Avaliação da capacidade antioxidante in vitro e in vivo contra radicais peroxila e hidroxila em amostras de plantas medicinais
Ano de defesa: | 2010 |
---|---|
Autor(a) principal: | |
Orientador(a): | |
Banca de defesa: | , , |
Tipo de documento: | Tese |
Tipo de acesso: | Acesso aberto |
Idioma: | por |
Instituição de defesa: |
Universidade Federal de Santa Maria
|
Programa de Pós-Graduação: |
Programa de Pós-Graduação em Química
|
Departamento: |
Química
|
País: |
BR
|
Palavras-chave em Português: | |
Palavras-chave em Inglês: | |
Área do conhecimento CNPq: | |
Link de acesso: | http://repositorio.ufsm.br/handle/1/4191 |
Resumo: | The present work reports the development of new methodologies to evaluate the in vitro and in vivo antioxidant capacity against peroxyl and hydroxyl radicals in five medicinal plant samples (Matricaria chamomilla L., Psidium guajava, Achyrocline satureoides, Baccharis genistelloides and Cymbopogon citratus) and seven phenolic compounds (rutin, quercetin, resveratrol, gallic acid, ferulic acid, caffeic acid and rosmarinic acid). The antioxidant capacity of the samples was analyzed by two independent methods. In the first one, a new approach was used to detect hydroxyl radicals indirectly using an electrochemical procedure, in which the radicals destroy a thiol self-assembled monolayer (SAM) on a gold electrode. This monolayer can block the electrochemical signal of a dissolved redox probe. When such an electrode with a SAM is exposed to free radicals, these radicals destroy the SAM and the electrochemical signal of a redox probe recovers to a degree proportional to the extent of dissolution of the SAM. In the second method, the evaluation of antioxidant capacity against peroxyl and hydroxyl radicals is based on the indirect detection of these reactive oxygen species (ROS) by fluorimetry (ex/em: 485/520 nm) employing 2 -7 -dichlorofluorescin diacetate (DCFH-DA) as a fluorescent probe. After the deacetilation reaction of DCFH-DA, it can be oxidized by ROS to the fluorescent compound DCF. The peroxyl radicals were produced at 37ºC by thermal decomposition of 2,2 -azobis (2 methylpropianamidine) dihydrochloride (ABAP), while hydroxyl radicals were generated by the Fenton reaction. In vivo assays were evaluated using zebrafish (Danio rerio) hepatocytes exposed to P. guajava and C. citratus extracts (better and worst in vitro results, respectively). The results obtained by the electrochemical and fluorimetric methods show that it is difficult to classify the tested plants according to their antioxidant capacity, since the results depended strongly on the extract concentration and composition as well as on the principle of the analytical method. However, there was a good correlation between the in vitro and in vivo assays for P. guajava and C. citratus extracts, since these results showed a reduction in the intracellular ROS concentration in the hepatocytes exposed to P. guajava extract. Furthermore, no antioxidant effect was observed in the assay with C. citrates extract, what is in agreement with the in vitro assays for this plant species. At last, the thesis intended to proof and to highlight the discrepant results obtained by independent methods for the same antioxidant species. Additionally, it aimed to compare the different methods according to the differences among the experimental procedures by using different ROS. Furthermore, the stability, reactivity and the half-life time of the free radicals are discussed. |
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2017-05-192017-05-192010-07-26HILGEMANN, Maurício. Evaluation of the in vitro and in vivo antioxidant capacity against peroxyl and hydroxyl radicals in medicinal plant samples. 2010. 146 f. Tese (Doutorado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2010.http://repositorio.ufsm.br/handle/1/4191The present work reports the development of new methodologies to evaluate the in vitro and in vivo antioxidant capacity against peroxyl and hydroxyl radicals in five medicinal plant samples (Matricaria chamomilla L., Psidium guajava, Achyrocline satureoides, Baccharis genistelloides and Cymbopogon citratus) and seven phenolic compounds (rutin, quercetin, resveratrol, gallic acid, ferulic acid, caffeic acid and rosmarinic acid). The antioxidant capacity of the samples was analyzed by two independent methods. In the first one, a new approach was used to detect hydroxyl radicals indirectly using an electrochemical procedure, in which the radicals destroy a thiol self-assembled monolayer (SAM) on a gold electrode. This monolayer can block the electrochemical signal of a dissolved redox probe. When such an electrode with a SAM is exposed to free radicals, these radicals destroy the SAM and the electrochemical signal of a redox probe