by the TRPV1 antagonists capsazepine and SB366791, which were prevented by AM251, suggesting that the endocannabinoid, anandamide may exert effects via actions at both CB 1 R and TRPV1 (Casarotto et al, 2012). In addition, the cannabinoid cannabichromene (CBC), naturally derived from the Cannabis sativa plant, is known to inhibit endocannabinoid reuptake and to activate TRP ankyrin 1-type (TRPA1) channels (Romano et al, 2013). Alfaxalone activates TRP channels which results in an inward current created by an influx of cations, resulting in a increase in intracellular Ca 2+ in the postsynaptic neuron.…”