Structure⁻Activity Relationship of Piplartine and Synthetic Analogues against Schistosoma mansoni and Cytotoxicity to Mammalian Cells.

Schistosomiasis, caused by helminth flatworms of the genus Schistosoma, is an infectious disease mainly associated with poverty that affects millions of people worldwide. Since treatment for this disease relies only on the use of praziquantel, there is an urgent need to identify new antischistosomal drugs. Piplartine is an amide alkaloid found in several Piper species (Piperaceae) that exhibits antischistosomal properties. The aim of this study was to evaluate the structure­function relationship between piplartine and its five synthetic analogues (19A, 1G, 1M, 14B and 6B) against Schistosoma mansoni adult worms, as well as its cytotoxicity to mammalian cells using murine fibroblast (NIH-3T3) and BALB/cN macrophage (J774A.1) cell lines. In addition, density functional theory calculations and in silico analysis were used to predict physicochemical and toxicity parameters. Bioassays revealed that piplartine is active against S. mansoni at low concentrations (5⁻10 µM), but its analogues did not. In contrast, based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays, piplartine exhibited toxicity in mammalian cells at 785 µM, while its analogues 19A and 6B did not reduce cell viability at the same concentrations. This study demonstrated that piplartine analogues showed less activity against S. mansoni but presented lower toxicity than piplartine.

Efficacy of spilanthol and Acmella oleracea (L.) R. K. Jansen (Asteraceae) extract against Schistosoma mansoni infection.

ETHNOPHARMACOLOGICAL RELEVANCE: Acmella oleracea (L.) R. K. Jansen, commonly referred to as "Jambu", is a valuable medicinal plant native to the Amazon regions. Inflorescences of A. oleracea is utilized as local anesthetic properties and for its insecticidal, antiparasitic, and anthelmintic attributes. AIMS OF THIS STUDY: This study aimed to evaluate the in vitro and in vivo antiparasitic properties of A. oleracea extract and spilanthol (SPL) against Schistosoma mansoni. MATERIALS AND METHODS: The ethanolic extract of A. oleracea inflorescences (AoE) was prepared, analyzed by HPLC-DAD, and characterized by UHPLC-HRMS/MS. SPL was isolated from AoE by chromatographic fractionation. The antischistosomal properties of AoE and SPL were evaluated in vitro against adult schistosomes and in preclinical assays using murine models of patent S. mansoni infection. RESULTS: Through UHPLC-HRMS/MS analysis, 14 alkamides were annotated in AoE. HPLC-DAD analysis of AoE revealed a peak with a substantial relative area of ∼85%, which was isolated and identified as SPL. AoE and SPL caused mortality of adult schistosomes ex vivo, showing EC50 values of 32.6 µg/mL and 27.8 µM, respectively, without affected Vero cells or Caenorhabditis elegans. In preclinical studies, the oral administration (400 mg/kg) of AoE and SPL resulted in significant reductions in worm burden of 28% and ∼42%, respectively. Additionally, SPL exhibits remarkable effects on oogram, decreasing egg burden and the number of immature eggs by over 80%, while also promoting significant reductions in hepato- and splenomegaly. CONCLUSIONS: The research underscores the antischistosomal activity of A. oleracea highlighting the potential of SPL as a lead for the development of new schistosomicidal drugs and encouraging further studies to validate the traditional anthelmintic use of A. oleracea inflorescences.

Anthelmintic activity of the natural compound (+)-limonene epoxide against Schistosoma mansoni.

Blood fluke of the genus Schistosoma are the etiological agents of human schistosomiasis, an important neglected tropical disease that afflicts over 200 million people worldwide. The treatment for this disease relies heavily on a single drug, praziquantel. Recent reports of praziquantel resistance raise concerns about future control of the disease and show the importance of developing new antischistosomal drugs. Currently, natural products have been a good source for drug development. (+)-Limonene epoxide is a mixture of cis and trans isomers found in many plants. Here, we report the in vitro effect of this natural compound on the survival time of Schistosoma mansoni adult worms. In addition, we examined alterations on the tegumental surface of adult schistosomes by means of confocal laser scanning microscopy. The effects of (+)-limonene epoxide at 25 µg/mL on S. mansoni adult worms were similar to those of the positive control (praziquantel), with reduction in motility and death of all worms after 120 h. Confocal laser scanning microscopy revealed that (+)-limonene epoxide-mediated worm killing was associated with tegumental destruction. Our results, along with the low toxicity of the (+)-limonene epoxide, suggest that this natural compound might be promising for the development of new schistosomicidal agents.

Artificial intelligence-guided approach for efficient virtual screening of hits against Schistosoma mansoni.

