new cannabinoid therapeutics
DESCRIPTION
http://www.cannabinoid-therapeutics.com/TRANSCRIPT
Tamema Choudhury Vincent Li David McNee
NEW CANNABINOID THERAPEUTICS
The endocannabinoid system
• Established cannabinoid receptors: CB1 and CB2.
• Other orphan receptors (e.g. GPR55) as potential targets.
• Endogenous ligands include Anandamide (AEA) and 2-arachidonoyl glycerol (2-AG).
• Variety of potential clinical uses including pain management, obesity and schizophrenia.
Orthosteric site
Pain & inflammation Multiple sclerosis
Suicide & depression
Euphoria, Memory loss, Hallucination
ORTHOSTERIC BLOCKERS
ORTHOSTERIC ACTIVATORS
Obesity & metabolic syndrome Nicotine addiction Mental illness Drug abuse
CB1 Receptor
Signals which control neuronal
excitability
α β γ
Endocannabinoids • Anandamide • 2-AG
Phytocannabinoids • Δ9THC
Synthetic small molecules • Agonists • Inverse Agonists
Orthosteric binding site
CB1 Receptor
Signals which control neuronal
excitability
Pain & inflammation Depression
α β γ
Endocannabinoids
Orthosteric binding site FAAH INHIBITORS
FAAH Inactive Metabolites
Fatty acid amino hydrolase (FAAH)
No side effects?
Effe
ct
Effe
ct
Time
Endogenous Agonist
Time
Allosteric inhibitor
Allosteric site
CB1 Receptor
Signals which control neuronal
excitability
α β γ
Orthosteric binding site
allosteric Novel small molecules
Endocannabinoids • Anandamide • 2AG
GTPγS
Method • Mouse Brain Membrane Preparation
• Homogenised and centrifuged several times with different speeds at 4°C. • Protein concentration determined using spectrophotometry.
• [35S]GTPγS Functional Assay • Measures the activity of G-protein
through the accumulation of membrane-bound Gα[35S]GTPγS.
• Beta particles emitted are detected with a liquid scintillation counter.
• Equilibrium Binding Assay (Affinity) • Measures displacement of [3H]CP55940 at the CB1 receptors orthosteric site. • Beta particles emitted are detected with a liquid scintillation counter.
α β γ
GDP
GPCR
Agonist
Results – JK263-2
-10 -9 -8 -7 -6 -5 -4
-20
0
20
40
60
80
100 DMSO1µm JK263-2
CP55940 log concentration (M)
% S
timul
atio
n [35
S]G
TPγS
Bin
ding
-11 -10 -9 -8 -7 -6 -5 -4
-100
-80
-60
-40
-20
0
20
40
60
80
100
120JK-263-2CP55940
log concentration (M)
% d
ispl
acem
ent o
f [3 H
]CP5
5940
-10 -9 -8 -7 -6 -5 -4
-20
0
20
40
60
80
100
120
140 DMSO100nM JK_263-2
AEA log concentration (M)
% S
timul
atio
n [35
S]G
TPγS
Bin
ding
Results – JK263-2 (cont.)
Results ORG-27569
-10 -9 -8 -7 -6 -5 -4
-20
0
20
40
60 DMSO1µm ORG27569
CP55940 log concentration (M)
% S
timul
atio
n [35
S]G
TPγS
Bin
ding
-10 -9 -8 -7 -6 -5 -4
-100
-80
-60
-40
-20
0
20
40
60
80
100
120ORG27569CP55940
log concentration (M)
% d
ispl
acem
ent o
f [3 H
]CP5
5940
Key findings • JK263-2: Increases both affinity and efficacy. Potential allosteric enhancer.
• ORG-27569: Increases affinity whilst inhibiting efficacy. Potential allosteric inhibitor.
Summary
• Cannabinoid compounds are an important area of pharmacological discovery. The compounds tested may be worthy of further investigation to produce novel clinical therapeutics. • JK263-2 as a treatment for chronic pain. • ORG27569 to assist combating obesity.
• Special thanks to Gemma Baillie, Professor Ross and others in the Cannabinoid Group.