RESUMO

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 ß-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 ß-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 ß-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.

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RESUMO

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.

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Leishmaniasis is a vector-borne disease caused by the protozoan Leishmania and it is one of the six most important infectious diseases in the world. The aim of this study was to conduct a research on the fauna and most frequented ecotopes by sandflies on islands of the Paraná River. The sandflies were collected with Falcão light traps in 10 islands in the municipalities of São Pedro do Paraná, Porto Rico, and Querência do Norte, in Paraná State, Brazil, from November 2012 to November 2014. In total, 76,145 specimens of Nyssomyia neivai, the only species found, were collected, of which 63,015 were female and 13,130, male. The largest number of sandflies was collected mainly in domiciles and peridomiciles. The islands of the Paraná River showed predominance of Ny. neivai, which is largely involved in the transmission of Leishmania and a risk of human leishmaniasis to the island inhabitants and tourists.

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Calophyllum brasiliense is a plant from the Brazilian rain forests and has been used in folk medicine for the treatment of various diseases, including leishmaniasis. This infectious disease depends on the Leishmania sp. and the host immune response. C. brasiliense antileishmanial activity is well known, but the effects on immune response remain to be investigated. This study showed the leishmanicidal and immunomodulatory effects of a 30 µg/mL of hydroalcoholic extract of C. brasiliense in murine macrophages before and after Leishmania (Leishmania) amazonensis infection. The semiquantitative cytokine RNA expression was determined by RT-PCR and the anti-Leishmania activity was measured by infection index (IF). Hydroalcoholic extract of C. brasiliense reduced more than 95% of IF when used before and after Leishmania infection, with 3 and 24 h of treatment (p < 0.05). C. brasiliense inhibited or reduced significantly (p < 0.05) the TNF-α, IL-1ß, IL-18, and IL-10 mRNA expression. The antileishmanial and anti-inflammatory effects showed the potential of C. brasiliense as an alternative therapy for leishmaniasis and it must be investigated.

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Leishmaniasis is a parasitic infectious disease with global repercussions. American cutaneous leishmaniasis (ACL) is endemic in southern Brazil and its pathogenesis varies according to parasite species, immune response, and host genetics. In terms of immunogenetics, many host genes, including HLA (human leukocyte antigen), could be involved in susceptibility to and protection against ACL. Accordingly, the aim of this study was to investigate the association between HLA class I genes (HLA-A, -B, and -C) and ACL in an endemic region of southern Brazil. The allele frequencies of 186 patients diagnosed with ACL and 278 healthy individuals were compared. HLA class I (HLA-A, -B, and -C) typing was carried out by PCR-SSO using Luminex technology. The results revealed an association between the HLA-C*04 allele and the patient study group, in which it appeared more frequently than in the control group [21.5 vs 13.49% (P = 0.0016 and Pc = 0.0258; OR = 1.7560; 95%CI = 1.2227-2.5240)], thereby suggesting an increased susceptibility to ACL. Additional allelic groups such as HLA-A*02, HLA-B*35, HLA-B*45, HLA-C*01, and HLA-C*15 were also implicated; however, further investigation is necessary to confirm their association with ACL. Therefore, the results obtained in this study demonstrate the involvement of HLA class I genes in the susceptibility or resistance to ACL, with significant association between HLA-C*04 and ACL susceptibility.

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This study was conducted to evaluate the effect of inclusion of propolis extraction residue in the feed of broilers from 1 to 21 d of age on phagocytic activity of macrophages, cutaneous basophil hypersensitivity response to phytohemagglutinin, antibody production against Newcastle disease, lymphoid organ weight and hematological profile and to determine the optimal level of inclusion. 120 chicks, reared in metabolism cages until 21 days of age, were distributed in a completely randomized design, with five treatments (0%, 1%, 2%, 3%, and 4% of propolis residue) and six replications. The relative weight of thymus and monocyte percentage were affected by propolis residue, with a quadratic response (p<0.05) and lowest values estimated at 2.38% and 2.49%, respectively. Changes in relative weight of cloacal bursa and spleen, percentage of lymphocyte, heterophil, basophil, eosinophil, and heterophil:lymphocyte ratio, antibody production against Newcastle disease, phagocytic activity of macrophages and the average number of phagocytosed erythrocytes were not observed. The nitric oxide production with regard to positive control (macrophages+erythrocytes) decreased linearly (p<0.05) with increased doses of propolis residue. The remaining variables of nitric oxide production (negative control - macrophages, and difference between the controls) were not affected by propolis residue. The cutaneous basophil hypersensitivity response to phytohemagglutinin as determined by the increase in interdigital skin thickness exhibited a quadratic response (p<0.05), which predicted a lower reaction response at a dose of 2.60% of propolis residue and highest reaction response after 43.05 hours of phytohemagglutinin injection. The inclusion of 1% to 4% of propolis extraction residue in broiler diets from 1 to 21 days of age was not able to improve the immune parameters, despite the modest changes in the relative weight in thymus, blood monocyte percentage, nitric oxide concentration, and interdigital reaction to phytohemagglutinin.