Background: The impact of schistosomiasis, which affects over 230 million people, emphasizes the urgency of developing new antischistosomal drugs. Artificial intelligence is vital in accelerating the drug discovery process. Methodology & results: We developed classification and regression machine learning models to predict the schistosomicidal activity of compounds not experimentally tested. The prioritized compounds were tested on schistosomula and adult stages of Schistosoma mansoni. Four compounds demonstrated significant activity against schistosomula, with 50% effective concentration values ranging from 9.8 to 32.5 µM, while exhibiting no toxicity in animal and human cell lines. Conclusion: These findings represent a significant step forward in the discovery of antischistosomal drugs. Further optimization of these active compounds can pave the way for their progression into preclinical studies.

Enhancing the antischistosomal activity of carvacryl acetate using nanoemulsion.

Aim: To formulate a carvacryl acetate nanoemulsion (CANE) and test its antischistosomal activity. Materials & methods: CANE was prepared and tested in vitro on Schistosoma mansoni adult worms and both human and animal cell lines. Next, CANE was administered orally to mice infected with either a prepatent infection or a patent infection of S. mansoni. Results: CANE was stable during 90 days of analysis. CANE showed in vitro anthelmintic activity, and no cytotoxic effects were observed. In vivo, CANE was more effective than the free compounds in reducing worm burden and egg production. Treatment with CANE was more effective for prepatent infections than praziquantel. Conclusion: CANE improves antiparasitic properties and may be a promising delivery system for schistosomiasis treatment.

Schistosoma mansoni: In vitro schistosomicidal activity of piplartine.

Schistosomiasis is one of the world's greatly neglected tropical diseases, and its control is largely dependent on a single drug, praziquantel. Here, we report the in vitro effect of piplartine, an amide isolated from Piper tuberculatum (Piperaceae), on Schistosoma mansoni adult worms. A piplartine concentration of 15.8 µM reduced the motor activity of worms and caused their death within 24h in a RPMI 1640 medium. Similarly, the highest sub-lethal concentration of piplartine (6.3 µM) caused a 75% reduction in egg production in spite of coupling. Additionally, piplartine induced morphological changes on the tegument, and a quantitative analysis carried out by confocal microscopy revealed an extensive tegumental destruction and damage in the tubercles. This damage was dose-dependent in the range of 15.8-630.2 µM. At doses higher than 157.6 µM, piplartine induced morphological changes in the oral and ventral sucker regions of the worms. It is the first time that the schistosomicidal activity has been reported for piplartine.

Antiparasitic Properties of Cardiovascular Agents against Human Intravascular Parasite Schistosoma mansoni.

The intravascular parasitic worm Schistosoma mansoni is a causative agent of schistosomiasis, a disease of great global public health significance. Praziquantel is the only drug available to treat schistosomiasis and there is an urgent demand for new anthelmintic agents. Adopting a phenotypic drug screening strategy, here, we evaluated the antiparasitic properties of 46 commercially available cardiovascular drugs against S. mansoni. From these screenings, we found that amiodarone, telmisartan, propafenone, methyldopa, and doxazosin affected the viability of schistosomes in vitro, with effective concentrations of 50% (EC50) and 90% (EC90) values ranging from 8 to 50 µM. These results were further supported by scanning electron microscopy analysis. Subsequently, the most effective drug (amiodarone) was further tested in a murine model of schistosomiasis for both early and chronic S. mansoni infections using a single oral dose of 400 mg/kg or 100 mg/kg daily for five consecutive days. Amiodarone had a low efficacy in chronic infection, with the worm and egg burden reduction ranging from 10 to 30%. In contrast, amiodarone caused a significant reduction in worm and egg burden in early infection (>50%). Comparatively, treatment with amiodarone is more effective in early infection than praziquantel, demonstrating the potential role of this cardiovascular drug as an antischistosomal agent.

New evidence for tamoxifen as an antischistosomal agent: in vitro, in vivo and target fishing studies.

Background: Praziquantel is the only drug available to treat schistosomiasis, and there is an urgent demand for new anthelmintic agents. Methodology & results: We conducted in-depth in vitro and in vivo studies and report a target fishing investigation. In vitro, tamoxifen was active against adult and immature worms at low concentrations (<5 µM). Tamoxifen at a single dose (400 mg/kg) or once daily for five consecutive days (100 mg/kg/day) in mice harboring either adult (patent infection) or juvenile (prepatent infection) significantly reduced worm burden (30-70%) and egg production (70-90%). Target fishing studies revealed propionyl-CoA carboxylase as a potential target for tamoxifen in Schistosoma mansoni and glucose uptake by S. mansoni was also significantly reduced. Conclusion: Our results provide news evidence of antiparasitic effect of tamoxifen and reveal propionyl-CoA carboxylase as a potential target.

