Molluscicidal and Cercaricidal Effects of Myrciaria floribunda Essential Oil Nanoemulsion.

Schistosomiasis is a tropical disease transmitted in an aqueous environment by cercariae from the Schistosoma genus. This disease affects 200 million people living in risk areas around the world. The control of schistosomiasis is realized by chemotherapy, wastewater sanitation, health education, and mollusk control using molluscicidal agents. This work evaluates the effects of a nanoemulsion containing essential oil from Myrciaria floribunda leaves as a molluscicidal and cercaricidal agent against Biomphalaria glabrata mollusks and Schistosoma mansoni cercariae. The Myrciaria floribunda essential oil from leaves showed nerolidol, ß-selinene, 1,8 cineol, and zonarene as major constituents. The formulation study suggested the F3 formulation as the most promising nanoemulsion with polysorbate 20 and sorbitan monooleate 80 (4:1) with 5% (w/w) essential oil as it showed a smaller droplet size of approximately 100 nm with a PDI lower than 0.3 and prominent bluish reflection. Furthermore, this nanoemulsion showed stability after 200 days under refrigeration. The Myrciaria floribunda nanoemulsion showed LC50 values of 48.11 µg/mL, 29.66 µg/mL, and 47.02 µg/mL in Biomphalaria glabrata embryos, juveniles, and adult mollusks, respectively, after 48 h and 83.88 µg/mL for Schistosoma mansoni cercariae after 2 h. In addition, a survival of 80% was observed in Danio rerio, and the in silico toxicity assay showed lower overall human toxicity potential to the major compounds in the essential oil compared to the reference molluscicide niclosamide. These results suggest that the nanoemulsion of Myrciaria floribunda leaves may be a promising alternative for schistosomiasis control.

Prevalence of intestinal parasitic infections versus knowledge, attitudes and practices of male residents in Brazilian urban slums: a cross-sectional study.

Intestinal parasitic infections (IPIs) are neglected diseases caused by helminths and protozoa, with the relationships between parasite, host and environment having the potential to produce high morbidity and incapacity to work and mortality in vulnerable areas. This study assessed the prevalence of IPIs concerning socio-environmental conditions and analyzed the knowledge, attitudes and practices related to these diseases among men living in the slums of Rio de Janeiro city, Rio de Janeiro State, Brazil. A cross-sectional study was conducted in an agglomeration of urban slums between 2018 and 2019, with men aged between 20 and 59 years. A socioeconomic status questionnaire and an IPIs knowledge, attitudes and practices questionnaire (KAPQ) were applied. Coproparasitological diagnoses (n=454) were performed using four methods and samples of water for household consumption (n=392) were subjected to microbiological and physicochemical analysis. A total of 624 participants were enrolled. About 40% of the households had "water unsuitable for consumption". Only one Major Area, MA 3 was not statistically significant for IPIs (AOR=0.75; 95% CI: 0.30-1.88; p=0.55). The overall prevalence of IPIs was 23.8%. Endolimax nana (n=65, 14.3%) and hookworm (n=8, 1.7%) were the most frequently identified parasites. The analysis of the frequency of responses to the KAPQ has shown that men reported to seeking medical care if they were suspicious of IPIs, and around 35% would self-medicate. The results have shown the need to adopt integrated health education practices targeting male residents in urban slums to qualify the care with water for human consumption and promote self-care about IPIs. The household can be considered strategic for Primary Health Care activities for men.

