Incarvillateine is a complex

monoterpene Monoterpenes are a class of terpenes that consist of two isoprene units and have the molecular formula C10H16. Monoterpenes may be linear (acyclic) or contain rings (monocyclic and bicyclic). Modified terpenes, such as those containing oxygen funct ...

alkaloid Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar ...

that is a derivative of α- truxillic acid. It can be isolated from the plant genus ''

Incarvillea ''Incarvillea'' is a genus of about 16 species''Incarvillea''.
Flora of China. ...

.''

Biological activity

Opioidergic

Incarvillateine isolated from '' Incarvillea sinensis'' has demonstrated significant

analgesic An analgesic drug, also called simply an analgesic (American English), analgaesic (British English), pain reliever, or painkiller, is any member of the group of drugs used to achieve relief from pain (that is, analgesia or pain management). It ...

activity when compared to the

opiate An opiate, in classical pharmacology, is a substance derived from opium. In more modern usage, the term ''opioid'' is used to designate all substances, both natural and synthetic, that bind to opioid receptors in the brain (including antagonis ...

alkaloid

morphine Morphine is a strong opiate that is found naturally in opium, a dark brown resin in poppies (''Papaver somniferum''). It is mainly used as a analgesic, pain medication, and is also commonly used recreational drug, recreationally, or to make ...

. Incarvillateine's pain-killing effect was partially blocked by administration of

naloxone Naloxone, sold under the brand names Narcan (4 mg) and Kloxxado (8 mg) among others, is a medication used to reverse or reduce the effects of opioids. It is commonly used to counter decreased breathing in opioid overdose. Effects begin within ...

norbinaltorphimine Norbinaltorphimine (nor-BNI or nBNI) is an opioid antagonist used in scientific research. It is one of the few opioid antagonists available that is highly selective for the κ-opioid receptor, and blocks this receptor without affecting the μ- ...

and beta-funaltrexamine, which are receptor antagonists with varying selectivity for mu and

kappa Kappa (uppercase Κ, lowercase κ or cursive ; el, κάππα, ''káppa'') is the 10th letter of the Greek alphabet, representing the voiceless velar plosive sound in Ancient and Modern Greek. In the system of Greek numerals, has a value o ...

opioid receptors.

Naltrindole Naltrindole is a highly potent, highly selective delta opioid receptor antagonist used in biomedical research. In May 2012 a paper was published in ''Nature'' with the structure of naltrindole in complex with the mouse δ-opioid G-protein coupled ...

, a

delta Delta commonly refers to: * Delta (letter) (Δ or δ), a letter of the Greek alphabet * River delta, at a river mouth * D (NATO phonetic alphabet: "Delta") * Delta Air Lines, US * Delta variant of SARS-CoV-2 that causes COVID-19 Delta may also re ...

opioid receptor antagonist, did not counteract the analgesic activity of incarvillateine. These findings indicate that incarvillateine may possess

opioidergic An opioidergic agent (or drug) is a chemical which functions to directly modulate the opioid neuropeptide systems (i.e., endorphin, enkephalin, dynorphin, nociceptin) in the body or brain. Examples include opioid analgesics such as morphine and ...

receptor activity, but it is worthy to note that some studies indicate that naloxone was ineffective at countering incarvillateine's analgesic activity.{{Cite journal, last=Wang, first=Mei-Liang, last2=Yu, first2=Gang, last3=Yi, first3=Shou-Pu, last4=Zhang, first4=Feng-Ying, last5=Wang, first5=Zhi-Tong, last6=Huang, first6=Bin, last7=Su, first7=Rui-Bin, last8=Jia, first8=Yan-Xing, last9=Gong, first9=Ze-Hui, date=2015-11-03, title=Antinociceptive effects of incarvillateine, a monoterpene alkaloid from Incarvillea sinensis, and possible involvement of the adenosine system, journal=Scientific Reports, language=en, volume=5, pages=16107, doi=10.1038/srep16107, pmid=26527075, pmc=4630779, issn=2045-2322, bibcode=2015NatSR...516107W

Adenosinergic

Incarvillateine's

antinociceptive Nociception (also nocioception, from Latin ''nocere'' 'to harm or hurt') is the Somatosensory system, sensory nervous system's process of encoding Noxious stimulus, noxious stimuli. It deals with a series of events and processes required for an org ...

effect was blocked by the administration of

adenosine Adenosine ( symbol A) is an organic compound that occurs widely in nature in the form of diverse derivatives. The molecule consists of an adenine attached to a ribose via a β-N9-glycosidic bond. Adenosine is one of the four nucleoside building ...

receptor

antagonists An antagonist is a character in a story who is presented as the chief foe of the protagonist. Etymology The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, riv ...

such as

theophylline Theophylline, also known as 1,3-dimethylxanthine, is a phosphodiesterase inhibiting drug used in therapy for respiratory diseases such as chronic obstructive pulmonary disease (COPD) and asthma under a variety of brand names. As a member of the ...

. This suggests that incarvillateine's main mechanism of action is mediated through the adenosine receptor.

References

Terpeno-phenolic compounds Alkaloids Carboxylate esters Opioids Adenosine receptor agonists Monoterpenes Cyclobutanes Cyclopentanes Methoxy compounds