Medicinal plants uses of the Tacana, an Amazonian Bolivian ethnic group.

We present the results of an ethnopharmacological investigation of a Bolivian lowland ethnic group, the Tacana. The Tacana have a long tradition of exchange with highland communities. Though facing rapid acculturation, highlighted by the loss of the Tacana language among the younger generations, the knowledge and uses of medicinal plants are still alive. Of the approximately 450 different plant species collected during this survey, 33% had medicinal uses. We present an overview of the traditional Tacana ethnomedicine and pharmacopoeia.

A search for natural bioactive compounds in Bolivia through a multidisciplinary approach. Part I. Evaluation of the antimalarial activity of plants used by the Chacobo Indians.

Thirty extracts of plants traditionally used by the Chacobos, a native community living in the Amazonian part of Bolivia, were screened in vitro and/or in vivo for antimalarial activity. Two of the four species designated as antimalarial, Geissospermum laeve and Maquira coriacea, displayed rather good activity, corroborating their traditional uses. However, they did show a rather high toxicity in vivo. Among twelve species used to cure symptoms relevant to malaria, five showed good activity: Apuleia leiocarpa, Bauhinia guianensis, Nectandra cuspidata, Sparattanthelium amazonum, Tanaecium jaroba. Two species, Qualea paraensis and Sclerolobium aff. guianense, used to treat scabies, showed interesting antimalarial activity in vivo; three other species (Iryanthera laevis, Prunus amplifolia, Pterocarpus aff. amazonum) used for various medicinal purposes, apparently not related with a Plasmodium infection, also showed antimalarial activity. Finally, one species (Derris amazonica) used as a piscicide displayed good in vitro activity, in the same way as one Annonaceae, Guatteria aff. schomburgkiana, used for construction purposes.

[Gastric stromal tumor with myxoid degeneration. Report of a case and review of the literature]. / Tumor estromal gástrico con degeneración mixoide. Reporte de un caso y revisión de la literatura.

BACKGROUND: Gastrointestinal stromal tumors (GIST's) represent a heterogeneous group of neoplasms that have as their common histologic denominator an immature proliferation of epithelioid or spindle cells. Although originally believed to represent atypical variants of leiomyoma or leiomyosarcoma, recent studies have demonstrated that only a subset of such tumors actually display well developed immunohistochemical, ultrastructural features of smooth muscle differentiation. Most gastrointestinal mesenchymal tumors are of uncertain histogenesis. Current studies have shown a striking morphological and immunophenotypic similarities of these tumors with the interstitial cells of Cajal. And that they may originate from stem cells that differentiate toward a pacemaker cell phenotype. Most GIST's have a co-expression of Kit (CD117) or CD34, which is also express in interstitial cells of Cajal. OBJECTIVE: This review will attempt to summarize the current knowledge and understanding of these lesions based on review of the literature, with an analysis of the criteria for distinguishing between benign and malignant tumors. METHOD: We report a Gastrointestinal Stromal Tumor of the stomach with prominent cystic degeneration. The patient had diarrhea, abdominal pain and was found to have abdominal mass. X-ray and computed axial tomography examination showed a lesion that seems to be a pancreatic cystic lesion. At laparotomy a large intramural tumor located in the stomach was found. Histologically, the lesion was composed of epithelioid and spindle cells embedded in an abundant myxoid stroma. Tumor cells showed positive staining for vimentin and CD34 positive. We conclude that the diagnosis of gastrointestinal stromal tumor whit prominent cystic degeneration can be made in this case.

Phytochemical and pharmacological studies of Guettarda acreana.

The present study examines the effects of the extracts [petroleum ether, CHCl3, CHCl3/MeOH (9:1) and MeOH], partially purified fractions and pure compounds from Guettarda acreana on the electrically induced contractions (E.C.I.) of the isolated guinea-pig ileum. The results of the experiments indicate that CHCl3/MeOH (9:1), MeOH extract, and the MeOH soluble part from CHCl3/MeOH extract tested at concentrations of 1.2, 2.5, and 5 micrograms/ml, dose-dependently reduced the guinea-pig ileum contractions. Furthermore, some partially purified fractions I-IV from the MeOH extract, each tested at the same concentrations of the extracts, and some pure compounds (6 x 10(-6), 3 x 10(-6), 1 x 10(-6) M) isolated from the above fractions significantly reduced, in a dose-dependent manner, the electrical contractions of the ileum. The active compounds were identified as the known indole alkaloids strictosidic acid, lyalosidic acid, 5 alpha-carboxystrictosidine, strictosidine, and sickingine, as well as the known quinic acid derivatives 5-caffeoylquinic acid, 4,5-dicaffeoylquinic acid, and shikimic acid by spectral data. Two known quinovic acid glycosides and a new triterpenic glycoside, quinovic acid 3 beta-O-alpha-rhamnopyranosyl-(1-->3)-(beta-glucopyranosyl-(1-->6)-beta- glucopyranoside, were also isolated and their structures established by NMR and M5 data.

4-Quinolinone alkaloids from Dictyoloma peruviana.

The stem-bark of Dictyoloma peruviana yielded two new piperidino [1,2-a] 4-quinolinones, dictyolomide A and dictyolomide B. Their structures were established by NMR spectroscopy.