Licochalcone A-loaded solid lipid nanoparticles improve antischistosomal activity in vitro and in vivo.

Aim: To isolate licochalcone A (LicoA) from licorice, prepare LicoA-loaded solid lipid nanoparticles (L-SLNs) and evaluate the L-SLNs in vitro and in vivo against Schistosoma mansoni. Materials & methods: LicoA was obtained by chromatographic fractionation and encapsulated in SLNs by a modified high shear homogenization method. Results: L-SLNs showed high encapsulation efficiency, with satisfactory particle size, polydispersity index and Zeta potential. Transmission electron microscopy revealed that L-SLNs were rounded and homogenously distributed. Toxicity studies revealed that SLNs decreased the hemolytic and cytotoxic properties of LicoA. Treatment with L-SLNs showed in vivo efficacy against S. mansoni. Conclusion: L-SLNs are efficient in reducing worm burden and SLNs may be a promising delivery system for LicoA to treat S. mansoni infections.

Self-nanoemulsifying drug-delivery systems improve oral absorption and antischistosomal activity of epiisopiloturine.

AIM: To develop a self-nanoemulsifying drug-delivery system (SNEDDS) able to improve oral absorption of epiisopiloturine (EPI), and test the antischistosomal activity in a mice model. RESULTS: SNEDDS had a nanoscopic size and was able to enhance EPI bioavailability after oral administration, and SNEDDS-EPI (40 mg.kg-1) improved the in vivo antischistosomal activity of EPI, demonstrating that SNEDDS was able to improve the pharmacokinetics of EPI, and to maintain the pharmacodynamic activity against Schistosoma mansoni in vivo. CONCLUSION: Taken together, these results indicate that SNEDDS-EPI is efficient in reducing worm burden in comparison to treatment with the free version of EPI. [Formula: see text].

4-Phenyl-1, 3-thiazole-2-amines as scaffolds for new antileishmanial agents

There is still a need for new alternatives in pharmacological therapy for neglected diseases, as the drugs available show high toxicity and parenteral administration. That is the case for the treatment of leishmaniasis, particularly to the cutaneous clinical form of the disease. In this study, we present the synthesis and biological screening of eight 4-phenyl-1,3-thiazol-2-amines assayed against Leishmania amazonensis. Herein we propose that these compounds are good starting points for the search of new antileishmanial drugs by demonstrating some of the structural aspects which could interfere with the observed activity, as well as suggesting potential macromolecular targets. Methods: The compounds were easily synthesized by the methodology of Hantzsch and Weber, had their purities determined by Gas Chromatography-Mass spectrometry and assayed against the promastigote forms of Leishmania amazonensis as well as against two white cell lines (L929 and THP-1) and the monkey's kidney Vero cells. PrestoBlue® and MTT viability assays were the methodologies applied to measure the antileishmanial and cytotoxic activities, respectively. A molecular modeling target fishing study was performed aiming to propose potential macromolecular targets which could explain the observed biological behavior. Results: Four out of the eight compounds tested exhibited important anti-promastigote activity associated with good selectivity indexes when considering Vero cells. For the most promising compound, compound 6, IC50 against promastigotes was 20.78 while SI was 5.69. Compounds 3 (IC50: 46.63 µM; SI: 26.11) and 4 (IC50: 53.12 µM; SI: 4.80) also presented important biological behavior. A target fishing study suggested that S-methyl-5-thioadenosine phosphorylase is a potential target to these compounds, which could be explored to enhance activity and decrease the potential toxic side effects. Conclusions: This study shows that 4-phenyl-1,3-thiazol-2-amines could be good scaffolds to the development of new antileishmanial agents. The S-methyl-5-thioadenosine phosphorylase could be one of the macromolecular targets involved in the action.(AU)

Contamination of public parks and squares from Guarulhos (São Paulo State, Brazil ) by Toxocara spp. and Ancylostoma spp.

