Researchers uncover pain-relief secrets in hot chili peppers

April 21, 2015 by Rick Remington, Rutgers University
Chili peppers contain the ingredient capsaicin that can relieve pain, a phenomenon at the heart of research at New Jersey Medical School.

Anyone who has ever bitten unknowingly into a red hot chili pepper remembers the unhappy result – burning, painful sensations that make one's mouth feel as though it has caught on fire. Yet the very chemical that causes that pain, capsaicin, has also become a popular pain-reliever found in over-the-counter and prescription medications.

This irony about the calming effects of hot chili peppers is old news for pros like Tibor Rohacs, an associate professor in the Department of Pharmacology and Physiology at Rutgers New Jersey Medical School. What's new are Rohacs' research findings as to how capsaicin works to calm painful nerves, muscles and joints.

In a research paper published recently in Science Signaling, Rohacs and a team of NJMS researchers reported new findings on how a nerve mechanism is activated by capsaicin to block pain signals. "This study gives one potential piece in the puzzle of how capsaicin works as a local analgesic," he said.

Rohacs said his NJMS laboratory has been studying found in sensory nerve terminals that respond to heat and other stimuli. In particular, his work has focused on an ion channel known as TRPV1, the capsaicin receptor, and Piezo2, a newly identified ion channel that mediates touch sensation.

"TRPV1 is a , at least physiologically, and it has a chemical activator, capsaicin, which we all know is in chili peppers," Rohacs explained. "They feel hot because they activate a heat-sensitive ion channel and they trick you into the sensation of heat. And it's also pretty painful.

"The idea is basically that this pain-causing, heat sensor ion channel does something to the nerve that in the long run sort of silences them or desensitizes them," he said. "The desensitizing effect, I believe, has a number of different components and different timescales."

Rohacs said capsaicin has been a popular research target and that multiple factors account for its calming effects on the nerves. "We found that capsaicin completely silenced the Piezo2 channels that are activated by mechanical stimuli," he said. "This may be an important part of how capsaicin inhibits mechanical pain."

His research also produced results that Rohacs found surprising.

"It's very fast, very robust, very long lasting," he said. "The magnitude of the effect was to me the really surprising part."

Rohacs said the jury was still out on the practical application of capsaicin as a , including the creams and patches already on the market. A high concentration capsaicin remedy has to be injected along with a local analgesic that numbs the burning sensations until the remedy can begin desensitizing the nerves.

Rohacs said his research will continue in multiple directions to gain a better understanding of just how the mechanosensors work, as well as how large amounts of calcium are released to help shut down .

Explore further: Enhancing mechanism of capsaicin-evoked pain sensation

More information: "Activation of TRPV1 channels inhibits mechanosensitive Piezo channel activity by depleting membrane phosphoinositides" Sci. Signal., 10 February 2015 Vol. 8, Issue 363, p. ra15 DOI: 10.1126/scisignal.2005667

Related Stories

Enhancing mechanism of capsaicin-evoked pain sensation

April 6, 2015

Drs. Takayama and Tominaga in National Institute for Physiological Sciences (NIPS) (Okazaki Institute for Integrative Bioscience) clarified that an interaction between capsaicin receptor TRPV1 and chloride channel anoctamin ...

Putting the fire out with light

July 25, 2013

Chili peppers contain an activator of heat-sensitive pain receptors. An LMU team has now converted an antagonist to the compound into a light-sensitive regulator of such receptors that can differentially modulate the effects ...

Chili peppers help to unravel the mechanism of pain

February 24, 2009

Capsaicin, the active ingredient in chili peppers, is most often experienced as an irritant, but it may also be used to reduce pain. A new work published by Drs. Feng Qin and Jing Yao in this week's PLoS Biology uses capsaicin ...

Treating pain by blocking the 'chili-pepper receptor'

August 20, 2014

Biting into a chili pepper causes a burning spiciness that is irresistible to some, but intolerable to others. Scientists exploring the chili pepper's effect are using their findings to develop a new drug candidate for many ...

Pepper and halt: Spicy chemical may inhibit gut tumors

August 1, 2014

Researchers at the University of California, San Diego School of Medicine report that dietary capsaicin – the active ingredient in chili peppers – produces chronic activation of a receptor on cells lining the intestines ...

Recommended for you

New theory shows how strain makes for better catalysts

April 20, 2018

Brown University researchers have developed a new theory to explain why stretching or compressing metal catalysts can make them perform better. The theory, described in the journal Nature Catalysis, could open new design ...

Machine-learning software predicts behavior of bacteria

April 19, 2018

In a first for machine-learning algorithms, a new piece of software developed at Caltech can predict behavior of bacteria by reading the content of a gene. The breakthrough could have significant implications for our understanding ...

Spider silk key to new bone-fixing composite

April 19, 2018

UConn researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

GLUT5 fluorescent probe fingerprints cancer cells

April 19, 2018

Determining the presence of cancer, as well as its type and malignancy, is a stressful process for patients that can take up to two weeks to get a diagnosis. With a new bit of technology—a sugar-transporting biosensor—researchers ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.