In vitro and ex vivo antiplasmodial activity of 1-(3-benzyloxy-4-methoxy-phenyl)-3-(3,4,5-trimethoxy-phenyl)-propan-1-one) against circulating strains of Plasmodium spp. in the state of Rondônia, Brazil

Abstract Malaria is a disease caused by Plasmodium spp. protozoa. The ability of Plasmodium to develop resistance to current antimalarial drugs makes the study of chemotherapeutic alternatives extremely important. This study aimed to evaluate the antimalarial activity of compound 3286938 (1-(3-benzyloxy-4-methoxy-phenyl)-3-(3,4,5-trimethoxy-phenyl)-propan-1-one), which presents in its structure a 3,4,5-trimethoxyphenyl group, in vitro, using the W2 strain of P. falciparum and against circulating strains of P. vivax and P. falciparum from the state of Rondônia. The compound 3286938 obtained an IC50 of 24.4 µM against the W2 strain of P. falciparum, and against the circulating strains, it presented a median (MD)=38.7 µM for P. vivax and MD=6.7 µM for P. falciparum. As for toxicity, 3286938 showed CC50 > 500 µM for VERO and HepG2 strains with a selectivity index greater than 12.9, a ratio calculated for P. falciparum and P. vivax regarding Vero and HepG2 cells. The compound was not considered hemolytic in in vitro assays, thus indicating the specificity of its antiplasmodial action. Based on the results presented, and considering the unprecedented character of the compound, it can be concluded that 3286938 was shown to be promising for complementary in vitro and in vivo studies aiming to produce effective antiplasmodial action.

Evaluation of triterpenes derivatives in the viability of Leishmania amazonensis and Trichomonas vaginalis

Trichomonas vaginalis and Leishmania spp. are protozoal species responsible for millions of cases of parasitic diseases worldwide. Considering the potential of natural products and the need for more effective and less toxic alternatives to treat trichomoniasis and leishmaniasis, this study aimed to evaluate the effect of two series of triterpenes derivatives with different modifications at C-3 and C-28 positions of the ursolic acid (UA) and betulinic acid (BA) against trophozoites of Trichomonas vaginalis and promastigotes forms of Leishmania (L.) amazonensis. The compounds modified just at C-3 were the most active. The 3β-acetyl betulinic acid (1b) reduced the trophozoites viability of T. vaginalis at 74%, followed by the 3-oxo ursolic acid and 3-oxo betulinic acid (3a and 3b) compounds (55% of reduction). The compound 3β-isobutyl ursolic acid (7a) inhibited the viability of L. amazonensis promastigotes by 55%. Therefore, analyzing the structure-activity relationship and the data of literature, it is possible to suppose that the inclusion of polar groups in the skeletons could improve the antiprotozoal activity. Overall, further studies are necessary to develop triterpenic derivatives with more powerful trichomonicidal and leishmanicidal properties.

Antiprotozoal action of synthetic cinnamic acid analogs

Abstract INTRODUCTION Leishmaniasis, Chagas disease, and malaria cause morbidity globally. The drugs currently used for treatment have limitations. Activity of cinnamic acid analogs against Leishmania spp., Trypanosoma cruzi, and Plasmodium falciparum was evaluated in the interest of identifying new antiprotozoal compounds. METHODS In vitro effects of analogs against L. braziliensis, L. infantum chagasi, T. cruzi, and P. falciparum, and hemolytic and cytotoxic activities on NCTC 929 were determined. RESULTS Three analogs showed leishmanicidal and tripanocidal activity. No antiplasmodial, hemolytic, or cytotoxic activity was observed. CONCLUSIONS Antiprotozoal activity of analogs against L. infantum braziliensis, L. infantum chagasi, and T. cruzi was demonstrated.

Antiplasmodial and antileishmanial activities of compounds from Piper tuberculatum Jacq fruits

Abstract INTRODUCTION This study assessed the activity of compounds from Piper tuberculatum against Plasmodium falciparum and Leishmania guyanensis. METHODS The effects of compounds from P. tuberculatum fruits on P. falciparum and L. guyanensis promastigote growth in vitro were determined. Hemolytic action and cytotoxicity in HepG2 and J774 cells were measured. RESULTS Three compounds showed strong antiplasmodial activity and one compound showed strong antileishmanial activity. Two compounds were non-toxic to HepG2 cells and all were toxic to J774 cells. The compounds showed no hemolytic activity. CONCLUSIONS The tested compounds from P. tuberculatum exhibited antiparasitic and cytotoxic effects.

Trichophoromyia auraensis is a putative vector

The sandfly Trichophoromyia auraensis has recently evolved as a proven vector of Leishmania (Viannia) endemic to state of Acre in the north of Brazil. This note is intended to propose a correction in the report of the first occurrence of natural infection of Leishmania (Viannia) in this species. We and the other scientific groups reinforced that Tr. auraensis is a possible vector involved in the transmission of American cutaneous leishmaniasis in Acre, Brazil.