recovers to a degree proportional to the extent of dissolution of the SAM. In the second method, the evaluation of antioxidant capacity against peroxyl and hydroxyl radicals is based on the indirect detection of these reactive oxygen species (ROS) by fluorimetry (ex/em: 485/520 nm) employing 2 -7 -dichlorofluorescin diacetate (DCFH-DA) as a fluorescent probe. After the deacetilation reaction of DCFH-DA, it can be oxidized by ROS to the fluorescent compound DCF. The peroxyl radicals were produced at 37ºC by thermal decomposition of 2,2 -azobis (2 methylpropianamidine) dihydrochloride (ABAP), while hydroxyl radicals were generated by the Fenton reaction. In vivo assays were evaluated using zebrafish (Danio rerio) hepatocytes exposed to P. guajava and C. citratus extracts (better and worst in vitro results, respectively). The results obtained by the electrochemical and fluorimetric methods show that it is difficult to classify the tested plants according to their antioxidant capacity, since the results depended strongly on the extract concentration and composition as well as on the principle of the analytical method. However, there was a good correlation between the in vitro and in vivo assays for P. guajava and C. citratus extracts, since these results showed a reduction in the intracellular ROS concentration in the hepatocytes exposed to P. guajava extract. Furthermore, no antioxidant effect was observed in the assay with C. citrates extract, what is in agreement with the in vitro assays for this plant species. At last, the thesis intended to proof and to highlight the discrepant results obtained by independent methods for the same antioxidant species. Additionally, it aimed to compare the different methods according to the differences among the experimental procedures by using different ROS. Furthermore, the stability, reactivity and the half-life time of the free radicals are discussed.O presente trabalho visa ao desenvolvimento de novas metodologias para a determinação da capacidade antioxidante in vitro e in vivo contra radicais peroxila e hidroxila em amostras de 5 plantas medicinais (Matricaria chamomilla L., Psidium guajava, Achyrocline satureoides, Baccharis genistelloides e Cymbopogon citratus) e sete compostos fenólicos (rutina, quercetina, resveratrol, ácido cafeico, ácido ferúlico, ácido gálico e ácido rosmarínico). A capacidade antioxidante das amostras foi determinada por dois métodos independentes. No primeiro, testou-se uma nova forma para a detecção de radicais hidroxila, usando-se um procedimento eletroquímico no qual os radicais destroem uma monocamada auto-organizada de hexanotiol sob um eletrodo de ouro. Esta monocamada consegue inibir o sinal eletroquímico de um par redox dissolvido, e, ao ser atacada por radicais livres, estes a destroem, e a recuperação do sinal eletroquímico do par redox se dá de forma proporcional à extensão de dissolução da monocamada. No segundo método, a determinação da capacidade antioxidante contra radicais peroxila e hidroxila ocorre através da detecção indireta destes radicais por fluorimetria (ex/em: 485/520 nm), empregando diacetato de 2 ,7 -diclorofluoresceína (DCFH-DA) como substrato. O DCFH-DA, após sofrer desacetilação, pode ser oxidado por espécies reativas de oxigênio (ERO), gerando fluorescência. Os radicais peroxila foram gerados através da termodegradação do reagente cloreto de 2,2 -azobis (2-metilamidinopropano) (ABAP) a 37ºC, enquanto os radicais hidroxila foram gerados pela reação de Fenton. Ensaios in vivo foram avaliados utilizando-se hepatócitos do peixe zebra (Danio rerio), expostos aos extratos das plantas P. guajava e C. citratus (melhor e pior desempenho in vitro, respectivamente). Os resultados obtidos pelos métodos eletroquímico e fluorimétrico demonstram que é extremamente difícil classificar as plantas de acordo com sua capacidade antioxidante, uma vez que o resultado obtido depende fortemente da concentração e da composição química dos extratos, além do princípio do método analítico empregado. Entretanto, obteve-se uma boa correlação entre os ensaios in vitro e in vivo feitos para os extratos das plantas P. guajava e C. citratus, já que os resultados obtidos mostraram uma redução da concentração de ERO intracelular em forma dose-dependete nos hepatócitos expostos a P. guajava, sem se observar efeito antioxidante no ensaio com C. citratus, a exemplo dos ensaios in vitro realizados. O presente trabalho pretende chamar a atenção para esses diferentes resultados obtidos, e compara os diferentes métodos levando em consideração as diferenças existentes entre as metodologias, assim como as diferenças existentes entre os radicais testados. Além disso, discute-se a estabilidade, a reatividade e tempo de meia-vida destas espécies.Conselho Nacional