Antileishmanial activity and immunomodulatory effect of secosubamolide, a butanolide isolated from Nectandra oppositifolia (Lauraceae)

Background:Visceral leishmaniasis is a complex neglected tropical disease caused by Leishmania donovani complex. Its current treatment reveals strong limitations, especially high toxicity. In this context, natural products are important sources of new drug alternatives for VL therapy. Therefore, the antileishmanial and immunomodulatory activity of compounds isolated from Nectandra oppositifolia (Lauraceae) was investigated herein.Methods:The n-hexane extract from twigs of N. oppositifolia were subjected to HPLC/HRESIMS and bioactivity-guided fractionation to afford compounds 1 and 2 which were evaluated in vitro against Leishmania (L.) infantum chagasi and NCTC cells.Results:The n-hexane extract displayed activity against L. (L.) infantum chagasi and afforded isolinderanolide E (1) and secosubamolide A (2), which were effective against L. (L.) infantum chagasi promastigotes, with IC50 values of 57.9 and 24.9 µM, respectively. Compound 2 was effective against amastigotes (IC50 = 10.5 µM) and displayed moderate mammalian cytotoxicity (CC50 = 42 µM). The immunomodulatory studies of compound 2 suggested an anti-inflammatory activity, with suppression of IL-6, IL-10, TNF with lack of nitric oxide.Conclusion:This study showed the antileishmanial activity of compounds 1 and 2 isolated from N. oppositifolia. Furthermore, compound 2 demonstrated an antileishmanial activity towards amastigotes associated to an immunomodulatory effect.(AU)

Antileishmanial activity and immunomodulatory effect of secosubamolide, a butanolide isolated from Nectandra oppositifolia (Lauraceae)

Visceral leishmaniasis is a complex neglected tropical disease caused by Leishmania donovani complex. Its current treatment reveals strong limitations, especially high toxicity. In this context, natural products are important sources of new drug alternatives for VL therapy. Therefore, the antileishmanial and immunomodulatory activity of compounds isolated from Nectandra oppositifolia (Lauraceae) was investigated herein. Methods: The n-hexane extract from twigs of N. oppositifolia were subjected to HPLC/HRESIMS and bioactivity-guided fractionation to afford compounds 1 and 2 which were evaluated in vitro against Leishmania (L.) infantum chagasi and NCTC cells. Results: The n-hexane extract displayed activity against L. (L.) infantum chagasi and afforded isolinderanolide E (1) and secosubamolide A (2), which were effective against L. (L.) infantum chagasi promastigotes, with IC50 values of 57.9 and 24.9 µM, respectively. Compound 2 was effective against amastigotes (IC50 = 10.5 µM) and displayed moderate mammalian cytotoxicity (CC50 = 42 µM). The immunomodulatory studies of compound 2 suggested an anti-inflammatory activity, with suppression of IL-6, IL-10, TNF with lack of nitric oxide. Conclusion: This study showed the antileishmanial activity of compounds 1 and 2 isolated from N. oppositifolia. Furthermore, compound 2 demonstrated an antileishmanial activity towards amastigotes associated to an immunomodulatory effect.(AU)

Polymerase chain reaction and real-time PCR for diagnosing of Leishmania infantum chagasi in dogs / Reação em Cadeia da Polimerase e PCR em tempo real para diagnóstico de Leishmania infantum chagasi em cães

The importance of dogs as a reservoir for Leishmania infantumchagasi in urban environments has stimulated numerous studies assessing diagnostic techniques. When performed properly, such procedures are an important step in preventing leishmaniasis in humans. Molecular methods have become prominent for this purpose. The aim of the present study was to determine the performance of the polymerase chain reaction (PCR) and real-time PCR (qPCR) for diagnosing of canine visceral leishmaniasis (CVL) using different biological samples. For this, 35 dogs from an area endemic for CVL were used. Bone marrow aspirate and lymph node and spleen fragments from these dogs were used for the molecular diagnosis. In the present study, qPCR was able to detect a greater number of positive animals than seen with PCR. Among the different biological samples used, there was no significant difference in L. infantumchagasi DNA detection between PCR and qPCR. However, considering that lymph nodes are easy to acquire, these can be considered to be the best samples for making molecular diagnoses of L. infantum chagasi infection.(AU)

