Evaluating the Potential Antihyperalgesic Effects of Curcumin on a Laboratory Model of Neuropathic Pain

Abstract

Curcumin is an anti-inflammatory and anti-oxidative, herbal supplement that has been utilized in the animal model to evaluate its potential for anti-inflammatory and anti-nociceptive effects among other benefits. This ongoing pilot study examined whether humans show a similar pattern of benefits after acute consumption of curcumin supplements for seven days. Participants underwent two laboratory visits in which capsaicin-induced spontaneous pain, neurogenic inflammation, primary and secondary hyperalgesia, and heat-pain detection thresholds were measured at baseline and post-treatment. Topical capsaicin mimics neuropathic pain by sensitizing the peripheral and central pain pathway. We hypothesized that curcumin would have anti-inflammatory and anti-hyperalgesic effects that would inhibit the neurogenic inflammatory flare response while also inducing an anti-hyperalgesic effect indicated by reduced ratings of spontaneous pain and stimulus-evoked primary and secondary hyperalgesia. Results have shown a decrease in suprathreshold pain intensity and unpleasantness ratings as well as capsaicin-induced spontaneous pain intensity and unpleasantness ratings. Furthermore, results suggest a marked increase in valence during pain testing during the second visit in addition to increased dominance ratings and decreased arousal. Preliminary results show that curcumin may be an effective anti-hyperalgesic supplement in a healthy undergraduate population. Ongoing tests will give further insight into curcumin’s potential on impacting pain processes.