RESUMO
Leishmania parasites cause leishmaniasis, one of the most epidemiologically important neglected tropical diseases. Leishmania exhibits a high ability of developing drug resistance, and drug resistance is one of the main threats to public health, as it is associated with increased incidence, mortality, and healthcare costs. The antimonial drug is the main historically implemented drug for leishmaniasis. Nevertheless, even though antimony resistance has been widely documented, the mechanisms involved are not completely understood. In this study, we aimed to identify potential metabolite biomarkers of antimony resistance that could improve leishmaniasis treatment. Here, using L. tropica promastigotes as the biological model, we showed that the level of response to antimony can be potentially predicted using 1H-NMR-based metabolomic profiling. Antimony-resistant parasites exhibited differences in metabolite composition at the intracellular and extracellular levels, suggesting that a metabolic remodeling is required to combat the drug. Simple and time-saving exometabolomic analysis can be efficiently used for the differentiation of sensitive and resistant parasites. Our findings suggest that changes in metabolite composition are associated with an optimized response to the osmotic/oxidative stress and a rearrangement of carbon-energy metabolism. The activation of energy metabolism can be linked to the high energy requirement during the antioxidant stress response. We also found that metabolites such as proline and lactate change linearly with the level of resistance to antimony, showing a close relationship with the parasite's efficiency of drug resistance. A list of potential metabolite biomarkers is described and discussed.
Assuntos
Antimônio/toxicidade , Antiprotozoários/toxicidade , Resistência a Medicamentos , Leishmania tropica/metabolismo , Metaboloma , Metabolismo Energético , Leishmania tropica/efeitos dos fármacos , Pressão Osmótica , Estresse OxidativoRESUMO
The leishmanicidal activity of 15 extracts and 4 pure metabolites obtained from Urechites andrieuxii, Colubrina greggii, Dorstenia contrajerva, and Tridax procumbens was evaluated using the newly developed MTS ({3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) assay, optimized for promastigotes of Leishmania major, Leishmania tropica, and Leishmania aethiopica, as well as for L. aethiopica axenic amastigotes. The assay was then used for calculating the percentage of viable stationary phase parasites after a 24-hr treatment with each plant extract or pure metabolite. The 3 most active samples, 2 from C. greggii (NCG-5C and DCG-3A) and 1 from T. procumbens (TPZ-2A), showed LD50 values of 62.4, 7.2, and 18.5 microg/ml, respectively, on stationary promastigotes, and of 94.2, 27.1, and 95.2 microg/ml, on amastigotes of L. aethiopica. Moreover, TPZ-2A and DCG-3A significantly reduced the percentage of infected monocyte-derived macrophages (THP-I). The percentage of infected cells decreased from 69.9% +/- 2.5% to 20.8% +/- 2% when the cells were treated with the DCG-3A fraction and to 14.9% +/- 0.5% when treated with TPZ-2A, without significantly decreasing the number of human cells. These findings indicate the presence of potentially bioactive metabolites in the roots of C. greggii and in T. procumbens and reflect the importance of pursuing the bioassay-guided purification of these metabolites.
Assuntos
Leishmania/efeitos dos fármacos , Leishmaniose Cutânea/parasitologia , Fitoterapia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Animais , Asteraceae/química , Humanos , Leishmania major/efeitos dos fármacos , Leishmania tropica/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Dose Letal Mediana , México , Monócitos/parasitologia , Moraceae/química , Testes de Sensibilidade Parasitária , Extratos Vegetais/uso terapêutico , Raízes de Plantas/química , Rhamnaceae/químicaRESUMO
Five new dihydro-beta-agarofuran sesquiterpenes (1-5) were isolated from the leaves of Maytenus chiapensis. The structures of 1-5 were determined by means of 1D and 2D NMR techniques. A semiselective HMBC technique was applied in order to obtain complete (13)C NMR assignments. Absolute configurations were determined by CD studies and chemical correlations and on biogenetic grounds. Compound 4 showed weak activity against a multidrug-resistant Leishmania tropica line.
Assuntos
Leishmania tropica/efeitos dos fármacos , Maytenus/química , Plantas Medicinais/química , Sesquiterpenos/isolamento & purificação , Animais , Isótopos de Carbono , Linhagem Celular/efeitos dos fármacos , Dicroísmo Circular , Resistência a Múltiplos Medicamentos , El Salvador , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Folhas de Planta/química , Sesquiterpenos/química , Sesquiterpenos/farmacologia , EstereoisomerismoRESUMO
This study was designed to evaluate the effectiveness of zinc sulphate both in vitro and in an animal model against both strains of old world cutaneous leshmaniasis. The in vitro sensitivities of promastigotes and axenic amastigotes of both Leishmania major and L. tropica to zinc suphate was determined, the LD50 calculated and compared to the standard treatment for cutaneous leishmaniais pentavalent antimony compounds. The results show that the two forms of both strains were sensitive to zinc sulphate and their respective LD50 were lower compared to the pentavalent antinomy compound. Furthermore the sensitivities of the forms of both strains were tested using a simple slide method and compared to results of the standard method. To confirm this result, zinc sulphate was administered orally to mice infected with cutaneous leishmaniasis both therapeutically and prophylactically. Results showed that oral zinc sulphate was effective in both treatment and prophylaxis for cutaneous leishmaniasis. These results encourage the use of oral zinc sulphate in the treatment of cutaneous leishmaniasis clinically.
Assuntos
Animais , Técnicas In Vitro , Leishmania major/efeitos dos fármacos , Leishmania tropica/efeitos dos fármacos , Leishmaniose Cutânea/terapia , Sulfato de Zinco/uso terapêuticoRESUMO
This study was designed to evaluate the effectiveness of zinc sulphate both in vitro and in an animal model against both strains of old world cutaneous leishmaniasis. The in vitro sensitivities of promastigotes and axenic amastigotes of both Leishmania major and L. tropica to zinc sulphate was determined, the LD50 calculated and compared to the standard treatment for cutaneous leishmaniasis pentavalent antimony compounds. The results show that the two forms of both strains were sensitive to zinc sulphate and their respective LD50 were lower compared to the pentavalent antimony compound. Furthermore the sensitivities of the forms of both strains were tested using a simple slide method and compared to results of the standard method. To confirm this result, zinc sulphate was administered orally to mice infected with cutaneous leishmaniasis both therapeutically and prophylactically. Results showed that oral zinc sulphate was effective in both treatment and prophylaxis for cutaneous leishmaniasis. These results encourage the use of oral zinc sulphate in the treatment of cutaneous leishmaniasis clinically.