Differential effect of opioid and cannabinoid receptor blockade on heroin‐seeking reinstatement and cannabinoid substitution in heroin‐abstinent rats

L Fattore, MS Spano , V Melis, P Fadda, W Fratta

British Journal of Pharmacology (2011) 163 1550–1562

doi: 10.1111/j.1476-5381.2011.01459.x

Opioids and cannabinoids interact in drug addiction and relapse. We investigated the effect of the opioid receptor antagonist naloxone and/or the cannabinoidCB1 receptor antagonist rimonabant on cannabinoid‐induced reinstatement of heroin seeking and on cannabinoid substitution in heroin‐abstinent rats.

Background & Purpose

*Determination and Characterization of a Cannabinoid Receptor in Rat Brain

December 1988 Molecular Pharmacology 34(5):605-13

William Devane, F.A. III Dysarz, M.R. Johnson, Allyn C Howlett

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.572.7935&rep=rep1&type=pdf

The determination and characterization of a cannabinoid receptor from brain are reported. A biologically active bicyclic cannabinoid analgetic CP-55,940 was tritium-labeled to high specific activity. Conditions for binding to rat brain P2 membranes and synaptosomes were established. The pH optimum was between 7 and 8, and specific binding could be eliminated by heating the membranes to 60 degrees. Binding to the P2 membranes was linear within the range of 10 to 50 micrograms of protein/ml. Specific binding (defined as total binding displaced by 1 microM delta 9-tetrahydrocannabinol (delta 9-THC) or 100 nM desacetyllevonantradol) was saturable. The Kd determined from Scatchard analysis was 133 pM, and the Bmax for rat cortical P2 membranes was 1.85 pmol/mg of protein. The Hill coefficient for [3H]CP-55,940 approximated 1, indicating that, under the conditions of assay, a single class of binding sites was determined that did not exhibit cooperativity. The binding was rapid (kon approximately 2.6 x 10(-4) pM-1 min-1) and reversible (Koff approximately 0.016 min-1) and (koff’ greater than 0.06 min-1). The two Kd values estimated from the kinetic constants approximately 55 pM and exceeded 200 pM, respectively. The binding of the agonist ligand [3H]CP-55,940 was decreased by the nonhydrolyzable GTP analog guanylylimidodiphosphate. The guanine nucleotide induced a more rapid dissociation of the ligand from the binding site, consistent with an allosteric regulation of the putative receptor by a G protein. The binding was also sensitive to MgCl2 and CaCl2. Binding of [3H]CP-55,940 was displaced by cannabinoid drugs in the following order of potency: CP-55,940 greater than or equal to desacetyllevonantradol greater than 11-OH-delta 9-THC = delta 9-THC greater than cannabinol. Cannabidiol and cannabigerol displaced [3H]CP-55,940 by less than 50% at 1 microM concentrations. The (-)-isomer of CP-55,940 displaced with 50-fold greater potency than the (+)-isomer. This pharmacology is comparable to both the inhibition of adenylate cyclase in vitro and the analgetic activity of these compounds in vivo. The criteria for a high affinity, stereoselective, pharmacologically distinct cannabinoid receptor in brain tissue have been fulfilled.

Abstract

D9 -Tetrahydrocannabinol and N-arachidonyl glycine are full agonists at GPR18 receptors and induce migration in human endometrial HEC-1B cells

Douglas McHugh, Jeremy Page, Emily Dunn and Heather B Bradshaw

British Journal of Pharamacology, 165 (8) 2012.

DOI: 10.1111/j.1476-5381.2011.01497.x

Endometriosis is a disorder in which the endometrium forms growths outside the uterus and is associated with chronic pain. Recent evidence suggests that endometrial motility plays a role in the aetiology of endometriosis. The endocannabinoid system regulates cellular migration. Given the growing involvement of the endocannabinoids in reproduction, we investigated the role of the endocannabinoid system in migration of endometrial cells.

Background & Purpose

Crystal Structure of the Human Cannabinoid Receptor CB1

Tian Hua, Kiran Vemuri, Mengchen Pu, Lu Qu, Gye Won Han, Yiran Wu,1 Suwen Zhao, Wenqing Shui, Shanshan Li, Anisha Korde, Robert B. Laprairie, Edward L. Stahl, Jo-Hao Ho, Nikolai Zvonok, Han Zhou, Irina Kufareva, Beili Wu, Qiang Zhao, Michael A. Hanson, Laura M. Bohn, Alexandros Makriyannis, Raymond C. Stevens, and Zhi-Jie Liu

Cell 167(3). 2016

Doi: 10.1016/j.cell.2016.10.004

Cannabinoid receptor 1 (CB1) is the principal target of Δ9-tetrahydrocannabinol (THC), a psychoactive chemical from Cannabis sativa with a wide range of therapeutic applications and a long history of recreational use. CB1 is activated by endocannabinoids and is a promising therapeutic target for pain management, inflammation, obesity, and substance abuse disorders. Here, we present the 2.8 Å crystal structure of human CB1 in complex with AM6538, a stabilizing antagonist, synthesized and characterized for this structural study. The structure of the CB1-AM6538 complex reveals key features of the receptor and critical interactions for antagonist binding. In combination with functional studies and molecular modeling, the structure provides insight into the binding mode of naturally occurring CB1 ligands, such as THC, and synthetic cannabinoids. This enhances our understanding of the molecular basis for the physiological functions of CB1 and provides new opportunities for the design of next-generation CB1-targeting pharmaceuticals.

Abstract

CB receptor ligands from plants.

Woelkart K, Salo-Ahen OM, Bauer R.

Curr Top Med Chem. 2008;8(3):173-86.

