흰쥐의 염증성 및 신경변성 통증에서 palmitoylethanolamide의 효과

Abstract

Background: Palmitoylethanolamide (PEA) is one of N-acylethanolamides, a family of signaling lipids, with anti-inflammatory effect. Compared with anti-inflammatory effect, little has been known about analgesic effect in chronic pain. This study aimed to clarify whether PEA could alleviate chronic pain from chronic inflammatory and neuropathic pain. Methods: Male Sprague-Dawley rats were injured by transection of left L5 and L6 spinal nerves for neuropathic pain or injected with monoiodoacetic acid (MIA) into the synovial cavity of knee joint for inflammatory pain. Pain was assessed by behavioral responses to stimuli; mechanical hyperalgesia by up and down methods with a series of von Frey filaments and cold allodynia by acetone application. Results: Neuropathic pain by SNT decreased mechanical threshold and increased frequency of response to acetone application. But cold allodynia from SNT not decreased withdrawal frequency. Mechanical hyperalgesia from chronic inflammation was significantly alleviated by both intraperitoneal and intra-articular injection of PEA. Conclusions: These results show that PEA could be effective in alleviating neuropathic and inflammatory pain, especially mechanical hyperalgesia.