RESUMO
Direct electric current has several therapeutic uses such as antibacterial and antiprotozoal action, tissues scarring and regeneration, as well as tumor treatment. This method has shown promising results in vivo and in vitro, with significant efficacy and almost no side effects. Considering lack of studies regarding direct electric current mutagenic and/or genotoxic effects, the present work evaluated both aspects by using five different bacterial experimental assays: survival of repair-deficient mutants, Salmonella-histidine reversion mutagenesis (Ames test), forward mutations to rifampicin resistance, phage reactivation, and lysogenic induction. In these experimental conditions, cells were submitted to an approach that allows evaluation of anodic, cathodic, and electro-ionic effects generated by 2 mA of direct electric current, with doses ranging from 0.36 to 3.60 Coulombs. Our results showed these doses did not induce mutagenic or genotoxic effects.
Assuntos
Eletricidade/efeitos adversos , Escherichia coli/genética , Testes de Mutagenicidade , Salmonella typhimurium/genética , Bacteriófagos/fisiologia , Farmacorresistência Bacteriana/genética , Escherichia coli/fisiologia , Escherichia coli/virologia , Viabilidade Microbiana/genética , Salmonella typhimurium/fisiologia , Salmonella typhimurium/virologiaRESUMO
Cisplatin is currently used in tumor chemotherapy to induce the death of malignant cells through blockage of DNA replication. It is a commonly used chemotherapeutic agent binding mono- or bifunctionally to guanines in DNA. Escherichia coli K12 mutant strains deficient in nucleotide excision repair (NER) were submitted to increasing concentrations of cisplatin, and the results revealed that uvrA and uvrB mutants are sensitive to this agent, while uvrC and cho mutants remain as the wild type strain. The time required for both gene expression turn-off and return to normal weight DNA in wild-type E. coli was not accomplished even after 4 h post-treatment with cisplatin, while the same process takes place within 1.5 h after ultraviolet radiation (UV). Besides, a heavily damaging action of cisplatin can be seen not only by persistent nicks on genomic DNA, but also by NER gene expression exceeding manifold that seen after equivalent lethal doses of UV. Moreover, cisplatin caused an increase in uvrB gene expression from its putative upstream promoter P3 in an SOS-independent manner.
Assuntos
Antineoplásicos/toxicidade , Cisplatino/toxicidade , Quebras de DNA de Cadeia Simples , Escherichia coli/genética , Resposta SOS em Genética/genética , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , DNA Helicases/genética , DNA Helicases/metabolismo , DNA Bacteriano/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica , Mutação , Regiões Promotoras Genéticas , Transcrição Gênica , Raios Ultravioleta , Regulação para CimaRESUMO
Introduction: Euphorbia tirucalli Lineu, commonly known as Aveloz, is a very common plant found in tropical regions [1]. The ingestion or contact with its latex causes symptoms such as vomiting and diarrhea, pallor, skin irritation, hepatotoxicity as well as carcinogenesis [2]. Moreover, the Aveloz latex is also responsible for a few important activities against some infectious and neoplastic diseases. Aveloz latex phytochemical composition may vary according to seasonal aspects and geographic location [3], and it is used either orally or topically in traditional medicine. Popularly known as an antitumoral agent (breast, prostate, lung, kidney), it is used not only in Brazil, but in several other countries. According to the literature, the latex could have a dual behaviour, activating or inhibiting tumoral events [3-6]. However, there are few reports discussing these mechanisms. Besides, the mutagenic and genotoxic potentials of phytochemical and homeopathic Aveloz have not yet been described. Several experimental methods have been used to evaluate the mutagenic and genotoxic effects, such as Inductest, the Ames test and the chromotest. Objective: This study aims to evaluate the genotoxic and mutagenic potentials of Aveloz latex and Aveloz phytotherapic and homeopathic solutions. Methodology: In this study, Aveloz 5 and 30cH are prepared according to Brazilian Homeopathic Pharmacopoeia [7], from Aveloz latex collected in the Center for Natural Products