Sinomenine is a promising analgesic and anti-hyperalgesic for pain and hypersensitivity in rheumatoid arthritis

摘要

In this issue of the Scandinavian Journal of Pain, Tianle Gao and coworkers in Zsuzsanna Wiesenfeld-Hallin's research group at Karolinska Institutet report on the effect of sinomenine to alleviate mechanical hypersensitivity in mice with experimentally-induced rheumatoid arthritis (RA) [1 ]. Sinomenine is isolated from the climbing plant Sinomenium acutum, and it is used in traditional medicine in Asia for its beneficial effects on auto immune diseases, especially RA [2]. In animal models of arthritis, sinomenine counteracts joint destruction and reduces several signs of inflammation including joint swelling, erythrocyte sedimentation rate, production of antibodies, and secretion of cytokines [3,4]. Besides its anti-inflammatory property, sinomenine also reduces pain behaviour in nociceptive, inflammatory, and neuropathic pain models in rodents [5-8]. Gao and co-workers are now following up the anti-nociceptive effect on inflammation-induced hypersensitivity with further analysis of the effect of sinomenine on mechanical hypersensitivity associated with RA [1 ]. Pain is a dominating symptom in human RA and the hyperalgesic symptoms often precede the inflammatory signs, and continues after the inflammation subsides. This suggests that it is not only inflammation that is involved in the pathophysiology of pain in RA [9].