Prevalence of intestinal parasitic infections versus knowledge, attitudes and practices of male residents in Brazilian urban slums: a cross-sectional study

ABSTRACT Intestinal parasitic infections (IPIs) are neglected diseases caused by helminths and protozoa, with the relationships between parasite, host and environment having the potential to produce high morbidity and incapacity to work and mortality in vulnerable areas. This study assessed the prevalence of IPIs concerning socio-environmental conditions and analyzed the knowledge, attitudes and practices related to these diseases among men living in the slums of Rio de Janeiro city, Rio de Janeiro State, Brazil. A cross-sectional study was conducted in an agglomeration of urban slums between 2018 and 2019, with men aged between 20 and 59 years. A socioeconomic status questionnaire and an IPIs knowledge, attitudes and practices questionnaire (KAPQ) were applied. Coproparasitological diagnoses (n=454) were performed using four methods and samples of water for household consumption (n=392) were subjected to microbiological and physicochemical analysis. A total of 624 participants were enrolled. About 40% of the households had "water unsuitable for consumption". Only one Major Area, MA 3 was not statistically significant for IPIs (AOR=0.75; 95% CI: 0.30-1.88; p=0.55). The overall prevalence of IPIs was 23.8%. Endolimax nana (n=65, 14.3%) and hookworm (n=8, 1.7%) were the most frequently identified parasites. The analysis of the frequency of responses to the KAPQ has shown that men reported to seeking medical care if they were suspicious of IPIs, and around 35% would self-medicate. The results have shown the need to adopt integrated health education practices targeting male residents in urban slums to qualify the care with water for human consumption and promote self-care about IPIs. The household can be considered strategic for Primary Health Care activities for men.

Events linked to Geosmin and 2-methylisoborneol (2-MIB) in a Water Supply Source in the State of Rio de Janeiro, Brazil: a case study / Eventos atrelados a Geosmina e 2-metilisoborneol (2-MIB) em Manancial de Abastecimento do Estado do Rio de Janeiro, Brasil: estudo de caso

Tastes and odors in tap water are problems faced by water companies all over the world, with complaints from consumers especially during the summer when cyanobacterial blooms occur that produce compounds such as geosmin and 2-methylisoborneol (2-MIB).  We analyzed data on the intensity of taste and odor, and total concentration of the substances geosmin and 2-MIB, present in drinking water and raw water collected by the sanitation company that supplies the metropolitan region of the state of RJ/Brazil, during water crises in the year 2020, and in the new event of 2021, despite the previous warnings made by experts. Statistical and correlation analysis of the public data, and metagenomic analysis of the raw water captured from the Guandu basin in the year 2020 were performed. Organoleptic data allowed us to signal the presence of these compounds in drinking water, the values of the intensity of taste were more times above the MPV of the Brazilian legislation, with the average of the data for 2020 being 37.5 and in the following year this average was 5 times lower, indicating that the measures to remove the compounds were more effective, but did not eliminate the problem. For the year 2020 there was a linear correlation of 0.97 between the taste organoleptic standard and the total concentration of the compounds. The metagenomic data of the raw water of the year 2020, related to the genes mtf, mic and glys indicated that the substance responsible for the taste and odor was 2-MIB, since the read rate for it was higher, both in the first visit and only in the second visit, when there was still perception of intensity of taste and odor. Modifications in the surveillance system of the quality of the water taken and consumed need to be adopted to circumvent the problems of cyanobacterial proliferation in the Guandu basin, since conditions favorable to blooms will occur as long as the sanitation problems in this watershed are not solved.