de Desenvolvimento Científico e Tecnológicoapplication/pdfporUniversidade Federal de Santa MariaPrograma de Pós-Graduação em QuímicaUFSMBRQuímicaCapacidade antioxidanteExtratos de plantas medicinaisCompostos fenólicosTestes in vitro × testes in vivoMétodos eletroquímicos e fluorimétricosAntioxidant capacityPlant extractsPhenolic compoundsElectrochemical and fluorimetric methodsIn vitro × in vivo assaysCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICAAvaliação da capacidade antioxidante in vitro e in vivo contra radicais peroxila e hidroxila em amostras de plantas medicinaisEvaluation of the in vitro and in vivo antioxidant capacity against peroxyl and hydroxyl radicals in medicinal plant samplesinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisCarvalho, Leandro Machado dehttp://lattes.cnpq.br/6652387343920028Monserrat, José Maríahttp://lattes.cnpq.br/8106459529828166Garcia, Solange Cristinahttp://lattes.cnpq.br/6687355709603379Rosa, Marcelo Barcellos dahttp://lattes.cnpq.br/0308293154958870http://lattes.cnpq.br/1360145554855167Hilgemann, Maurício1006000000004003003003003003009da44f2c-6556-4846-9d66-386f290b802f066b45cb-46bf-4d5b-9005-5ed79998e892b5472080-62c6-4a3d-95a4-32cdf82b1007e30bd757-0c42-4a80-93ef-ae76f1cd7d706b7df45a-693c-426f-849a-d3d7a08bd80finfo:eu-repo/semantics/openAccessreponame:Manancial - Repositório Digital da UFSMinstname:Universidade Federal de Santa Maria (UFSM)instacron:UFSMORIGINALHILGEMANN, MAURICIO.pdfapplication/pdf1262884http://repositorio.ufsm.br/bitstream/1/4191/1/HILGEMANN%2c%20MAURICIO.pdfb44dbf632d0dc14501bf37f79b8d9623MD51TEXTHILGEMANN, MAURICIO.pdf.txtHILGEMANN, MAURICIO.pdf.txtExtracted texttext/plain240937http://repositorio.ufsm.br/bitstream/1/4191/2/HILGEMANN%2c%20MAURICIO.pdf.txt481723e7ea4d96e28ee1bd9d1ca859bdMD52THUMBNAILHILGEMANN, MAURICIO.pdf.jpgHILGEMANN, MAURICIO.pdf.jpgIM Thumbnailimage/jpeg5213http://repositorio.ufsm.br/bitstream/1/4191/3/HILGEMANN%2c%20MAURICIO.pdf.jpg90505e1fe29b76b42ad0095a7a04e519MD531/41912022-06-01 11:33:59.002oai:repositorio.ufsm.br:1/4191Repositório Institucionalhttp://repositorio.ufsm.br/PUBhttp://repositorio.ufsm.br/oai/requestopendoar:39132022-06-01T14:33:59Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM)false |
dc.title.por.fl_str_mv |
Avaliação da capacidade antioxidante in vitro e in vivo contra radicais peroxila e hidroxila em amostras de plantas medicinais |
dc.title.alternative.eng.fl_str_mv |
Evaluation of the in vitro and in vivo antioxidant capacity against peroxyl and hydroxyl radicals in medicinal plant samples |
title |
Avaliação da capacidade antioxidante in vitro e in vivo contra radicais peroxila e hidroxila em amostras de plantas medicinais |
spellingShingle |
Avaliação da capacidade antioxidante in vitro e in vivo contra radicais peroxila e hidroxila em amostras de plantas medicinais Hilgemann, Maurício Capacidade antioxidante Extratos de plantas medicinais Compostos fenólicos Testes in vitro × testes in vivo Métodos eletroquímicos e fluorimétricos Antioxidant capacity Plant extracts Phenolic compounds Electrochemical and fluorimetric methods In vitro × in vivo assays CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
title_short |
Avaliação da capacidade antioxidante in vitro e in vivo contra radicais peroxila e hidroxila em amostras de plantas medicinais |
title_full |
Avaliação da capacidade antioxidante in vitro e in vivo contra radicais peroxila e hidroxila em amostras de plantas medicinais |
title_fullStr |
Avaliação da capacidade antioxidante in vitro e in vivo contra radicais peroxila e hidroxila em amostras de plantas medicinais |
title_full_unstemmed |
Avaliação da capacidade antioxidante in vitro e in vivo contra radicais peroxila e hidroxila em amostras de plantas medicinais |
title_sort |
Avaliação da capacidade antioxidante in vitro e in vivo contra radicais peroxila e hidroxila em amostras de plantas medicinais |
author |
Hilgemann, Maurício |
author_facet |
Hilgemann, Maurício |
author_role |
author |
dc.contributor.advisor1.fl_str_mv |
Carvalho, Leandro Machado de |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/6652387343920028 |
dc.contributor.referee1.fl_str_mv |
Monserrat, José María |
dc.contributor.referee1Lattes.fl_str_mv |
http://lattes.cnpq.br/8106459529828166 |
dc.contributor.referee2.fl_str_mv |
Garcia, Solange Cristina |
dc.contributor.referee2Lattes.fl_str_mv |
http://lattes.cnpq.br/6687355709603379 |
dc.contributor.referee3.fl_str_mv |
Rosa, Marcelo Barcellos da |
dc.contributor.referee3Lattes.fl_str_mv |
http://lattes.cnpq.br/0308293154958870 |
dc.contributor.authorLattes.fl_str_mv |
http://lattes.cnpq.br/1360145554855167 |
dc.contributor.author.fl_str_mv |
Hilgemann, Maurício |
contributor_str_mv |
Carvalho, Leandro Machado de Monserrat, José María Garcia, Solange Cristina Rosa, Marcelo Barcellos da |
