Trypanocidal constituents in plants: 7. Mammea-type coumarins

Calophyllum brasiliense and Mammea americana (Clusiaceae) are two trees from the tropical rain forests of the American continent. A previous screening showed high trypanocidal activity in the extracts of these species. Several mammea-type coumarins, triterpenoids and biflavonoids were isolated from the leaves of C. brasiliense. Mammea A/AA was obtained from the fruit peels of M. americana. These compounds were tested in vitro against epimastigotes and trypomastigotes of Trypanosoma cruzi, the etiologic agent of Chagas disease. The most potent compounds were mammea A/BA, A/BB, A/AA, A/BD and B/BA, with MC100 values in the range of 15 to 90 g/ml. Coumarins with a cyclized ,-dimethylallyl substituent on C-6, such as mammea B/BA, cyclo F + B/BB cyclo F, and isomammeigin, showed MC100 values > 200 g/ml. Several active coumarins were also tested against normal human lymphocytes in vitro, which showed that mammea A/AA and A/BA were not toxic. Other compounds from C. brasiliense, such as the triterpenoids, friedelin, canophyllol, the biflavonoid amentoflavone, and protocatechuic and shikimic acids, were inactive against the epimastigotes. The isopropylidenedioxy derivative of shikimic acid was inactive, and its structure was confirmed by X-ray diffraction. Our results suggest that mammea-type coumarins could be a valuable source of trypanocidal compounds.

Circulation of hantaviruses in the influence area of the Cuiabá-Santarém Highway

We describe evidence of circulation of hantaviruses in the influence area of the Santarém-Cuiabá Highway (BR-163) in the Brazilian Amazon through the prevalence of specific antibodies against hantaviruses in inhabitants living in four municipalities of this area: Novo Progresso (2.16%) and Trairão (4.37%), in state of Pará (PA), and Gua-rantã do Norte (4.74%) and Marcelândia (9.43%), in state of Mato Grosso. We also demonstrate the ongoing association between Castelo dos Sonhos virus (CASV) and hantavirus pulmonary syndrome (HPS) cases in the Castelo dos Sonhos district (municipality of Altamira, PA) and the first report of CASV in the municipalities of Novo Progresso and Guarantã do Norte. The results of this work highlight the risk for a possible increase in the number of HPS cases and the emergence of new hantavirus lineages associated with deforestation in this Amazonian area after the conclusion of paving works on BR-163 Highway.

Host genetic factors in American cutaneous leishmaniasis: a critical appraisal of studies conducted in an endemic area of Brazil

American cutaneous leishmaniasis (ACL) is a vector-transmitted infectious disease with an estimated 1.5 million new cases per year. In Brazil, ACL represents a significant public health problem, with approximately 30,000 new reported cases annually, representing an incidence of 18.5 cases per 100,000 inhabitants. Corte de Pedra is in a region endemic for ACL in the state of Bahia (BA), northeastern Brazil, with 500-1,300 patients treated annually. Over the last decade, population and family-based candidate gene studies were conducted in Corte de Pedra, founded on previous knowledge from studies on mice and humans. Notwithstanding limitations related to sample size and power, these studies contribute important genetic biomarkers that identify novel pathways of disease pathogenesis and possible new therapeutic targets. The present paper is a narrative review about ACL immunogenetics in BA, highlighting in particular the interacting roles of the wound healing gene FLI1 with interleukin-6 and genes SMAD2 and SMAD3 of the transforming growth factor beta signalling pathway. This research highlights the need for well-powered genetic and functional studies on Leishmania braziliensis infection as essential to define and validate the role of host genes in determining resistance/susceptibility regarding this disease.

A comparative cross-sectional study on the prevalence and morbidity of schistosomiasis in a community in northeastern Brazil (1979-2010)

A cross-sectional study on the prevalence and morbidity of schistosomiasis was conducted in the main settlement of the municipality of Alhandra, in the southern coastal region of the state of Paraíba, in 2010. The results of this study were compared with the results of a previous study conducted in the same area in 1979. The systematic sampling per family conglomerate included approximately 10% of the resident population in the urban area of Alhandra. Faecal examinations were performed using the Kato-Katz method. The clinical forms of the disease were classified in accordance with FS Barbosa as Type I - intestinal form, Type II - hepatointestinal form and Type III - hepatosplenic form. The prevalence of the infection in 2010 was 10.05%, whereas in 1979 it was 46.6% among untreated patients. The percentages of the three clinical forms in 2010 were as follows: 95.3% Type I, 4.6% Type II and 0% Type III; in 1979, the percentages were 94.4%, 3% and 2.6% for Types I, II and III, respectively. In 1979, 6.07% of the Biomphalaria glabrata specimens (the intermediate host in this area) excreted cercariae, where in 2010 only 1.27% of the specimens caught excreted the parasite.