Avaliação do efeito protetor do urucum e da bixina sobre a genotoxicidade induzida pelo antitumoral cisplatina em células da linhagem PC12
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Data
2008-12-12
Autores
Santos, Graciela Cristina dos [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A neuropatia induzida por drogas quimioterápicas é uma complicação no tratamento do câncer e outras doenças por ser freqüentemente dolorosa e requerer a interrupção da terapia. O antitumoral cisplatina é comumente usado contra muitas formas de câncer há aproximadamente 40 anos. Entretanto, sua aplicação é associada a muitos efeitos tóxicos, como neurotoxicidade, nefrotoxicidade, perda da audição e vômitos. Estes efeitos adversos têm levado ao desenvolvimento de agentes específicos para amenizar a toxicidade do fármaco. Alguns estudos sugerem que a administração de antioxidantes é capaz de reduzir os danos e proteger os tecidos. Dessa forma, os carotenóides são mais uma opção a ser avaliada, pois são considerados eficazes agentes antioxidantes. O urucum é uma fonte natural de corantes vermelhos e além da bixina (fração lipossolúvel do extrato), estão presentes nas suas sementes, outros carotenóides, como a norbixina, o bcaroteno, a criptoxantina, a luteína e a zeaxantina. Neste estudo, foi avaliada a genotoxicidade e a antigenotoxicidade do urucum e da bixina sobre a toxicidade induzida pelo antitumoral cisplatina em culturas de células PC12. A citotoxicidade foi determinada pelo método do MTT, a frequência de danos cromossômicos pelo Teste do Micronúcleo e a extensão de danos primários ao DNA pelo Ensaio do Cometa. O urucum e a bixina foram avaliados preliminarmente quanto a sua genotoxicidade. O urucum nas concentrações 0,2, 0,5 e 1,0 mg/mL e a bixina nas concentrações 0,05, 0,08 e 0,10 mg/mL não foram citotóxicos e nem genotóxicos às células PC12. Assim, essas concentrações foram utilizadas nos experimentos para verificar a proteção do urucum e da bixina contra os danos induzidos pela cisplatina. Embora o efeito protetor do urucum e da bixina não tenha sido evidente nos resultados obtidos pelo Ensaio do Cometa, eles se mostraram...
The neuropathy induced by chemotherapeutic drugs is a complication in the treatment of cancer and other diseases, because it is often painful and requires discontinuation of the therapy. Cisplatin has been commonly used against many forms of cancer for approximately 40 years. However, its application is associated with many toxic effects such as neurotoxicity, nephrotoxicity, hearing loss and vomiting. These adverse effects have led to the development of specific agents to lessen the toxicity of the drug. Some studies have suggested that the administration of antioxidants is able to reduce the damage and protect the tissues. Thus, the carotenoids are one more option to be evaluated, because they are considered to be effective antioxidants. Annatto is a natural source of red dyes and pigments and in addition to bixin (liposoluble fraction of the extract), other carotenoids are present in its seeds, such as norbixin, B-carotene, cryptoxanthin, lutein and zeaxanthin. In the present study, the genotoxicity and antigenotoxicity of annatto and bixin on the cisplatin induced-toxicity in PC12 cell cultures was assessed. Cytotoxicity was determined by the MTT assay, chromosomal damage by the Micronucleus test and the extent of primary damage to the DNA by the Comet assay. Annatto and bixin were first assessed with respect to their genotoxicity. Annatto concentrations of 0.2, 0.5 and 1.0 mg/ml and bixin concentrations of 0.05, 0.08 and 0.10 mg/ml were neither cytotoxic nor genotoxic to the PC12 cells. Thus, these concentrations were used in experiments to verify the protective effect of annatto and bixin against damage induced by cisplatin. Although the protective effect of annatto and bixin was not evident in the results obtained by the Comet assay, effective inhibition of the chromosomal damage (Micronucleus test) induced by cisplatin was shown. Annatto and bixin protected... (Complete abstract click electronic access below)
The neuropathy induced by chemotherapeutic drugs is a complication in the treatment of cancer and other diseases, because it is often painful and requires discontinuation of the therapy. Cisplatin has been commonly used against many forms of cancer for approximately 40 years. However, its application is associated with many toxic effects such as neurotoxicity, nephrotoxicity, hearing loss and vomiting. These adverse effects have led to the development of specific agents to lessen the toxicity of the drug. Some studies have suggested that the administration of antioxidants is able to reduce the damage and protect the tissues. Thus, the carotenoids are one more option to be evaluated, because they are considered to be effective antioxidants. Annatto is a natural source of red dyes and pigments and in addition to bixin (liposoluble fraction of the extract), other carotenoids are present in its seeds, such as norbixin, B-carotene, cryptoxanthin, lutein and zeaxanthin. In the present study, the genotoxicity and antigenotoxicity of annatto and bixin on the cisplatin induced-toxicity in PC12 cell cultures was assessed. Cytotoxicity was determined by the MTT assay, chromosomal damage by the Micronucleus test and the extent of primary damage to the DNA by the Comet assay. Annatto and bixin were first assessed with respect to their genotoxicity. Annatto concentrations of 0.2, 0.5 and 1.0 mg/ml and bixin concentrations of 0.05, 0.08 and 0.10 mg/ml were neither cytotoxic nor genotoxic to the PC12 cells. Thus, these concentrations were used in experiments to verify the protective effect of annatto and bixin against damage induced by cisplatin. Although the protective effect of annatto and bixin was not evident in the results obtained by the Comet assay, effective inhibition of the chromosomal damage (Micronucleus test) induced by cisplatin was shown. Annatto and bixin protected... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Cisplatina, Bioquímica, Toxicologia genética, Bixina, Urucum, Bixin, Cisplatin
Como citar
SANTOS, Graciela Cristina dos. Avaliação do efeito protetor do urucum e da bixina sobre a genotoxicidade induzida pelo antitumoral cisplatina em células da linhagem PC12. 2008. vii, 105 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Ciências Farmacêuticas, 2008.