Senna (Cassia angustifolia Vahl.) is widely used as laxative, but data from Ames test and animal and/or human studies with this agent have shown a mutagenic and carcinogenic potentiality. Using thee experimental models (bacterial inactivation test; bacterail mutagenisis assayMutoxitest; and growth Inhibition test, we investigated the toxicity of senna. Our data suggest an absence of mutagenic and citotoxic potentiality of senna.
ResumoSena (Cassia angustifolia Vahl.) é uma espécie amplamente empregada como laxativa, mas dados mutagênicos realizados com teste de Ames e estudos animais e/ou em humanos com esse agente tem mostrado uma potencialidade mutagênica e carcinogênica. Usando três diferentes testes (inativação de bactérias; ensaio de mutagênese em bactérias -Mutoxitest; teste de inibição de crescimento), foi investigada a toxidade dessa planta. Nossos dados sugerem uma ausência da potencialidade mutagênica e citotoxicidade de sena.The use of medicinal plants has increased in the last decades all over the world. However, little information is available on their potential risk to health. Many plants contain mutagenic and/or carcinogenic substances and their frequent use has been correlated with a high incidence of tumors in the population 1,2 . Senna (Cassia angustifolia Vahl) is widely used in clinical practice and as a self-medication for chronic constipation. Chronic use or abuse of this agent can lead to a number of symptoms and signs, such as abdominal pain, nausea and diarrhoea 3,4,5 . Many studies have investigated the mutagenic and carcinogenic effects of senna in bacterial strains, animals and humans 4,5,6 . Ames test detected a weak mutagenic potentiality in Salmonella typhimurium TA102 and a stronger mutagenicity in Salmonella typhimurium TA97 and TA98
5. The purpose of this work was to evaluate the cytotoxic and mutagenic effects of senna using Eschericha coli strains. Three experimental models were used to perform these studies: (a) bacterial inactivation test; (b) bacterial mutagenesis assays (Mutoxitest) 3 and growth inhibition test. The data obtained indicate that senna, in the concentrations studied, did not exhibit cytotoxic effect to E. coli strains (Table 1). This was observed for E. coli AB1157, DNA repair wild-type strain and BW9091, repair mutant strain that is deficient in exonuclease III. This protein is closely associated to the processing step of oxidative damage in the base excision repair system.Another assay for investigating the toxic effect of senna comprised using Growth inhibition test. The results obtained with E. coli IC203, IC204, IC205, IC206 and IC207 strains, specific indicators of lesions induced by ROS attack to DNA, were negative to all the concentrations of senna (Table 2). In addition, the results obtained in Mutoxitest showed that senna did not present mutagenic activity to E. coli IC203 and IC205 strains in the concentrations tested (Table 3).The results obtained in this work, with E. coli strains, reinforce those from literature obtained with Salmon...