Evaluation of the antiplasmodial and leishmanicidal potential of Myrciaria dubia (Myrtaceae) extract

Abstract INTRODUCTION: Malaria and leishmaniasis are prevalent in tropical regions, which have environmental characteristics that are highly favorable to protozoa and vectors of these diseases; the transmission of these infections in sub-tropical regions, although recognized, represents only a small fraction of cases. Plants are constantly being used in the search for and acquisition of new drugs, and many compounds derived from them have been used to combat various diseases. In this study, we evaluated the action of the dichloromethanolic extract of Myrciaria dubia leaves against the protozoa Plasmodium falciparum, Leishmania amazonensis, Leishmania braziliensis, and Leishmania chagasi through bioassays. METHODS The extract from M. dubia was tested for its anti-P. falciparum activity in an anti-histidine-rich protein II immunosorbent assay. The antileishmanial assays were performed using the resazurin method, while cytotoxicity against human hepatoma (HepG2) strain was determined using the colorimetric MTT [3-(4, 5-dimethyl-2- thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide] method. RESULTS The M. dubia extract presented a half-maximal inhibitory concentration equal to 2.35 (1.05)μg/mL for P. falciparum, 190.73 (6.41) μg/mL for L. amazonensis, and greater than equal to 200µg/mL for L. chagasi and L. braziliensis strains. The cytotoxic concentration for 50% of the cells was above 500μg/mL for HepG2, indicating no toxicity and greater selectivity against parasites. CONCLUSIONS The results obtained indicate the presence of antiplasmodial and leishmanicidal bioactive compounds in the dichloromethanolic extracts of M. dubia leaves, and point towards future studies to elucidate the mechanism of action for each physiological effect.

Phlebotomine sandfly (Diptera: Psychodidae) diversity and their Leishmania DNA in a hot spot of American Cutaneous Leishmaniasis human cases along the Brazilian border with Peru and Bolivia

In this study, we identified the phlebotomine sandfly vectors involved in the transmission of American Cutaneous Leishmaniasis (ACL) in Assis Brasil, Acre, Brazil, which is located on the Brazil-Peru-Bolivia frontier. The genotyping of Leishmania in phlebotomines was performed using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism. A total of 6,850 sandflies comprising 67 species were captured by using CDC light traps in rural areas of the municipality. Three sandfly species were found in the state of Acre for the first time: Lutzomyia georgii, Lu. complexa and Lu. evangelistai. The predominant species was Lu. auraensis/Lu. ruifreitasi and Lu. davisi (total 59.27%). 32 of 368 pools were positive for the presence of Leishmania DNA (16 pools corresponding to Lu. davisi, and 16 corresponding to Lu. auraensis/Lu. ruifreitasi), with a minimal infection prevalence of 1.85% in Lu. davisi and 2.05% in Lu. auraensis/Lu. ruifreitasi. The Leishmania species found showed maximum identity with L. (Viannia) guyanensis and L. (V.) braziliensis in both phlebotomine species. Based on these results and similar scenarios previously described along the Brazil/Peru/Bolivia tri-border, the studied area must take into consideration the possibility of Lu. davisi and Lu. auraensis/Lu. ruifreitasi as probable vectors of ACL in this municipality.

Molecular characterization of american Cutaneous Leishmaniasis in the tri-border border area of Assis Brasil, Acre State, Brazil / Caracterização molecular da Leishmaniose Tegumentar americana em área de tríplice fronteira, Assis Brasil, Estado do Acre,Brasil

SUMMARYIn this study, Leishmaniaspecies were identified by Polymerase Chain Reaction (PCR). The epidemiology of patients suspected of having American Cutaneous Leishmaniasis in the municipality of Assis Brasil, Acre State, located in the Brazil/Peru/Bolivia triborder was also investigated. By PCR, the DNA of Leishmaniawas detected in 100% of the cases (37 samples) and a PCR-Restriction Fragment Length Polymorphism (RFLP) of the hsp 70gene identified the species in 32 samples: Leishmania (Viannia) braziliensis (65.6%) , L. (V.) shawi (28.1%) , L. (V.) guyanensis (3.1%) and mixed infection L. (V.) guyanensisand L. (Leishmania) amazonensis(3.1%)This is the first report of L. (V.) shawiand L. (L.) amazonensisin Acre. The two predominant species were found in patients living in urban and rural areas. Most cases were found in males living in rural areas for at least three years and involved in rural work. This suggests, in most cases, a possible transmission of the disease from a rural/forest source, although some patients had not engaged in activities associated with permanence in forestall areas, which indicate a possible sandflies adaptation to the periurban setting.

