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

Yangonin, a kavalactone from Piper methysticum , is a novel CB1 receptor ligand István Ujváry 1 , Alessia Ligresti 2 , Rosaria Villano 2 , Marco Allarà 2 and Vincenzo Di Marzo 2 1 iKem BT, Budapest, Hungary 2 Endocannabinoid Research Group, Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Pozzuoli, Italy 22 nd Annual Symposium of the International Cannabinoid Research Society July 22 – 27, 2012, Freiburg, Germany

Structural diversity of selected “ phytocannabinoids ” H 3 C CH 3 O H 3 C H 3 C CH 3 CH 3 AcO N H CH 3 H 3 C O CH 2 N N O CH 3 CH 3 H 2 C O H H b -caryophyllene Echinacea isobutylamide diindolylmethane rutamarin CB 2 receptor agonist CB 1 receptor agonist CB 2 receptor agonist CB 2 receptor ligand Raduner et al , 2006 Gertsch et al , 2008 Yin et al , 2009 Rollinger et al , 2009 H 3 C CH 3 CH 3 CH 3 H O O CH 3 O CH 3 H 3 C O O N CH 3 H H H 2 C O P OH N H H O OH OCH 3 H H 3 C CO 2 CH 3 OH OH falcarinol desulfohaplosamate (from sponge) 3,6-oxidovoacangine CB 2 receptor antagonist CB 2 receptor ligand CB 2 receptor antagonist Leonti et al , 2010 Chianese et al , 2011 Kitajima et al , 2011 H 3 C CO 2 CH 3 CH 3 OH O OH O H 3 C CH 3 O NH 2 CH 3 H O O H O CH 3 OH CH 3 oleamide kaempferol pristimerin FAAH inhibitor FAAH inhibitor MAGL inhibitor Maurelli et al , 2005 Thors et al , 2008 King et al , 2009

The kava plant ( Piper methysticum Forster; Piperaceae) 21 November 2011, Vanuatu

The kava drink (kawa, kava-kava, yaquna) and preparations from it awa – bitter ; me θ usm έ nos - 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 oder 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 Main effects • 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 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) +12 minor kavalactones (~5%) OCH 3 OCH 3 5 8 6 O O O O 7 kavain 7,8-dihydrokavain OCH 3 OCH 3 O O O O CH 3 O yangonin desmethoxyyangonin OCH 3 OCH 3 O O O O O O O O methysticin 7,8-dihydromethysticin

Reported pharmacological targets of kavalactones GABA A receptor , NE uptake, DA uptake , 5-HT level , kavain PGE 2 / TXA 2 formation inhibition, COX inhibition , voltage-gated Na + channels 7,8-dihydrokavain GABA A receptor, DA uptake , 5-HT level , voltage-gated Na + channels, COX inhibition , MAO-B inhibition GABA A receptor , DA level , COX inhibition , MAO-B inhibition yangonin desmethoxyyangonin GABA A receptor , DA level , 5-HT level , COX inhibition , MAO-B inhibition methysticin GABA A receptor, NE uptake , COX inhibition , MAO-B inhibition 7,8-dihydromethysticin GABA A receptor , 5-HT level , voltage-gated Na + channels , COX inhibition , MAO-B inhibition kavalactone-rich extract GABA A receptor, DA level , D 2 receptor , opioid receptors , 5-HT 7 receptors Character size indicates level of activity: < 1 m M ; 1 – 100 m M; 100 – 500 m M ; low but measurable effect

Binding of kavalactones to human recombinant CB 1 receptors in vitro displacement of [ 3 H]CP 55,940 binding (mean values, n = 3) K i Displacement at compound m M 10 m M (%) 7,8-dihydrokavain >10 23.6 ( ± )-kavain >10 14.1 7,8-dihydromethysticin >10 20.1 methysticin >10 29.1 65.4 0.72 ± 0.21 yangonin (98.4% at 25 m M) D 9 -THC 0. 0041 not tested For experimental details, see: Ligresti A et al (2012) Pharmacol Res , 66 , 163

Binding of kavalactones to human recombinant CB 2 receptors in vitro displacement of [ 3 H]CP 55,940 binding (mean values, n = 3) K i Displacement compound m M at 10 m M (%) 7,8-dihydrokavain >10 8.16 ( ± )-kavain >10 16.4 7,8-dihydromethysticin >10 12.6 methysticin >10 9.55 yangonin >10 38.2 D 9 -THC 0.0089 not tested For experimental details, see: Ligresti A et al (2012) Pharmacol Res , 66 , 163

Displacement curves of THC and yangonin binding to CB receptors each symbol represents the mean per cent displacement ± SEM ( n = 3)  D 9 -THC (CB 1 )  yangonin (CB 1 ) % displacement of  D 9 -THC (CB 2 )  yangonin (CB 2 ) [ 3 H] CP 55,940 binding concentration , log M

Binding of selected new synthetic kavalactone analogues to hCB 1 and hCB 2 receptors % displacement at 10 m M* compound CB 1 CB 2 OCH 3 16.4 45.4 H 3 C O O OCH 3 10.4 25.7 H 3 C O O OH O O 16.5 8.8 OCH 3 O 20.5 3.5 O O OCH 3 0 19.5 O O * K i values for both receptors are >10 m M for all analogues

Effect of kavalactones on endocannabinoid catabolism Background OCH 3 Glutathione has been implicated in the metabolism of kavalactones O O kavain Interaction with Ser / Cys residues at / near active site? FAAH inhibition (rat brain enzyme preparation using AEA as substrate) IC 50 > 10 m M for all natural and synthetic compounds (1.4 – 28.3 % inhibition at 10 m M) MAGL inhibition (cytosolic COS enzyme preparation using 2-AG as substrate) IC 50 > 10 m M for all natural and synthetic compounds (0 – 25.2 % inhibition at 10 m M) For experimental details, see: Ligresti A et al (2012) Pharmacol Res , 66 , 163

Summary  yangonin is a CB 1 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 CH 3 OCH 3 OH O O H 3 C O CH 3 CH 3 O H 3 C