DOI: 10.2174/156802608783498023

Advances in understanding the physiology and pharmacology of the endogenous cannabinoid system have potentiated the interest of cannabinoid receptors as potential therapeutic targets. Cannabinoids have been shown to modulate a variety of immune cell functions and have therapeutic implications on central nervous system (CNS) inflammation, chronic inflammatory conditions such as arthritis, and may be therapeutically useful in treating autoimmune conditions such as multiple sclerosis. Many of these drug effects occur through cannabinoid receptor signalling mechanisms and the modulation of cytokines and other gene products. Further, endocannabinoids have been found to have many physiological and patho-physiological functions, including mood alteration and analgesia, control of energy balance, gut motility, motor and co-ordination activities, as well as alleviation of neurological, psychiatric and eating disorders. Plants offer a wide range of chemical diversity and have been a growing domain in the search for effective cannabinoid ligands. Cannabis sativa L. with the known plant cannabinoid, Delta(9-)tetrahydrocannabinol (THC) and Echinacea species with the cannabinoid (CB) receptor-binding lipophilic alkamides are the best known herbal cannabimimetics. This review focuses on the state of the art in CB ligands from plants, as well their possible therapeutic and immunomodulatory effects.

Abstract

CB2 Cannabinoid Receptor As Potential Target against Alzheimer’s Disease

Ester Aso, Isidro Ferrer

Frontiers in Neuroscience. (10) 31 May, 2016.

https://www.nature.com/articles/npjamd201612

DOI: 10.3389/fnins.2016.00243

The CB2 receptor is one of the components of the endogenous cannabinoid system, a complex network of signaling molecules and receptors involved in the homeostatic control of several physiological functions. Accumulated evidence suggests a role for CB2 receptors in Alzheimer’s disease (AD) and indicates their potential as a therapeutic target against this neurodegenerative disease. Levels of CB2 receptors are significantly increased in post-mortem AD brains, mainly in microglia surrounding senile plaques, and their expression levels correlate with the amounts of Aβ42 and β-amyloid plaque deposition. Moreover, several studies on animal models of AD have demonstrated that specific CB2 receptor agonists, which are devoid of psychoactive effects, reduce AD-like pathology, resulting in attenuation of the inflammation associated with the disease but also modulating Aβ and tau aberrant processing, among other effects. CB2 receptor activation also improves cognitive impairment in animal models of AD. This review discusses available data regarding the role of CB2 receptors in AD and the potential usefulness of specific agonists of these receptors against AD.

Abstract

Time course of cannabinoid accumulation and chemotype development during the growth of Cannabis sativa L

D. Pacifico · F. Miselli · A. Carboni · A. Moschella · G. Mandolino

Euphytica (2008) 160:231–240

DOI 10.1007/s10681-007-9543-y

The time course of cannabinoid accumulation in the leaves of individual plants of three Cannabis accessions was determined by gaschromatographic analysis in greenhouse-grown plants. The total amounts and the concentration ratios of CBD, THC and CBG were determined; two accessions (an experimental hybrid, (21R £ 15R) £ NL, and plants from a seized seed lot) were found chemotypically uniform, with all plants belonging to chemotpe II (mixed) and I (high THC) respectively. The Carmagnola accession showed chemotypic heterogeneity, with a majority of plants belonging to chemotype III. The CBD/THC and CBG/CBD ratios were shown to be largely constant in the leaves, since 28 and until 103 days after sowing, and consistent with the ratios determined on mature inflorescences. CBD and THC maximum amounts in the leaves showed a peak in the leaves around 80 days from sowing, and were shown to be simultaneous during the growth period, irrespective of the. Callus cultures were obtained from all the five different chemotypes (I, II, III, IV, V), and GC analyses were performed. Independently of the type and amount of cannabinoids in the mother plants, it was confirmed that callus cultures of Cannabis were not able to produce detectable amounts of any cannabinoids.

Abstract

Safety and pharmacokinetics of oral delta-9-tetrahydrocannabinol in healthy older subjects: A randomized controlled trial

Amir I.A.Ahmed, GekeA.H.van den Elsen, Angela Colbers, Marjolein A. van der Marck, David M.Burger, TonB.Feuthe, Marcel G.M.Olde Rikkert, Cornelis Kramersc

European Neuropsychopharmacology(2014) 24, 1475–1482

DOI: 10.1016/j.euroneuro.2014.06.007

There is a great concern about the safety of THC-based drugs in older people( >65 years),as most of THC-trials did not include such group. In this phase 1, randomized, double-blind, double-dummy, placebo-controlled, cross-overtrial, we evaluated the safety and pharmacokinetics of three oral doses of Namisols, a novel THC in tablet form, in older subjects. Twelve healthy older subjects (6male;meanage72+5 years) randomly received a single oral dose of 3 mg, 5mg, or 6.5mg of THC or matching placebo, in a crossover manner, on each intervention day. The data for 11 subjects were included in the analysis. The data of 1 subject were excluded due to non compliance to study medication THC was safe and well tolerated. The most frequently reported adverse events (AEs) were drowsiness (27%) and drymouth (11%). Subjects reported more AEs with THC 6.5 mg than with3mg (p=0.048), 5mg (p=0.034) and placebo (p=0.013). There was a wide inter-individual variability in plasma concentrations of THC. Subjects for whom the Cmax fell within the sampling period (over2h), Cmax was 1.42– _4.57 ng/mLand Tmax was 67–92 min.TheAUC0–2 h (n=11) was1.67–3.51 ng/mL .Overall, the pharmacodynamic effects of THC were smaller than effects previously reported in young adults.

Abstract