RESUMOO presente estudo caracterizou as espécies de Leishmaniapela Reação em Cadeia da Polimerase (PCR). Também descreveu os aspectos epidemiológicos de pacientes com suspeita de leishmaniose tegumentar americana do município de Assis Brasil, Estado do Acre, Brasil, localizado na tríplice fronteira Brasil/Peru/Bolívia. A PCR detectou DNA de Leishmaniaem 100% dos casos (37 amostras) e a PCR- Restriction Fragment Length Polymorfism(RFLP) do gene hsp 70identificou as espécies em 32 amostras: Leishmania (Viannia) braziliensis (65,6%) , L. (V.) shawi (28,1%) , L. (V.) guyanensis (3,1%) e infecção mista L. (V.) guyanensise L. (Leishmania) amazonensis(3,1%)Esse é o primeiro registro de L. (V.) shawie L. (L.) amazonensisno Acre. As duas espécies predominantes foram encontradas em indivíduos residentes em áreas rurais e urbanas. O maior número de casos foi notificado entre indivíduos de áreas rurais, sexo masculino, de ocupação rural e tempo de residência maior que três anos. Esses dados sugerem possível transmissão da doença em ambiente rural/florestal na maioria dos casos, no entanto alguns pacientes não tinham envolvimento com atividades relacionadas com a permanência na floresta, indicando possível adaptação de flebotomíneos no ambiente periurbano.

Efeito leishmanicida in vitro do látex de Croton lechleri (Euphorbiaceae) / In vitro leishmanicidal effect of Croton lechleri latex

A Leishmaniose Tegumentar Americana é uma infecção causada por uma variedade de espécies de Leishmania, é transmitida ao homem por flebotomíneos. Os antimoniais pentavalentes são utilizados na quimioterapia dessa doença; no entanto, esses fármacos provocam uma série de efeitos colaterais, além de apresentar altos índices de toxicidade. Na busca por novos agentes leishmanicidas, avaliamos in vitro o extrato do látex de Croton lechleri (Sangue de dragão) frente a formas promastigotas de Leishmania amazonensis e Leishmania guyanensis. O extrato foi obtido através da desidratação do látex de C. lechleri e diluído em solução 10% de etanol em salina tamponada com fosfato. As promastigotas de Leishmania foram cultivadas juntamente com o extrato nas concentrações de 6,25; 12,5 e 25µg/ mL por 72 horas. O extrato apresentou eficácia em todas as concentrações testadas apresentando um IC50 (concentração inibitória) de 5,04µg/mL para L. amazonensis e IC50 de 9,05µg/mL para L. guyanensis. Foi realizada a avaliação citotóxica em células J774 nas mesmas concentrações usadas no ensaio leishmanicida, porém a concentração de 25µg/mL apresentou índice de toxicidade de aproximadamente 50% para a célula hospedeira. Os testes realizados mostraram-se promissores, pois o extrato testado também foi capaz de inibir o crescimento de promastigotas de L. amazonensis após ensaio de infecção com células J774.

Cutaneous Leishmaniasis is an infection caused by a several species of Leishmania, is transmitted to humans by phlebotomine sandflies. Pentavalent antimonial compounds are used in the chemotherapy of this disease; however, these drugs cause several collateral effects, besides presenting high levels of toxicity. The search for new antiLeishmanial agents, we assessed in vitro the extract of Croton lechleri latex (Blood Dragon) against the promastigote forms of Leishmania amazonensis and Leishmania guyanensis. The extract was obtained by dehydration C. lechleri latex mass and the solution was diluted with 10% ethanol in phosphate buffered saline solution. The Leishmania promastigotes were grown with the extract following concentrations 6.25; 12.5 and 25µg/mL for 72 hours. The extract showed efficacy in all concentrations tested showing an IC50 (inhibitory concentration) of 5.04 µg/mL for L. amazonensis and IC50 of 9.05 µg/mL for L. guyanensis. Cytotoxic evaluation was performed in J774 cells at the same concentrations used in the leishmanicidal assay, but the concentration of 25µg/mL showed toxicity index of approximately 50% for the host cell. Tests carried out proved promising, since the extracts tested was also able to inhibit the L. amazonensis promastigotes growth after infection assay with J774 cells.

