Micronized palmitoylethanolamide reduces joint pain and glial cell activation.

Abstract

OBJECTIVE AND DESIGN:

Temporomandibular disorder (TMD) is a common painful condition in the temporomandibular joint (TMJ). Joint inflammation is believed to be a chief cause of pain in patients with TMD, through the release of pro-inflammatory cytokines that induce peripheral sensitization of nerve terminals followed by microglial stimulation.

MATERIALS AND SUBJECT:

TMJ was induced in rats with the injection of complete Freund's adjuvant (CFA) emulsion into the left TMJ capsule.

TREATMENT:

The present study would assess the effects of micronized palmitoylethanolamide (m-PEA) on glial activation and trigeminal hypersensitivity.

METHODS:

Ten mg/kg m-PEA or corresponding vehicle was administered 1 h after CFA and mechanical allodynia and edema were evaluated at 24 and 72 h after CFA injection.

RESULTS:

CFA-injected animals showed TMJ edema and ipsilateral mechanical allodynia accompanied by a robust growth in GFAP protein-positive satellite glial cells and activation of resident macrophages in the TG. Moreover, m-PEA administration significantly reduced the degree of TMJ damage and pain, macrophage activation in TG and up-regulation of Iba1.

CONCLUSIONS:

The results confirm that m-PEA could represent a novel approach for monitoring pain during trigeminal nerve sensitization.

• Authors: Maria Lavinia Bartolucci, Ida Marini, Francesco Bortolotti, Daniela Impellizzeri, Rosanna Di Paola, Giuseppe Bruschetta, Rosalia Crupi, Marco Portelli, Angela Militi, Giacomo Oteri, Emanuela Esposito, Salvatore Cuzzocrea
• Journal: Inflammation research : official journal of the European Histamine Research Society ... [et al.] (Inflamm Res) Vol. 67 Issue 10 Pg. 891-901 (Oct 2018) ISSN: 1420-908X [Electronic] Switzerland
• PMID: 30121836 (Publication Type: Journal Article)

Chemical References

• Amides
• Analgesics
• Anti-Inflammatory Agents, Non-Steroidal
• Ethanolamines
• GFAP protein, rat
• Glial Fibrillary Acidic Protein
• Palmitic Acids
• palmidrol
• Freund's Adjuvant

Topics

• Amides
• Analgesics (therapeutic use)
• Animals
• Anti-Inflammatory Agents, Non-Steroidal (therapeutic use)
• Arthralgia (chemically induced, drug therapy, metabolism)
• Edema (chemically induced, drug therapy, metabolism)
• Ethanolamines (therapeutic use)
• Freund's Adjuvant
• Glial Fibrillary Acidic Protein (metabolism)
• Hyperalgesia (chemically induced, drug therapy, metabolism)
• Male
• Neuroglia (drug effects, metabolism)
• Palmitic Acids (therapeutic use)
• Rats, Sprague-Dawley
• Temporomandibular Joint