OBJECTIVES We analysed, in a cell-by-cell study, the in vitro susceptibility of Giardia duodenalis strains, including Mexican isolates and their clones to 5-nitroimidazoles and benzimidazoles. METHODS Fluorogenic dye staining (FDA-PI) and cell morphology (CM) assays, two fast and direct techniques, replaced the indirect 'gold standard' method (subculture in liquid medium) in the evaluation of...

Nitroimidazoles exhibit high microbicidal activity, but mutagenic, genotoxic and cytotoxic properties have been attributed to the presence of the nitro group. However, we synthesised nitroimidazoles with activity against the trypomastigotes of Trypanosoma cruzi, but that were not genotoxic. Herein, nitroimidazoles (11-19) bearing different substituent groups were investigated for their potentia...

The mechanism of the trichomonicidal activity of metronidazole and other 5-nitroimidazoles appears to depend on the ferredoxin-mediated reduction of their nitro group, with generation of a reactive metabolite or metabolites which interact with DNA leading to a subsequent inhibition of nucleic acid and protein synthesis. Redox cycling of these compounds under aerobic conditions appears to be a d...

The kinetics of the electron transfer reaction between reduced [2Fe-2S] ferredoxins and select nitroimidazole antimicrobial agents is reported. The ferredoxins from the protozoan Trichomonas vaginalis and the cyanobacterium Anabaena sp. strain 7120 were studied because they are the proximal electron donors to nitroimidazoles in these two organisms with significantly different nitroimidazole sus...

Nitroimidazoles are radiosensitizers and hypoxia detecting chemosensitizers. Intially nitroimidazoles were single dose antibiotic drugs. Recently, nitroimidazole derivatives have emerged as multifunctional “drug-biomarker monitors” chemical compounds with importance in treatment of tumors, monitoring hypoxia and safer imaging contrast agents to monitor the therapeutic progress. Additionally, th...

The nitroimidazoles used in the treatment of anaerobic infection are well-tolerated by patients. With the possible exception of neurotoxic effects associated with high dosage, signs and symptoms of toxicity are transient and disappear soon after withdrawal of treatment. Teratogenicity tests in animals have given negative results in the case of metronidazole, ornidazole and tinidazole, and in th...

Hypoxia, a deficiency in the levels of oxygen, is common feature most solid tumors and induces many characteristics cancer. Hypoxia associated with metastases strong resistance to radio- chemotherapy, can decrease accuracy cancer prognosis. Non-invasive imaging methods such as positron emission tomography (PET) single-photon computed (SPECT) using hypoxia-targeting radiopharmaceuticals have bee...

Ronidazole, a nitroimidazole that has in vivo antiparasitic and antimycoplasmal activity, also has some in vivo antibacterial activity.