RESUMO

The influence of supplementing the diet of broiler breeder hens with arginine (Arg) on their offspring's humoral and cell-mediated immune response was evaluated in two experiments. In experiments I and II, breeder hens were fed diets containing graded levels of Arg (0.943, 1.093, 1.243, 1.393 and 1.543% digestible Arg). In experiment I, the offspring was randomly grouped according to the treatment received by the breeder hens, with five levels of Arg in the maternal diet and six replicates, giving a total 30 experimental units. In experiment II, the offspring were grouped in accordance with the treatment received by the breeder hens; however, Arg was added to the starter diet (1.300, 1.450, 1.600, 1.750 and 1.900% digestible Arg) and also the growing diet (1.150, 1.300, 1.450, 1.600 and 1.750% digestible Arg). Supplementation of the broiler breeder hen diet did not influence (p > 0.05) the development of the lymphoid organs (cloacal bursa, thymus and spleen) of the offspring, whether their diet were supplemented or not. Nevertheless, greater weight and dimensions cloacal bursa were found in the supplemented offspring in comparison with the nonsupplemented offspring. Macrophage phagocytic activity was found to be unaffected (p > 0.05), independently of the Arg supplementation. The offspring fed with supplemented diets showed a linear reduction in the antibody titer against Newcastle Disease (p < 0.05) at seven days of age, and a quadratic response (p < 0.05) at 28 days of age. The antibody titer in the non-supplemented offspring was not influenced (p > 0.05) by the breeder hen diet. This study concluded that supplementing the breeder hen diet with arginine is insufficient to improve the humoral and cellular immune response, requiring supplementation of the offspring diet.(AU)

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RESUMO

The influence of supplementing the diet of broiler breeder hens with arginine (Arg) on their offspring's humoral and cell-mediated immune response was evaluated in two experiments. In experiments I and II, breeder hens were fed diets containing graded levels of Arg (0.943, 1.093, 1.243, 1.393 and 1.543% digestible Arg). In experiment I, the offspring was randomly grouped according to the treatment received by the breeder hens, with five levels of Arg in the maternal diet and six replicates, giving a total 30 experimental units. In experiment II, the offspring were grouped in accordance with the treatment received by the breeder hens; however, Arg was added to the starter diet (1.300, 1.450, 1.600, 1.750 and 1.900% digestible Arg) and also the growing diet (1.150, 1.300, 1.450, 1.600 and 1.750% digestible Arg). Supplementation of the broiler breeder hen diet did not influence (p > 0.05) the development of the lymphoid organs (cloacal bursa, thymus and spleen) of the offspring, whether their diet were supplemented or not. Nevertheless, greater weight and dimensions cloacal bursa were found in the supplemented offspring in comparison with the nonsupplemented offspring. Macrophage phagocytic activity was found to be unaffected (p > 0.05), independently of the Arg supplementation. The offspring fed with supplemented diets showed a linear reduction in the antibody titer against Newcastle Disease (p 0.05) by the breeder hen diet. This study concluded that supplementing the breeder hen diet with arginine is insufficient to improve the humoral and cellular immune response, requiring supplementation of the offspring diet.

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Leishmanicide potential of Calophyllum brasiliense leaves on promastigote and amastigote of Leishmania (Leishmania) amazonensis is evaluated. The LD(50) of dichloromethane extract and hexane fraction for promastigotes was respectively 40 microg/ml and 20 microg/ml. In mouse peritoneal macrophages infected with Leishmania amastigotes the Infection Index decreased respectively 100% and 84.2% in 80 microg/ml and 40 microg/ml concentrations of dichloromethane extract. Hexane fraction decreased infection index respectively by 98.7% and 91.3% within the same concentrations. It was found that pretreatment with dichloromethane extract or with hexane fraction of experimentally infected BALB/c mice decrease the volume of the lesions by L. (L.) amazonensis. Moreover, animals treated topically also revealed healing lesions. Besides, the parasite load in the animals' popliteal lymph nodes was significantly reduced in treated animals, showing that plant components actually control infection. Results show that crude extract and hexane fraction of C. brasiliense reveal a significant in vitro and in vivo leishmanicide activity.

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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.(AU)

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