title: Inhibition of axenically grown Entamoeba histolytica by purine nucleoside analogs and actions of natural nucleosides.
abstract: The effects of the nucleoside analogs tubercidin, nebularin, formycin B and 3'-deoxyinosine on axenically grown Entamoeba histolytica were tested. Both tubercidin and nebularin showed pronounced inhibitory action, 50% of growth inhibition (IC50) being obtained at 0.14 and 0.82 microM, respectively. Formycin B and 3'-deoxyinosine were essentially inactive or weakly active at concentrations above 10 microM. Natural nucleosides, including adenosine, inosine, guanosine, thymidine, uridine and cytidine caused no significant effects at concentrations of 0.01-1 microM, however, significant inhibitory action was observed at or above 10 microM with cytidine and thymidine. The exploration of cytotoxic nucleosides as antiamebal drugs is of continued interest.
authors.affiliation: Department of Biological and Medical Research, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
authors.forename: S R
authors.initials: SR
authors.lastname: Das
authors.forename: H P
authors.initials: HP
authors.lastname: Baer
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D000981:Antiprotozoal Agents / Q000737:chemistry / Q000494:pharmacology; D004748:Entamoeba histolytica / Q000187:drug effects* / Q000254:growth & development; D005573:Formycins / Q000737:chemistry / Q000494:pharmacology; D007288:Inosine / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology; D015394:Molecular Structure; D011684:Purine Nucleosides / Q000737:chemistry / Q000494:pharmacology*; D012263:Ribonucleosides / Q000737:chemistry / Q000494:pharmacology; D014372:Tubercidin / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D000981:Antiprotozoal Agents; D005573:Formycins; D011684:Purine Nucleosides; D012263:Ribonucleosides; C070014:3'-deoxyinosine; C034561:formycin B; D007288:Inosine; C005248:nebularine; D014372:Tubercidin