Chilli Activates Same Pain Receptor as Spider Bites
November 21st 2006 05:14
Chilli Activates Same Pain Receptor as Spider Bites
New research has found that molecules in ‘hot peppers’ (i.e. chilli) and in a certain spider’s venom target the same receptor on neurons. This find was reported in Science News Online last week.
It has already been discovered that a channel on neurons is opened by ‘capsaicin’ which is the active component of chilli and is responsible for the associated burning sensation that occurs at any body tissue capsaicin comes into contact with. It is this burn which is responsible for the spiciness and the feeling of heat in a meal with chilli. There is even a scale which measures the degree of heat found in chilli called The Scoville Scale. Using this scale, ‘bell pepper’ (i.e. capsicum) measures 0 and pure capsaicin has a 15 – 16,000,000 rating. Jalapenos average about 5,000 and Thai Chilli at 50 – 100,000.
Chemistry: Why Doesn’t Water Help After Taking Chilli?
Wikipedia says that Capsaicin is a nonpolar molecule, and is therefore hydrophobic (doesn't dissolve in water, but it is ‘lipophilic’ – i.e. dissolves in fats). So drinking water to reduce the burning of chilli doesn’t work, as the nonpolar capsaicin is unable to dissolve in the polar water molecules, and is instead spread across the surface of the mouth. This works by the same principle that causes oil and water to separate.
So you’re better off eating or drinking something high in fats and oils like milk or bread and butter. This way, the capsaicin molecules will be mixed in with whatever you take and can be flushed from the mouth. And if you’ve got an open bottle of wine or something at your ready, alcohol also helps to get rid of the burning as ethanol is a solvent.
Chilli and Spider Bites
Research on capsaicin over the years has showed that the channel for capsaicin is a member of a family of cell-surface receptors that sense both chemicals and temperature. When these channels are activated, ions flood into neurons and cause them to fire.
Scientists have very much studied the components of spider venom that cause shock, paralysis, and death, but not much is known about the molecules that cause the pain from a spider bite. David Julius of the University of California, San Francisco and his research team wondered whether pain-inducing venom ingredients might activate the dual-purpose cell-surface channels (that were found to respond to capsaicin).
The team looked at the venom from spider, scorpion, and snail species that are known to deliver painful bites. The researchers diluted the venoms and added them to dishes containing human-kidney cells that had been genetically altered to carry various types of channels.
It was found that the venom of one West Indian tarantula species, Psalmopoeus cambridgei, sent a flood of ions into cells which had the same receptor that's sent by capsaicin.
Julius says that because triggering this studied receptor produces such strong sensations of pain, it's not surprising that organisms as distantly related as pepper (chilli) plants and tarantulas use the same defensive mechanism.
"Different organisms have figured out how to tap this site as a way of telling predators, 'You won't be comfortable if you mess with me,'" he says.
Image part of Public Domain
New research has found that molecules in ‘hot peppers’ (i.e. chilli) and in a certain spider’s venom target the same receptor on neurons. This find was reported in Science News Online last week.
It has already been discovered that a channel on neurons is opened by ‘capsaicin’ which is the active component of chilli and is responsible for the associated burning sensation that occurs at any body tissue capsaicin comes into contact with. It is this burn which is responsible for the spiciness and the feeling of heat in a meal with chilli. There is even a scale which measures the degree of heat found in chilli called The Scoville Scale. Using this scale, ‘bell pepper’ (i.e. capsicum) measures 0 and pure capsaicin has a 15 – 16,000,000 rating. Jalapenos average about 5,000 and Thai Chilli at 50 – 100,000.
Chemistry: Why Doesn’t Water Help After Taking Chilli?
Wikipedia says that Capsaicin is a nonpolar molecule, and is therefore hydrophobic (doesn't dissolve in water, but it is ‘lipophilic’ – i.e. dissolves in fats). So drinking water to reduce the burning of chilli doesn’t work, as the nonpolar capsaicin is unable to dissolve in the polar water molecules, and is instead spread across the surface of the mouth. This works by the same principle that causes oil and water to separate.
So you’re better off eating or drinking something high in fats and oils like milk or bread and butter. This way, the capsaicin molecules will be mixed in with whatever you take and can be flushed from the mouth. And if you’ve got an open bottle of wine or something at your ready, alcohol also helps to get rid of the burning as ethanol is a solvent.
Chilli and Spider Bites
Research on capsaicin over the years has showed that the channel for capsaicin is a member of a family of cell-surface receptors that sense both chemicals and temperature. When these channels are activated, ions flood into neurons and cause them to fire.
Scientists have very much studied the components of spider venom that cause shock, paralysis, and death, but not much is known about the molecules that cause the pain from a spider bite. David Julius of the University of California, San Francisco and his research team wondered whether pain-inducing venom ingredients might activate the dual-purpose cell-surface channels (that were found to respond to capsaicin).
The team looked at the venom from spider, scorpion, and snail species that are known to deliver painful bites. The researchers diluted the venoms and added them to dishes containing human-kidney cells that had been genetically altered to carry various types of channels.
It was found that the venom of one West Indian tarantula species, Psalmopoeus cambridgei, sent a flood of ions into cells which had the same receptor that's sent by capsaicin.
Julius says that because triggering this studied receptor produces such strong sensations of pain, it's not surprising that organisms as distantly related as pepper (chilli) plants and tarantulas use the same defensive mechanism.
"Different organisms have figured out how to tap this site as a way of telling predators, 'You won't be comfortable if you mess with me,'" he says.
Image part of Public Domain
| 75 |
| Vote |
Add To: 
subscribe to this blog