Gostos e odores na água da torneira são problemas enfrentados por empresas produtoras de água em todo o mundo, com reclamações dos consumidores principalmente durante o verão, quando ocorrerem florações de cianobactérias produtoras dos compostos como geosmina e o 2-metilisoborneol (2-MIB).  Foram analisados dados de intensidade do gosto e do odor, e concentração total das substâncias geosmina e 2-MIB, presente na água  potável e na água bruta captada pela empresa de saneamento, que abastece a região metropolitana do estado do RJ/Brazil,  durante  crises hídricas do ano 2020, e no novo evento de 2021, a despeito dos alertas prévios feitos por especialistas. Foram realizadas análises estatísticas e de correlação dos dados públicos, e analise metagenômica da água bruta captada no manancial da Bacia do Guandu, no ano de 2020. Dados organolépticos permitiram sinalizar a presença desses compostos na água de consumo, os valores da intensidade do gosto estiveram maior número de vezes acima do VMP da legislação brasileira, sendo a  média dos dados de 2020 de 37,5 e no ano seguinte esta média foi 5 vezes menor, indicando que as medidas para retirar dos compostos foram mais eficazes, mas não eliminaram o problema. Para o ano de 2020 houve correlação linear de 0,97 entre o padrão organoléptico gosto e a concentração total dos compostos. Os dados metagenômicos da água bruta do ano 2020, relacionados com os genes mtf, mic e glys indicaram que a substância responsável pelo gosto e odor foi o 2-MIB, visto o índice de reads para ele ter sido maior, tanto na primeira visita e único na segunda, quando ainda havia percepção de intensidade de gosto e odor. Modificações no sistema de vigilância da qualidade da água captada e de consumo precisam ser adotadas para contornar os problemas de proliferação de cianobactérias na bacia do Guandu, pois condições favoráveis às florações irão acontecer enquanto não forem resolvidos os problemas de saneamento dessa bacia hidrográfica.

Characterization of Periods of Crisis and Post-Crisis in the Raw Water of Guandu System through Quality Parameters / Caracterização dos Períodos de Crise e Pós-Crise Hídrica da Água Bruta da Bacia do Guandu através de Parâmetros de Qualidade

At the beginning of the year 2020, about 9 million inhabitants of the Metropolitan Region of Rio de Janeiro dependent of the Water Guandu System, experienced a crisis in the water supply, receiving water with taste and odor issues. In this way, this work carried out the analysis of the sanitary quality of raw water that is captured from this system, at two different moments, "in crisis" and "post-crisis", in relations to the presence of cyanobacteria and cyanotoxins in raw water, through studies of metagenomics and quantification of microcystin (MC) and  saxitoxin (SXT) cyanotoxins by ELISA test, comparing extraction and processing methods. The analysis of raw water quality parameters was also carried out, through the evaluation of the levels of total coliforms and Escherichia coli and some physical-chemical parameters in order to compare with data from INEA analyzes. The raw water collected at both times had levels of Escherichia coli above the Maximum Acceptable Values (MAV) described in Resolution no. 357/2000 of CONAMA, while it presented satisfactory levels in the analyzed physical-chemical parameters as well as for cyanotoxin levels, for SXT. However, it is noteworthy that in the filter extraction methodology, the sample "after crisis" was not within the MAV for MC, so if it were done by this same method the samples of the moment ¨ in crisis¨ would have the values ​​of MC also much higher of the MAV, since in the commonly used methodology the value for MC was above the value for the moment ¨after crisis¨. Therefore, in the review of the Potability Ordinance, it is necessary to describe an extraction methodology that can express the real risk in relation to the levels of cyanotoxins present in raw water. Thus, it is important that sanitation be carried out as soon as possible in the cities upstream of the water treatment plant, so that events such as those that occurred during the "water crisis" are not experienced again. In addition, in the short term, it is necessary to perform periodic monitoring of reservoirs, integrating genomics, biogeochemistry and toxicity analyzes, in order to signal any problems in advance and guarantee the quality of supply, in addition to being able to support data on the implementation of the Contingency Plan, as a precaution so that the flowering situation does not increase.

