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
First aid
Move victim to fresh air. Call 911 or emergency
medical service. Give artificial respiration if victim is not
breathing. Do not use mouth-to-mouth method if victim
ingested or inhaled the substance; give artificial respiration with the aid of a pocket mask equipped with a one-way
valve or other proper respiratory medical device.
Administer oxygen if breathing is difficult. Remove and
isolate contaminated clothing and shoes. In case of contact
with substance, immediately flush skin or eyes with running water for at least 20 minutes. For minor skin contact,
avoid spreading material on unaffected skin. Keep victim
warm and quiet. Effects of exposure (inhalation, ingestion,
or skin contact) to substance may be delayed. Ensure that
medical personnel are aware of the material(s) involved
and take precautions to protect themselves. Medical observation is recommended for 24 to 48 hours after breathing
overexposure, as pulmonary edema may be delayed. As
first aid for pulmonary edema, a doctor or authorized paramedic may consider administering a drug or other inhalation therapy.
Shipping
UN2811 Toxic solids, organic, n.o.s., Hazard
Class: 6.1; Labels: 6.1-Poisonous materials, Technical
Name Required.
Incompatibilities
Slowly hydrolyzes in water, releasing
ammonia and forming acetate salts.
Chemical Properties
Crystalline solid, rectangular plates, or scales.
Pungent odor and burning taste.
Chemical Properties
N-(4-Hydroxy-3-methoxybenzyl)-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
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
Physical properties
Appearance: crystalline white powder, with highly volatile and pungent odor.
Solubility: freely soluble in alcohol, ether, benzene, and chloroform; slightly soluble
in carbon disulfide, petroleum, and hydrochloric acid; insoluble in water. Melting
point: 65?°C.
Occurrence
The pungent principle in the fruits of various Capsicum species (Solanaceae)
Definition
ChEBI: Capsaicin is a capsaicinoid. It has a role as a non-narcotic analgesic, a voltage-gated sodium channel blocker and a TRPV1 agonist.
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.
General Description
Capsaicin occurs as the active ingredient of hot/red pepper and was first obtained by Thresh in 1846. It is a lipophilic vanilloid compound responsible for the acrid taste of hot peppers.
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™ .
Biochem/physiol Actions
Prototype vanilloid receptor agonist. Neurotoxin; activates sensory neurons that give rise to unmyelinated C-fibers, many of which contain substance P. Topical application desensitizes the sensory nerve endings giving a paradoxical antinociceptive effect; systemic administration can be neurotoxic to capsaicin-sensitive cells, especially in newborn animals. Active component of chili peppers.
Pharmacology
Hbgyes, A. (1878) first reported that capsaicin has a strong stimulating effect,
which is the first pharmacological study on capsaicin. And then, a serial of pharmacological effects were discovered. The discovery of capsaicin receptor further
explains the mechanism of capsaicin. The capsaicin receptor, also known as transient voltage receptor cation channel V1 (TRPV1), is a nonselective ligand-gated
cation channel. TRPV1 is widely distributed in the body, mainly in sensory neurons,
and can also be activated by heat and friction damage.
Studies on the analgesic effect of capsaicin were carried out earlier and more
thoroughly. Capsaicin can act on sensory nerve C primary afferent fibers, bind the
end of the neuronal TRPV1 receptor. Capsaicin (1?μM) can result in inward calcium
influx, cell depolarization, neuronal excitation, and glutamate release. The sustained neuron excitement and then failure can result in analgesic and antipruritic
effects.
The mutation of the capsaicin receptor can not only induce obesity but also may
be associated with the occurrence of diabetes. Capsaicin can activate and recruit
brown fat to prevent obesity. Brown fat can produce non-shivering heat in cold
environment and participate in energy consumption. A 10–130?mg daily capsaicin
can significantly increase the body’s energy and fat consumption.
Capsaicin also has a protective effect on the cardiovascular system. Treatment of
capsaicin with rats at a dose of 15?mg/kg can not only promote animal blood circulation and strengthen the cardiovascular function but also reduce the blood pressure
, the serum cholesterol, and triglyceride levels.
The study result of capsaicin on tumor is still controversial. The epidemiology
and basic research have suggested that capsaicin can not only be used as a carcino400
gen but also can prevent cancer. It has been shown that capsaicin can induce cancer
cell apoptosis, and animal experiments have shown that prolonged use of capsaicin
on the skin can induce skin cancer.
Capsaicin is able to scavenge free radicals and inhibit oxidative stress. Capsaicin
can promote gastric secretion, increase appetite, relieve flatulence, improve digestive function, and also prevent gastrointestinal infection and diarrhea. Capsaicin can
improve the performance of sports and anti-fatigue. Capsaicin is capable of thinning
lung mucus, in favor of sputum discharging, enhancing lung tissue perfusion, and
preventing and treating emphysema. Capsaicin is also beneficial on psoriasis, frostbite, cold, etc. In addition, capsaicin is also used for the paralysis of peripheral
nerve function for hypertension treatment.
Capsaicin can be absorbed by the intestine and skin and is able to pass through
the blood-brain barrier.
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).
Clinical Use
In clinical practice, capsaicin is mainly used for topical administration, such as in
the treatment of osteoarthritis and rheumatoid arthritis pain, diabetic nerve pain,
pain after surgery, chemotherapy- or radiotherapy-induced oral pain, psoriasis, etc.
Capsaicin irritates the mucous membrane to cause sneezing, nose bleeding,
coughing, mucus secretion, tears, bronchoconstriction, breathing difficulties, and
other symptoms. The main adverse effects of capsaicin preparations are contact
dermatitis, skin inflammation or blisters, and in severe situation burn-like lesion.
Synthesis
From 3-chloro-2-isopropyltetrahydropyran; biosynthesis from Capsicum frutescens; separation from cis-capsaicin, pelargonic acid vanillamide and dihydrocapsaicin; reaction of capsaicin
Purification Methods
Recrystallise capcaicin from pet ether (b 40-60o), or pet ether/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].
References
1) Gunthorpe et al. (2002) The diversity in the vanilloid (TRPV) receptor family of ion channels; Trends Pharmacol. Sci. 23 183
2) Van Der Stelt and Di Marzo (2004) Endovanilloids. Putative endogenous ligands of transient receptor potential vanilloid 1 channels; Eur. J. Biochem. 271 1827
3) Perkins and Campbell (1992) Capsazepine reversal of the antinociceptive action of capsaicin in vivo; Br. J. Pharmacol. 107 329
4) Kim et al..(2003) Capsaicin exhibits anti-inflammatory property by inhibiting IkB-a degradation in LPS-stimulated peritoneal macrophages; Cell. Signal., 15 299
5) Di Marzo et al. (2001) Hypolocomotor effects in rats of capsaicin and two long chain capsaicin homologues; Eur. J. Pharmacol., 420 123
