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| Author(s): |
Carolina Maciel Nogueira
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD) |
| Defense date: | 2010-09-29 |
| Examining board members: |
Aytan Miranda Sipahi;
Dulce Reis Guarita;
Wellington Monteiro Machado
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| Advisor: | Aytan Miranda Sipahi |
| Abstract | |
Introduction: Titanium dioxide (TiO2) is a white pigment widely found as micro and nano-sized particles added to food, drugs, cosmetics, etc. Studies involving the pulmonary tract warn about adverse effects resulting from exposure to TiO2, emphasizing its inflammatory potential. Although the gastrointestinal tract is considerably exposed to TiO2 particles at daily basis there are few information regarding its adverse effects on intestine. Objectives: We aimed to investigate the effects of TiO2 nanoparticles (NP) and microparticles (MP) on inflammatory response in the small intestine of mice. Methods: Bl 57/6 mice received suspensions containing TiO2 (100 mg/Kg/day) as TiO2 NP (66 nm), or TiO2 MP (260 nm) by gavage for 10 days, once a day; control group received only distilled water. At the end of the treatment, the small intestine were extracted for assessment of cytokines (IL-1b, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, IL-17, IL-23, TNFa, IFNg e TGFb) by ELISA and quantification of inflammatory cells (T CD4+, T CD8+, dendritic cells, and natural killer) by immunohistochemistry. Results: We found increased levels of T CD4+ cells and cytokines (IL-12, TNFa, IFNg, IL-4, IL-23, and TGFb) on groups receiving TiO2 when compared to control group. Cytokines production was more important on the ileum, local presenting greater concentration of M cells, which represent the main pathway of particles uptake on gut. Conclusion: Our findings indicate that TiO2 particles induce a Th1 mediated inflammatory response on small bowel in mice. These results represent an in vivo evidence of the inflammatory potential of TiO2 particles on the gastrointestinal tract (AU) | |