ABSTRACT
Cassia angustifolia Vahl. (senna) is commonly used in self-medication and is frequently used to treat intestine constipation. A previous study involving bacteria and plasmid DNA suggested the possible toxicity of the aqueous extract of senna (SAE). The aim of this study was to extend the knowledge concerning SAE genotoxicity mechanisms because of its widespread use and its risks to human health. We investigated the impact of SAE on nuclear DNA and on the stability of mitochondrial DNA in Saccharomyces cerevisiae (wt, ogg1, msh6, and ogg1msh6) strains, monitoring the formation of petite mutants. Our results demonstrated that SAE specifically increased Can(R) mutagenesis only in the msh6 mutant, supporting the view that SAE can induce misincorporation errors in DNA. We observed a significant increase in the frequency of petite colonies in all studied strains. Our data indicate that SAE has genotoxic activity towards both mitochondrial and nuclear DNA.
Subject(s)
Cell Nucleus/genetics , Genome, Mitochondrial/drug effects , Genomic Instability/drug effects , Plant Extracts/pharmacology , Saccharomyces cerevisiae/genetics , Senna Plant/chemistry , Water/chemistry , Saccharomyces cerevisiae/drug effectsABSTRACT
Senna (Cassia angustifolia Vahl.) is widely used as a laxative, although potential side effects, such as toxicity and genotoxicity, have been reported. This study evaluated genotoxic and mutagenic effects of senna aqueous extract (SAE) by means of four experimental assays: inactivation of Escherichia coli cultures; bacterial growth inhibition; reverse mutation test (Mutoxitest) and DNA strand break analysis in plasmid DNA. Our results demonstrated that SAE produces single and double strand breaks in plasmid DNA in a cell free system. On the other hand, SAE was not cytotoxic or mutagenic to Escherichia coli strains tested. In effect, SAE was able to avoid H(2)O(2)-induced mutagenesis and toxicity in Escherichia coli IC203 (uvrA oxyR) and IC205 (uvrA mutM) strains, pointing to a new antioxidant/antimutagenic action of SAE.
Subject(s)
Mutagens/toxicity , Senna Extract/toxicity , Antimutagenic Agents/pharmacology , Antimutagenic Agents/toxicity , Antioxidants/pharmacology , Antioxidants/toxicity , DNA Breaks, Double-Stranded/drug effects , DNA Breaks, Single-Stranded/drug effects , Escherichia coli/drug effects , Escherichia coli/genetics , Escherichia coli/growth & development , Hydrogen Peroxide/metabolism , In Vitro Techniques , Mutagenicity Tests/methods , Mutagens/pharmacology , Plasmids/drug effects , Plasmids/metabolism , Senna Extract/pharmacology , Senna Plant/chemistryABSTRACT
A utilização de extratos vegetais em produtos farmacêuticos e cosméticos tem mostrado ser uma tendência mundial e cresceu substancialmente nas duas últimas décadas. No entanto, há ainda poucos relatos na literatura com relação à atividade mutagênica ou fototóxica de extratos vegetais. No presente trabalho foi avaliada a atividade fototóxica e o screening mutagênico de extratos fuidos e secos de própolis, Aloe spp. e Hamamelis virginiana. Na investigação de fototoxicidade foram realizados ensaios microbiológicos, utilizando cepas de Candida albicans e Saccharomyces cerevisiae, bem como ensaios biológicos com cobaias albinos. Extratos etanólicos de Ruta graveolens e Citrus spp., além de 8-metoxipsoraleno (fármaco sintético padrão), foram usados como controles positivos de ambos os testes. A atividade mutagênica foi avaliada qualitativamente segundo o spot test descrito por Maron & Ames, com cepas de Salmonella typhimurium TA97, TA98, TA100 e TA102, empregando como controle positivo o óxido de 4-nitroquinolina. Não foi observada atividade fototóxica, em ambos os ensaios realizados, para qualquer dos extratos. O ensaio microbiológico demonstrou uma atividade fungistática ou fungicida nos extratos secos de hamamélis. Os resultados obtidos nos ensaios microbiológicos com a levedura S. cerevisiae indicam que este microrganismo apresentou eficiência no procedimento de screening de atividade fototóxica comparável à obtida com C. albicans. Os extratos vegetais não apresentaram atividade mutagênica nos ensaios preliminares realizados
Subject(s)
Rats , Animals , Aloe , Dermatitis, Phototoxic , Plant Extracts/toxicity , Hamamelis , Mutagenesis , Propolis , Mutagenicity Tests , Plants, MedicinalABSTRACT
Dorstenin, 5-[3-(4,5-dihydro-5,5-dimethyl-4-oxo-2-furanyl)-butoxy]-7H-furo[3, 2-g] benzopyran-7-one, is a psoralen analog recently isolated from Dorstenia species (Moraceae). In order to characterize its biological activity, its photosensitizing and mutational properties were measured in wild-type E. coli and S. cerevisiae and also in strains carrying mutations which affect DNA repair. Compared to the high activities of psoralen and bergapten, dorstenin showed lower genotoxic effect.