A principios del año 2020, aproximadamente 9 millones de habitantes de la Región Metropolitana de Río de Janeiro dependientes del Sistema Guandu del Agua, experimentaron una crisis en el suministro de agua, recibiendo agua con problemas de sabor y olor. De esta manera, este trabajo llevó a cabo el análisis de la calidad sanitaria del agua cruda que se captura de este sistema, en dos momentos diferentes, "en crisis" y "postcrisis", en relación con la presencia de cianobacterias y cianotoxinas en agua cruda, a través de estudios de metagenómica y cuantificación de cianotoxinas de microcistina (MC) y saxitoxina (SXT) por prueba ELISA, comparando métodos de extracción y procesamiento. El análisis de los parámetros de calidad del agua cruda también se llevó a cabo, a través de la evaluación de los niveles de coliformes totales y Escherichia coli y algunos parámetros físico-químicos para comparar con los datos de los análisis del INEA. El agua cruda recolectada en ambos momentos tenía niveles de Escherichia coli por encima de los valores máximos aceptables (MAV) descritos en la Resolución no. 357/2000 de CONAMA, si bien presentó niveles satisfactorios en los parámetros físico-químicos analizados, así como para los niveles de cianotoxina, para SXT. Sin embargo, es digno de mención que en la metodología de extracción de filtro, la muestra "después de la crisis" no estaba dentro del VAM para MC, por lo que si se hiciera por este mismo método, las muestras del momento "en crisis" tendrían los valores de MC también mucho más alto que el MAV, ya que en la metodología comúnmente utilizada el valor de MC estaba por encima del valor por el momento "después de la crisis". Por lo tanto, en la revisión de la Ordenanza de Potabilidad, es necesario describir una metodología de extracción que pueda expresar el riesgo real en relación con los niveles de cianotoxinas presentes en el agua cruda. Por lo tanto, es importante que el saneamiento se lleve a cabo lo antes posible en las ciudades aguas arriba de la planta de tratamiento de agua, para que los eventos como los que ocurrieron durante la "crisis del agua" no se vuelvan a experimentar. Además, a corto plazo, es necesario realizar un monitoreo periódico de los reservorios, integrando análisis de genómica, biogeoquímica y toxicidad, para señalar de antemano cualquier problema y garantizar la calidad del suministro, además de poder respaldar datos sobre La implementación del Plan de Contingencia, como precaución para que la situación de floración no aumente.

No início do ano de 2020, cerca de 9 milhões de habitantes da Região Metropolitana do Rio de Janeiro dependente do Sistema Guandu, vivenciou uma crise no abastecimento de água, recebendo água com gosto e odor. Este trabalho realizou a análise da qualidade sanitária da água bruta, captada por esse sistema, em dois momentos distintos, "na crise" e "pós-crise", quanto à presença de cianobactérias e cianotoxinas na água bruta, através de estudos de metagenômica e de quantificação de cianotoxinas, microcistina (MC) e saxitoxina (SXT) por ELISA, comparando métodos de extração e processamento. Foram também realizadas análises de parâmetros de qualidade da água bruta, através da determinação dos níveis de coliformes totais e de Escherichia coli e de alguns parâmetros físico-químicos, de modo a se comparar com dados de análises do INEA. A água bruta captada nos dois momentos estava com níveis de Escherichia coli, acima da faixa de valores máximo permitidos (VMP) descrito na Resolução n. 357/2000 do CONAMA, enquanto os parâmetros físico-quimicos analisados apresentaram níveis satisfatórios, assim como os níveis das cianotoxinas, para SXT. Entretanto, destaque-se que na metodologia de extração por filtro, a amostra "pós-crise¨ não estava dentro do VMP para a cianotoxina MC. Portanto, caso a análise tivesse sido feita por esta mesma metodologia, é provável que os valores de MC das amostras no momento da crise também estariam acima do VMP. Isto porque, na metodologia comumente usada, o valor para MC foi acima do VMP para o momento ¨pós-crise¨. Portanto, na revisão da Portaria de Potabilidade se faz necessário descrever uma metodologia de extração que possa expressar o real risco em relação aos níveis de cianotoxinas presentes na água bruta. Desta forma, é importante que seja implementado, o quanto antes, o saneamento nas cidades a montante da captação de água bruta desse manancial, a fim de que eventos como os acontecidos durante a "crise hídrica" não seja vivenciado novamente. Além disso, a curto prazo, é necessária a realização de monitoramento periódico dos reservatórios, integrando as análises de genômica, biogeoquímica e de toxicidade, para que estação de tratamento tome as decisões adequadas para evitar algum problema e garantir a qualidade do abastecimento. Outrossim, esse recomendado procedimento poderá fornecer dados para a realização do Plano de Contingência, para que o quadro de floração não se amplie.

