Targeting fatty acid amide hydrolase as a therapeutic strategy for antitussive therapy

Area of Science:

• Pharmacology
• Neuroscience
• Respiratory Medicine

Background:

• Cough is a common medical complaint with limited treatment options.
• Fatty acid amide hydrolase (FAAH) degrades endocannabinoids; its inhibition has anti-inflammatory and analgesic effects.
• Cannabinoids suppress cough reflexes, suggesting FAAH inhibition may offer antitussive benefits.

Purpose of the Study:

• To investigate the potential of fatty acid amide hydrolase (FAAH) inhibition as a novel antitussive therapy.
• To explore the role of fatty acid amides in modulating vagal afferent nerve activity.
• To determine the mechanism underlying FAAH inhibition-induced cough suppression.

Main Methods:

• Utilized primary vagal ganglia neurons, tissue bioassays, in vivo electrophysiology, and a conscious guinea pig cough model.
• Measured plasma levels of fatty acid amides following FAAH inhibition.
• Investigated the cellular pathways involved in palmitoylethanolamide's effects on neuronal activation.

Main Results:

• FAAH inhibition demonstrated significant antitussive activity in guinea pigs.
• Concomitant elevation of endocannabinoids, including anandamide and palmitoylethanolamide, was observed.
• Palmitoylethanolamide inhibited neuronal activation in the vagus nerve via a CB2 receptor and protein phosphatase 2A pathway.

Conclusions:

• FAAH inhibition represents a promising therapeutic strategy for developing new cough medicines.
• This approach may provide antitussive effects without the adverse effects associated with direct cannabinoid agonists.
• Targeting FAAH offers a novel pathway for managing chronic cough.