Navigation Links
Activation of thermoreceptors mediates raw garlic's burning pungency

The worldwide popularity of garlic as a food ingredient and its therapeutic stature in folklore both stem in part from the distinctive pungency associated with its raw, uncooked state. Researchers this week report that this pungency, manifested as a characteristic mixture of burning and prickling sensations and flavor, can be ascribed largely to the effects of a particular compound and its ability to activate specific protein thermoreceptors in the mouth.

The findings are reported in the May 24 issue of Current Biology by a team led by Ardem Patapoutian of The Scripps Research Institute and the Genomics Institute of the Novartis Research Foundation.

Despite garlic's popularity, the compounds responsible for its pungency, as well as the receptors through which we perceive those compounds, have remained unknown. In their new work, the researchers found that raw, but not baked, garlic was capable of eliciting responses from two so-called TRP ("trip") channels, TRPV1 and TRPA1, which belong to a remarkable family of receptors that can be activated by temperature and chemicals. Some TRP channels, including TRPA1 and TRPV1, respond to both temperature and chemical compounds: TRPV1 is known to respond to noxious (painful) heat and to the pungent component of chili peppers, whereas TRPA1 is activated by noxious cold and by pungent compounds found in cinnamon oil, mustard oil, and wintergreen oil. These past findings, as well as the present work, indicate that thermosensitive TRP channels play a key role in the phenomenon of chemesthesis (the somatosensory contribution to the sense of taste), which is experienced, for example, in the heat of chili peppers or the coolness of peppermint. Both TRPV1 and TRPA1 are found in pain-sensing neurons that innervate the mouth and tongue.

The researchers went on to identify the sulfide compound allicin, an unstable chemical found in bruised, cut, or crushed garlic, as the chemical responsible for the activation of TRPV1 and TRPA1 and as the likely key chemical component responsible for garlic's pungency. Allicin is converted to a variety of more stable sulfide compounds over time or with heating, in correspondence with the significantly milder taste of roasted garlic.

Garlic's pungency most likely evolved as a defense mechanism against browsing by animals, and indeed many animals--though clearly not all humans--are known to be repelled by it.

The researchers include Lindsey J. Macpherson, Michael Bandell, Samer R. Eid, SunWook Hwang, and Ardem Patapoutian of the The Scripps Research Institute; Bernhard H. Geierstanger, Veena Viswanath, Michael Bandell, SunWook Hwang, and Ardem Patapoutian of the Genomics Institute, Novartis Research Foundation; and SunWook Hwang of the College of Medicine, Korea University. The authors are supported by grants from the National Institute of Neurological Disorders and Stroke. S.R.E. is supported by a fellowship from the Swiss Foundation for Medical-Biological Stipends. A.P. is a Damon Runyon Scholar.

Lindsey Macpherson, Bernhard H. Geierstanger, Veena Viswanath, Michael Bandell, Samer R. Eid, SunWook Hwang, and Ardem Patapoutian: "The Pungency of Garlic: Activation of TRPA1 and TRPV1 in Response to Allicin." Current Biology, Vol. 15, 929?34, May 24, 2005.


Source:Cell Press

Related biology news :

1. An HIV Protein Plays a Surprising Role in Gene Activation
2. Activation of a protein solidifies fear memory in the brain
3. Activation of microRNA inhibits cancer gene in human cancer cells
4. Bugs expose underground carbon traffic system 10 times more important than fossil fuel burning
Post Your Comments:

(Date:6/22/2016)...  The American College of Medical Genetics and Genomics was ... as one of the fastest-growing trade shows during the Fastest ... in Las Vegas . ... in each of the following categories: net square feet of ... attendees. The 2015 ACMG Annual Meeting was ranked 23 out ...
(Date:6/16/2016)... SAN FRANCISCO , June 16, 2016 /PRNewswire/ ... Market size is expected to reach USD ... report by Grand View Research, Inc. Technological proliferation ... and banking applications are expected to drive the ... ) , The development of ...
(Date:6/3/2016)... 3, 2016 Das ... Nepal hat ein 44 ... geprägter Kennzeichen, einschließlich Personalisierung, Registrierung und IT-Infrastruktur, ... Produktion und Implementierung von Identitätsmanagementlösungen. Zahlreiche renommierte ... Januar teilgenommen, aber Decatur wurde als konformste ...
Breaking Biology News(10 mins):
(Date:6/27/2016)...  Sequenom, Inc. (NASDAQ: SQNM ), a ... the development of innovative products and services, announced today ... States denied its petition to review decisions ... U.S. Patent No. 6,258,540 (",540 Patent") are not patent ... Supreme Court,s Mayo Collaborative Services v. Prometheus Laboratories decision.  ...
(Date:6/27/2016)... ... June 27, 2016 , ... Rolf K. Hoffmann, ... faculty of the University of North Carolina Kenan-Flagler Business School effective ... at UNC Kenan-Flagler, with a focus on the school’s international efforts, leading classes ...
(Date:6/24/2016)... DIEGO , June 24, 2016 ... more sensitively detects cancers susceptible to PARP inhibitors ... circulating tumor cells (CTCs). The new test has ... HRD-targeted therapeutics in multiple cancer types. ... targeting DNA damage response pathways, including PARP, ATM, ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... announce the launch of their brand, UP4™ Probiotics, into Target stores nationwide. The ... is proud to add Target to its list of well-respected retailers. This list ...
Breaking Biology Technology: