RESUMO
Liquid holing recovery (LHR) consist of an increase in the survival of UV-irradiated cells when they ar held under non-nutrient conditions before palting. In this study we investigated in E. coli B cells the effect of the growth inhibition induced by near UV (365 nm) illumination (growth delay, GD) before irradiation with UV-254 nm on the amplitude of LHR and the induction of an SOS function (filamentation) during the liquid holding period. Our results demonstrated that pre-illumination with near-UV inhibitis LHR and the induction of filamentation when the cells are incubated in nutrient medium. Moreover, this inhibition is due to GD, an effect caused by a photoproduct in the E. coli t-RNA, the 8-13 link
Assuntos
Sobrevivência Celular/efeitos da radiação , Escherichia coli/efeitos da radiação , Raios Ultravioleta , Divisão Celular/efeitos da radiação , Meios de Cultura , Escherichia coli/citologia , Doses de RadiaçãoRESUMO
The development of short term tests for measuring the mutagenic activity of genotoxic chemicals has been helpful in increasing security. Natural products from the flora are largely used in popular medicine. Using the Salmonella/mammalian-microsome assay, we investigated the genetic toxicity of two plant species popularly used in malaria treatment, Pothomorphe umbrellata and Pothomorphe peltata. The data show the absence of genetic toxicity for both plant species
Assuntos
Extratos Vegetais/toxicidade , Plantas Medicinais , Salmonella typhimurium/genética , Malária/tratamento farmacológico , Testes de Mutagenicidade , Extratos Vegetais/uso terapêuticoRESUMO
High sensitivity to ionizing raddiation is observed in Escherichia coli radC mutants. This is not seen for H2O2-treated cells but when polA mutation is also presente, cells are more sensitive than in the presence of the recA mutation. an increase in inactivation was observed for strains tested when cells are grown in minimal medium and starvation- induced resistance is observed in H2O2- treated cells
Assuntos
Meios de Cultura , Escherichia coli/efeitos da radiação , Mutação , Peróxido de Hidrogênio/farmacologia , Reparo do DNA , Escherichia coli/efeitos dos fármacosRESUMO
The present study analyzes the possible scavenger capacity of several anti-inflammatory drugs on growth of Escherichia coli K12, Bw9109, a strain hypersensitive to H2O2, in medium containing H2)2. although all cyclo-oxygenase and/or lipoxygenase inhibitors protected the cells against H2O2, no correlation was found between their relative protective abilities and reported anti-inflammatory potencies