Ocotea pulchellaas an alternative against schistosomiasis: chemical analysis, development of nanoemulsion and biological control activity / Ocotea pulchellacomo una alternativa ante esquistosomiasis: análisis químico, desarrollo de una nanoemulsión y actividad en control biológico

The aim of this work was to evaluate the potential of the essential oil (EO) from Ocotea pulchella leaves as an alternative in the control of schistosomiasis. It was tested O. pulchella EO nanoformulation to assess its activity against adult Biomphalaria glabrata, their spawning and Schistossoma mansoni cercariae. Additionally, the EO chemical composition was investigated by gas-chromatography. Nanoemulsion were elaborated by the low energy method. The adult mollusks, their spawning and cercariae were placed in contact with nanoemulsion to calculate lethal concentrations. Myristicin, bicyclogermacrene and α-Pinene were the main substances in the EO. Nanoemulsion caused mortality of adult B. glabrata, its egg embryos and S. mansoni. These results suggest the use of this nanoemulsion as an alternative in the control of the schistosomiasis cycle.

El objetivo de este trabajo fue evaluar el potencial de los aceites esenciales (AE) de las hojas de Ocotea pulchellacomo una alternativa en el control de esquistosomiasis. Se probó una nanoformulación de AE de O. pulchellapara evaluar su actividad ante adultos de Biomphalaria glabrata, sus huevos y cercarías de Schistossoma mansoni. La nanoemulsión fue elaborada por el método de baja energía. Los moluscos adultos, sus huevos y cercarías se colocaron en contacto con la nanoemulsión para calcular concentraciones letales. Los compuestos mayoritarios en el AE fueron miristicina, biciclogermacreno y α-pineno. La nanoemulsión causó mortalidad en adultos de B. glabrata, sus huevos y a S. mansoni. Los resultados sugieren el uso de esta nanoemulsión como una alternativa en el control del ciclo de esquistosomiasis.

Nanoemulsion containing essential oil from Xylopia ochrantha Mart. produces molluscicidal effects against different species of Biomphalaria (Schistosoma hosts).

BACKGROUND: This work describes a chemical study of the essential oil from leaves of Xylopia ochrantha, an endemic Annonaceae species from Brazil, and its activity against Biomphalaria species. Considering its poor solubility in aqueous medium, the essential oil was nanoemulsified to evaluate its action on controlling some mollusc species of genus Biomphalaria, snail hosts of Schistosoma mansoni that causes schistosomiasis, which mainly affects tropical and subtropical countries. OBJECTIVES: The main aims of this work were to analyse the chemical composition of essential oil from X. ochrantha, and to evaluate the effect of its nanoemulsion on molluscs of genus Biomphalaria and their oviposition. METHODS: Chemical analysis was performed by gas chromatography coupled to mass spectrometry. Nanoemulsions were prepared by a low energy method and characterised by particle size and polydispersity index. Biological assays evaluating the mortality of adult species of B. glabrata, B. straminea and B. tenagophila and their ovipositions upon contact with the most stable nanoemulsion during 24 and 48 h were performed. FINDINGS: Chemical analysis by mass spectrometry revealed the majority presence of bicyclogermacrene and germacrene D in the essential oil. The formulation with a hydrophilic-lipophilic balance (HLB) of 9.26 was the most suitable for the oil delivery system. This nanoemulsion caused the mortality in B. tenagophila, B. straminea and B. glabarata of different sizes at levels ranging from 50 to 100% in 48 h. Additionally, the formulation could inhibit the development of deposited eggs. CONCLUSION: Thus, these results suggest the use of nanoemulsified essential oil from X. ochrantha as a possible alternative in controlling some Biomphalaria species involved in the schistosomiasis cycle.