The contaminated soil with mammal feces is an important factor of risk to infection with zoonotic diseases. Amongst these zoonoses are visceral larva migrans and cutaneous larva migrans caused by Toxocara spp. and Ancylostoma spp., respectively. The aim of this study was to assess the environmental contamination by Toxocara spp. eggs and hookworms (Ancylostoma spp.) in public parks and squares in the city of Guarulhos, a metropolitan area of São Paulo, São Paulo State, Brazil. Soil samples were collected, between September and December 2010, and examined using the centrifugal flotation technique with sodium dichromate and zinc sulphate as well as the modified Baermann method. Notably, 35 (74.5%) of the 47 districts surveyed in Guarulhos possessed samples contaminated with Toxocara spp. and/or eggs or larvae of Ancylostoma spp. The frequency of Toxocara spp. and Ancylostoma spp. in the samples from public areas was 68.1% and 46.8%, respectively. Overall, the eastern side of Guarulhos is the region with the highest occurrence of causative agents of larva migrans. In all collection sites, the presence of feces from dogs and cats accompanied by their owners and stray animals were observed. Notably, it is important to adopt measures to control dog and cat breeding, to treat infected animals, and provide health education to the population.

Schistosoma mansoni and other larval trematodes in Biomphalaria tenagophila (Planorbidae) from Guarulhos, São Paulo State, Brazil.

A total of 909 Biomphalaria tenagophila were collected from two areas in Guarulhos (Metropolitan area of São Paulo, São Paulo State, Brazil) to assess larval trematode infections. In all collection sites, only this species was found and 183 (20.13%) harbored trematode infections. In these collections, four morphologically distinguishable types of cercariae were identified by confocal microscopy. Xiphidiocercaria (Cercaria lutzi) was the most common type of cercaria recovered, contributing 76.5% of all infections. Schistosoma mansoni cercariae were recovered and comprised the total of 13.11%. Strigea cercaria (Cercaria caratinguensis) and Brevifurcate pharyngeate Clinostomatoide cercaria (Cercaria ocellifera) contributed 8.33% and 2.22% of all infections, respectively. Double infections (S. mansoni and C. lutzi) were found in twelve snails, contributing 6.55% of all infections. In all sites studied, small vertebrates were found in snail habitats and it was observed human contact with the water. The presence of trematode infected snails in large cities has public health implications. It further provides a starting point for some comprehensive studies on snail-related aspects of transmission and biology of trematode of medical and veterinary importance.

Contamination of public parks and squares from Guarulhos (São Paulo State, Brazil ) by Toxocara spp. and Ancylostoma spp. / Contaminação de parques e praças públicas por Toxocara spp. e Ancylostoma spp., no município de Guarulhos, São Paulo, Brasil

The contaminated soil with mammal feces is an important factor of risk to infection with zoonotic diseases. Amongst these zoonoses are visceral larva migrans and cutaneous larva migrans caused by Toxocara spp. and Ancylostoma spp., respectively. The aim of this study was to assess the environmental contamination by Toxocara spp. eggs and hookworms (Ancylostoma spp.) in public parks and squares in the city of Guarulhos, a metropolitan area of São Paulo, São Paulo State, Brazil. Soil samples were collected, between September and December 2010, and examined using the centrifugal flotation technique with sodium dichromate and zinc sulphate as well as the modified Baermann method. Notably, 35 (74.5%) of the 47 districts surveyed in Guarulhos possessed samples contaminated with Toxocara spp. and/or eggs or larvae of Ancylostoma spp. The frequency of Toxocara spp. and Ancylostoma spp. in the samples from public areas was 68.1% and 46.8%, respectively. Overall, the eastern side of Guarulhos is the region with the highest occurrence of causative agents of larva migrans. In all collection sites, the presence of feces from dogs and cats accompanied by their owners and stray animals were observed. Notably, it is important to adopt measures to control dog and cat breeding, to treat infected animals, and provide health education to the population.

A contaminação do solo com fezes de animais mamíferos representa importante fator de risco para a ocorrência de zoonoses, sobretudo a larva migrans visceral e a larva migrans cutânea, causadas por Toxocara spp. e Ancylostoma spp., respectivamente. O presente estudo teve como objetivo verificar a contaminação ambiental por Toxocara spp. e Ancylostoma spp. em amostras de solos coletadas de praças e parques públicos do município de Guarulhos, região metropolitana de São Paulo (São Paulo, Brasil). No período de setembro a dezembro de 2010 as amostras do solo foram coletadas e examinadas pela técnica de centrífugo-flutuação, com dicromato de sódio e sulfato de zinco, e pelo método de Baermann modificado. Dos 47 distritos analisados, 35 (74,5%) estavam contaminadas com ovos de Toxocara spp. e/ou ovos ou larvas de Ancylostoma spp., sendo que a frequencia de Toxocara spp. e Ancylostoma spp. foi de 68,1% e 46,8%, respectivamente. No geral, a Zona Leste de Guarulhos foi a região com maior ocorrência desses parasitas com potencial zoonótico. Em todas as áreas públicas, dos 47 distritos, notou-se a presença de fezes de cães e gatos, assim como animais errantes ou acompanhados de seus proprietários. Faz-se necessário salientar a importância da adoção de medidas de controle reprodutivo de cães e gatos, o tratamento dos animais infectados, assim como medidas educativas para reduzir os riscos de crianças e adultos à exposição desses parasitas causadores de zoonoses.

