Curcumin produces an antihyperalgesic effect via antagonism of TRPV1.

J Dent Res. 2010 Feb;89(2):170-4.
Curcumin produces an antihyperalgesic effect via antagonism of TRPV1.

Yeon KY, Kim SA, Kim YH, Lee MK, Ahn DK, Kim HJ, Kim JS, Jung SJ, Oh SB.

Dental Research Institute and Department of Physiology, Seoul National University, Yeongeon-Dong Chongno-Ku, Korea.

Curcumin has diverse therapeutic effects, such as anti-inflammatory, anti-oxidant, anti-cancer, and antimicrobial activities. The vanilloid moiety of curcumin is considered important for activation of the transient receptor potential vanilloid 1 (TRPV1), which plays an important role in nociception. However, very little is known about the effects of curcumin on nociception. In the present study, we investigated whether the anti-nociceptive effects of curcumin are mediated via TRPV1 by using nociceptive behavioral studies and in vitro whole-cell patch-clamp recordings in the trigeminal system. Subcutaneous injection of capsaicin in the vibrissa pad area of rats induced thermal hyperalgesia. Intraperitoneally administered curcumin blocked capsaicin-induced thermal hyperalgesia in a dose-dependent manner. Whereas curcumin reduced capsaicin-induced currents in a dose-dependent manner in both trigeminal ganglion neurons and TRPV1-expressing HEK 293 cells, curcumin did not affect heat-induced TRPV1 currents. Taken together, our results indicate that curcumin blocks capsaicin-induced TRPV1 activation and thereby inhibits TRPV1-mediated pain hypersensitivity.