Avaliação in vitro dos possíveis efeitos citotóxicos, genotóxicos e mutagênicos das drogas antimaláricas artemisinina e artemeter em linfócitos humanos

A artemisinina é uma substância extraída da planta chinesa Artemisia annua L., sendo bastante utilizada na medicina natural como um terapêutico em várias patologias. Já o artemer é uma substância sintetizada a partir da artemisinina. Estas drogas se enquadram em um grupo especial de moléculas denominadas de lactonas sesquiterpênicas sendo amplamente administradas na terapêutica da malária. Embora sejam considerados eficientes anti-maláricos, muito pouco se sabe sobre os efeitos genotóxicos e citotóxicos destes fármacos. Portanto, no presente trabalho, avaliamos os efeitos citotóxicos, genotóxicos e mutagênicos da artemisinina e do artemeter em cultura de linfócitos humanos por meio do ensaio cometa, do teste do micronúcleo e do ensaio de citotoxicidade para detecção de necrose e apoptose por marcação fluorescente diferencial com laranja de acridina/brometo de etídio (LA/BE), respectivamente. Nossos resultados demonstraram um aumento significativo (p<0,05) no índice de dano do DNA avaliado pelo ensaio do cometa, bem como na frequência de micronúcleos em ambas as substâncias testadas. Foi observado também, que apenas a artemisinina induziu um aumento estatisticamente significativo (p<0.05) no número de células necróticas nos linfócitos em 48 h de tratamento. Desta forma, demonstrou-se em nosso trabalho, que estas duas drogas exercem efeitos citotóxicos, genotóxicos e mutagênicos em culturas de linfócitos humanos, nas condições avaliadas. Nossos dados apontam a necessidade de cautela no uso de tais medicamentos, uma vez que efeitos genotóxicos/mutagênicos podem aumentar o risco de carcinogênese.

Ação do licopeno na proteção contra danos induzidos no DNA in vivo e in vitro

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mecanismos de antimutagenicidade do cogumelo Agaricus brasiliensis sobre lesões no DNA induzidas in vivo e in vitro

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Immediate graft histological assay, post pig's liver transplantation

PURPOSE: To describe the vascular and tissue histopathological changes in seven sequential experimental liver transplantations in pigs. METHODS: Fourteen female pigs, Sus domesticus species, with body mass between 5 and 8 kg were utilized. After the end of all anastomoses of the graft implantation in the receptor, the animal was monitored for 30 minutes, and at its end one of the biopsies was collected for histological analysis. The histological criteria utilized were: lytic hepatocyte necrosis, density of septal and portal inflammatory infiltrated, sinusoidal congestion and hemorrhage. The analysis was performed separately for the portal region in zone 1, 2 and 3. RESULTS: Among the structural changes undergone by the graft, those with greater frequency and intensity were vascular congestion and steatosis, which stood out in transplantations 5, 6 and 7. CONCLUSIONS: The technique demonstrated vascular alterations represented by vasocongestion, edema and minimum inflammatory reaction. In relation to the parenchyma, was observed macrovacuolar pan-acinar steatosis, focal lytic and occasional hemorrhages, beyond the accumulation of hemosiderin in Kuppfer's cells.

Profile of micronucleus frequencies and nuclear abnormalities in different species of electric fishes (Gymnotiformes) from the Eastern Amazon

The frequency of spontaneous micronucleus (MN) formation in fish species needs to be determined to evaluate their usefulness for genotoxic biomonitoring. The definition of a good bioindicator takes into account the current knowledge of its metabolic traits as well as other factors including its feeding behavior and relationship to the environment. In this study, we compared the basal frequencies of micronucleated erythrocytes and nuclear abnormalities (NA) among different species of the fish Order Gymnotiformes (Rhamphichthys marmoratus, Steatogenys elegans, Sternopygus macrurus, Parapteronotus hasemani, Gymnotus mamiraua, Gymnotus arapaima, Brachyhypopomus beebei, Brachyhypopomus n. sp. BENN) sampled in several localities of the Eastern Amazon. A baseline of MN and NA frequency in these fish was determined, enabling the identification of potentially useful species as models for genotoxicity studies. Only one impacted sample collected at a site in the River Caripetuba showed a significant number of NAs, which may be due to the release of wastewater by neighbouring mining industries and by the burnt fuel released by the small boats used by a local community. Our results may provide support for further studies in areas of the Eastern Amazon affected by mining, deforestation and other anthropogenic activities.

Application of the comet assay in erythrocytes of Oreochromis niloticus (Pisces): a methodological comparison

The present study applied the comet assay to erythrocytes of Oreochromis niloticus with the aim of improving protocols to detect DNA damage in these cells, by using two distinct pHs (pH = 12.1 and pH > 13) and evaluating whether there is a correspondence between silver and ethidium bromide staining. Comets were visually examined and, the frequency of cells with and without damage was obtained, as well as the distribution of classes and scores. By using the Kruskal-Wallis test, our results revealed that pH 12.1 is more effective, although both pHs can be used. Our findings also suggest that silver staining can substitute ethidium bromide, an expensive and highly toxic stain that requires specific equipment for examination.

Padronização e aplicação da técnica de ELISA (Enzyme-linked immunosorbent assay) indireto com anticorpo de captura para a detecção de anticoepos contra o cicovírus suíno tipo 2

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo do potencial genotóxico da Gutiferona A em diferentes células de camundongos in vitro

Pós-graduação em Biologia Geral e Aplicada - IBB

Compounds used to produce cloned animals are genotoxic and mutagenic in mammalian assays in vitro and in vivo

The compounds 6-dimethylaminopurine and cycloheximide promote the successful production of cloned mammals and have been used in the development of embryos produced by somatic cell nuclear transfer. This study investigated the effects of 6-dimethylaminopurine and cycloheximide in vitro, using the thiazolyl blue tetrazolium bromide colorimetric assay to assess cytotoxicity, the trypan blue exclusion assay to assess cell viability, the comet assay to assess genotoxicity, and the micronucleus test with cytokinesis block to test mutagenicity. In addition, the comet assay and the micronucleus test were also performed on peripheral blood cells of 54 male Swiss mice, 35 g each, to assess the effects of the compounds in vivo. The results indicated that both 6-dimethylaminopurine and cycloheximide, at the concentrations and doses tested, were cytotoxic in vitro and genotoxic and mutagenic in vitro and in vivo, altered the nuclear division index in vitro, but did not diminish cell viability in vitro. Considering that alterations in DNA play important roles in mutagenesis, carcinogenesis, and morphofunctional teratogenesis and reduce embryonic viability, this study indicated that 6-dimethylaminopurine and cycloheximide utilized in the process of mammalian cloning may be responsible for the low embryo viability commonly seen in nuclear transfer after implantation in utero.

A liquid-phase-blocking concanavalin A enzyme-linked immunosorbent assay for the detection of antibodies against Newcastle disease virus in serum of free-ranging pigeons

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dengue-4 false negative results by Panbio (R) Dengue Early ELISA assay in Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Development and validation of a microbiological assay by turbidimetry to determine the potency of cefazolin sodium in the lyophilized powder form

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Development and validation of a rapid turbidimetric assay to determine the potency of ampicillin sodium in powder for injectable solution

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Benzophenone guttiferone A from Garcinia achachairu Rusby (Clusiaceae) Presents Genotoxic Effects in Different Cells of Mice

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)