Capsaicin-d₃is intended for use as an internal standard for the quantification of capsaicin by GC- or LC-MS. Capsaicin is a terpene alkaloid that has been found inCapsicumand has diverse biological activities.^1,2,3,4It induces inward currents in HEK293 cells expressing rat transient receptor potential vanilloid 1 (TRPV1; EC₅₀= 0.64 µM at neutral pH), an effect that can be blocked by the TRPV1 inhibitor A-425619.¹Capsaicin (10 and 50 µM) decreases LPS-induced prostaglandin E₂production, as well as reduces LPS- and IFN-induced nitric oxide (NO) release in isolated mouse peritoneal macrophages.²Capsaicin induces substance P release in rat spinal cord slices with an EC₅₀value of 2.3 µM.³It reduces acetylcholine- or phenylquinone-induced writhing (ED₅₀s = 1.33 and 1.38 mg/kg, respectively, s.c.) but has no effect on the latency to paw withdrawal in the hot plate test in mice (ED₅₀= >20 mg/kg, s.c.).⁴Formulations containing capsaicin have been used in the treatment of nerve pain associated with shingles.

1.Neelands, T.R., Jarvis, M.F., Han, P., et al.Acidification of rat TRPVI alters the kinetics of capsaicin responsesMol. Pain128(2005) 2.Kim, C.-S., Kawada, T., Kim, B.-S., et al.Capsaicin exhibits anti-inflammatory property by inhibiting IkB-a degradation in LPS-stimulated peritoneal macrophagesCell. Signal.15(3)299-306(2003) 3.MarvizÓn, J.C.G., Wang, X., Matsuka, Y., et al.Relationship between capsaicin-evoked substance P release and neurokinin 1 receptor internalization in the rat spinal cordNeuroscience118(2)535-545(2003) 4.Hayes, A.G., Skingle, M., and Tyers, M.B.Effects of single doses of capsaicin on nociceptive thresholds in the rodentNeuropharmacology20(5)505-511(1981)