In vitro effects of lapachol and β-lapachone against Leishmania amazonensis

Leishmaniasis is a neglected disease that affects millions of people worldwide, and special attention should be given to treatment because the available drugs have limitations, which can lead to low therapeutic adherence and parasitic resistance. This study evaluated the activity of the bioactive naphthoquinones, lapachol and β-lapachone, against Leishmania amazonensis. The cell alterations were evaluated in vitro on promastigote and amastigote forms. The lethal dose (LD50) at 24, 48, and 72 h on the promastigote's forms using lapachol was 75.60, 72.82, and 58.85 μg/mL and for β-lapachone was 0.65, 1.24, and 0.71 μg/mL, respectively. The naphthoquinones significantly inhibited the survival rate of L. amazonensis amastigotes at 83.11, 57.59, and 34.95% for lapachol (82.28, 41.14, and 20.57 µg/mL), and 78.49, 83.25, and 80.22% for β-lapachone (3.26, 1.63, and 0.815 µg/mL). The compounds on the promastigote's forms led to the loss of mitochondrial membrane potential, induced changes in the integrity of the membrane, caused damage to cells suggestive of the apoptotic process, and showed inhibition of tumor necrosis factor (TNF)-α and interleukin (IL)-6 production. The results showed that these naphthoquinones are promising candidates for research on new drugs with anti-Leishmania activity derived from natural products.

Cell migration induced by Leishmania (Leishmania) amazonensis, Leishmania (Leishmania) major and Leishmania (Viannia) braziliensis into the peritoneal cavity of BALB/c mice

In American cutaneous leishmaniasis, the initial infection phase is characterized by recruitment of neutrophils and monocytes. The migration of these cells in response to the presence of Leishmania in the peritoneum of affected animals remains unclear. The objective of this study was to investigate cell migration to the peritoneum of BALB/c mice after infection with Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis and Leishmania (Leishmania) major. Initially, Leishmania spp. was intraperitoneally inoculated in five groups of six animals each and the cell migration was analyzed 0, 3, 6, 12, 24 and 48 hours after infection. Different cell counts were performed with a staining kit and showed a higher percentage of polymorphonuclear than mononuclear cells in all three species studied. The total cell count revealed peak migration in L. (L.) amazonensis and L. (L.) major at six hours, and in L. (V.) braziliensis at 12 hours. These results suggest that factors released from different cell types probably act by attracting polymorphonuclear cells, with the peak migration most likely depending on the species of Leishmania inoculated into the host.

American cutaneous leishmaniasis in dogs from an endemic urban area in Cianorte municipality, Paraná State, Brazil

American cutaneous leishmaniasis (ACL) was investigated in dogs from an urban endemic area in Cianorte, Paraná state, Brazil. Of 169 studied dogs, none presented suspected ACL lesions. Eleven animals (6.6 percent) had anti-Leishmania braziliensis antibodies (titers > 40) detected by the immunofluorescent antibody test (IFAT) while four (2.4 percent) showed L. braziliensis-complex DNA by the polymerase chain reaction (PCR). Although no associations were found between IFAT or PCR results and age, sex, origin, free-roaming animals or length of residence at the address, the majority of IFAT- or PCR-positive dogs were from the urban area of the city and were allowed to roam freely beyond their neighborhood. The presence of anti-Leishmania braziliensis antibodies and L. braziliensis-complex DNA in dogs from this urban area near a native-forest park indicates the importance of following up on these dogs to confirm the ACL diagnosis.

Ocorrência de leishmaniose tegumentar em cães de área endêmica no Estado do Paraná / Occurrence of cutaneous leishmaniasis in dogs of endemic area, Paraná State

Investigou-se a infecção por parasitas do complexo Leishmania braziliensis em 50 cães da cidade de Maringá, PR, onde ocorreram casos humanos de leishmaniose tegumentar americana (LTA), entre agosto e dezembro de 2006. Os casos humanos de LTA ocorreram nos anos de 2003 a 2004. Nenhum animal apresentou lesão, mas 12 (24,0 por cento) tinham sorologia e/ou PCR positivas, e a positividade tanto da IFI como da PCR foi de 14,0 por cento. Trinta e cinco animais eram de residências, e oito deles (22,8 por cento) tiveram testes laboratoriais para LTA positivos. Os outros 15 eram cães errantes, sendo que quatro deles (26,7 por cento) apresentaram PCR positiva. A presença de animais com infecção assintomática por Leishmania em área onde a LTA é endêmica pode ser um indicador do potencial de sua transmissão para o homem e uma referência para a implantação de medidas de controle e prevenção da doença.

