Full text
| |
| Author(s): |
Juliana Mara Serpeloni
Total Authors: 1
|
| Document type: | Doctoral Thesis |
| Press: | Ribeirão Preto. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Ciências Farmacêuticas de Ribeirão Preto (PCARP/BC) |
| Defense date: | 2012-03-30 |
| Examining board members: |
Lusania Maria Greggi Antunes;
Ilce Mara de Syllos Colus;
Andréia Machado Leopoldino;
Fabio Vieira dos Santos
|
| Advisor: | Lusania Maria Greggi Antunes |
| Abstract | |
The natural pigments, in addition to providing color and beauty to the different organisms, play important biological role, including the vital functions of photosynthesis, cellular respiration and antioxidant action. Thus, this study investigated the genotoxic and protective potential of natural pigments, alone and in combination, chlorophyll b (CLb) and lutein (LT), in concentrations usually consumed in the diet. For this purpose, we used the micronucleus test in bone marrow and peripheral blood cells and the comet assay in peripheral blood, kidney and liver of mice. Biochemical parameters of oxidative stress were also evaluated, such as glutathione and thiobarbituric acid reactive substances in the kidney and liver and catalase and glutathione in peripheral blood in order to investigate the antioxidant properties of these pigments. The ability of lutein to alter the expression of genes involved in oxidative stress response and antioxidant defense was evaluated in liver tissue of mice using the technique of real-time PCR (RT-qPCR) array. To verify the protective activity of the pigments, cisplatin (cDDP) was used as an inducer of oxidative stress and DNA damage. Additionally, we assessed the genotoxic and antioxidant potential of LT in cell cultures of human hepatocellular carcinoma using the test of MTT [3 - (4,5-dimethyl-2-thiazolyl) -2,5-diphenyl-2H-tetrazolium], comet assay and assessment of biochemical parameters of oxidative stress, in order to make comparisons between results in vitro and in vivo, as well to propose mechanisms to antigenotoxic effects of LT. Our results showed that treatment with the pigments, both the LT and the CLb, alone or in combination, did not cause any DNA damage in the tests employed and offered protection against DNA damage induced by cDDP in both in vitro and in vivo. Antioxidant effects were observed for both pigments in peripheral blood, kidney and liver, and LT also improved the oxidative stress parameters measured in vitro. In the evaluation of the expression of genes involved in response to oxidative stress in liver cells of mice, cDDP decreased the expression of 16 genes, among them, important genes responsible for maintaining the redox status of the cell. Moreover, LT showed that it can act as an antioxidant not only acting directly in the scavenging of free radicals, but also by inducing the expression of 11 of the 84 genes evaluated and 15 when LT was associated to cDDP. In summary, our results showed that the LT and CLb, alone or in combination, at concentrations usually consumed in the diet can contribute to health promotion considering their antigenotoxic and antioxidant effects. (AU) | |
| FAPESP's process: | 08/06793-4 - Antigenotoxic activity of compounds in the diet and its effect in the expression of genes in response to oxidative stress |
| Grantee: | Juliana Mara Serpeloni |
| Support Opportunities: | Scholarships in Brazil - Doctorate |