Cannabinoids Alleviate Experimentally Induced Intestinal Inflammation by Acting at Central and Peripheral Receptors

Background and Aims: In an attempt to further investigate the role of cannabinoid (CB) system in the pathogenesis of inflammatory bowel diseases, we employed two recently developed ligands, AM841 (a covalently acting CB agonist) and CB13 (a peripherally-restricted CB agonist) to establish whether central and peripheral CB sites are involved in the anti-inflammatory action in the intestine. Methods and Results: AM841 (0.01, 0.1 and 1 mg/kg, i.p.) significantly decreased inflammation scores in dextran sulfate sodium (DSS)- and 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)-treated mice when administered before induction of colitis or as a treatment of existing intestinal inflammation. The effect was absent in CB1, CB2 and CB1/2-deficient mice. A peripherally-restricted agonist CB13 did not alleviate colitis when given i.p. (0.1 mg/kg), but significantly decreased inflammation score after central administration (0.1 mu g/animal). Conclusions: This is the first evidence that central and peripheral CB receptors are responsible for the protective and therapeutic action of cannabinoids in mouse models of colitis. Our observations provide new insight to CB pharmacology and validate the use of novel ligands AM841 and CB13 as potent tools in CB-related research

Cannabinoids Alleviate Experimentally Induced Intestinal Inflammation by Acting at Central and Peripheral Receptors

Background and Aims: In an attempt to further investigate the role of cannabinoid (CB) system in the pathogenesis of inflammatory bowel diseases, we employed two recently developed ligands, AM841 (a covalently acting CB agonist) and CB13 (a peripherally-restricted CB agonist) to establish whether central and peripheral CB sites are involved in the anti-inflammatory action in the intestine. Methods and Results: AM841 (0.01, 0.1 and 1 mg/kg, i.p.) significantly decreased inflammation scores in dextran sulfate sodium (DSS)- and 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)-treated mice when administered before induction of colitis or as a treatment of existing intestinal inflammation. The effect was absent in CB1, CB2 and CB1/2-deficient mice. A peripherally-restricted agonist CB13 did not alleviate colitis when given i.p. (0.1 mg/kg), but significantly decreased inflammation score after central administration (0.1 mu g/animal). Conclusions: This is the first evidence that central and peripheral CB receptors are responsible for the protective and therapeutic action of cannabinoids in mouse models of colitis. Our observations provide new insight to CB pharmacology and validate the use of novel ligands AM841 and CB13 as potent tools in CB-related research

Novel Electrophilic and Photoaffinity Covalent Probes for Mapping the Cannabinoid 1 Receptor Allosteric Site(s)

ACKNOWLEDGMENTS The work was supported by National Institutes of Health grants DA027113 and EY024717 to G.A.T. and DA09158 to A.M. A portion of this work was submitted in 2011 by A. Kulkarni in partial fulfillment of M.S. degree requirements from Northeastern University, Boston, MA.Peer reviewedPublisher PD

One-Pot C–N/C–C Cross-Coupling of Methyliminodiacetic Acid Boronyl Arenes Enabled by Protective Enolization

Iterative cross-coupling is a highly efficient and versatile strategy for modular construction in organic synthesis, though this has historically been demonstrated solely in the context of C–C bond formation. A C–N cross-coupling of haloarene methyliminodiacetic acid (MIDA) boronates with a wide range of aromatic and aliphatic amines is reported. Successful cross-coupling of aliphatic amines was realized only through protective enolization of the MIDA group. This reaction paradigm was subsequently utilized to achieve a one-pot C–N/C–C cross-coupling sequence

Protective effect of CB 13 after central (0.1 µg/animal, i.c.v, OD), but not peripheral (0.1 mg/kg, i.p., OD) administration for 3 days on TNBS-induced colitis in mice.

<p>Figure shows data for (A) macroscopic score, (B) MPO activity and (C) ulcer score. **p<0.01, as compared with TNBS-treated mice. Data represent means ± SEM, n = 6–8.</p

Protective effect of AM841 (0.1 mg/kg, i.p.) injected once daily for 3 days on TNBS-induced colitis in mice.

<p>Figure shows data for (A) macroscopic score, (B) MPO activity, (C) ulcer score and (D) body weight. $$$p<0.001, as compared with control animals. **p<0.01, ***p<0.001, as compared with TNBS-treated mice. Data represent means ± SEM, n = 6–8.</p

Therapeutic effect of AM841 (0.1 mg/kg, i.p.) injected once or twice daily from day 4 on DSS-induced colitis in mice.

<p>Figure shows data for (A) macroscopic score, (B) MPO activity and (C) body weight. $$p<0.01,$$$p<0.001, as compared with control animals. *p<0.05, **p<0.01, as compared with DSS-treated mice. Data represent means ± SEM, n = 6–8.</p

Chemotactic assay with murine neutrophils.

<p>AM841 (0.1–100 nM) inhibited neutrophil migration to 10 nM fMLP in a concentration-dependent manner. $p<0.05,$$$p<0.001, as compared with vehicle-treated controls. Data represent means ± SEM of 4 independent experiments performed in duplicate.</p

Protective effect of AM841 (0.01, 0.1 and 1 mg/kg, i.p.) injected once daily for 7 days on DSS-induced colitis in mice.

<p>Figure shows data for (A) macroscopic score, (B) MPO activity, (C) body weight, (D) representative micrographs for hematoxylin and eosin staining of colon wall sections (i, control; ii, DSS; iii, DSS+AM841 0.01 mg/kg; iv, DSS+AM841 0.1 mg/kg; v, DSS+AM841 1 mg/kg; scale bar = 100 µm) and (E) microscopic score. $$$p<0.001, as compared with control animals. *p<0.05, ***p<0.001, as compared with DSS-treated mice. Data represent means ± SEM, n = 6–8.</p