The infection by Leishmania braziliensis complex was studied in 50 dogs from Maringá, PR, where American Cutaneous Leishmaniasis (ACL) in humans have been detected. Data were collected from August to December 2006 in an area in which ACL cases in humans were reported from 2003 to 2004. Indirect immunofluorescent test (IIF) and polymerase chain reaction (PCR) were applied. No lesions were found in the animals, although 12 (24.0 percent) had positive IIF and/or PCR. Positiveness was 14.0 percent for IIF and PCR. Lab tests showed that eight (22.8 percent) out of the 35 home animals were ACL positive. The other 15 animals were stray dogs, out of which four (26.7 percent) were PCR positive. The appearance of asymptomatic Leishmania-infected dogs in an ACL endemic area may be an indicator of ACL transmission potential for humans and a reference for the establishment of control measures and disease prevention.

Aspectos epidemiológicos da Leishmaniose Tegumentar Americana na região Noroeste do Estado do Paraná / Epidemiological aspects of American Cutaneous Leismaniasis in the northwest region of the state of Paraná

No Estado do Paraná, a primeira notificação de leishmaniose tegumentar americana ocorreu em 1917 e a partir de 1980 observou-se um aumento do número de casos, mantendo-se endêmica e acometendo pessoas de todas as faixas etárias e em ambos os sexos. Este estudo teve como objetivo realizar um levantamento epidemiológico sobre a ocorrência de LTA em pacientes atendidos no Laboratório de Ensino e Pesquisa em Análises Clínicas da Universidade Estadual de Maringá (LEPAC/UEM). Foi realizado um estudo retrospectivo e descritivo em base de dados secundário de 1986 a 2005, com 1656 pacientes segundo as variáveis: sexo, idade, ocupação, procedência, local de moradia, forma clínica e diagnóstico. A maioria dos pacientes era do sexo masculino (72,6%) e adquiriu a infecção no Estado do Paraná (97,8%), residia em área urbana (64,3%) dos quais 51,3% adquiriu a infecção durante atividades de lazer. O diagnóstico da maioria dos pacientes foi estabelecido nos dois primeiros meses de evolução das lesões (54,0%) e apresentando a forma cutânea da doença (88,9%). Uma parcela (34,4%) significativa dos pacientes que residiam em área rural adquiriu a infecção no domicílio ou peridomicílio. O estudo mostra a predominância da forma cutânea da leishmaniose tegumentar americana e sugere a atividade de lazer e o ambiente do domicilio como fatores preditivos importantes para a infecção.

The first notification of American cutaneous Leishmaniasis (LTA) in the state of Paraná, Brazil, occurred in 1917 and an increasing number of cases has been reported since 1980. This parasitic skin disease, spread by the bite of infected sandflies, is still an endemic problem, with recurrence in both sexes and in all age groups. The objective of this study was to perform a survey on the occurrence of American cutaneous Leishmaniasis in patients attended at the Teaching and Research Clinical Analysis laboratory at the State University of Maringá (LEPAC/UEM). A retrospective and descriptive study was carried out, based on secondary data (1986-2005) on 1656 patients, relating to their sex, age and occupation and the origin, clinical forms and positive diagnosis of the disease. Most of the patients were male (72.6%), lived in the urban area (64.3%) and acquired the infection during outdoor leisure activities (51.3%) in the State of Paraná (97.8%). The cutaneous form of the infection predominated (88.9%) and the diagnosis was made in the first two months of development of the lesions (54.0%). A significant part (34.4%) of the patients who lived in the rural area acquired the infection inside or close to their homes. The study shows the predominance of the cutaneous form of American cutaneous Leishmaniasis and suggests that leisure activity and housing conditions could be useful predictive factors for the infection.

Serological survey for Leishmania sp. infection in wild animals from the municipality of Maringá, Paraná state, Brazil

Leishmania sp. infection was investigated in wild animals from the Ingá Park, in the municipality of Maringá, Paraná state, Brazil, where American cutaneous leishmaniasis (ACL) is an endemic disease. Sixty-five mammals, comprising Didelphis albiventris, Cerdocyon thous, Lycalopex vetulus, Cebus apella, Dasyprocta azarae, Dasypus novemcinctus, Procyon cancrivorus and Nasua nasua, were captured. Blood samples were collected for parasite cultivation. Antibodies were investigated by direct agglutination test (DAT) using Leishmania (Viannia) braziliensis as antigen. Flagellates were observed in blood cultures of 14 (35.9 percent) Didelphis albiventris. Anti-Leishmania antibodies were detected in 31 (51.6 percent) specimens of Cerdocyon thous, Lycalopex vetulus, Cebus apella, Dasyprocta azarae, Procyon cancrivorus and Nasua nasua. These results suggest that Cerdocyon thous and Lycalopex vetulus (crab-eating fox), Cebus apella (capuchin monkey), Dasyprocta azarae (agouti), Procyon cancrivorus (crab-eating raccoon) and Nasua nasua (coati) play an important role in the ACL transmission cycle in the northwestern region of Paraná, Brazil.

Comparação entre imunofluorescência indireta e aglutinação direta para o diagnóstico sorológico da leishmaniose tegumentar americana em cães errantes / Comparison between indirect immunofluorescence and direct agglutination for the serologic diagnosis of American cutaneous leishmaniasis in stray dogs

Estudaram-se 92 cães errantes com o objetivo de comparar a imunofluorescência indireta (IFI) e a aglutinação direta (AD) na investigação da leishmaniose tegumentar americana (LTA) canina, no período de outubro de 1999 a novembro de 2001. Os animais foram examinados quanto à presença de lesões e submetidos à intradermorreação de Montenegro (IDRM) e à pesquisa de anticorpos anti-Leishmania por IFI e AD. A IFI apresentou sensibilidade de 78,9 por cento e especificidade de 93,8 por cento (título >40), e a AD sensibilidade de 57,9 por cento e especificidade de 68,8 por cento (título >80). Dois cães apresentavam lesão, mas a pesquisa do parasito foi negativa. A IDRM, realizada em 89 cães, foi positiva em três (3,4 por cento). Trinta e quatro cães (37,0 por cento) foram positivos para a IFI, 61 (66,3 por cento) para a AD e 69 (75,0 por cento) para a IFI e/ou a AD. Dos cães com a IFI positiva, sete eram de Floresta, 13 de Maringá, 12 de Leópolis, um de São Jorge do Ivaí e um (50,0 por cento) de Campo Mourão. Os resultados sugerem o contato prévio desses animais com o parasito.

Ninety-two stray dogs were studied in order to compare indirect immunofluorescence (IIF) and direct agglutination (DA) in the investigation of American cutaneous leishmaniasis (ACL), from October 1999 to November 2001. The dogs were evaluated for the presence of lesions, and submitted to the Montenegro skin test (MST) and the search for anti-Leishmania antibodies by IIF and DA. IIF showed 78.9 percent sensitivity and 93.8 percent specificity (titers >40), and DA presented 57.9 percent sensitivity and 68.8 percent specificity (titers >80). In two dogs there were lesions, but the parasite was not detected. The MST was positive in 3 (3.4 percent) out of 89 dogs. Thirty-four (37.0 percent) dogs showed anti-Leishmania antibodies through IIF, 61 (66.3 percent) through DA, and 69 (75.0 percent) through IIF and/or DA. Of the dogs with positive IIF, 7 came from the municipal areas of Floresta, 13 of Maringá, 12 of Leópolis, 1 of São Jorge do Ivaí and 1 (50.0 percent) of Campo Mourão. These data suggest previous contact of these animals with the parasite.

Influence of peri-domiciliar environmental conditions in the dispersion and proliferation of phlebotomine sandflies in Parana state, southern Brazil

The results of phlebotomine collections with Falcäo light traps are described. The collections were made in an area of the Mururê farm, in the Terra Boa County, Paraná State, south of Brazil. One trap was installed at the border of a modified primitive forest and seven in animal shelters (poultry sheds and pigsties) distant 10 to 600m from this forest. Of a total of 5,122 phlebotomine 4,046 (79 per cent) were caught in an pigsty 10m from the border of the forest. The dominant species was Lutzomya whitmani. Dispersion of phlebotomine was near to 600m from the border of the forest and suggests that good environmental conditions for effective breeding in peridomiciliary areas in Mururê farm were not found, what explains the rare occurrence of tegumentary leishmaniasis there

Leishmania brasiliensis: isolation of carbohydrate-containing antigen and possibility of its use in the immunodiagnosis of american cutaneous leishmaniasis

A Leishmania brasiliensis e um dos agentes causadores da Leishmaniose Tegumentar Americana (LTA). A cepa 034-jcg, isolada de paciente da regiao norte do estado do Parana, Brasil, foi cultivada em meio Blood Agar Base, liofilizada e submetida a extracao com fenol-agua e o extrato obtido foi tratado com RNase I. O antigeno contendo carboidrato (AgCHO) mostrou-se imunogenico para coelhos e apresentou pelo menos uma fracao com poucas cargas negativas em pH 8,2. Este antigeno apresenta reacao cruzada com extrato fenolico do meio de cultura usado para o cultivo de promastigotas...