A importância do cão como reservatório de L. infantum chagasi no meio urbano tem estimulado a realização de inúmeros trabalhos de avaliação de técnicas de diagnóstico, uma vez que este procedimento, quando realizado corretamente, torna-se um importante passo na prevenção da doença em humanos. Dentre os métodos de diagnóstico, as técnicas moleculares têm adquirido destaque. Objetivou-se neste trabalho verificar o desempenho da Reação em Cadeia da Polimerase (PCR) e da PCR em tempo real (qPCR) para diagnóstico da Leishmaniose Visceral Canina (LVC) utilizando diferentes amostras biológicas. Para tanto foram utilizados 35 cães provenientes de uma área endêmica para LVC, onde foram utilizados para o diagnóstico molecular, aspirado de medula óssea, fragmentos de linfonodo e baço. Neste estudo a qPCR foi capaz de detectar um maior número de animais positivos quando comparada com a PCR. Já entre as diferentes amostras biológicas utilizadas não foi observada diferença significativa na detecção de DNA de L. infantumchagasi por meio da PCR e qPCR. Mesmo assim, considerando a facilidade de obtenção, o linfonodo pode ser considerada como a melhor amostra para diagnóstico molecular da infecção por L. infantum chagasi.(AU)

Design of primer pairs for species-specific diagnosis of Leishmania (Leishmania) infantum chagasi using PCR / Construção de pares de primers para a detecção espécie-específica de Leishmania (Leishmania) infantum chagasi por PCR

The objective of this study was to design and evaluate new primers for species-specific detection of L. infantum chagasi using PCR. Two combinations of primer pairs were established with the aim of obtaining specific amplification products from the L. infantum chagasi 18S rRNA gene. The combinations of the primer pairs and the respective sizes of the PCR products, based on the U422465 GenBank reference sequence of L. infantum chagasi, were: LCS1/LCS3 (259 bp) and LCS2/LCS3 (820 bp). It was concluded that the new PCR assays optimized using the primer pairs LCS1/LCS3 and LCS2/LCS3 were effective for specific detection of L. infantum chagasi, with analytical sensitivity to detect 1 pg/µL of DNA.

Objetivou-se com este trabalho construir e avaliar novos primers para a detecção espécie-específicos de L. infantum chagasi por PCR. Foram estabelecidas duas combinações de pares de primers com a finalidade de obter produtos de amplificação específicos para o gene 18S rRNA de L. infantum chagasi. As combinações dos pares de primers e os respectivos tamanhos dos produtos de PCR, previstos conforme a sequência de referência utilizada (GenBank U422465) foram: LCS1/LCS3 (259 pb); LCS2/LCS3 (820 pb). Pôde-se concluir que os novos ensaios de PCR otimizados neste estudo, empregando os pares de primers LCS1/LCS3 e LCS2/LCS3, foram efetivos para a detecção específica de L. infantum chagasi, com sensibilidade analítica para detectar 1 pg/µL de DNA.

Design of primer pairs for species-specific diagnosis of Leishmania (Leishmania) infantum chagasi using PCR / Construção de pares de primers para a detecção espécie-específica de Leishmania (Leishmania) infantum chagasi por PCR

The objective of this study was to design and evaluate new primers for species-specific detection of L. infantum chagasi using PCR. Two combinations of primer pairs were established with the aim of obtaining specific amplification products from the L. infantum chagasi 18S rRNA gene. The combinations of the primer pairs and the respective sizes of the PCR products, based on the U422465 GenBank reference sequence of L. infantum chagasi, were: LCS1/LCS3 (259 bp) and LCS2/LCS3 (820 bp). It was concluded that the new PCR assays optimized using the primer pairs LCS1/LCS3 and LCS2/LCS3 were effective for specific detection of L. infantum chagasi, with analytical sensitivity to detect 1 pg/µL of DNA.

Objetivou-se com este trabalho construir e avaliar novos primers para a detecção espécie-específicos de L. infantum chagasi por PCR. Foram estabelecidas duas combinações de pares de primers com a finalidade de obter produtos de amplificação específicos para o gene 18S rRNA de L. infantum chagasi. As combinações dos pares de primers e os respectivos tamanhos dos produtos de PCR, previstos conforme a sequência de referência utilizada (GenBank U422465) foram: LCS1/LCS3 (259 pb); LCS2/LCS3 (820 pb). Pôde-se concluir que os novos ensaios de PCR otimizados neste estudo, empregando os pares de primers LCS1/LCS3 e LCS2/LCS3, foram efetivos para a detecção específica de L. infantum chagasi, com sensibilidade analítica para detectar 1 pg/µL de DNA.