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:11/17/2015)... , November 17, 2015 ... au 19 novembre  2015.  --> Paris ... --> DERMALOG, le leader de l,innovation biométrique, ... la fois passeports et empreintes sur la même surface ... les passeports et l,autre pour les empreintes digitales. Désormais, ...
(Date:11/16/2015)... Nov 16, 2015  Synaptics Inc. (NASDAQ: ... solutions, today announced expansion of its TDDI product ... touch controller and display driver integration (TDDI) solutions ... These new TDDI products add to the previously-announced ... TD4302 (WQHD resolution), and TD4322 (FHD resolution) solutions. ...
(Date:11/12/2015)... 11, 2015   Growing need for low-cost, ... has been paving the way for use of ... discrete analytes in clinical, agricultural, environmental, food and ... used in medical applications, however, their adoption is ... to continuous emphasis on improving product quality and ...
Breaking Biology News(10 mins):
(Date:12/1/2015)... Dec. 1, 2015 Frost & Sullivan ... This program addresses ways companies can innovate and ... --> ... --> ... as well as the disrupting factors altering the ...
(Date:12/1/2015)... ... December 01, 2015 , ... Park Systems , world ... scanning ion conductance microscopy module to Park NX10 that is the only product ... SICM benefits virtually all materials characterization that require measurements in liquid such as ...
(Date:12/1/2015)... December 1, 2015 Dr. Harry Lander , President of ... as Chief Science Officer and recruits five distinguished ... Lander , President of Regen, expands his role to include ... recruits five distinguished scientists to join advisory team ... expands his role to include serving as ...
(Date:11/30/2015)... (PRWEB) , ... November 30, 2015 , ... Global ... and development stages of a new closed system for isolating adipose-derived stem cells. The ... vascular fraction (SVF) of adipose tissue. SVF is a component of the lipoaspirate obtained ...
Breaking Biology Technology: