RESUMO

The use of medicinal plants as raw material for extracts production and pure substances isolation and subsequence development of new drugs represents a constantly growing area. However, some stages are indispensable before pharmacologically evaluating natural products such as medicines. Toxicity tests in mammalian cells are essential to initiate new drugs development or verify the substance's biocompatibility. Thus, we verified the toxicity of crude extracts and fractions with different polarities obtained from the leaves and stems of eight plant species. The toxic effect was evaluated on macrophages obtained from the bone marrow and peritoneal cavity of a Swiss webster mouse and J774 macrophages. G8 cell lineage. These macrophages were cultured in a 96-well plate, and the compounds were added at a concentration of 100 µg/mL for 24 hours. After this time, the supernatant was removed. The toxicity was evaluated for lactate dehydrogenase (LDH) release assay and the resazurin assay, which uses an indicator dye to measure oxidation-reduction reactions. The results showed a difference in the percentage of toxicity when comparing the same extract in different types of macrophages. This outcome indicates that these cells from different origins may exhibit different responses when exposed to the same natural compounds.

Assuntos

RESUMO

The use of medicinal plants as raw material for extracts production and pure substances isolation and subsequence development of new drugs represents a constantly growing area. However, some stages are indispensable before pharmacologically evaluating natural products such as medicines. Toxicity tests in mammalian cells are essential to initiate new drugs development or verify the substance's biocompatibility. Thus, we verified the toxicity of crude extracts and fractions with different polarities obtained from the leaves and stems of eight plant species. The toxic effect was evaluated on macrophages obtained from the bone marrow and peritoneal cavity of a Swiss webster mouse and J774 macrophages. G8 cell lineage. These macrophages were cultured in a 96-well plate, and the compounds were added at a concentration of 100 µg/mL for 24 hours. After this time, the supernatant was removed. The toxicity was evaluated for lactate dehydrogenase (LDH) release assay and the resazurin assay, which uses an indicator dye to measure oxidation-reduction reactions. The results showed a difference in the percentage of toxicity when comparing the same extract in different types of macrophages. This outcome indicates that these cells from different origins may exhibit different responses when exposed to the same natural compounds.

A utilização de plantas medicinais como matéria-prima para a produção de extratos e isolamento de substâncias puras para o desenvolvimento de novos fármacos representa uma área em constante crescimento. No entanto, existem processos a serem realizados antes de avaliar farmacologicamente produtos naturais como medicamentos. Os testes de toxicidade em células de mamíferos são fundamentais para iniciar o desenvolvimento de novas drogas ou verificar a biocompatibilidade de substâncias. Assim, verificamos a toxicidade de extratos brutos e frações com diferentes polaridades obtidos de folhas e caule de oito espécies de planta. Para comparar o efeito tóxico, os testes foram realizados em macrófagos obtidos da medula óssea e cavidade do peritônio de camundongo Swiss webster, bem como no macrófago da linhagem celular J774.G8. Esses macrófagos foram cultivados em placa de 96 poços e os compostos adicionados na concentração de 100 µg/mL por 24 horas. Após esse período o sobrenadante foi removido. A toxicidade foi avaliada pelos ensaios de detecção da enzima lactato-desidrogenase (LDH) e pelo ensaio de resazurina, que usa um corante indicador para medir as reações de oxidação-redução. Os resultados mostraram uma diferença na porcentagem de toxicidade quando comparamos o mesmo extrato em diferentes tipos de macrófagos. Este resultado indica que essas células de várias origens podem exibir respostas distintas quando expostas aos mesmos compostos naturais.

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RESUMO

Toxoplasmosis is a zoonosis determined by the protozoan Toxoplasma gondii with wide geographic distribution, which affects homeothermic animals, with felids being their definitive hosts and other mammals and birds being their intermediate hosts. Regarding the Latin American bird species Cairina moschata, there are few reports in Brazil of the exposure of these animals to this protozoan. Based on the above, this study aimed to report for the first time the exposure of C. moschata to infection by this parasite in Rio de Janeiro, Brazil, determining the serological frequency of anti-T. gondii antibodies in birds of this species. Sixty-seven specimens of C. moschata were captured in the vicinity of the Rio de Janeiro Zoo, and these animals at the time of capture were sorted by gender and type of feather. Blood samples from these animals were obtained by venipuncture to obtain the serum. The serum samples were subjected to IFAT for anti-T. gondii IgG. In general, the frequency of positive results was 58.21% (n=39), with a statistically significant association (p<0.05) between the animals with adult plumage and seropositivity. The exposure of ducks to T. gondii in the vicinity of the Zoo may indicate contamination of this area with protozoan oocysts.

Toxoplasmose é uma zoonose determinada pelo protozoário Toxoplasma gondii de ampla distribuição geográfica, que acomete animais homeotérmicos, sendo os felídeos os seus hospedeiros definitivos, e outros mamíferos e aves os seus hospedeiros intermediários. Em relação à espécie de ave latino-americana Cairina moschata, há poucos relatos no Brasil da exposição desses animais a esse protozoário. Mediante o exposto, este estudo teve como objetivo relatar pela primeira vez a exposição de C. moschata à infecção por esse parasito no Rio de Janeiro, Brasil, determinando a frequência sorológica de anticorpos anti-T. gondii em aves dessa espécie. Foram capturados, nos arredores do Zoológico do Rio de Janeiro, 67 espécimes de C. moschata, sendo esses animais, no momento da captura, triados pelo gênero e pelo tipo de pena. Amostras de sangue desses animais foram obtidas por venopunção para obtenção do soro. As amostras de soro foram submetidas à RIFI para pesquisa de anticorpos IgG anti-T. gondii. De forma geral, a frequência de positividade evidenciada foi de 58,21% (n=39), sendo observada associação estatística significativa (P<0,05) entre animais com plumagem de adultos e soropositividade. A exposição dos patos a T. gondii nos arredores do zoológico pode indicar a contaminação dessa área com oocistos do protozoário.

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RESUMO

Since free-range chickens are important for the epidemiology of toxoplasmosis, this study evaluated the sensitivity and specificity of different laboratory techniques for the diagnosis of Toxoplasma gondii in these animals. Serum samples from 135 adult domestic chickens were tested for anti-T. gondii antibodies by the indirect fluorescent antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA), modified agglutination test (MAT), and indirect hemagglutination test (IHAT). Tissue samples from all animals were analyzed by histopathology, immunohistochemistry and mouse bioassay (gold standard). Fifty-four chickens were positive for T. gondii in the bioassay. The sensitivity and specificity of the different tests were, respectively, 85% and 56% for ELISA; 80% and 52% for IFAT; 76% and 68% for MAT; 61% and 80% for IHAT; 7% and 98% for immunohistochemistry, and 6% and 98% for histopathology. The MAT was the most effective method for the diagnosis of T. gondii infection in chickens, followed by ELISA. Histopathology and immunohistochemistry are useful tools for the diagnosis of T. gondii infection in chickens due to their specificity.

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RESUMO

The prevalence of T. gondii infection was investigated in free-range chickens for human consumption in the county of Rio Bonito, Rio de Janeiro, Brazil. Thus, a search for antibodies to T. gondii by indirect fluorescent antibody test was done in the serum of 220 chickens from twenty two farms. Titres equal or greater than 16 were considered positive. The prevalence of toxoplasmic infection found in chickens was 27.6% (61/220). There were positive cases in eighteen (77.2%) farms. The more frequent titre was 16 (12.5%) and the highest was 4096 (0.4%). The high prevalence of T. gondii in chickens and the high percentage of farms with positive cases indicate environmental contamination in the studied area showing the possibility of human and animal infection.

Assuntos

RESUMO

The prevalence of T. gondii infection was investigated in free-range chickens for human consumption in the county of Rio Bonito, Rio de Janeiro, Brazil. Thus, a search for antibodies to T. gondii by indirect fluorescent antibody test was done in the serum of 220 chickens from twenty two farms. Titres equal or greater than 16 were considered positive. The prevalence of toxoplasmic infection found in chickens was 27.6% (61/220). There were positive cases in eighteen (77.2%) farms. The more frequent titre was 16 (12.5%) and the highest was 4096 (0.4%). The high prevalence of T. gondii in chickens and the high percentage of farms with positive cases indicate environmental contamination in the studied area showing the possibility of human and animal infection.