Genotoxic and antigenotoxic effects of Fucus vesiculosus extract on cultured human lymphocytes using the chromosome aberration and Comet assays

The brown seaweed Fucus vesiculosus (Fucales, Fucaceae) was screened for its protective activity using doxorubicin-induced DNA damage in human lymphocytes. In this study, we assessed the genotoxic and antigenotoxic potential of three different concentrations (0.25, 0.5 and 1.0 mg mL-1) of F. vesiculosus aqueous extract using the chromosome aberration and Comet assays. Treatment of human lymphocyte cultures with 0.25, 0.5 and 1.0 mg mL-1 F. vesiculosus aqueous extract had no effect on the chromosome aberration frequency or on the extent of DNA damage detected by the Comet assay. The antigenotoxic effects of the extract were tested in human lymphocyte cultures treated with 15 æg mL-1 of doxorubicin, either alone or combined with the different concentrations of the extract, which was added to the cultures before, simultaneously with or after the doxorubicin. Only when lymphocytes were pre-treated with extract there was a reduction in doxorubicin-induced chromosome aberrations and DNA damage as detected by the Comet assay. These results demonstrate that F. vesiculosus aqueous extract is not genotoxic in cultured human lymphocytes and indicate that when added to lymphocyte cultures before doxorubicin it has antigenotoxic activity against doxorubicin-induced DNA damage.

Effects of H2O2, Fe2+ and Fe3+ on curcumin-induced chromosomal aberrations in CHO cells

The effects of H2O2, Fe2+ and Fe3+ on curcumin-induced clastogenicity were evaluated in CHO cells. Curcumin combined with H2O2 did not increase the chromosomal aberrations more than expected based on a simple additive effect. In contrast, the combination of curcumin-Fe significantly decreased the total number of chromosomal aberrations and the number of abnormal metaphases. The clastogenicity of curcumin may be related to its pro-oxidant properties and its ability to generate free radicals.

Clastogenic activity of 2-chlorodeoxyadenosine in mammalian somatic cells

The base analogue 2-chlorodeoxyadenosine (2-CdA) used for therapy in chronic resistant and advanced lymphoproliferative disorders, is cytotoxic for both dividing and non-dividing lymphocytes. The present work evaluated the clastogenic potential of this drug in vitro in human lymphocytes in culture and in vivo in BALB/c mice bone marrow cells. In human lymphocytes, the clastogenic effect of 2-CdA was studied in G1, S and G2 phases of the cell cycle, using three different concentrations (10, 20 and 40 mug/mL). The endpoints analyzed included mitotic index (MI), proliferation index (PI), sister chromatid exchange (SCE), and chromosomal aberration (CA). Statistical analysis by a variance (ANOVA) test showed a significant increase (p < 0.05) in CA frequencies for cells treated during the S phase, but the MI did not vary. The concentrations tested did not produce a significant increase in the mean frequency of SCEs, nor did they change the cell PI in the G1 and S phases. The concentrations in vivo tested were 0.25, 0.375 and 0.5 mg/kg body weight. In this assay, alterations in CA frequencies and MI were not observed at the dose levels tested. Therefore, the results indicate a clastogenic effect of 2-CdA in human lymphocyte cultures.

Olive oil protects against chromosomal aberrations induced by doxorubicin in wistar rat bone marrow cells

There is considerable interest in identifying dietary compounds which have the capacity to protect against chromosomal aberrations induced by antitumor agents. Fatty acids and their constituents are able to act as free radical scavengers. Doxorubicin (DXR) is an important chemotherapeutic agent, that also induces chromosome aberrations. Rat bone marrow cells treated simultaneously with olive oil (10 ml/kg body weight) and DXR (90 mg/kg body weight) developed significantly fewer chromosomal aberrations and abnormal metaphases than those treated with DXR alone.

