Effects of capsaicin on fecal water genotoxicity and colonic apoptosis during initiation of rat colon carcinogenesis

• Grant number: 15/21667-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2016
• End date: January 31, 2017
• Field of knowledge: Health Sciences - Medicine - Pathological Anatomy and Clinical Pathology
• Principal Investigator: Luís Fernando Barbisan
• Grantee: Natália Elias Ferreira Pereira
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Capsaicin (8-methyl-N-vanillyl-(trans)-6-nonenamide), a lipophilic alkaloid compound exhibiting anti-bacterial, anti-inflammatory and anti-oxidant properties, is the major pungent ingredient found in red peppers. This project aims at evaluating whether fecal water derived from capsaicin-treated animals possess genotoxic activity on colon carcinogenesis induced by 1,2-dimethylhidrazine (DMH). Male Wistar rats will be randomly allocated into six groups (5 animals each). Over the first four weeks, animals will receive three intragastric doses of either capsaicin 5mg/kg (G2 and G4), 50 mg/kg (G3 and G5) or corn oil (capsaicin vehicle, G1 and G6), during four weeks. 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. All animals will receive drinking water and a basal chow ad libitum. At the end of week 4, animals from each group will be sacrificed. The colons (medial and distal) will be removed, fixed and processed for histopathological and immunohistochemistry (PARP-1) analyses. CaCO-2 cells harvested in DMEM high-glucose will be exposed with fecal water and evaluated for cell viability by Trypan blue exclusion assay. Genotoxicity testing will be conducted by the Single Cell Gel Electrophoresis (Comet) Assay. Data analysis will be performed using ANOVA or Kruskal-Wallis test.