Faculty Collaboration Database

Full Fatty Acid Amide Hydrolase Inhibition Combined with Partial Monoacylglycerol Lipase Inhibition: Augmented and Sustained Antinociceptive Effects with Reduced Cannabimimetic Side Effects in Mice. J Pharmacol Exp Ther 2015 Aug;354(2):111-20

Date

05/23/2015

Pubmed ID

25998048

Pubmed Central ID

PMC4518073

DOI

10.1124/jpet.115.222851

Scopus ID

2-s2.0-84941557533 (requires institutional sign-in at Scopus site)   34 Citations

Abstract

Inhibition of fatty acid amide hydrolase (FAAH) or monoacylglycerol lipase (MAGL), the primary hydrolytic enzymes for the respective endocannabinoids N-arachidonoylethanolamine (AEA) and 2-arachidonylglycerol (2-AG), produces antinociception but with minimal cannabimimetic side effects. Although selective inhibitors of either enzyme often show partial efficacy in various nociceptive models, their combined blockade elicits augmented antinociceptive effects, but side effects emerge. Moreover, complete and prolonged MAGL blockade leads to cannabinoid receptor type 1 (CB1) receptor functional tolerance, which represents another challenge in this potential therapeutic strategy. Therefore, the present study tested whether full FAAH inhibition combined with partial MAGL inhibition would produce sustained antinociceptive effects with minimal cannabimimetic side effects. Accordingly, we tested a high dose of the FAAH inhibitor PF-3845 (N-​3-​pyridinyl-​4-​[[3-​[[5-​(trifluoromethyl)-​2-​pyridinyl]oxy]phenyl]methyl]-​1-​piperidinecarboxamide; 10 mg/kg) given in combination with a low dose of the MAGL inhibitor JZL184 [4-nitrophenyl 4-(dibenzo[d][1,3]dioxol-5-yl(hydroxy)methyl)piperidine-1-carboxylate] (4 mg/kg) in mouse models of inflammatory and neuropathic pain. This combination of inhibitors elicited profound increases in brain AEA levels (>10-fold) but only 2- to 3-fold increases in brain 2-AG levels. This combination produced significantly greater antinociceptive effects than single enzyme inhibition and did not elicit common cannabimimetic effects (e.g., catalepsy, hypomotility, hypothermia, and substitution for Δ(9)-tetrahydrocannabinol in the drug-discrimination assay), although these side effects emerged with high-dose JZL184 (i.e., 100 mg/kg). Finally, repeated administration of this combination did not lead to tolerance to its antiallodynic actions in the carrageenan assay or CB1 receptor functional tolerance. Thus, full FAAH inhibition combined with partial MAGL inhibition reduces neuropathic and inflammatory pain states with minimal cannabimimetic effects.

Author List

Ghosh S, Kinsey SG, Liu QS, Hruba L, McMahon LR, Grim TW, Merritt CR, Wise LE, Abdullah RA, Selley DE, Sim-Selley LJ, Cravatt BF, Lichtman AH

Author

Qing-song Liu PhD Professor in the Pharmacology and Toxicology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Amidohydrolases
Analgesics
Animals
Benzodioxoles
Brain
Cannabinoid Receptor Agonists
Cannabinoid Receptor Antagonists
Drug Therapy, Combination
Hyperalgesia
Male
Mice
Mice, Inbred C57BL
Monoacylglycerol Lipases
Piperidines
Pyridines
Receptor, Cannabinoid, CB1
Time Factors
Treatment Outcome