The pungency of garlic: activation of TRPA1 and TRPV1 in response to allicin.
Garlic's pungent flavor has made it a popular ingredient in cuisines around the world and throughout history. Garlic's health benefits have been elevated from folklore to clinical study. Although there is some controversy as to the efficacy of garlic, garlic products are one of the most popular herbal supplements in the U.S. Chemically complex, garlic contains different assortments of sulfur compounds depending on whether the cloves are intact, crushed, cooked, or raw. Raw garlic, when cut and placed on the tongue or lips, elicits painful burning and prickling sensations through unknown mechanisms. Here, we show that raw but not baked garlic activates TRPA1 and TRPV1, two temperature-activated ion channels that belong to the transient receptor potential (TRP) family. These thermoTRPs are present in the pain-sensing neurons that innervate the mouth. We further show that allicin, an unstable component of fresh garlic, is the chemical responsible for TRPA1 and TRPV1 activation and is therefore likely to cause garlic's pungency.
Macpherson
Lindsey J
LJ
Department of Cell Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
Geierstanger
Bernhard H
BH
Viswanath
Veena
V
Bandell
Michael
M
Eid
Samer R
SR
Hwang
SunWook
S
Patapoutian
Ardem
A
D000818:Animals; D017487:Ankyrins; D016466:CHO Cells; D015220:Calcium Channels / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D006224:Cricetinae; D003412:Cricetulus; D004220:Disulfides; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D005470:Fluorometry; D005737:Garlic / Q000737:chemistry*; D007473:Ion Channels / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D010936:Plant Extracts; D051381:Rats; D013441:Sulfinic Acids / Q000378:metabolism / Q000494:pharmacology*; D000074025:TRPA1 Cation Channel; D050052:TRPC Cation Channels; D050916:TRPV Cation Channels
D017487:Ankyrins; D015220:Calcium Channels; D004220:Disulfides; D007473:Ion Channels; D010936:Plant Extracts; D013441:Sulfinic Acids; D000074025:TRPA1 Cation Channel; D050052:TRPC Cation Channels; D050916:TRPV Cation Channels; C480976:Trpa1 protein, rat; C493922:Trpv1 protein, rat; C006452:allicin