Francisco Carlos da Silva

Antigenotoxic effect of acute, subacute and chronic treatments with Amazonian camu-camu (Myrciaria dubia) juice on mice blood cells.

Myrciaria dubia, a plant native to the Amazon region, stands out as a fruit rich in vitamin C and other metabolites with nutritional potential. We evaluated the antioxidant, genotoxic and antigenotoxic potential of M. dubia juice on blood cells of mice after acute, subacute and chronic treatments. Flavonoids and vitamin C present in the fruit of M. dubia were quantified. In vitro antioxidant activity was evaluated by DPPH assay. Blood samples were collected for analysis after treatment, and the alkaline comet assay was used to analyze the genotoxic and antigenotoxic activity (ex vivo analysis using H(2)O(2)). The amount of vitamin C per 100mL of M. dubia was 52.5mg. DPPH assay showed an antioxidant potential of the fruit. No M. dubia concentration tested exerted any genotoxic effect on mice blood cells. In the ex vivo test, the juice demonstrated antigenotoxic effect, and acute treatment produced the most significant results. After the treatments, there was no evidence of toxicity or death. In conclusion, our data show that M. dubia juice has antigenotoxic and antioxidant activities, though with no genotoxicity for blood cells. Nevertheless, more in-depth studies should be conducted to assess the safety of this fruit for human consumption.

Adaptation of the Micronucleus Technique in Allium Cepa, For Mutagenicity Analysis of the Jamari River Valley, Western Amazon, Brazil

This study aimed to make technique adjustment of micronuclei in Allium cepa, recommended by Fiskejo [1], by replacing methanol and Giemsa by triarilmetano the 0,1%, xantenos the 0,1% and tiazinas the 0,1%. We obtained good results with the replacement, as its efficiency in stain nucleic acids, obtaining a good visualization of cells, mitotic index, micronuclei, anaphase and telophase bridges, and this methodology is indicated in future examinations of mutagenicity in the river Vale do Jamari.

New method for detection of mutagenicity in oral mucosa the through of micronucleus test

Background: The micronucleus assay using a tissue rapidly dividing, such as human oral mucosa, allows for assessment of damage of genetic material, without the need for a stage of ex vivo cell replication. Methods: The present study describes a new protocol for the detection of MN in oral mucosa, replacing methanol and giemsa by triarilmetano, xanthene and thiazine. Results: The blades were well visible with ungrouped cells, having a good view of the cell boundaries. Conclusions: Good results were obtained with the substitution of methanol and giemsa by triarilmetano, thiazine and xanthene, because of its efficiency in blush nucleic acid, getting a good visualization of cell nuclei and micronucleus, and this methodology it is indicated for mutagenicity analysis of the oral mucosa.

Potencial de citotoxicidade e mutagenicidade das águas do rio Jaru, estado de Rondônia, em células de Allium cepa

O presente estudo teve como objetivo avaliar o potencial mutagenico e citotoxico por meio da analise das celulas da raiz de Allium cepa expostas a amostras de aguas superficiais do rio Jaru, municipio de Jaru, Estado de Rondonia. As amostras foram obtidas nos periodos de seca, agosto de 2011 e chuvoso, fevereiro de 2012 em tres pontos distintos, sendo o P1 localizado na bomba de captacao de aguas da CAERD (Companhia de Agua e Esgoto de Rondonia), o P2 em local de despejo de efluentes laticinios, e o P3 na zona rural a jusante da sede do municipio. Bioensaios com bulbos de cebola expostos a agua de cada ponto foram conduzidos, comparando-se com o controle negativo que levou apenas agua destilada. Em seguida as amostras dos bulbos passaram por tratamentos e cortes histologicos nas regioes dos meristemas apicais da raiz para avaliar o indice de crescimento, o indice mitotico e indice de micronucleo. No periodo de seca com relacao ao crescimento das raizes foi observada uma diferenca estatisticamente significante para P1 (P<0,05) e P2 (P<0,01) em relacao ao controle negativo. Ja no periodo chuvoso nao houve diferenca estatistica. Quanto as analises de indice mitotico, nao foi constatada diferenca significante em nenhuma das estacoes analisadas. Ja a analise de mutagenicidade mostrou diferencas significantes em P2 (P<0,05) quando comparado ao grupo controle na estacao seca. Com base nesses resultados e possivel concluir que houve maior interferencia de agentes genotoxicos no ponto onde efluentes de laticinios sao lancados.