Assessment of the genotoxicity potential of the nematicide insecticide carbofuran in wheat cells

Carbofuran (Furadan), an insecticide-nematicide, is widely used for seed treatment in Brazil, against pests in crops such as wheat, rice and corn. It was assessed for its cytotoxic and or clastogenic potential in root meristems of Triticum aestivum (tested in vivo). Seed samples (1OO grams each) were individually treated with one, two, four and eight liters of the pure commercial product/lOO kg seed and germinated on three substrates: virgin soil, sterilized soil and growth chamber (on paper). For all treatments, no cytotoxic or clastogenic effects were observed in the meristem root cells.

Evaluation of the genotoxic activity of the sesquiterpene lactone goyazensolide in mammalian systems in vitro and in vivo

A lactona sesquiterpênica goyazensolide apresenta atividades esquistossomicida e citotóxica. Essa substância química foi testada em sistemas de mamíferos in vitro (cultura de linfócitos do sangue periférico humano) e in vivo (células de medula óssea de ratos Wistar) para determinar seu efeito clastogênico. In vitro foram testadas as concentraçöes de 0,1; 0,3; 0,6 e 1,0 µg/ml de meio de cultura, e in vivo as concentraçöes de 0,4; 0,8; 1,6 e 3,2 mg/100g de peso corpóreo. A análise do número de células com gaps cromossômicos demonstrou que todos tratamentos com goyazensolide in vitro e somente o tratamento com 0,8 mg in vivo foram significativamente maiores do que nos controles. Contudo, na análise estatística do número de células com quebras cromossômicas demonstramos, somente in vitro, que o tratamento com 0,6 mg goyazensolide/ml de meio de cultura tem uma açäo clastogênica. O goyazensolide näo causou efeito sobre a induçäo de SCE in vitro. A dose tóxica foi determinada tanto in vitro (1,0 µg/ml) como in vivo (3,2 mg/100g)

Effect of pretreatment with venon of Apis mellifera bees on the yield of gamma-ray induced chromosome aberrations in human blood lymphocytes

O veneno da abelha Apis mellifera tem sido considerado como um agente terapêutico potencialmente valioso, com atividade radioprotetora e anti-inflamatória in vivo. Essa toxina mostrou um efeito protetor contra cromossomos dicêntricos induzidos por radiaçäo gama (2,0 Gy) em linfócitos do sangue periférico humano em cultura. Esse efeito foi observado somente quando as culturas foram tratadas com o veneno (0,00015 µl/ml de meio) 6 horas antes da irradiaçäo (2,0 Gy). Nas culturas em que o veneno foi adicionado imediatamente antes da irradiaçäo com 0,25; 1,0 e 2,0 Gy, näo foram observadas diferenças significativas no número de cromossomos dicêntricos induzidos, quando comparado com as culturas submetidas a irradiaçäo somente. O veneno näo apresentou efeito clastogênico e nem aumentou a freqüência de trocas entre cromátides irmäs

Action of an extract of Stryphnodendron obovatum benth seed on rat bone marrow and on human lymphocytes

O Brasil é um país rico em plantas medicinais e o Stryphnodendron obovatum Benth (Barbatimäo), é uma importante fonte de tanino usado em indústrias. Esta planta tem diferentes atividades biológicas causando inibiçäo do desenvolvimento embrionário em ratos, toxicidade ao gado que a ingere e é usada também, na cura de diversas doenças do homen. Devido a sua ampla distribuiçäo e uso estudamos o efeito do extrato de sementes de Barbatimäo em células de medula óssea de ratos Wistar (in vivo) e em linfócitos de sangue periférico humano (in vitro), avaliando o seu efeito ao nível mutagênico e na induçäo de metáfases-colchicínicas. Os tratamentos näo causaram um aumento estatisticamente significativo no número de alteraçöes cromossômicas e de SCEs nos dois sistemas-testes avaliados. Nos testes em ratos houve pequena induçäo de metáfases-colchícinicas e nas culturas de linfócitos esta induçäo foi dependente do tempo e da forma do tratamento. Nas culturas de linfócitos ocorreu um efeito citotóxico dependente do aumento da concentraçäo e do tempo de exposiçäo ao extrato. Algumas metáfases tratadas apresentaram cromossomos bandados