Nanoemulsion containing essential oil from Xylopia ochrantha Mart. produces molluscicidal effects against different species of Biomphalaria (Schistosoma hosts)

BACKGROUND This work describes a chemical study of the essential oil from leaves of Xylopia ochrantha, an endemic Annonaceae species from Brazil, and its activity against Biomphalaria species. Considering its poor solubility in aqueous medium, the essential oil was nanoemulsified to evaluate its action on controlling some mollusc species of genus Biomphalaria, snail hosts of Schistosoma mansoni that causes schistosomiasis, which mainly affects tropical and subtropical countries. OBJECTIVES The main aims of this work were to analyse the chemical composition of essential oil from X. ochrantha, and to evaluate the effect of its nanoemulsion on molluscs of genus Biomphalaria and their oviposition. METHODS Chemical analysis was performed by gas chromatography coupled to mass spectrometry. Nanoemulsions were prepared by a low energy method and characterised by particle size and polydispersity index. Biological assays evaluating the mortality of adult species of B. glabrata, B. straminea and B. tenagophila and their ovipositions upon contact with the most stable nanoemulsion during 24 and 48 h were performed. FINDINGS Chemical analysis by mass spectrometry revealed the majority presence of bicyclogermacrene and germacrene D in the essential oil. The formulation with a hydrophilic-lipophilic balance (HLB) of 9.26 was the most suitable for the oil delivery system. This nanoemulsion caused the mortality in B. tenagophila, B. straminea and B. glabarata of different sizes at levels ranging from 50 to 100% in 48 h. Additionally, the formulation could inhibit the development of deposited eggs. CONCLUSION Thus, these results suggest the use of nanoemulsified essential oil from X. ochrantha as a possible alternative in controlling some Biomphalaria species involved in the schistosomiasis cycle.

New morphological data of Litomosoides chagasfilhoi (Nematoda: Filarioidea) parasitizing Nectomys squamipes in Rio de Janeiro, Brazil.

Litomosoides chagasfilhoi, originally described by Moraes Neto, Lanfredi & De Souza (1997) parasitizing the abdominal cavity of the wild rodent, Akodon cursor (Winge, 1887), was found in the abdominal cavity of Nectomys squamipes (Brants, 1827), from the municipality of Rio Bonito, Rio de Janeiro State, Brazil. This study led to addition of new morphological data and a new geographical distribution for this filarioid in Brazil. Several characters were detailed and emended to previous records of L. chagasfilhoi in N. squamipes, and confirming the original description in A. cursor: buccal capsule longer than wide with walls thinner than the lumen, right spicule slightly sclerotized, with membranous distal extremity slender, with a small tongue-like terminal portion, left spicule with handle longer than the blade, whose edges form large membranous wings folded longitudinally.

New morphological data of Litomosoides chagasfilhoi (Nematoda: Filarioidea) parasitizing Nectomys squamipes in Rio de Janeiro, Brazil / Novos dados morfológicos de Litomosoides chagasfilhoi (Nematoda: Filarioidea): parasitando Nectomys squamipes no Rio de Janeiro, Brasil

Abstract Litomosoides chagasfilhoi, originally described by Moraes Neto, Lanfredi & De Souza (1997) parasitizing the abdominal cavity of the wild rodent, Akodon cursor (Winge, 1887), was found in the abdominal cavity of Nectomys squamipes (Brants, 1827), from the municipality of Rio Bonito, Rio de Janeiro State, Brazil. This study led to addition of new morphological data and a new geographical distribution for this filarioid in Brazil. Several characters were detailed and emended to previous records of L. chagasfilhoi in N. squamipes, and confirming the original description in A. cursor: buccal capsule longer than wide with walls thinner than the lumen, right spicule slightly sclerotized, with membranous distal extremity slender, with a small tongue-like terminal portion, left spicule with handle longer than the blade, whose edges form large membranous wings folded longitudinally.

