Leishmaniasis: current situation and new perspectives.
ABSTRACT Leishmaniasis represents a complex of diseases with an important clinical and epidemiological diversity. Visceral leishmaniasis (VL) is of higher priority than cutaneous leishmaniasis (CL) as it is a fatal disease in the absence of treatment. Anthroponotic VL foci are of special concern as they are at the origin of frequent and deathly epidemics (e.g. Sudan). Leishmaniasis burden remains important: 88 countries, 350 million people at risk, 500,000 new cases of VL per year, 1-1.5 million for CL and DALYs: 2.4 millions. Most of the burden is concentrated on few countries which allows clear geographic priorities. Leishmaniasis is still an important public health problem due to not only environmental risk factors such as massive migrations, urbanisation, deforestation, new irrigation schemes, but also to individual risk factors: HIV, malnutrition, genetic, etc em leader Leishmaniasis is part of those diseases which still requires improved control tools. Consequently WHO/TDR research for leishmaniasis has been more and more focusing on the development of new tools such as diagnostic tests, drugs and vaccines. The ongoing effort has already produced significant results. The newly available control tools should allow a scaling up of control activities in priority areas. In anthroponotic foci, the feasibility of getting a strong impact on mortality, morbidity and transmission, is high.
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ABSTRACT: The present study aims to evaluate the in vitro and in vivo antileishmanial activities of Pistacia khinjuk Stocks (Anacardiaceae) alcoholic extract and to compare its efficacy with a reference drug, meglumine antimoniate (MA, Glucantime), against Leishmania tropica and Leishmania major.This extract (0–100 𝜇g/mL) was evaluated in vitro against promastigote and intracellular amastigote forms of L. tropica (MRHO/IR/75/ER) and then tested on cutaneous leishmaniasis (CL) in male BALB/c mice with L. major to reproduce the antileishmanial activity topically. In vitro, P. khinjuk extract significantly (𝑃 < 0.05) inhibited the growth rate of promastigote (IC50 58.6 ± 3.2 𝜇g/mL) and intramacrophage amastigotes (37.3 ± 2.5 𝜇g/mL) of L. tropica as a dose-dependent response. In the in vivo assay, after 30 days of treatment, 75% recovery was observed in the infected mice treated with 30% extract. After treatment of the subgroups with the concentration of 20 and 30% of P. khinjuk extract, mean diameter of lesions was significantly (𝑃 < 0.05) reduced. To conclude, the present investigation demonstrated that P. vera extract had in vitro and in vivo effectiveness against L. major. Obtained findings also provide the scientific evidences that natural plants could be used in the traditional medicine for the prevention and treatment of CL.Evidence-based Complementary and Alternative Medicine 02/2015; 2(2):6. DOI:10.1155/2015/149707 · 2.18 Impact Factor
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ABSTRACT: Stryphnodendron obovatum Benth. is a Brazilian tree used to treat skin ulceration, promote wound healing, and inhibit the growth of protozoa, including Trypanosoma and Leishmania species. Bioguided fractionation of the ethanol extract of S. obovatum stem bark was performed, and antileishmanial and antioxidant activities of the standardized fractions were analyzed. Stationary-phase Leishmania amazonensis promastigotes, murine macrophages, and human red blood cells (RBCs) were exposed to plant extract, standardized fractions or isolated compounds for 48h at 37°C to evaluate their antiparasitic activity and cytotoxicity. The 2,2-diphenyl-1-picryl-hidrazyl assay was used to evaluate antioxidant activity. The S. obovatum extract and fractions showed antileishmanial and antioxidant activity; however, the organic fraction (OF) showed the best efficacy. We identified gallic acid, gallocatechin, epigallocatechin, catechin, and epigallocatechin gallate in the OF fraction. These compounds effectively inhibited L. amazonensis activity, with gallic acid, gallocatechin, and epigallocatechin gallate showing the highest selectivity. Furthermore, the evaluated compounds had no significant effect on murine macrophages and human RBCs. The compounds present in the S. obovatum plant bark ethanol extract may provide an alternative therapeutic approach for L. amazonensis treatment. Copyright © 2015. Published by Elsevier Ireland Ltd.Journal of Ethnopharmacology 02/2015; 165. DOI:10.1016/j.jep.2015.02.047 · 2.94 Impact Factor
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ABSTRACT: Human visceral (VL, also known as Kala-azar) and cutaneous (CL) leishmaniasis are important infectious diseases affecting countries in East Africa that remain endemic in several regions of Ethiopia. The transmission and epidemiology of the disease is complicated due to the complex life cycle of the parasites and the involvement of various Leishmania spp., sand fly vectors and reservoir animals besides human hosts. Particularly in East Africa, the role of animals as reservoirs for human VL remains unclear. Isolation of Leishmania donovani parasites from naturally infected rodents has been reported in several endemic countries; however, the status of rodents as reservoirs in Ethiopia remains unclear. Here, we demonstrated natural Leishmania infections in rodents. Animals were trapped in 41 localities of endemic and non-endemic areas in eight geographical regions of Ethiopia and DNA was isolated from spleens of 586 rodents belonging to 21 genera and 38 species. Leishmania infection was evaluated by real-time PCR of kinetoplast (k)DNA and confirmed by sequencing of the PCR products. Subsequently, parasite species identification was confirmed by PCR and DNA sequencing of the 18S ribosomal RNA internal transcribed spacer one (ITS1) gene. Out of fifty (8.2%) rodent specimens positive for Leishmania kDNA-PCR and sequencing, 10 were subsequently identified by sequencing of the ITS1 showing that five belonged to the L. donovani complex and five to L. tropica. Forty nine kDNA-positive rodents were found in the endemic localities of southern and eastern Ethiopia while only one was identified from north-western Ethiopia. Moreover, all the ten ITS1-positive rodents were captured in areas where human leishmaniasis cases have been reported and potential sand fly vectors occur. Our findings suggest the eco-epidemiological importance of rodents in these foci of leishmaniasis and indicate that rodents are likely to play a role in the transmission of leishmaniasis in Ethiopia, possibly as reservoir hosts. Copyright © 2015. Published by Elsevier B.V.Acta Tropica 02/2015; 13. DOI:10.1016/j.actatropica.2015.02.006 · 2.52 Impact Factor