is a novel CB1 receptor ligand Istvn Ujvry 1 , Alessia Ligresti 2 , - - PowerPoint PPT Presentation

István Ujváry1, Alessia Ligresti2, Rosaria Villano2, Marco Allarà2 and Vincenzo Di Marzo2

1iKem BT, Budapest, Hungary 2Endocannabinoid Research Group, Institute of Biomolecular Chemistry,

Consiglio Nazionale delle Ricerche, Pozzuoli, Italy

Yangonin, a kavalactone from Piper methysticum, is a novel CB1 receptor ligand

22nd Annual Symposium of the International Cannabinoid Research Society July 22–27, 2012, Freiburg, Germany

Structural diversity of selected “phytocannabinoids”

kaempferol FAAH inhibitor Thors et al, 2008 Echinacea isobutylamide CB2 receptor agonist Raduner et al, 2006 b-caryophyllene CB1 receptor agonist Gertsch et al, 2008 falcarinol CB2 receptor antagonist Leonti et al, 2010 pristimerin MAGL inhibitor King et al, 2009 desulfohaplosamate (from sponge) CB2 receptor ligand Chianese et al, 2011 rutamarin CB2 receptor ligand Rollinger et al, 2009 diindolylmethane CB2 receptor agonist Yin et al, 2009

• leamide

FAAH inhibitor Maurelli et al, 2005

N H O CH3 CH3 CH3 CH3 C H2 C H3 C H3 N H N H O O O CH2 AcO CH3 C H3 CH3 C H3 O H C H2 C H3 O C H3 CH3 CH3 C H3 CH3 CO2CH3 O H CH3 OH O H O OH O OH

3,6-oxidovoacangine CB2 receptor antagonist Kitajima et al, 2011

CH3 NH2 O O H OH CH3 OH OH H O C H3 CH3 H CH3 C H3 CH3 O P OCH3 O OH H N H N O CH3 CO2CH3 CH3O

The kava plant (Piper methysticum Forster; Piperaceae)

21 November 2011, Vanuatu

The kava drink (kawa, kava-kava, yaquna) and preparations from it

awa –bitter; meθusmέnos - inebriating drink

John LaFarge (1891)

Lebot V, Merlin M & Lindstrom L (1992) Kava – The Pacific Elixir

Allgemeine Wirkungen des Kawagetränkes

...Wirkung wie die einer starken Dose eines spirituösen Getränkes

• der vielmehr eine Betäubung, wie sie Opium hervorruft, beobachtet
• wurde. Auch mit der Wirkung des Lattichs und der des Haschisch ist

die Kawawirkung verglichen worden.

Pharmacology of kava

• mood enhancer
• anxiolytic
• sedative
• sleep inducer
• local anesthetic
• analgetic
• anticonvulsant

Other physiological effects observed after drinking kava: paresthesia (face, extremities), body sway, ataxia, muscle relaxation, hypothermia, slightly bloodshot eyes Cognitive processes only slightly affected. Preparations form various parts of the plant are used in traditional medicine Main effects

For some commercial kavalactone extracts hepatotoxicity of unknown etiology has been reported leading to the restriction / ban of sales of such extracts in several countries in Europe (since 2002).

The main kavalactones (a-kavapyrones) (1927–1959)

kavain 7,8-dihydrokavain

5 6 8 7

O O OCH3 CH3O O O OCH3

yangonin desmethoxyyangonin methysticin 7,8-dihydromethysticin +12 minor kavalactones (~5%)

O O OCH3 O O OCH3 O O OCH3 O O O O OCH3 O O

kavain

GABAA receptor, NE uptake, DA uptake, 5-HT level,

PGE2 / TXA2 formation inhibition, COX inhibition, voltage-gated Na+ channels 7,8-dihydrokavain GABAA receptor, DA uptake, 5-HT level, voltage-gated Na+ channels, COX inhibition, MAO-B inhibition yangonin

GABAA receptor, DA level, COX inhibition, MAO-B inhibition

desmethoxyyangonin

GABAA receptor, DA level, 5-HT level, COX inhibition,

MAO-B inhibition methysticin GABAA receptor, NE uptake, COX inhibition, MAO-B inhibition 7,8-dihydromethysticin GABAA receptor, 5-HT level, voltage-gated Na+ channels,

COX inhibition, MAO-B inhibition

kavalactone-rich extract GABAA receptor, DA level, D2 receptor, opioid receptors,

5-HT7 receptors

Reported pharmacological targets of kavalactones

Character size indicates level of activity:

< 1 mM; 1–100 mM; 100–500 mM; low but measurable effect

Binding of kavalactones to human recombinant CB1 receptors

compound Ki mM Displacement at 10 mM (%) 7,8-dihydrokavain >10 23.6 (±)-kavain >10 14.1 7,8-dihydromethysticin >10 20.1 methysticin >10 29.1 yangonin 0.72 ± 0.21 65.4

(98.4% at 25 mM)

D9-THC

• 0. 0041

not tested For experimental details, see: Ligresti A et al (2012) Pharmacol Res, 66, 163

in vitro displacement of [3H]CP 55,940 binding (mean values, n = 3)

Binding of kavalactones to human recombinant CB2 receptors

compound Ki mM Displacement at 10 mM (%) 7,8-dihydrokavain >10 8.16 (±)-kavain >10 16.4 7,8-dihydromethysticin >10 12.6 methysticin >10 9.55 yangonin >10 38.2 D9-THC 0.0089 not tested

For experimental details, see: Ligresti A et al (2012) Pharmacol Res, 66, 163

in vitro displacement of [3H]CP 55,940 binding (mean values, n = 3)

 yangonin (CB1)

 yangonin (CB2)

concentration, log M % displacement of [3H]CP 55,940 binding

Displacement curves of THC and yangonin binding to CB receptors

each symbol represents the mean per cent displacement ± SEM (n = 3)  D9-THC (CB1)  D9-THC (CB2)

Binding of selected new synthetic kavalactone analogues to hCB1 and hCB2 receptors

compound % displacement at 10 mM* CB1 CB2 16.4 45.4 10.4 25.7 16.5 8.8 20.5 3.5 19.5 *Ki values for both receptors are >10 mM for all analogues

O O OCH3 C H3 O O OCH3 C H3 O O OCH3 O O OH OCH3 O O O

Effect of kavalactones on endocannabinoid catabolism

kavain Interaction with Ser / Cys residues at / near active site? Glutathione has been implicated in the metabolism

• f kavalactones

Background

FAAH inhibition (rat brain enzyme preparation using AEA as substrate) IC50 > 10 mM for all natural and synthetic compounds

(1.4–28.3 % inhibition at 10 mM)

MAGL inhibition (cytosolic COS enzyme preparation using 2-AG as substrate) IC50 > 10 mM for all natural and synthetic compounds

(0–25.2 % inhibition at 10 mM)

O O OCH3

For experimental details, see: Ligresti A et al (2012) Pharmacol Res, 66, 163

Summary

 yangonin is a CB1 receptor ligand  kavalactones may contribute to the complex pharmacology of kava

drink & kava preparations

 kavalactones are novel phytocannabinoid chemotypes  structure optimization of synthetic analogues might lead to more

active receptor ligands

O C H3 C H3 CH3 OH CH3 O O OCH3 CH3O