dc.subject.por.fl_str_mv |
Capacidade antioxidante Extratos de plantas medicinais Compostos fenólicos Testes in vitro × testes in vivo Métodos eletroquímicos e fluorimétricos |
topic |
Capacidade antioxidante Extratos de plantas medicinais Compostos fenólicos Testes in vitro × testes in vivo Métodos eletroquímicos e fluorimétricos Antioxidant capacity Plant extracts Phenolic compounds Electrochemical and fluorimetric methods In vitro × in vivo assays CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
dc.subject.eng.fl_str_mv |
Antioxidant capacity Plant extracts Phenolic compounds Electrochemical and fluorimetric methods In vitro × in vivo assays |
dc.subject.cnpq.fl_str_mv |
CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
description |
The present work reports the development of new methodologies to evaluate the in vitro and in vivo antioxidant capacity against peroxyl and hydroxyl radicals in five medicinal plant samples (Matricaria chamomilla L., Psidium guajava, Achyrocline satureoides, Baccharis genistelloides and Cymbopogon citratus) and seven phenolic compounds (rutin, quercetin, resveratrol, gallic acid, ferulic acid, caffeic acid and rosmarinic acid). The antioxidant capacity of the samples was analyzed by two independent methods. In the first one, a new approach was used to detect hydroxyl radicals indirectly using an electrochemical procedure, in which the radicals destroy a thiol self-assembled monolayer (SAM) on a gold electrode. This monolayer can block the electrochemical signal of a dissolved redox probe. When such an electrode with a SAM is exposed to free radicals, these radicals destroy the SAM and the electrochemical signal of a redox probe recovers to a degree proportional to the extent of dissolution of the SAM. In the second method, the evaluation of antioxidant capacity against peroxyl and hydroxyl radicals is based on the indirect detection of these reactive oxygen species (ROS) by fluorimetry (ex/em: 485/520 nm) employing 2 -7 -dichlorofluorescin diacetate (DCFH-DA) as a fluorescent probe. After the deacetilation reaction of DCFH-DA, it can be oxidized by ROS to the fluorescent compound DCF. The peroxyl radicals were produced at 37ºC by thermal decomposition of 2,2 -azobis (2 methylpropianamidine) dihydrochloride (ABAP), while hydroxyl radicals were generated by the Fenton reaction. In vivo assays were evaluated using zebrafish (Danio rerio) hepatocytes exposed to P. guajava and C. citratus extracts (better and worst in vitro results, respectively). The results obtained by the electrochemical and fluorimetric methods show that it is difficult to classify the tested plants according to their antioxidant capacity, since the results depended strongly on the extract concentration and composition as well as on the principle of the analytical method. However, there was a good correlation between the in vitro and in vivo assays for P. guajava and C. citratus extracts, since these results showed a reduction in the intracellular ROS concentration in the hepatocytes exposed to P. guajava extract. Furthermore, no antioxidant effect was observed in the assay with C. citrates extract, what is in agreement with the in vitro assays for this plant species. At last, the thesis intended to proof and to highlight the discrepant results obtained by independent methods for the same antioxidant species. Additionally, it aimed to compare the different methods according to the differences among the experimental procedures by using different ROS. Furthermore, the stability, reactivity and the half-life time of the free radicals are discussed. |
publishDate |
2010 |
dc.date.issued.fl_str_mv |
2010-07-26 |
dc.date.accessioned.fl_str_mv |
2017-05-19 |
dc.date.available.fl_str_mv |
2017-05-19 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
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doctoralThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
HILGEMANN, Maurício. Evaluation of the in vitro and in vivo antioxidant capacity against peroxyl and hydroxyl radicals in medicinal plant samples. 2010. 146 f. Tese (Doutorado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2010. |
dc.identifier.uri.fl_str_mv |
http://repositorio.ufsm.br/handle/1/4191 |
identifier_str_mv |
HILGEMANN, Maurício. Evaluation of the in vitro and in vivo antioxidant capacity against peroxyl and hydroxyl radicals in medicinal plant samples. 2010. 146 f. Tese (Doutorado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2010. |
url |
http://repositorio.ufsm.br/handle/1/4191 |
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Química |
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Universidade Federal de Santa Maria |
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