| Description |
Capsaicin is the main chemical that makes chili peppers hot. Capsaicin is an animal repellent that is also used against insects and mites. Capsaicin was first registered for use in the United States in 1962. The U.S. Environmental Protection Agency considers it to be a biochemical pesticide because it is a naturally occurring substance.
The chemical compound capsaicin (8-methyl-N-vanillyl-6-nonenamide) is the active component of chili peppers, which are plants belonging to the genus Capsicum. It is an irritant for mammals, including humans, and produces a sensation of burning in any tissue it comes in contact with. Capsaicin and several related compounds are called capsaicinoids and are produced as a secondary metabolite by chili peppers, probably as deterrents against herbivores. Pure capsaicin is a hydrophobic, colorless, odorless, crystalline to waxy compound. |
| History |
Capsaicin is a naturally occurring substance that is responsible for the burning, pungent sensation associated with the ingestion of hot peppers from the Capsicum genus. The effect elicited by these peppers is at the origin of the name Capsicum, which derives from the Greek kapto, meaning “to bite”.
Hot peppers are a native plant from the American tropics and their use can be traced back to the Aztec and Inca civilizations. The Aztecs named them “chilies” and used them for culinary purposes. After discovery of the New World, chili pods were introduced in Europe and their cultivation expanded to other parts of the globe. Nowadays, hot peppers are found in nearly every country and are an important part of the culinary tradition of many different cultures.
The active component of chili peppers was initially isolated by J. C. Thresh in 1846. The compound was named “capsaicin” and its chemical structure was later determined by E. K. Nelson in 1919. The complete chemical synthesis of 8-methyl-N- vanillyl-6-nonenamide (capsaicin’s IUPAC* name) was reported in 1930 by Spath &Darling. In the 1960’s, Japanese investigators identified additional substances from Capsicum extracts with similar chemical and pharmacological properties that were termed “capsaicinoids”. Currently, this family of chemical analogues includes both natural (homodihydrocapsaicin, dihydrocapsaicin, nordihydrocapsaicin, homocapsaicin and capsaicin) and synthetic (nonivamide) members. |
| Uses |
Capsaicin is what makes chili peppers hot. It is an irritant.for mam- mals, but not for birds. This may be because birds spread the seeds better than mammals. It causes a burning sensation in any mam- malian tissue with which it comes in contact.
Capsaicin is a nonpolar molecule; it dissolves in fats and oils, not in water. This is why water does not take away the burning sensation, but whole milk or other fat-containing liquids or foods will.
As an ingredient in medicines, capsaicin is used to relieve pain from arthritis, muscle aches, and sprains. It is a rubefacient, meaning it dilates blood vessels. The heat effect overwhelms nerves, causing a localized numbing sensation.
Capsaicin is also used in pepper spray. |
| Application in Particular Diseases |
In Osteoarthritis:
- Capsaicin, an extract of red peppers that causes release and ultimately depletion of substance P from nerve fibers, has been beneficial in providing pain relief in OA when applied topically over affected joints. It may be used alone or in combination with oral analgesics or NSAIDs.
- To be effective, capsaicin must be used regularly, and it may take up to 2 weeks to work. It is well tolerated, but some patients experience temporary burning or stinging at the site of application. Patients should be warned not to get the cream in their eyes or mouth and to wash their hands after application.
- Application of the cream, gel, or lotion is recommended four times daily, but tapering to twice-daily application may enhance long-term adherence with adequate pain relief.
