antagonist
An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain.capsaicin
Capsaicin (8-methyl-''N''-vanillyl-6-nonenamide) (, rarely ) is an active component of chili peppers, which are plants belonging to the genus ''Capsicum''. It is a potent Irritation, irritant for Mammal, mammals, including humans, and produces ...
. It is used as a biochemical tool in the study of
TRPV
TRPV is a family of transient receptor potential cation channels (TRP channels) in animals. All TRPVs are highly calcium selective.
TRP channels are a large group of ion channels consisting of six protein families, located mostly on the plasm ...
ion channel
Ion channels are pore-forming membrane proteins that allow ions to pass through the channel pore. Their functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by Gating (electrophysiol ...
s.
Pharmacology
Capsazepine blocks the painful sensation of heat caused by capsaicin (the active ingredient of
chilli pepper
Chili peppers, also spelled chile or chilli ( ), are varieties of berry-fruit plants from the genus ''Capsicum'', which are members of the nightshade family Solanaceae, cultivated for their pungency. They are used as a spice to add pungency ( ...
) which activates the
TRPV1
The transient receptor potential cation channel subfamily V member 1 (TRPV1), also known as the capsaicin receptor and the vanilloid receptor 1, is a protein that, in humans, is encoded by the ''TRPV1'' gene. It was the first isolated member of ...
ion channel. Capsazepine is therefore considered to be a TRPV1
antagonist
An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain.mammalians. Capsazepine blocks the activation of TRPV1 channels by other chemicals, but not by other painful stimuli such as heat. Depending on the pharmacological assay, the IC50 is in the
nanomolar
Molar concentration (also called molarity, amount concentration or substance concentration) is the number of moles of solute per liter of solution. Specifically, It is a measure of the concentration of a chemical species, in particular, of a so ...
to low micromolar range. In addition to its effects on TRPV1 channels, it was also shown to activate the noxious chemical sensor
TRPA1
Transient receptor potential cation channel, subfamily A, member 1, also known as transient receptor potential ankyrin 1, TRPA1, or The Mustard and Wasabi Receptor, is a protein that in humans is encoded by the ''TRPA1'' (and in mice and rats by ...
channel, inhibit the cold activated
TRPM8
Transient receptor potential cation channel subfamily M (melastatin) member 8 (TRPM8), also known as the cold and menthol receptor 1 (CMR1), is a protein that in humans is encoded by the ''TRPM8'' gene. The TRPM8 channel is the primary molecular ...
nicotinic acetylcholine receptor
Nicotinic acetylcholine receptors, or nAChRs, are Receptor (biochemistry), receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine. They are found in the c ...
s. It mainly serves as a tool to study the TRPV1 ion channel.
Development
Capsazepine was discovered by a research group working for
Novartis
Novartis AG is a Swiss multinational corporation, multinational pharmaceutical company, pharmaceutical corporation based in Basel, Switzerland. Novartis is one of the largest pharmaceutical companies in the world and was the eighth largest by re ...
. Its synthesis and chemical properties were published in 1994. It was found by modification of the chemical backbone of capsaicin.
Use in biotechnology
By incorporation of an
azobenzene
Azobenzene is a photoswitchable chemical compound composed of two phenyl rings linked by a azo compound, N=N double bond. It is the simplest example of an aryl azo compound. The term 'azobenzene' or simply 'azo' is often used to refer to a wide c ...
unit, a photoswitchable version of capsazepine (AC4) was developed in 2013 that allows for optical control of
TRPV1
The transient receptor potential cation channel subfamily V member 1 (TRPV1), also known as the capsaicin receptor and the vanilloid receptor 1, is a protein that, in humans, is encoded by the ''TRPV1'' gene. It was the first isolated member of ...
Menthol
Menthol is an organic compound, specifically a Monoterpene, monoterpenoid, that occurs naturally in the oils of several plants in the Mentha, mint family, such as Mentha arvensis, corn mint and peppermint. It is a white or clear waxy crystallin ...
JWH-133
JWH-133 (Dimethylbutyl-deoxy-Delta-8-THC) is a potent selective CB2 receptor agonist with a Ki of 3.4nM and selectivity of around 200x for CB2 over CB1 receptors. It was discovered by and named after John W. Huffman.
JWH-133 has been confuse ...