Subject(s)
Escherichia coli/drug effects , Ficusin/pharmacology , Furocoumarins/pharmacology , Methoxsalen/analogs & derivatives , Moraceae , Photosensitizing Agents/pharmacology , Saccharomyces cerevisiae/drug effects , 5-Methoxypsoralen , Escherichia coli/genetics , Ficusin/isolation & purification , Furocoumarins/chemistry , Furocoumarins/isolation & purification , Light , Methoxsalen/isolation & purification , Methoxsalen/pharmacology , Mutagenesis/drug effects , Mutagenicity Tests , Photosensitizing Agents/isolation & purification , Plant Extracts/chemistry , Rhizome/chemistry , Saccharomyces cerevisiae/geneticsABSTRACT
Aqueous extracts of Ilex paraguarariensis (mate-chimarrão), a species that belongs to the Aquifoliaceae family, were analyzed for the presence of genotoxic, mutagenic, and clastogenic activities through bacterial trials based on the induction of the SOS functions, as well as in human lymphocytes in vitro and in mammalian cells in vivo. The extracts of mate-chimarrão were genotoxic, as assessed by lysogenic induction in Escherichia coli, and they also induced mutagenesis in Salmonella typhimurium. They addition of S9 microsomal fraction, catalase, thiourea, or dipyridyl counteracted the genotoxic activity of mate-chimarrão, suggesting that oxygen reactive species play an essential role in the genotoxicity of mate-chimarrão extracts. The extracts were not clastogenic in vivo (bone marrow cells of rats) in our experimental conditions, but we have observed an increased frequency of chromosomal aberrations in mate-chimarrão-treated human peripheral lymphocytes. Our results suggest that a high consumption of mate-chimarrão can potentiate carcinogenesis in the human oropharynx and esophagus.
Subject(s)
Beverages/adverse effects , Esophageal Neoplasms/etiology , Oropharyngeal Neoplasms/etiology , Plant Extracts/adverse effects , Animals , Chromosome Aberrations , Diet , Escherichia coli/genetics , Humans , Mutagenicity Tests , Rats , Reactive Oxygen Species , Salmonella typhimurium/geneticsABSTRACT
Aqueous extracts of Paullinia cupana (guarana), a species that belongs to the Sapindaceae family, were analyzed for the presence of genotoxic activities in bacterial cells. The extracts of guarana were genotoxic as assessed by lysogenic induction in Escherichia coli and they were also able to induce mutagenesis in Salmonella typhimurium. Addition of S9 microsomal fraction, catalase, superoxide dismutase or thiourea counteracted the genotoxic activity of guarana, suggesting that oxygen reactive species play an essential role in the genotoxicity of aqueous guarana extracts. The genotoxic activity in the extracts was related to the presence of a molecular complex formed by caffeine and a flavonoid (catechin or epicatechin) in the presence of potassium.
Subject(s)
Mutation , Plant Extracts/toxicity , Plants, Medicinal/chemistry , Caffeine/analysis , Catalase/pharmacology , Catechin/analysis , Escherichia coli/drug effects , Microsomes, Liver/metabolism , Mutagenicity Tests , Plant Extracts/chemistry , Potassium/analysis , Salmonella typhimurium/drug effects , Superoxide Dismutase/pharmacology , Virus Activation/drug effectsABSTRACT
Aqueous extracts of Achyrocline satureoides (Marcela and/or Macela) were tested for the presence of genotoxic activity in microorganisms. This species belongs to the family Compositae and is used on a large scale by the population of South Brazil. The extracts showed genotoxic activity in the presence of S9 mix in the Ames test TA100, TA98 and TA102 strains, 'SOS' spot chromotest and Microscreen phage-induction assay. The positive results were related to the presence of quercetin and caffeic acid in the aqueous extracts.