title: Development of novel valerolactam-benzimidazole hybrids anthelmintic derivatives: Diffusion and biotransformation studies in helminth parasites.
abstract: In the search for new anthelmintics able to overcome the resistance problem against all available drugs in livestock, the synthesis of novel valerolactam-benzimidazole hybrid compounds was reported. This allowed us to obtain these in vitro and in vivo bioactive compounds using Nippostrongylus brasiliensis rat model by integrating physiology-based assays and ex vivo diffusion studies. In order to further study those novel hybrid molecules, Haemonchus contortus (a sheep gastrointestinal nematode of interest) and Mesocestoides vogae tetrathyridia (a useful system to study the efficacy of anthelmintic drugs against cestoda) were used as parasite models to compare the ex vivo patterns of diffusion and biotransformation of benzimidazoles and their valerolactam-benzimidazole hybrid derivatives. On average, a nine-fold higher intraparasitic concentration of compounds was found in M. vogae compared with H.contortus, with similarities regarding the order of entry of compounds, highlighting febendazole (FEB) and its hybrid compound 10, while valerolactam compound 2 practically did not penetrate the parasites. Interestingly, sulphoxidation drug metabolism was observed and measured, revealing percentages of oxidation of 8.2% and 14.5% for albendazole (ABZ) and febendazole respectively in M. vogae, while this effect was more relevant in H. contortus parasite. More importantly, significant differences were observed between anthelmintic-susceptible adult parasites (Hc S) and those from sheep farms (Hc U). In fact, the percentages of oxidation of FEB and the hybrid compound 8 were higher in Hc U (25.5%, 54.1%, respectively) than in Hc S (8.8%, 38.2%). Interestingly, sulphoxidation of hybrid compound 10 was neither observed in M. vogae nor in H. contortus parasites, suggesting that increased drug metabolism (oxidation reactions) could not be used by these parasites as a defense mechanism against this novel drug.
authors: Cátedra de Farmacología, Laboratorio de Experimentación Animal, Depto. CIENFAR, Facultad de Química, Universidad de la República (Udelar), Av. General Flores 2124, Montevideo, Uruguay.
authors: Beatriz
authors: B
authors: Munguía
authors: Cátedra de Farmacología, Laboratorio de Experimentación Animal, Depto. CIENFAR, Facultad de Química, Universidad de la República (Udelar), Av. General Flores 2124, Montevideo, Uruguay.
authors: Mauricio
authors: M
authors: Michelena
authors: Cátedra de Farmacología, Laboratorio de Experimentación Animal, Depto. CIENFAR, Facultad de Química, Universidad de la República (Udelar), Av. General Flores 2124, Montevideo, Uruguay.
authors: Elisa
authors: E
authors: Melian
authors: Cátedra de Farmacología, Laboratorio de Experimentación Animal, Depto. CIENFAR, Facultad de Química, Universidad de la República (Udelar), Av. General Flores 2124, Montevideo, Uruguay.
authors: Jenny
authors: J
authors: Saldaña
authors: Cátedra de Farmacología, Laboratorio de Experimentación Animal, Depto. CIENFAR, Facultad de Química, Universidad de la República (Udelar), Av. General Flores 2124, Montevideo, Uruguay.
authors: Ximena
authors: X
authors: Ures
authors: Cátedra de Química Farmacéutica, Depto. DQO, Facultad de Química, Udelar, Av. General Flores 2124, Montevideo, Uruguay. Electronic address: emanta@fq.edu.uy.
authors: Eduardo
authors: E
authors: Manta
authors: Cátedra de Farmacología, Laboratorio de Experimentación Animal, Depto. CIENFAR, Facultad de Química, Universidad de la República (Udelar), Av. General Flores 2124, Montevideo, Uruguay. Electronic address: ldoming@fq.edu.uy.
authors: Laura
authors: L
authors: Domínguez
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001562:Benzimidazoles / Q000737:chemistry / Q000494:pharmacology*; D001711:Biotransformation; D005260:Female; D006374:Helminthiasis, Animal / Q000188:drug therapy* / Q000469:parasitology; D006376:Helminths / Q000187:drug effects* / Q000254:growth & development; D007769:Lactams / Q000737:chemistry / Q000494:pharmacology*; D008297:Male; D051379:Mice; D051381:Rats; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy* / Q000469:parasitology
chemical_list: D000871:Anthelmintics; D001562:Benzimidazoles; D007769:Lactams; C511520:valerolactam; C031000:benzimidazole
keywords: Cestodes; Drug resistance; Haemonchus contortus; Mesocestoides vogae; Nematodes; Valerolactam-benzimidazole hybrids