Incidência bacteriana e perfil de resistência a antimicrobianos em pacientes pediátricos de um hospital público de Rondônia, Brasil / Bacterial incidence and resistance profile against the antibiotics in pediatric patients at a public hospital in Rondônia, Brazil

As infecções de maiores preocupações dos profissionais da área de saúde são as que ocorrem nas unidades que atendem pacientes mais suscetíveis à infecção - Pediatria, Unidades de Terapia Intensiva (UTI) e Unidades Oncológicas. Dentre os fatores contribuintes para altas taxas de infecções e mortalidade estão: gravidade da doença, procedimentos que requerem mais tempo e os invasivos, e longos períodos de internação. Foi realizado um estudo de caráter retrospectivo, transversal, não controlado nas unidades pediátricas ? Clínicas Pediátricas, UTI Pediátrica e Oncopediatria de um hospital público do Estado de Rondônia, Brasil. Ponderando-se o levantamento dos resultados de culturas e antibiogramas isolados nas unidades pediátricas do hospital, no período de janeiro a julho de 2010, foram analisados 313 antibiogramas. Destes, 19,2% apresentaram crescimento bacteriano, dos quais a maior parte (38%) foram Hemoculturas. Os microrganismos mais comumente encontrados foram os Bacilos Não Fermentadores (BNF) (28,3%), Escherichia coli (25%) e Enterobacter spp. (20%). Algumas cepas chamam a atenção com relação ao aparecimento de resistência, como as cepas de Pseudomonas aeruginosa, cuja resistência as cefalosporinas de terceira geração foi analisada em mais de 90% e as cepas de Enterobacter spp., que apresentaram resistência aos carbapenêmicos. A ala da Oncopediatria mostrou-se a menos afetada com relação às outras, pois apenas 4% das amostras coletadas para exame microbiológico obtiveram crescimento bacteriano, já em pacientes da UTI Pediátrica houve crescimento bacteriano em 29,2%. Para evitar o crescimento da resistência dos microrganismos e o uso empírico e indiscriminado de antimicrobianos é necessária uma avaliação do perfil de resistência bacteriana que norteie a prescrição racional e adequada destes fármacos.

The most worrying infections for health professionals are those that occur in hospital units that treat patients particularly susceptible to infection - Pediatrics, Intensive Care Unit (ICU) and Oncology Units. The factors that contribute to high rates of infection and mortality are: severity of the disease, procedures that require more time and / or are invasive and long periods of hospitalization. We conducted a retrospective, cross-sectional, uncontrolled study in the pediatric units - Pediatric Clinic, Pediatric ICU and Pediatric Oncology - in a public hospital in Rondonia, a state of Brazil. Taking into account the survey results of cultures and antibiograms of isolates taken in pediatric hospital units in the period from January to July 2010, 313 antibiograms were analyzed. Of these, 19.2% had bacterial growth, of which the majority (38%) were blood cultures. The microorganisms most commonly found were non-fermentative bacilli (28.3%), Escherichia coli (25%) and Enterobacter spp. (20%). Some strains of bacteria gave cause for concern, due to the development of resistance, such as strains of Pseudomonas aeruginosa, more than 90% of which exhibited resistance to third generation cephalosporins, and the strain of Enterobacter spp., which showed resistance to carbapenems. The unit of pediatric oncology proved to be the least affected of the three, since only 4% of the strains isolated there showed bacterial growth, while in the ICU the bacterial growth was found in 29.2% of the exams. To prevent the increasing resistance of microorganisms found in this hospital and the empirical and indiscriminate use of antibiotics, it will be necessary to assess the bacterial resistance profile, to guide rational and appropriate prescribing of these drugs.

Epidemiological aspects of American cutaneous leishmaniasis and phlebotomine sandfly population, in the municipality of Monte Negro, State of Rondônia, Brazil

Introduction: This work was carried out on the purpose of identifying the species of phlebotomine sandflies in the municipality of Monte Negro, state of Rondonia, Brazil, that may have been transmitting the American cutaneous leishmaniasis (ACL), and concisely describe epidemiological aspects of disease. METHODS: The epidemiologic and socioeconomical indicators were obtained from government institutions and the local Municipal Secretary of Health. Phlebotomine sandflies were captured using CDC light traps between July 2006 to July 2008. The total of 1,240 of female sandflies were examined by PCR method directed to k-DNA. RESULTS: There has been a significant decrease in the incidence of ACL of about 50% over the last ten years in the municipality. A total of 1,935 specimens of 53 sandfly species were captured, three of the genus Brumptomyia genus and 50 of the genus Lutzomyia. The predominant species was Lutzomyia acanthopharynx, Lutzomyia whitmani, Lutzomyia geniculata and Lutzomyia davisi. None were positive for Leishmania sp. CONCLUSIONS: Four sandflies species were found in the State of Rondonia for the first time: Brumptomyia brumpti, Lutzomyia tarapacaensis, Lutzomyia melloi and Lutzomyia lenti. The presence of Lutzomyia longipalpis, was also captured. Socioeconomical improvement of Brazilian economy and the increase of environmental surveillance in the last 15 years collaborated in the decrease of people exposed to vectors, reducing the incidence of ACL.