Effects of Corydalis yanhusuo and Angelicae dahuricae on cold pressor-induced pain in humans: a controlled trial.

Pain is considered the most common complaint worldwide for which patients seek treatment. Conventional analgesic agents play an important role in modern pain therapy, but they cause several adverse effects. Therefore, newer and better analgesics continue to be investigated. In this controlled clinical trial, the authors evaluated the analgesic effects of 2 herbal medicines, Corydalis yanhusuo and Angelicae dahuricae. They used the cold-pressor test-a simple, reliable, and widely used model in humans-for induction of tonic pain. They demonstrated that after a single, oral administration of the extracts of C. yanhusuo and A. dahuricae, the pain intensity and pain bothersomeness scores significantly decreased (both P < .01). Dose-related analgesic effect was also observed. Results from this study suggest that C. yanhusuo and A. dahuricae may have a potential clinical value for treating mild to moderate pain.