Capsaicin metabolism after oral administration is unclear, however it is expected to undergo metabolism in the liver with minimal metabolism in the gut lumen. _In vitro_ studies with human hepatic microsomes and S9 fragments indicate that capsaicin is rapidly metabolized, producing three major metabolites, 16-hydroxycapsaicin, 17-hydroxycapsaicin, and 16,17-hydroxycapsaicin, whereas vanillin was a minor metabolite. It is proposed that cytochrome P450 (P450) enzymes may play some role in hepatic drug metabolism. _In vitro_ studies of capsaicin in human skin suggest slow biotransformation with most capsaicin remaining unchanged.
Capsaicin and dihydrocapsaicin are the major active components in pepper spray products, which are widely used for law enforcement and self-protection. The use of pepper sprays, due to their irreversible and other health effects has been under a strong debate. In this study, we compared metabolism and cytotoxicity of capsaicin and dihydrocapsaicin using human and pig liver cell fractions and human lung carcinoma cell line (A549) in vitro. Metabolites were screened and identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Using liver cell fractions, a novel aliphatic hydroxylated metabolite (m/z 322) was detected to dihydrocapsaicin but no structure was found corresponding to capsaicin. Instead, a novel phase I metabolite of capsaicin, corresponding to the structure of aliphatic demethylation and dehydrogenation (m/z 294) was identified. In addition, two novel conjugates, glycine conjugates (m/z 363 and m/z 365) and bi-glutathione (GSH) conjugates (m/z 902 and m/z 904), were identified for both capsaicin and dihydrocapsaicin. The medium of the exposed A549 cells contained omega-hydroxylated (m/z 322) and alkyl dehydrogenated (m/z 304) forms, as well as a glycine conjugate of capsaicin. As to dihydrocapsaicin, an alkyl dehydrogenated (m/z 306) form, a novel alkyl hydroxylated form, and a novel glycine conjugate were found. In A549 cells, dihydrocapsaicin evoked vacuolization and decreased cell viability more efficiently than capsaicin. Furthermore, both compounds induced p53 protein and G1 phase cell cycle arrest. Usefulness of the found metabolites as biomarkers for capsaicinoid exposures will need further investigations with additional toxicity endpoints.
... Dehydrogenation of capsaicin was a novel metabolic pathway and produced unique macrocyclic, diene, and imide metabolites. Metabolism of capsaicin by microsomes was inhibited by 1-aminobenzotriazole (1-ABT). Metabolism was catalyzed by CYP1A1, 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, and 3A4. Addition of GSH (2 mM) to microsomal incubations stimulated the metabolism of capsaicin and trapped several reactive electrophilic intermediates as their GSH adducts. /Study conducted with recombinant P450 enzymes and hepatic and lung microsomes from various species, including humans/
The objectives of this study are to characterize capsaicin glucuronidation using liver microsomes and to determine the contribution of individual UDP-glucuronosyltransferase (UGT) enzymes to hepatic glucuronidation of capsaicin. The rates of glucuronidation were determined by incubating capsaicin with uridine diphosphoglucuronic acid-supplemented microsomes. Kinetic parameters were derived by model fitting. Determination of the relative activity factors, expression-activity correlation and activity correlation analysis were performed to identify the main UGT enzymes contributing to capsaicin metabolism. Capsaicin was efficiently glucuronidated in pooled human liver microsomes (pHLM). UGT1A1, 1A9 and 2B7 (as well as the gastrointestinal enzymes UGT1A7 and 1A8) showed considerable activities. Capsaicin glucuronidation was significantly correlated with 3-O-glucuronidation of beta-estradiol (r=0.637; p=0.014) and with UGT1A1 protein levels (r=0.616; p=0.019) in a bank of individual HLMs (n=14). Also, capsaicin glucuronidation was strongly correlated with zidovudine glucuronidation (r=0.765; p<0.01) and with UGT2B7 protein levels (r=0.721; p<0.01). UGT1A1, 1A9 and 2B7 contributed 30.3, 6.0 and 49.0% of total glucuronidation of capsaicin in pHLM, respectively. Further, glucuronidation of capsaicin by liver microsomes showed marked species difference.