Resumo Litomosoides chagasfilhoi, originalmente descrito por Moraes Neto, Lanfredi & De Souza (1997) parasitando a cavidade abdominal do roedor silvestre Akodon cursor (Winge, 1887), foi encontrado na cavidade abdominal de Nectomys squamipes (Brants, 1827), no município de Rio Bonito, Estado do Rio de Janeiro, Brasil. Este estudo propiciou a adição de novos dados morfológicos e uma nova distribuição geográfica deste filarídeo no Brasil. Vários caracteres foram detalhados e adicionados ao registro anterior de L. chagasfilhoi em N. squamipes, e confirmando a descrição original em A. cursor: cápsula bucal mais alta do que larga com paredes mais finas que o lúmen, espículo direito ligeiramente esclerotizado, com extremidade distal membranosa mais estreita, com uma pequena porção terminal em forma de língua, espículo esquerdo com cabo mais longo do que a lâmina, cujas bordas formam grandes asas membranosas dobradas longitudinalmente.

Caracterização da atividade analgésica do extrato aquoso e frações do extrato metanólico de folhas da Rheedia longifolia Planch e Triana, 1860 / Caracterization of analgesic activity of aqueous extract and fractions of methanol extract of leaves of Rheedia longifolia Planch e Triana, 1860

O presente trabalho avaliou o efeito analgésico do extrato aquoso e frações do extrato metanólico de folhas da Rheedia longifolia (Clusiaceae) em diferentes modelos de estudo da dor, com doses de 0,1; 1 e 10 mg/kg. Inicialmente os animais foram tratados com o extrato e as frações, no modelo de capsaicina, utilizado para avaliação da dor de origem neurogênica, determinado o tempo de lambedura da pata para cada animal durante 5 minutos. O segundo modelo de estudo foi o da formalina, que apresenta duas fases: na primeira (0 – 5 min) verifica-se a dor de origem neurogênica e na segunda (15 – 30 min) a dor de origem inflamatória. No modelo de von Frey os animais foram estimulados com carragenina e a seguir foram submetidos à hipernocicepção mecânica com filamento von Frey nos tempos de 1 e 3 horas. Os tratamentos com extrato e frações não interferiram na reação álgica evocada por capsaicina e por formalina, com até 5 min de observação. Por outro lado, o tratamento com extrato aquoso inibiu significativamente a reação à formalina, na segunda fase, assim como extrato e frações foram eficazes no modelo von Frey, apresentando efeito analgésico significativo nos períodos de 1 e 3 h. Com base nos dados obtidos para a atividade analgésica – que sugeriram um potencial efeito na dor de origem inflamatória – avaliamos então a possível toxicidade do extrato aquoso e seu efeito em um modelo de formação de úlcera gástrica. Utilizamos o extrato aquoso de folhas, na dose de 10 mg/kg via oral (v.o) no teste de lesão gástrica aguda em ratos induzida com indometacina (20 mg/kg). Foi possível demonstrar que o extrato aquoso teve importante atividade protetora gástrica, reduzindo o índice de úlceras. Observamos ainda que o extrato na dose de 2000 mg/kg, não apresentou toxicidade letal sobre camundongos. Na tentativa de identificarmos os possíveis mecanismos envolvidos na bioatividade detectada, avaliamos a capacidade do extrato de folhas da R. longifolia e suas frações em bloquear a atividade do receptor P2X7, que tem sido ligado à dor inflamatória. Para tal, utilizamos o ensaio de permeabilização celular e observamos inibição da ativação do receptor P2X7 em macrófagos estimulados com ATP. Com base nos resultados obtidos, podemos sugerir que o extrato aquoso e frações de folhas da R. longifolia administrados por v.o. apresentam atividade analgésica sobre a dor de origem inflamatória, não promovem lesão gástrica e apresentam baixa toxicidade. Os dados indicam ainda um potencial efeito antagonista do receptor P2X7 para o extrato e frações da R. longifolia, sugerindo uma possível participação desse receptor da bioatividade detectada.