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| Description |
Capsaicin has a mild, warm-herbaceous odor and a burning pungent taste (at 10 ppm). It is used in compounded flavors for sauces where the pungent note is desired. This substance is present in several species of Capsicum (Family, Solanaceae). The sensation of pain, accompanied by irritation and inflammation, is due to substance P depletion from sensory (afferent) nerve fibers. These properties are used to study the physiology of pain and the effects as a counterirritant and gastrointestinal stimulant. This substance may be prepared from 3-chloro-2-isopropyltetrahydropyran; biosynthesis from Capsicum frutescens; separation form cis-capsaicin, pelargonic acid vanilamide, and dihydrocapsaicin, reaction of capsaicin. |
| Chemical Properties |
N-(4-Hydroxy-3-benzyl)-8-methyl-6-nonenamide has a mild, warm-herbaceous odor and burning, pungent taste (10 ppm). It is used in compounded flavors for sauces where the pungent note is desired. |
| Chemical Properties |
Off-White Crystalline Solid |
| Chemical Properties |
Crystalline solid, rectangular plates, or scales. Pungent odor and burning taste. |
| Occurrence |
The pungent principle in the fruits of various Capsicum species (Solanaceae) |
| Uses |
A representative lot is a 5:1 E:Z mixture. It is used as a tool in neurobiological research. Prototype vanilloid receptor agonist. Topical analgesic. |
| Uses |
K channel blocker; multiple sclerosis therapy |
| Uses |
analgesic (topical), depletes Substance P, neurotoxic |
| Uses |
Capsaicin analogue (C175680). It is used as a tool in neurobiological research. Prototype vanilloid receptor agonist. Topical analgesic. |
| Uses |
Capsaicin is used in many topical ointments used to relieve the pain of peripheral neuropathy (treatment of pain in the nerve endings near the surface of the skin). |
| Uses |
As a tool in neurobiological research. |
| Indications |
Capsaicin (Zostrix) is approved for the relief of pain following herpes zoster infection (postherpetic neuralgia). The drug depletes neurons of substance P, an endogenous neuropeptide that may mediate cutaneous pain. It is applied to affected skin after open lesions have healed. Local irritation is common. |
| Biological Activity |
Prototypic vanilloid receptor agonist (pEC 50 values are 7.97 and 7.10 at rat and human VR1 receptors respectively). Excites a subset of primary afferent sensory neurons, with subsequent antinociceptive and anti-inflammatory effects. Reversibly inhibits aggregation of platelets. Also available as part of the Vanilloid TRPV1 Receptor Tocriset™ . |
| Anticancer Research |
Capsaicin is the major pungent ingredient in red and green chili pepper. It is reportedto induce apoptosis selectively in cancer cells and can suppress the activation ofNF-κB through suppression of NF-κB inhibitor IκBα (Aggarwal and Shishodia 2004). It shows anticancer effects in animal models and suppresses carcinogenesisin colon, skin, lung, tongue, and prostate cancers by altering the metabolism ofcarcinogens. It selectively suppresses the human cancer cell growth of prostate,leukemic, glioma, gastric, and hepatic cancers. It inhibited the tumorigenesis linkedand IL-6-induced activation of STAT-3 and STAT3-regulated gene products likecyclin D1, Bcl-2, Bcl-xL, survivin, and VGEF. It arrests cells in G1 phase andinduces apoptosis (Aggarwal et al. 2008; Clark and Lee 2016). |
| Chemical Synthesis |
From 3-chloro-2-isopropyltetrahydropyran; biosynthesis from Capsicum frutescens; separation from cis-capsaicin, pelargonic acid vanillamide and dihydrocapsaicin; reaction of capsaicin |
| Potential Exposure |
Botanical animal and insect repellent used to repel birds, voles, deer, rabbits, squirrels, insects, and attacking dogs. Capsaicin, which is made from the Capsicum red chili pepper can be used indoors to protect carpets and upholstered furniture, and outdoors to protect fruit and vegetable crops, flowers, ornamental plants, shrubbery, trees, and lawns. It is also used in pepper sprays such as MACE, and as an analgesic in creams, lotions and solid sticks to reduce arthritic, postoperative and neuopathic pain, such as shingles. Capsaicin is obtained by grinding dried, ripe Capsicum frutescens L. chili peppers into a fine powder. The oleoresin is derived by distilling the powder in a solvent and evaporating the solvent. The resulting highly concentrated liquid has little odor but has an extremely pungent taste |
| Shipping |
UN2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required. |
| Purification Methods |
Recrystallise capcaicin from pet r (b 40-60o), or pet r/Et2O (9:1). Also purify it by chromatography on neutral Al2O3 (grade V) and elute successively with *C6H6, *C6H6/EtOAc (17:3) then *C6H6/EtOAc (7:3), and distil it at 120o/10-5mm, then repeatedly recrystallise the needles from isopropanol (charcoal). [Crombie et al. J Chem Soc 11025 1955, Bennett & Kirby J Chem Soc(C) 442 1968.] It causes pain and is neurotoxic [Bevan & Szolcsanyi Trends in Pharmacol Sci 11 330 1990, Beilstein 13 IV 2588]. |
| Incompatibilities |
Slowly hydrolyzes in water, releasing ammonia and forming acetate salts. |
| Waste Disposal |
Do not discharge into drains or sewers. Dispose of waste material as hazardous waste using a licensed disposal contractor to an approved landfill. Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Incineration with effluent gas scrubbing is recommended. In accordance with 40CFR165, follow recommendations for the disposal of pesticides and pesticide containers. Noncombustible containers should be crushed and buried under more than 40 cm of soil. Must be disposed properly by following package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office |
