Ação antioxidante in vitro e in vivo da Camellia sinensis nas formas de chá verde, chá preto e chá branco

• Ano de defesa: 2011
• Autor(a) principal: Guimarães, Raquel Diegues
• Orientador(a): Cardoso, Maria das Graças
• Banca de defesa: Sbampato, Cristiane Gattini, Sousa, Raimundo Vicente de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: UNIVERSIDADE FEDERAL DE LAVRAS
• Programa de Pós-Graduação: DCA - Programa de Pós-graduação
• País: BRASIL
• Palavras-chave em Português: Edulcorantes; Infusões; Antioxidante; Lipoperoxidação
• Área do conhecimento CNPq: CNPQ_NÃO_INFORMADO
• Link de acesso: https://repositorio.ufla.br/handle/1/4598

This study aims to evaluate the antioxidant activity of Camellia sinensis in vivo and in vitro, drawing a comparison between three ways of processing plant: white (CB), green (CV) and black tea (CP). The teas were prepared for testing using the methodology of preparation of infusions. For in vitro tests, it was used the free radical scavenger method - DPPH and -carotene / linoleic acid system (BCAL) to three teas, pure or added of white (AB) and brown sugar (AM), and sweeteners stevia (ST) and saccharin / cyclamate (Sac / Cicl). The in vivo tests were conducted to evaluate the tea action, without added sweeteners. To do so, was induced liver injury in Wistar rats by administration of carbon tetrachloride intraperitoneally. The animals were treated with teas, by gavage for seven days, and after this period, the extent of injury was measured by assessing lipid peroxidation in the livers, and biochemical parameters, such as determination of serum glucose, GGT, AST and ALT. Histopathological evaluation of the livers was also performed. All in vitro tests showed the three teas important action, and the ability of radical scavenging activity following the order: CP = CB > CV. With the exception of stevia, a sweetened reduced the antioxidant action of the three teas, and the most significant reduction was observed when brown sugar was added. In the evaluation of antioxidant activity by the system BCAL, the ability to stabilize the system followed the order: CB> CP> CV. The CB was the only one of the teas that of AA decreased with added sweeteners. The CV had its high action with added sweeteners, except the brown sugar, which reduced this action. Black tea had increased activity with the addiction of the sweetener Sac / Cicl, and other sweeteners did not cause any changes. On in vivo assays, the three teas were able to inhibit lipid peroxidation (p<0.05) when compared to the control group. This hepatoprotective effect was confirmed by the results obtained through the measurement of liver enzymes in blood and histopathological examinations of the livers of animals. Thus, the teas from the Camellia sinensis showed significant antioxidant and hepatoprotective effect.