Trypanocidal constituents in plants 5. Evaluation of some Mexican plants for their trypanocidal activity and active constituents in the seeds of Persea americana.

Crude extracts of Mexican medicinal plants were screened for trypanocidal activity against Trypanosoma cruzi, which is the etiological agent for Chagas' disease, one of the most serious protozoan diseases in Latin America. There were 71 kinds of methanolic and other organic extracts from 65 plants, which were newly examined by a preliminary screening test to observe immobilization of epimastigotes and trypomastigotes of T. cruzi in vitro.

Genotypic variation among lineages of Trypanosoma cruzi and its geographic aspects.

Isozyme analysis with 18 enzyme loci was conducted on 146 isolates of Trypanosoma cruzi from Mexico, Guatemala, Colombia, Ecuador, Peru, Brazil, Bolivia, Paraguay and Chile. Forty-four different MLGs (groups of isolates with identical multilocus genotypes) were identified and a phylogeny was constructed. The phylogenetic tree consisted of two main groups (T.

Trypanocidal constituents in plants 4. Withanolides from the aerial parts of Physalis angulata.

The constituents of the aerial parts of Physalis angulata (Solanaceae) were investigated based on the plant's trypanocidal activity against epimastigotes of Trypanosoma cruzi, the etiologic agent for Chagas' disease. Four new withanolides were isolated, along with six known ones, from the active fraction. Their structures were determined by spectroscopic analysis.

Trypanocidal constituents in plants 3. Leaves of Garcinia intermedia and heartwood of Calophyllum brasiliense.

The constituents of the leaves of Garcinia intermedia and heartwood of Calophyllum brasiliense were investigated based on their trypanocidal activity against epimastigotes of Trypanosoma cruzi, the etiologic agent of Chagas' disease. As the active components, the polyisoprenylated benzophenone derivative guttiferone A and the xanthone 8-desoxygartanin were isolated along with the biflavonoids podocarpusflavone A and amentoflavone, and friedelin from the former. Three xanthones, jacareubin, 6-deoxyjacareubin, and 1,3,5,6-tetrahydroxy-2-(3-methyl-2-butenyl)xanthone from the latter showed activity.

Trypanocidal constituents in plants 2.xanthones from the stem bark of Garcinia subelliptica.

The constituents of the stem bark of Garcinia subelliptica (Guttiferae) were investigated based on its trypanocidal activity against epimastigotes of Trypanosoma cruzi, the etiologic agent for Chagas' disease. As the active components, nine xanthones were isolated including two new ones, 4-hydroxybrasilixanthone B and 1,3,5,6-tetrahydroxy-4,7,8-tri(3-methyl-2-butenyl)xanthone. Their structures were determined by spectroscopic analysis.

Ursolic acid as a trypanocidal constituent in rosemary.

The MeOH extract of the leaves of rosemary (Rosmarinus officinalis L.) completely inhibited the motility of cultured epimastigotes of Trypanosoma cruzi at the concentration of 2 mg/ml after 2 h of incubation. Activity-guided fractionation of the MeOH extract has resulted in the isolation of three triterpene acids, betulinic, oleanolic and ursolic acids.

Trypanocidal constituents in plants 1. Evaluation of some Mexican plants for their trypanocidal activity and active constituents in Guaco, roots of Aristolochia taliscana.

Crude extracts of Mexican medicinal plants were screened for trypanocidal activity against Trypanosoma cruzi, which is the etiological agent for Chagas' disease, one of the most serious protozoan diseases in Latin America. There were 43 kinds of methanolic and other organic extracts from 39 plants which were examined by the preliminary screening test to see immobilization of epimastigotes of T. cruzi in vitro.

Study of the ethiological agent of gnathostomosis in Nayarit, Mexico.

In order to clarify the specific identity of the etiological agent of human gnathostomosis in Nayarit State, Mexico, morphological and molecular studies were conducted on advanced third stage larvae obtained from human and fish tissue. Cathorops fuerthii from Agua Brava lagoons complex, was the only fish species found to be infected among four species surveyed. Morphological variability does not allow specific identification of the larvae.

Morphology of Gnathostoma spp. isolated from natural hosts in Sinaloa, Mexico.

Gnathostomosis is an emerging public health problem in Sinaloa, Mexico, where an increasing number of human cases have been diagnosed since 1989. The present study was carried out to determine the presence of the parasite in other natural hosts from the area. Birds, fish, opossums and raccoons were captured from local dams and lagoons.