title: Proteomic and ultrastructural analysis of the effect of a new nitazoxanide-N-methyl-1H-benzimidazole hybrid against Giardia intestinalis.
abstract: In an effort to develop alternative drugs for the treatment of giardiasis our research group has synthesized and evaluated a novel nitazoxanide and N-methyl-1H-benzimidazole hybrid molecule, named CMC-20. It showed an IC50 of 0.010 μM on Giardia intestinalis, lower than the IC50 values of 0.015, 0.037 and 1.224 μM for nitazoxanide, albendazole and metronidazole, respectively. In addition, we report studies carried out on its mechanism of action and effect at the ultrastructural level on G. intestinalis. The proteomic analysis of trophozoites treated with CMC-20 revealed significant changes in the expression level of proteins of the cytoskeleton, alpha and beta tubulin, alpha-1, beta giardin and axoneme-associated protein, among other molecules. Ultrastructural studies demonstrated that CMC-20 induces morphological changes on the parasite that loses its characteristic pear shape. Uncommon large bulbous structure at the flagella end, and parasites showing flange membrane bending and a concave depression in the ventral region, resembling an encystation process, were also observed. In addition, some apoptotic and autophagic-like features, such as membrane blebbing, intense vacuolation, chromatin condensation and multilamellar bodies were detected. Phosphatidylserine externalization was determined as an apoptotic marker by flow cytometry and immunofluorescence microscopy; however, a typical ladder-like DNA fragmentation profile was not detected. Although it was found that CMC-20 triggers the encystation process, damage to the cyst wall indicates loss of viability.
authors.affiliation: Departamento de Parasitología, Escuela Nacional de Ciencias Biológicas-Instituto Politécnico Nacional, 11340 Mexico City, Mexico; Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias-Pediatría Instituto Mexicano del Seguro Social, 06720 Mexico City, Mexico.
authors.forename: Félix
authors.initials: F
authors.lastname: Matadamas-Martínez
authors.affiliation: Departamento de Farmacia, Facultad de Química, UNAM, 04510 Mexico City, Mexico.
authors.forename: Rafael
authors.initials: R
authors.lastname: Castillo
authors.affiliation: Departamento de Farmacia, Facultad de Química, UNAM, 04510 Mexico City, Mexico.
authors.forename: Alicia
authors.initials: A
authors.lastname: Hernández-Campos
authors.affiliation: Departamento de Farmacia, Facultad de Química, UNAM, 04510 Mexico City, Mexico.
authors.forename: Carlos
authors.initials: C
authors.lastname: Méndez-Cuesta
authors.affiliation: Instituto de Biofisica Carlos Chagas Filho, Laboratorio de Ultraestrutura Celular Hertha Meyer, UFRJ, 21949-900, Rio de Janeiro, Brazil; Diretoria de Metrologia Aplicada a Ciências da Vida, Instituto Nacional de Metrologia, Qualidade e Tecnologia, Rio de Janeiro, Brazil.
authors.forename: Wanderley
authors.initials: W
authors.lastname: de Souza
authors.affiliation: Instituto de Biofisica Carlos Chagas Filho, Laboratorio de Ultraestrutura Celular Hertha Meyer, UFRJ, 21949-900, Rio de Janeiro, Brazil; Diretoria de Metrologia Aplicada a Ciências da Vida, Instituto Nacional de Metrologia, Qualidade e Tecnologia, Rio de Janeiro, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Gadelha
authors.affiliation: Departamento de Parasitología, Escuela Nacional de Ciencias Biológicas-Instituto Politécnico Nacional, 11340 Mexico City, Mexico.
authors.forename: Benjamín
authors.initials: B
authors.lastname: Nogueda-Torres
authors.affiliation: Departamento de Biología Celular, Centro de Investigación y Estudios Avanzados IPN, 07360 Mexico City, Mexico.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Hernández
authors.affiliation: Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias-Pediatría Instituto Mexicano del Seguro Social, 06720 Mexico City, Mexico. Electronic address: lilianyepez@yahoo.com.
authors.forename: Lilián
authors.initials: L
authors.lastname: Yépez-Mulia
mesh_terms: D000981:Antiprotozoal Agents / Q000494:pharmacology*; D001562:Benzimidazoles / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D016829:Giardia lamblia / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D005873:Giardiasis / Q000188:drug therapy; D009574:Nitro Compounds; D009928:Organ Specificity; D020543:Proteome / Q000187:drug effects*; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism; D013844:Thiazoles / Q000494:pharmacology*; D053058:Trophozoites / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D000981:Antiprotozoal Agents; D001562:Benzimidazoles; D009574:Nitro Compounds; D020543:Proteome; D015800:Protozoan Proteins; D013844:Thiazoles; C041747:nitazoxanide
keywords: Apoptosis-like; G. intestinalis; Hybrid compound