title: Hydrosoluble formazan XTT: its application to natural products drug discovery for Leishmania.
abstract: A colorimetric method for measuring the viability of Leishmania promastigotes is described that is based on the reduction of the tetrazolium salt, XTT, to a water-soluble formazan. Values obtained by the XTT method correlated well with parasite number (r=0.965) and with methods that rely upon the reduction of MTT or MTS (r=0.96 and 0.97, respectively). The IC(50) values obtained by XTT method with amphotericin-B, miltefosine and ketoconazole were similar to those previously reported by other methods. The XTT method proved to be a reliable and convenient method for the screening of methanolic extracts from 1059 plants and was used for the bioassay-guided fractionation of the alkaloid aegeline from Sarcorhachis naranjoana.
authors: Smithsonian Tropical Research Institute, Panama, Panama.
authors: Cornelly
authors: C
authors: Williams
authors: Omar A
authors: OA
authors: Espinosa
authors: Hector
authors: H
authors: Montenegro
authors: Luis
authors: L
authors: Cubilla
authors: Todd L
authors: TL
authors: Capson
authors: Eduardo
authors: E
authors: Ortega-Barría
authors: Luz I
authors: LI
authors: Romero
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D007202:Indicators and Reagents / Q000737:chemistry*; D020128:Inhibitory Concentration 50; D007894:Leishmania mexicana / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D010946:Plants, Medicinal / Q000737:chemistry; D013778:Tetrazolium Salts / Q000737:chemistry*
chemical_list: D000981:Antiprotozoal Agents; D007202:Indicators and Reagents; D013778:Tetrazolium Salts; C059087:2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-((phenylamino)carbonyl)-2H-tetrazolium hydroxide