Schistosoma mansoni and other larval trematodes in Biomphalaria tenagophila (Planorbidae) from Guarulhos, São Paulo State, Brazil / Infecção por Schistosoma mansoni e outros trematódeos em Biomphalaria tenagophila (Planorbidae) de Guarulhos, São Paulo, Brasil

A total of 909 Biomphalaria tenagophila were collected from two areas in Guarulhos (Metropolitan area of São Paulo, São Paulo State, Brazil) to assess larval trematode infections. In all collection sites, only this species was found and 183 (20.13%) harbored trematode infections. In these collections, four morphologically distinguishable types of cercariae were identified by confocal microscopy. Xiphidiocercaria (Cercaria lutzi) was the most common type of cercaria recovered, contributing 76.5% of all infections. Schistosoma mansoni cercariae were recovered and comprised the total of 13.11%. Strigea cercaria (Cercaria caratinguensis) and Brevifurcate pharyngeate Clinostomatoide cercaria (Cercaria ocellifera) contributed 8.33% and 2.22% of all infections, respectively. Double infections (S. mansoni and C. lutzi) were found in twelve snails, contributing 6.55% of all infections. In all sites studied, small vertebrates were found in snail habitats and it was observed human contact with the water. The presence of trematode infected snails in large cities has public health implications. It further provides a starting point for some comprehensive studies on snail-related aspects of transmission and biology of trematode of medical and veterinary importance.

Um total de 909 exemplares de Biomphalaria tenagophila foi coletado de duas regiões em Guarulhos (área Metropolitana de São Paulo, Estado de São Paulo, Brasil) a fim de que fosse verificada infecção por larvas de trematódeos. Em todos os locais de coleta, somente essa espécie foi encontrada e 183 (20,13%) caramujos estavam infectados. Nestes locais, quatro tipos de cercárias foram identificadas com microscópio confocal. Xiphidiocercaria (Cercaria luzti) foi o tipo de cercária mais comum, contribuindo com 76,5% de toda infecção. Cercárias de Schistosoma mansoni foram encontradas, obtendo um total de 13,11%. Strigea cercaria (Cercaria caratinguensis) e Brevifurcate pharyngeate Clinostomatoide cercaria (Cercaria ocellifera) contribuíram com 8,33% e 2,22% de toda infecção, respectivamente. Dupla infecção foi encontrada em doze caramujos, contribuindo com 6,55% de toda infecção. Em todos os locais, pequenos vertebrados foram encontrados e foi observado contato humano com a água. A presença de caramujos infectados por trematódeos que infectam o homem em grandes cidades tem implicações na saúde pública. Deve-se salientar a importância de mais estudos epidemiológicos e biológicos destes parasitas de importância médica e veterinária.

Análise microbiológica de hortaliças cultivadas pelos processos convencional e hidropônico comercializadas em Guarulhos, SP / Microbiological analysis of vegetables grown by conventional processes and hydroponic commercialized in Guarulhos, SP

As hortaliças constituem um importante veículo de transmissão de micro-organismos patogênicos. As bactérias da família Enterobacteriaceae têm sido utilizadas rotineiramente como indicadoras de qualidade higiênico-sanitária de alimentos. Neste estudo foi avaliada a qualidade microbiológica de hortaliças cultivadas pelos processos convencional e hidropônico comercializadas em supermercados da região central do município de Guarulhos, área metropolitana de São Paulo. A análise microbiológica foi efetuada em amostras de alface crespa (Lactuca sativa), almeirão (Chicorium intybus), escarola (Chicorium sp) e rúcula (Eruca sativa), cujos parâmetros bacteriológicos examinados foram: contagem total de enterobactérias, contagem de coliformes totais e fecais, bem como a identificação dos micro-organismos. (...) Todas as hortaliças, de ambos os cultivos, apresentaram elevados índices de enterobactérias, coliformes fecais e totais. Considerando a resolução RDC 12/01 da Agência Nacional de Vigilância Sanitária (ANVISA), verifica-se que 100% dos alimentos estavam acima do limite estabelecido pela legislação, indicando condições higiênico-sanitárias insatisfatórias. Estes resultados salientam a importância da adoção de boas práticas de higiene durante o cultivo, transporte e armazenamento de produtos hortícolas para evitar a contaminação dos vegetais com micro-organismos patogênicos.