Monepantel (MOP) belongs to a new class of anthelmintic drugs known as aminoacetonitrile derivatives. It was approved for use in veterinary practice in Czech Republic in 2011. So far, biotransformation and transport of MOP in target animals have been studied insufficiently, although the study of metabolic pathways of anthelmintics is very important for the efficacy of safety of therapy and evaluation of the risk of drug-drug interactions. The aim of this study was to identify MOP metabolites and to suggest the metabolic pathways of MOP in sheep. For this purpose, primary culture of ovine hepatocytes was used as a model in vitro system. After incubation, medium samples and homogenates of hepatocytes were extracted separately using solid-phase extraction. Analysis was performed using a hybrid quadrupole-time-of-flight analyzer with respect to high mass accuracy measurements in full scan and tandem mass spectra for the confirmation of an elemental composition. The obtained results revealed S-oxidation to sulfoxide and sulfone and arene hydroxylation as MOP phase I biotransformations. From phase II metabolites, MOP glucuronides, sulfates, and acetylcysteine conjugates were found. Based on the obtained results, a scheme of the metabolic pathway of MOP in sheep has been proposed.
- MeSH
- aminoacetonitrily analogy a deriváty metabolismus MeSH
- anthelmintika metabolismus MeSH
- extrakce na pevné fázi MeSH
- hepatocyty metabolismus MeSH
- kultivované buňky MeSH
- metabolické sítě a dráhy MeSH
- ovce metabolismus MeSH
- tandemová hmotnostní spektrometrie MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Ivermectin (IVE), one of the most important anthelmintics, is often used in the treatment of haemonchosis in ruminants. The objective of our work was (1) to find and identify phase I and II metabolites of IVE formed by the Barber's pole worm (Haemonchus contortus), and (2) to compare IVE metabolites in helminths with IVE biotransformation in sheep (Ovis aries) as host species. Ultrahigh-performance liquid chromatography/tandem mass spectrometry (UHPLC/MS/MS) was used for this purpose. During in vitro incubations, microsomes (from adult worms or from ovine liver) and a primary culture of ovine hepatocytes were incubated with IVE. In the ex vivo study, living H. contortus adults were incubated in the presence of 1 μM IVE for 24 h. The results showed that the H. contortus enzymatic system is not able to metabolize IVE. On the other hand, 7 different phase I as well as 9 phase II IVE metabolites were detected in ovine samples using UHPLC/MS/MS analyses. Most of these metabolites have not been described before. Haemonchus contortus is not able to deactivate IVE through biotransformation; therefore, biotransformation does not contribute to the development of IVE-resistance in the Barber's pole worm.
- MeSH
- anthelmintika chemie metabolismus terapeutické užití MeSH
- chromatografie kapalinová MeSH
- Haemonchus účinky léků růst a vývoj metabolismus MeSH
- hemonchóza farmakoterapie parazitologie veterinární MeSH
- hepatocyty metabolismus MeSH
- hmotnostní spektrometrie MeSH
- ivermektin chemie metabolismus terapeutické užití MeSH
- kultivované buňky MeSH
- mikrozomy metabolismus MeSH
- nemoci ovcí farmakoterapie parazitologie MeSH
- ovce domácí metabolismus MeSH
- ovce metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Supplementation of the rumen ciliate Diploplastron affine growth medium with commercial chitin stimulated growth of ciliates and the density of their population was positively correlated with chitin doses (r = 0.95; p < 0.01). The cell-free extracts prepared from bacteria-free ciliates degraded chitin to N-acetyl-D: -glucosamine and chitobiose. Three exochitinases, two endochitinases and two beta-N-acetylglucosaminidases were identified in the cell-free extract of protozoa. The molar mass of exochitinases was 80, 65 and 30 kDa, and endochitinases 75 and 50 kDa; the molar mass of one of the identified beta-N-acetylglucosaminidases was 45 kDa.
- MeSH
- bachor metabolismus parazitologie MeSH
- chitin metabolismus MeSH
- chitinasy chemie klasifikace metabolismus MeSH
- Ciliophora enzymologie růst a vývoj MeSH
- kultivační média chemie MeSH
- ovce metabolismus parazitologie MeSH
- protozoální proteiny klasifikace metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- MeSH
- dusičnany aplikace a dávkování metabolismus škodlivé účinky MeSH
- finanční podpora výzkumu jako téma MeSH
- glukosinoláty aplikace a dávkování metabolismus škodlivé účinky MeSH
- jod metabolismus nedostatek MeSH
- ovce metabolismus MeSH
- štítná žláza cytologie fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- MeSH
- bachor metabolismus MeSH
- epitel metabolismus MeSH
- lysin metabolismus MeSH
- ovce metabolismus MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