Molluscicidal activity of crown of Christ (Euphorbia splendens var. hislopii) (Euphorbiaceae) latex submitted to pH variation

Laboratory and field bioassays have confirmed the specificity of the molluscicidal activity of the Euphorbia splendens var. hislopii latex (crown of Christ) (Euphorbiaceae) over snails of the species Biomphalaria glabrata, B. tenagophila, B. straminea, B. pfeifferi and Bulinus sp. in the control of Schistosoma mansoni. In the present study, the effect of the pH variation on lethal concentration (LC90) over B. tenagophila was evaluated. Bioassays with the aqueous solutions of the latex ranging from 0.4 to 12 æl/l were adjusted for pH of 5.0; 6.0; 7.0 and 8.0, and tested in accordance with methods standardized by World Health Organization. The results obtained indicated that the minor concentration of the latex occurred at pH 6.0 (LC90 = 3.2 æl/l) and the maximum at pH 8.0 (LC90 = 10.3 æl/l). Lethal concentrations adjusted for pH 5.0 and 7.0 were 3.4 æl/l and 4,7æl/l, respectively. From the results it could be concluded that the molluscicidal toxicity was not altered when the concentrations were adjusted for pH 5.0 and 6.0, as we observed that mortality rate was 100 percent starting at a concentration of 2.0 æl/l, not the same for the concentrations with adjustment for pH 7.0 and 8.0

Infecçäo experimental de Physa cubensis Pfeiffer 1839 e Lymnaea columella com miracídios de Fasciola hepatica Linnaeus, 1758 / Experimental infection of Physa cubensis Pfeiffer, 1839 and Lymnaea columella with Fasciola hepatica miracidiae Linnaeus, 1758

Foi realizada a infecçäo experimental de Physa cubensis Pfeiffer, 1839, com miracídios de Fasciola hepatica. Para tanto, cada um dos cem moluscos, selecionados para o experimento, foram infectados com três miracídeos. Alguns exemplares, escolhidos ao acaso, foram mantidos até o 60º dia para observaçäo da emergência de formas larvais. Os moluscos restantes foram fixados após 0,5; 1; 2; 3; 4; 5; 24; 48; 72; 96; 120 e 144 horas de infecçäo, utilizando Raillet & Henry. O trabalho foi realizado de forma comparativa com Lymnaea columella. Os resultados demonstraram o desenvolvimento das formas larvais do trematódeo em L. columella e a presença de esporocistos em vários estágios de degeneraçäo na regiäo cefalopodal e na regiäo do manto nos primeiros dias de infecçäo em P. cubensis

Alteraçöes histológicas em Lymnaea columella provocadas pelo látex de Euphorbia splendens var. hislopii / Histological changes in Lymnaea columella caused by the Euphorbia splendens's latex

Observaçöes histológicas em moluscos da espécie Lymnaea columella foram realizadas para determinar a existência ou näo de alteraçöes provocadas pelo uso do látex de Euphorbia splendens var. hislopii. O experimento foi realizado de acordo com os métodos padronizados pela OMS. Cinqüenta exemplares de L. columella, com comprimento de concha de 6±1mm, foram submetidos a 200ml das soluçöes nas concentraçöes de 0,47µl/L; 0,76µl/L; 0,94µl/L e 1,51µl/L, durante 24 horas. Após o evento experimental, os moluscos foram colocados em soluçäo de Raillet & Henry, para sacrifício e fixaçäo. Os resultados demonstraram lesöes caracterizadas por degeneraçäo, necrose e acúmulo de líquido na glândula digestiva e no rim, em exemplares submetidos a concentraçöes a partir de 0,47 mil/L

Fasciola hepatica em búfalos (Bubalus bubalis) no município de Maricá, Rio de Janeiro, Brasil / Fasciola hepatica in buffaloes (Bubalus bubalis) in Maricá, Rio de Janeiro, Brazil

Através do exame de fezes, realizado pela técnica de Quatro tamises, demonstrou-se a presença de ovos de Fasciola hepatica em búfalos jovens e adultos procedentes do município de Maricá, Estado do Rio de Janeiro. O resultado assinala o primeiro relato desta parasitose na espécie bubalina no Estado, registrando um índice de ocorrência de 2,5 por cento, na amostra avaliada