The
chemical compound capsaicin (8-methyl N-vanillyl 6-nonenamide) is the active component of
chili peppers (
Capsicum). It is an irritant to
mammalian epithelial[?] cells and produces a burning sensation in the
mouth, which some people enjoy.
Plants produce the compound to deter
predation[?].
There are actually several capsaicinoids, which are present in different amounts in different species. This accounts for the delayed reaction to C. chinense (habanero) as compared to other species.
- trans-8-methyl N-vanillyl 6-nonenamide
- 8-methyl N-vanillyl nonamide
- 7-methyl N-vanillyl octamide
- 9-methyl N-vanillyl decamide
- trans-9-methyl N-vanillyl 7-decenamide
Uses
Because of the burning sensation capsaicin is commonly used in food products to give them added spice. Typically the capsaicin is obtained by using
chili peppers as the source. Another common source is hot
sauces (which may contain pure capsaicin). These sources are preferred over pure capsaicin for reasons of safety resulting from the lower concentration.
Capsaicin is used in topical
ointments[?] used to relieve the pain of
peripheral neuropathy[?]. The treatment typically involves the application of a topical
anesthetic until the area is numb. Then the capsaicin is applied by a therapist wearing rubber gloves and a face mask. The capsaicin remains on the skin until the patient starts to feel the heat at which point it is promptly removed. The result appears to be that the
nerves are overwhelmed from the burning sensation and are unable to report pain for an extended period of time.
Capsaicin is also the active ingredient in the chemical
riot control agent pepper spray. When the spray comes in contact with skin, especially eyes or mucous membranes it is very painful.
Mechanism of Action
The burning and painful sensations associated with capsaicin result from capsaicin's chemical interaction with sensory neurons. Capsaicin, as a member of the vanilloid[?] family, binds to a chemical receptor called the vanilloid receptor subtype 1 (VR1). VR1, which can also be stimulated with heat and physical abrasion, permits positively-charged cations to pass into the cell membrane from the region of high concentration just outside the cell when activated, stimulating the neuron to send a signal to the brain. (See the article action potential for a full description of this phenomenon.) By binding to the VR1 receptor, the capsaicin molecule produces the same effect that excessive heat or abrasive damage would cause, explaining why the spiciness of capsaicin is described as a burning sensation.
External Links
All Wikipedia text
is available under the
terms of the GNU Free Documentation License