Comparison of tetrazolium salt assays for evaluation of drug activity against Leishmania spp.
In French Guiana, leishmaniasis is an essentially cutaneous infection. It constitutes a major public health problem, with a real incidence of 0.2 to 0.3%. Leishmania guyanensis is the causal species most frequently encountered in French Guiana. The treatment of leishmaniasis is essentially drug based, but the therapeutic compounds available have major side effects (e.g., liver damage and diabetes) and must be administered parenterally or are costly. The efficacy of some of these agents has declined due to the emergence of resistance in certain strains of Leishmania. There is currently no vaccine against leishmaniasis, and it is therefore both necessary and urgent to identify new compounds effective against Leishmania. The search for new drugs requires effective tests for evaluations of the leishmanicidal activity of a particular molecule or extract. Microculture tetrazolium assays (MTAs) are colorimetric tests based on the use of tetrazolium salts. We compared the efficacies of three tetrazolium salts-3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT), and 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium (WST-8)-for quantification of the promastigotes of various species of Leishmania. We found that the capacity of Leishmania to metabolize a tetrazolium salt depended on the salt used and the species of Leishmania. WST-8 was the tetrazolium salt best metabolized by L. guyanensis and gave the best sensitivity.
Université des Antilles et de la Guyane, Laboratoire d'Épidémiologie des Parasitoses Tropicales EA 3593, Labex CEBA UFR de Médecine, Cayenne, French Guiana.
Marine
M
Ginouves
Université des Antilles et de la Guyane, Laboratoire d'Épidémiologie des Parasitoses Tropicales EA 3593, Labex CEBA UFR de Médecine, Cayenne, French Guiana Laboratoire Hospitalo-Universitaire de Parasitologie et Mycologie, Centre Hospitalier de Cayenne, Cayenne, French Guiana.
Bernard
B
Carme
Université des Antilles et de la Guyane, Laboratoire d'Épidémiologie des Parasitoses Tropicales EA 3593, Labex CEBA UFR de Médecine, Cayenne, French Guiana Service de Dermatologie, Centre Hospitalier de Cayenne, Cayenne, French Guiana.
Pierre
P
Couppie
Université des Antilles et de la Guyane, Laboratoire d'Épidémiologie des Parasitoses Tropicales EA 3593, Labex CEBA UFR de Médecine, Cayenne, French Guiana fac.prevot@gmail.com.
Ghislaine
G
Prevot
D000981:Antiprotozoal Agents / Q000494:pharmacology*; D003124:Colorimetry / Q000379:methods*; D005616:French Guiana; D006801:Humans; D007891:Leishmania / Q000187:drug effects*; D021261:Parasitic Sensitivity Tests / Q000379:methods; D012680:Sensitivity and Specificity; D013778:Tetrazolium Salts / Q000032:analysis*
D000981:Antiprotozoal Agents; D013778:Tetrazolium Salts