IDENTIFICATION AND USE: Capsaicin is a pure dark red solid. It is used as a topical medication and a tool in neurobiological research. A number of health benefits have been ascribed to capsaicin and its derivatives, including anticancer activity, anti-inflammatory activity, anti-obesity activity, and analgesia. Topical capsaicin is used in the treatment of postherpetic neuralgia, osteoarthritis, and painful diabetic neuropathy. However, the strong pungency of these substances and potential for neurotoxicity limit their use in food, nutritional supplements, and pharmaceuticals. HUMAN EXPOSURE AND TOXICITY: Capsaicin is a powerful irritant; initial administration causes intense pain. Prolonged treatment causes insensitivity to painful stimuli and induces selective degeneration of certain primary sensory neurons. Painful exposures to capsaicin-containing peppers are among the most common plant-related exposures presented to poison centers. They cause burning or stinging pain to the skin, and if ingested in large amounts by adults or small amounts by children, can produce nausea, vomiting, abdominal pain, and burning diarrhea. Eye exposure produce intense tearing, pain, conjunctivitis, and blepharospasm. The irritating effect on the eyes has been utilized in pressurized dog repellent sprays which incorporate capsaicin. One boy accidentally had his eyes sprayed with this material. His eyes immediately smarted, teared, and became red, but were normal by the next day. "Hunan hand" is a contact dermatitis resulting from the direct handling of chili peppers containing capsaicin. In human lung and prostate cancer cells capsaicin stimulated both DNA double strand breaks and micronuclei production. Capsaicin was also found to be a DNA hypermethylating agent in A549 cells. ANIMAL STUDIES: Fifty ug/mL applied on the eyes of rats has caused obvious pain and blepharospasm. The blood vessels of the conjunctivae and lids became abnormally permeable to Evans blue dye injected intravenously. Application of local anesthetic prevented pain, but did not alter the vascular reaction. Intravitreal injection of capsaicin in rabbits causes miosis and breakdown of the blood-aqueous barrier. Oral LD50 values were 118.8 mg/kg for male and 97.4 mg/kg for female mice, and 161.2 mg/kg for male and 148.1 mg/kg for female rats. Major toxic symptoms in mice were salivation, erythema of skin, staggering gait, bradypnea, and cyanosis. Some animals showed tremor, clonic convulsion, dyspnea and lateral or prone position and then died 4 to 26 min after dosing. Survivors recovered within 6 hr in mice and 24 hr in rats. Toxic symptoms of rats were almost the same as mice, but rats showing higher incidence of cyanosis, clonic or tonic convulsion, dyspnea and lateral position, and the recovery was later than mice. Capsaicin caused developmental neurotoxicity in rats. The results of genotoxicity testing confirm the absence of genotoxic activity of high-purity capsaicin in the bacterial mutation and chromosome aberration tests. In addition, no evidence of cytotoxicity or genotoxicity was seen in the rat bone marrow micronucleus test. Repeated applications of capsaicin onto the shaven backs of female mice following a single-initiation dose of 7,12-dimethylbenz(a)anthracene did not cause any significant increase in papilloma formation and abnormal hyperplastic or inflammatory skin lesions, compared with the solvent control. Topical application of capsaicin did not induce the epidermal ornithine decarboxylase activity. The compound ameliorated the mouse skin carcinogenesis when given simultaneously with the tumor promoter, 12-o-tetradecanoylphorbol-13-acetate.
The burning and painful sensations associated with capsaicin result from its chemical interaction with sensory neurons. Capsaicin, as a member of the vanilloid family, binds to the vanilloid receptor 1 (VR1). VR1 permits cations to pass through the cell membrane and into the cell when activated. The resulting depolarization of the neuron stimulates it to signal the brain. By binding to the VR1 receptor, the capsaicin molecule produces the same sensation that excessive heat or abrasive damage would cause, explaining why the spiciness of capsaicin is described as a burning sensation. (L1246)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
致癌物分类
未列在IARC的名单上。
Not listed by IARC.
来源:Toxin and Toxin Target Database (T3DB)
毒理性
健康影响
辣椒素是一种强烈的刺激物，过度暴露可能导致死亡。
Capsaicin is a powerful irritant and severe over-exposure can result in death. (L1246)
◉ Summary of Use during Lactation:No information is available on the clinical use of topical capsaicin during breastfeeding. However, capsaicin is poorly absorbed after topical application, so it is not likely to reach the bloodstream of the infant or cause any adverse effects in breastfed infants.
◉ Effects in Breastfed Infants:Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk:Relevant published information was not found as of the revision date.
**Oral**: Following oral administration, capsaicin may be absorbed by a nonactive process from the stomach and whole intestine with an extent of absorption ranging between 50 and 90%, depending on the animal. The peak blood concentration can be reached within 1 hour following administration. Capsaicin may undergo minor metabolism in the small intestine epithelial cells post-absorption from the stomach into the small intestines. While oral pharmacokinetics information in humans is limited, ingestion of equipotent dose of 26.6 mg of pure capsaicin, capsaicin was detected in the plasma after 10 minutes and the peak plasma concentration of 2.47 ± 0.13 ng/ml was reached at 47.1 ± 2.0 minutes. **Systemic**: Following intravenous or subcutaneous administration in animals, the concentrations in the brain and spinal cord were approximately 5-fold higher than that in blood and the concentration in the liver was approximately 3-fold higher than that in blood. **Topical**: Topical capsaicin in humans is rapidly and well absorbed through the skin, however systemic absorption following topical or transdermal administration is unlikely. For patients receiving the topical patch containing 179 mg of capsaicin, a population analysis was performed and plasma concentrations of capsaicin were fitted using a one-compartment model with first-order absorption and linear elimination. The mean peak plasma concentration was 1.86 ng/mL but the maximum value observed in any patient was 17.8 ng/mL.
It is proposed that capsaicin mainly undergoes renal excretion, as both the unchanged and glucuronide form. A small fraction of unchanged compound is excreted in the feces and urine. _In vivo_ animal studies demonstrates that less than 10 % of an administered dose was found in faces after 48 h.
