Journal of Clinical Pharmacy and Therapeutics, 2000
To describe application of a new method for the evaluation of anti-Trypanosoma cruzi activity aga... more To describe application of a new method for the evaluation of anti-Trypanosoma cruzi activity against intracellular forms. Vero fibroblasts in 96-well tissue culture plates were infected with trypomastigote forms of T. cruzi. Amastigotes growth was estimated after 24 and 96 h both by microscopic counts of Giemsa-stained monolayers and enzyme-linked immunoIsorbent assay (ELISA). ELISA was performed directly on the fixed cultures using a rabbit anti-T. cruzi immunoIglobulin as the first antibody and a peroxidase-labelled antirabbit immunoglobulin as the second antibody. Three chemical series of structural analogous of gentian violet, thiadiazines and derivatives of 5-nitrothiophene-2-carbaldehyde as well as three reference compounds (nifurtimox, benznidazole and gentian violet) were then assayed. The anti-T. cruzi activity of all of them had been determined previously by microscopic counting of Giemsa-stained infected cultures. None of the assayed compounds showed better activity than the reference ones, but the application of the enzyme immunoassay to quantify the inhibition of growth amastigotes is of great interest, as it yielded results comparable with microscopic counts. ELISA can be applied to pharmacological screening, with some advantages over the microscopic examination, including possible automation, rapidity and objectivity in assessment.
Eight thiadiazine 1,1-dioxide derivatives were evaluated for antitrichomonal and antitrypanosomal... more Eight thiadiazine 1,1-dioxide derivatives were evaluated for antitrichomonal and antitrypanosomal activities. In vivo tests were performed on a murine model for trichomoniasis standardized in our laboratory. The capacity of compounds to clear visceral lesions in experimentally infected animals as well as their effects on the mortality time of mice were used as criteria for activity. One of the thiadiazines (compound 7b) showed an efficacy similar to that obtained with the reference drug metronidazole, although higher doses were required. Its toxicity on cell proliferation in tissue culture was moderate. In vitro assays on amastigote forms of Trypanosoma cruzi were carried out using cultures of Vero cells infected with metacyclic trypomastigotes. For one compound (1) trypanocidal activity resembled that of nifurtimox as assessed by microscopic counts of infected and uninfected cells. Unfortunately, this compound showed a high degree of cytotoxicity on Vero cell cultures.
International Journal for Parasitology, Aug 1, 1995
The experimental pathogenic effects in vivo and in vitro of 6 different isolates of Trichomonas v... more The experimental pathogenic effects in vivo and in vitro of 6 different isolates of Trichomonas vaginalis were studied following their inoculation into NMRI mice and on to adherent cultures of HeLa cells. Contact between the parasite and the adherent monolayer of cells was necessary to induce the monolayer to detach. The strains which were more virulent to mice also showed a greater weighted index of adherence; the weighted index of cytotoxicity in vitro did not, on the other hand, correlate with experimental pathology in vivo.
Bis(indazol-3-ol) derivatives (5, 30-38) were prepared by alkylation of 3-alkoxyindazoles with al... more Bis(indazol-3-ol) derivatives (5, 30-38) were prepared by alkylation of 3-alkoxyindazoles with alpha,omega-dibromides, followed by removal of the O-protecting groups. These compounds were subsequently evaluated as inhibitors of biocrystallization of ferriprotoporphyrin IX (heme) to hemozoin, a Plasmodium detoxification specific process. Most bis(5-nitroindazol-3-ols) were good inhibitors, however, a denitro analogue (38), the intermediate bis(3-alkoxyindazoles) (15-29) as well as bis(indazolin-3-ones) (39-42) were not active, showing the importance of the NO(2) and OH groups in the inhibition process.
Journal of Clinical Pharmacy and Therapeutics, 2000
To describe application of a new method for the evaluation of anti-Trypanosoma cruzi activity aga... more To describe application of a new method for the evaluation of anti-Trypanosoma cruzi activity against intracellular forms. Vero fibroblasts in 96-well tissue culture plates were infected with trypomastigote forms of T. cruzi. Amastigotes growth was estimated after 24 and 96 h both by microscopic counts of Giemsa-stained monolayers and enzyme-linked immunoIsorbent assay (ELISA). ELISA was performed directly on the fixed cultures using a rabbit anti-T. cruzi immunoIglobulin as the first antibody and a peroxidase-labelled antirabbit immunoglobulin as the second antibody. Three chemical series of structural analogous of gentian violet, thiadiazines and derivatives of 5-nitrothiophene-2-carbaldehyde as well as three reference compounds (nifurtimox, benznidazole and gentian violet) were then assayed. The anti-T. cruzi activity of all of them had been determined previously by microscopic counting of Giemsa-stained infected cultures. None of the assayed compounds showed better activity than the reference ones, but the application of the enzyme immunoassay to quantify the inhibition of growth amastigotes is of great interest, as it yielded results comparable with microscopic counts. ELISA can be applied to pharmacological screening, with some advantages over the microscopic examination, including possible automation, rapidity and objectivity in assessment.
Eight thiadiazine 1,1-dioxide derivatives were evaluated for antitrichomonal and antitrypanosomal... more Eight thiadiazine 1,1-dioxide derivatives were evaluated for antitrichomonal and antitrypanosomal activities. In vivo tests were performed on a murine model for trichomoniasis standardized in our laboratory. The capacity of compounds to clear visceral lesions in experimentally infected animals as well as their effects on the mortality time of mice were used as criteria for activity. One of the thiadiazines (compound 7b) showed an efficacy similar to that obtained with the reference drug metronidazole, although higher doses were required. Its toxicity on cell proliferation in tissue culture was moderate. In vitro assays on amastigote forms of Trypanosoma cruzi were carried out using cultures of Vero cells infected with metacyclic trypomastigotes. For one compound (1) trypanocidal activity resembled that of nifurtimox as assessed by microscopic counts of infected and uninfected cells. Unfortunately, this compound showed a high degree of cytotoxicity on Vero cell cultures.
International Journal for Parasitology, Aug 1, 1995
The experimental pathogenic effects in vivo and in vitro of 6 different isolates of Trichomonas v... more The experimental pathogenic effects in vivo and in vitro of 6 different isolates of Trichomonas vaginalis were studied following their inoculation into NMRI mice and on to adherent cultures of HeLa cells. Contact between the parasite and the adherent monolayer of cells was necessary to induce the monolayer to detach. The strains which were more virulent to mice also showed a greater weighted index of adherence; the weighted index of cytotoxicity in vitro did not, on the other hand, correlate with experimental pathology in vivo.
Bis(indazol-3-ol) derivatives (5, 30-38) were prepared by alkylation of 3-alkoxyindazoles with al... more Bis(indazol-3-ol) derivatives (5, 30-38) were prepared by alkylation of 3-alkoxyindazoles with alpha,omega-dibromides, followed by removal of the O-protecting groups. These compounds were subsequently evaluated as inhibitors of biocrystallization of ferriprotoporphyrin IX (heme) to hemozoin, a Plasmodium detoxification specific process. Most bis(5-nitroindazol-3-ols) were good inhibitors, however, a denitro analogue (38), the intermediate bis(3-alkoxyindazoles) (15-29) as well as bis(indazolin-3-ones) (39-42) were not active, showing the importance of the NO(2) and OH groups in the inhibition process.
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Papers by Jose A Escario