Research (NPPN) at the Universidade Federal do Rio de Janeiro [8]. The Aveloz phytochemical solution was prepared following the doses used in folk medicine: 2 drops diluted in 250ml of water and 2 drops diluted in 25 ml of water. All test solutions were submitted to the following methodologies: (a) Inductest: assesses the ability of physical or chemical agents to promote lysogenic induction as a response to DNA damage in lysogenic bacteria; (b) The Ames test: uses indicator strains of Salmonella typhimurium, which are sensitive to substances that can induce different types of mutation; (c) Chromotest: evaluates the genotoxicity of chemicals through the induction of the bacterial SOS system. Results: In the Inductest there was no decrease in bacterial survival fraction and no increase in lysogenic cycle. As measured by The Ames test and the chromotest no mutagenic or genotoxic potentials were detected. Discussion: The homeopathic and the phytochemical Aveloz solutions were unable to produce lysogenic induction or mutagenesis in bacterial cells and they were also unable to produce genotoxic effects, as measured by chromotest. Conclusion: Our results showed that no mutagenic or genotoxic damages were induced by all Aveloz preparations studied, thus we are led to believe that patients using Aveloz as a complementary therapy present no side effects in relation to mutagenesis and genotoxicity. (AU)
Assuntos
Medicamentos Homeopáticos Novos , LátexRESUMO
Introduction: Euphorbia tirucalli Lineu, commonly known as Aveloz, is a very common plant found in tropical regions [1]. The ingestion or contact with its latex causes symptoms such as vomiting and diarrhea, pallor, skin irritation, hepatotoxicity as well as carcinogenesis [2]. Moreover, the Aveloz latex is also responsible for a few important activities against some infectious and neoplastic diseases. Aveloz latex phytochemical composition may vary according to seasonal aspects and geographic location [3], and it is used either orally or topically in traditional medicine. Popularly known as an antitumoral agent (breast, prostate, lung, kidney), it is used not only in Brazil, but in several other countries. According to the literature, the latex could have a dual behaviour, activating or inhibiting tumoral events [3-6]. However, there are few reports discussing these mechanisms. Besides, the mutagenic and genotoxic potentials of phytochemical and homeopathic Aveloz have not yet been described. Several experimental methods have been used to evaluate the mutagenic and genotoxic effects, such as Inductest, the Ames test and the chromotest. Objective: This study aims to evaluate the genotoxic and mutagenic potentials of Aveloz latex and Aveloz phytotherapic and homeopathic solutions. Methodology: In this study, Aveloz 5 and 30cH are prepared according to Brazilian Homeopathic Pharmacopoeia [7], from Aveloz latex collected in the Center for Natural Products Research (NPPN) at the Universidade Federal do Rio de Janeiro [8]. The Aveloz phytochemical solution was prepared following the doses used in folk medicine: 2 drops diluted in 250ml of water and 2 drops diluted in 25 ml of water. All test solutions were submitted to the following methodologies: (a) Inductest: assesses the ability of physical or chemical agents to promote lysogenic induction as a response to DNA damage in lysogenic bacteria; (b) The Ames test: uses indicator strains of Salmonella typhimurium, which are sensitive to substances that can induce different types of mutation; (c) Chromotest: evaluates the genotoxicity of chemicals through the induction of the bacterial SOS system. Results: In the Inductest there was no decrease in bacterial survival fraction and no increase in lysogenic cycle. As measured by The Ames test and the chromotest no mutagenic or genotoxic potentials were detected. Discussion: The homeopathic and the phytochemical Aveloz solutions were unable to produce lysogenic induction or mutagenesis in bacterial cells and they were also unable to produce genotoxic effects, as measured by chromotest. Conclusion: Our results showed that no mutagenic or genotoxic damages were induced by all Aveloz preparations studied, thus we are led to believe that patients using Aveloz as a complementary therapy present no side effects in relation to mutagenesis and genotoxicity.