The potential of secondary metabolites from plants as drugs or leads against protozoan neglected diseases - part I

Infections with protozoan parasites are a major cause of disease and mortality in many tropical countries of the world. Diseases caused by species of the genera Trypanosoma (Human African Trypanosomiasis and Chagas Disease) and Leishmania (various forms of Leishmaniasis) are among the seventeen "Neglected Tropical Diseases" (NTDs) defined as such by WHO due to the neglect of financial investment into research and development of new drugs by a large part of pharmaceutical industry and neglect of public awareness in high income countries. Another major tropical protozoan disease is malaria (caused by various Plasmodium species), which -although not mentioned currently by the WHO as a neglected disease- still represents a major problem, especially to people living under poor circumstances in tropical countries. Malaria causes by far the highest number of deaths of all protozoan infections and is often (as in this review) included in the NTDs. The mentioned diseases threaten many millions of lives world-wide and they are mostly associated with poor socioeconomic and hygienic environment. Existing therapies suffer from various shortcomings, namely, a high degree of toxicity and unwanted effects, lack of availability and/or problematic application under the life conditions of affected populations. Development of new, safe and affordable drugs is therefore an urgent need. Nature has provided an innumerable number of drugs for the treatment of many serious diseases. Among the natural sources for new bioactive chemicals, plants are still predominant. Their secondary metabolism yields an immeasurable wealth of chemical structures which has been and will continue to be a source of new drugs, directly in their native form and after optimization by synthetic medicinal chemistry. The current review, published in two parts, attempts to give an overview on the potential of such plant-derived natural products as antiprotozoal leads and/or drugs in the fight against NTDs.

Prevalencia de infección por HTLV-I/II en donantes de sangre de la Provincia de Santa Fe, Argentina / Prevalence of HTLV-I/II infection among blood donors in Santa Fe Province, Argentina

Subsequent to the National Epidemiologic Surveillance Program developed in 1997 by the National AIDS Program, anti-HTLV-I/II antibodies among blood donors in Santa Fe Province started to be detected. On the basis of this initial finding, it was regarded of interest to evaluate the true HTLV-I/II seroprevalence in this population during a four-year survey. Thus, from 1997 up to 2002, 9425 samples were studied from 17 out of the 19 provincial departments. Out of the total sampling, 38 proved reactive by agglutination techniques, 18 of which were confirmed by western blot (WB). Out of the latter, 10 were HTLV-I/II seropositive with a final prevalence of 0.1% (10/9425), whereas 7 were indeterminate and 1 negative. Among these 10 confirmed sera, 2 (0.02%) were HTLV, 3 (0.03%) HTLV-I and 5 (0.05%) HTLV-II. It should be highlighted that the presence of HTLV-I/II infection in blood donors in Santa Fe Province was demonstrated for the first time, with a prevalence greater than that reported for blood donors in non-endemic Argentine areas. Such findings confirm the need of corresponding systematic screening through regulatory blood bank norms in Santa Fe Province.

Subsecuentemente a que en 1997 el Programa Nacional de SIDA implementó un Programa de Vigilancia Epidemiológica a escala nacional, se comenzaron a detectar anticuerpos anti-HTLV-I/II en donantes de sangre de la Provincia de Santa Fe. En base a ese hallazgo inicial, se consideró pertinenteestimar la seroprevalencia de HTLV-I/II en donantes santafecinos en el curso de los 4 años siguientes. Así,desde 1997 hasta 2002, se estudiaron 9425 muestras provenientes de 17 de los 19 departamentos de laProvincia. Del total de muestras, 38 resultaron reactivas por técnicas de tamizaje, y de ellas 18 fueron confirmadas por western blot (WB). De esas muestras, 10 fueron HTLV-I/II seropositivas con una prevalencia finalde 0.1% (10/9425), en tanto que 7 resultaron indeterminadas y 1 negativa. De las seropositivas, 2 (0.02 %)eran HTLV, 3 (0.03 %) HTLV-I, y 5 (0.05 %) HTLV-II. Cabe destacar que por primera vez se constató lapresencia de infección por HTLV-I/II en donantes de sangre de Santa Fe, y con una prevalencia mayor a lasreferidas para donantes de sangre de áreas no endémicas de Argentina. Estos datos fundamentan la necesidadde un screening sistemático para la infección por HTLV-I/II mediante normas regulatorias en bancos desangre de esta provincia..