Prescription and nonprescription products for topical management of pain, including cream, lotion and patch forms, contain capsaicin (CAP) and dihydrocapsaicin (DHC). There are few in vivo studies on absorption, bioavailability, and disposition of CAP and DHC. We established a sensitive and rapid LC-MS/MS assay to determine CAP and DHC levels in rabbit plasma and tissue. Bio-samples prepared by liquid-liquid extraction using n-hexane-dichloromethane-isopropanol (100: 50: 5, v/v/v) mixture were separated by isocratic chromatography with an Extend C18 column. The mobile phase was acetonitrile-water-formic acid (70: 30: 0.1, v/v/v). The method was linear from 0.125 to 50 ng/mL for a 100 uL bio-sample, and the lower quantification limit was 0.125 ng/mL. Total run time to analyze each sample was 3.5 min. We used this validated method to study pharmacokinetics and tissue distribution of CAP gel administered topically to rabbits. A very small amount of CAP and DHC was absorbed into the systemic circulation. The highest plasma concentration was 2.39 ng/mL, and the mean peak plasma concentration value after 12 h of CAP gel application was 1.68 ng/mL. Drug concentration in treated skin was relatively high, with low concentration in other tissues. Thus, topical CAP gel had strong local effects and weaker systemic effects.
[EN] COMPOUNDS AND THEIR USE AS BACE INHIBITORS<br/>[FR] COMPOSÉS ET LEUR UTILISATION EN TANT QU'INHIBITEURS DE BACE
申请人：ASTRAZENECA AB
公开号：WO2016055858A1
公开（公告）日：2016-04-14
The present application relates to compounds of formula (I), (la), or (lb) and their pharmaceutical compositions/preparations. This application further relates to methods of treating or preventing Αβ-related pathologies such as Down's syndrome, β- amyloid angiopathy such as but not limited to cerebral amyloid angiopathy or hereditary cerebral hemorrhage, disorders associated with cognitive impairment such as but not limited to MCI ("mild cognitive impairment"), Alzheimer's disease, memory loss, attention deficit symptoms associated with Alzheimer's disease, neurodegeneration associated with diseases such as Alzheimer's disease or dementia, including dementia of mixed vascular and degenerative origin, pre-senile dementia, senile dementia and dementia associated with Parkinson's disease.
[EN] ARYL ETHER-BASE KINASE INHIBITORS<br/>[FR] INHIBITEURS DE KINASES DE TYPE ARYLÉTHER-BASE
申请人：BRISTOL MYERS SQUIBB CO
公开号：WO2015038112A1
公开（公告）日：2015-03-19
The present disclosure is generally directed to compounds which can inhibit AAK1 (adaptor associated kinase 1), compositions comprising such compounds, and methods for inhibiting AAK1.
[EN] PYRAZOLO[1,5-a]PYRIMIDINE-BASED COMPOUNDS, COMPOSITIONS COMPRISING THEM, AND METHODS OF THEIR USE<br/>[FR] COMPOSÉS À BASE DE PYRAZOLO[1,5-A] PYRIMIDINE, COMPOSITIONS LES COMPRENANT ET UTILISATIONS DE CEUX-CI
申请人：LEXICON PHARMACEUTICALS INC
公开号：WO2013134228A1
公开（公告）日：2013-09-12
Pyrazolo[1,5-a]pyrimidine-based compounds of the formula: are disclosed, wherein R1, R2 and R3 are defined herein. Compositions comprising the compounds and methods of their use to treat, manage and/or prevent diseases and disorders mediated by mediated by adaptor associated kinase 1 activity are also disclosed.
[EN] TRIPARTITE MODULATORS OF ENDOSOMAL G PROTEIN-COUPLED RECEPTORS<br/>[FR] MODULATEURS TRIPARTITES DE RÉCEPTEURS COUPLÉS AUX PROTÉINES G DES ENDOSOMES
申请人：TAKEDA PHARMACEUTICALS CO
公开号：WO2017112792A1
公开（公告）日：2017-06-29
The present invention relates to tripartite compounds comprising a modulator moiety for endosomal G protein-coupled receptors like neurokinin-1 receptor, a linker and a lipid anchor suitable for anchoring the tripartite compound into a plasma membrane. The present invention also relates to a prodrug and a pharmaceutical composition comprising the tripartite compound and the use of the tripartite compound for the treatment of a disease or disorder mediated by endosomal G protein-coupled receptors signalling like NK1R signalling.
Substituted Heteroaromatic Carboxamide and Urea Compounds as Vanilloid Receptor Ligands
申请人：Frank Robert
公开号：US20120115903A1
公开（公告）日：2012-05-10
Substituted heteroaromatic carboxamide and urea compounds corresponding to formula (i)
processes for the preparation thereof, pharmaceutical compositions containing these compounds and also a method of using these compounds in pharmaceutical compositions for treating or inhibiting pain and other conditions mediated at least in part via the vanilloid receptor 1.
