|Support type:||Scholarships in Brazil - Master|
|Effective date (Start):||December 01, 2015|
|Effective date (End):||February 28, 2017|
|Field of knowledge:||Health Sciences - Medicine - Pathological Anatomy and Clinical Pathology|
|Principal Investigator:||Luís Fernando Barbisan|
|Grantee:||Brunno Felipe Ramos Caetano|
|Home Institution:||Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil|
Capsaicin (8-Methyl-N-vanillyl-(trans)-6-nonenamide), a lipophilic antibacterial, antiinflammatory and antioxidant alkaloid compound, is the major pungent ingredient in red peppers. This study aims at evaluating capsaicin potential chemopreventive effect during the initiation of colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH). Male Wistar rats will be randomly allocated into six groups (10-15 animals each). Over the first four weeks, a basal chow or basal chow containing 0.25% and 0.05% capsaicin will be given to groups 1 and 6, 2 and 4 and 3 and 5, respectively. By the end of week 2, all animals will receive four subcutaneous injections of either DMH (groups 1-3, 40mg/kg b.w) or EDTA (groups 4-6, DMH vehicle), twice a week. Thereafter, all animals will receive drinking water and a basal chow ad libitum. Peripheral blood samples will be collected by puncturing the retro-orbital plexus, 4 and 12 hours after the last DMH injection. Genotoxicity testing will be performed by the comet assay. Five animals from each group will be sacrificed 24 hours after the last DMH injection. Colon and liver tissue fragments will be collected and either stored at -80ºC for RNA extraction, or fixed in formaldehyde and stored in 70% ethanol for later. histopathological and immunohistochemical analyses. RNA samples will be analyzed by the TaqMan Low Density Array® (TLDA), which assesses 95 different genes involved in oxidative metabolism, pro- and antioxidant activity, cell proliferation, DNA damage, DNA repair and apoptosis. Ten animals from each group will be sacrificed at the end of week 22. Their colons (medial and distal) will be removed, fixed and stored in 70% ethanol. After fixation, colon specimens will be stained with 0.2% methylene blue for the stereoscopic detection of Aberrant Crypt Foci (ACF, incidence and multiplicity), and histopathological analysis. By the end of this study, we expect to have a better understanding of capsaicin modulation capability in DMH-induced colon carcinogenesis.