Evaluation of serum and tissue oxidative stress in bitches with malignant mammary neoplasia

• Grant number: 22/14408-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2023
• End date: December 31, 2023
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Pathology
• Principal Investigator: Breno Fernando Martins de Almeida
• Grantee: Beatriz Domingos
• Host Institution: Centro Universitário Faculdades Integradas de Ourinhos. Fundação Educacional Miguel Mofarrej. Ourinhos , SP, Brazil

Abstract

Breast cancer is one of the most common neoplasms in females, especially in dogs, and oxidative stress may be involved in the development of neoplasms. Oxidative stress is triggered by the reduction of antioxidants and increase of oxidants, which can generate damage to cellular constituents, such as DNA itself, favoring genetic alterations and mutations that stimulate cell proliferation. In addition, the provision of antioxidant substances when the neoplasm is already established seems to favor tumor progression. In this context, the present project aims to evaluate serum and tissue oxidative stress parameters in healthy bitches and bitches with malignant mammary neoplasia. For this, after histopathological evaluation of the breast tissue and staging, 10 healthy adult bitches will be selected for control and 10 adult bitches with malignant mammary neoplasia without comorbidities. Blood will be collected from these bitches for hematological, biochemical and oxidative stress evaluation and breast tissue fragments for histopathological evaluation and production of tissue homogenate to evaluate tissue oxidative stress. Oxidative stress will be determined by the total antioxidant capacity (TAC) by four methods: reduction of the ABTS cation (TAC-ABTS), reduction of the ABTS cation associated with peroxidase (TAC-ABTS+HRP), ferric (TAC-FRAP) and copper reduction (TAC-CUPRAC); in addition to the determination of the total oxidizing capacity (TOC), lipid peroxidation by thiobarbituric acid reactive substances (TBARS) and the antioxidants uric acid and albumin. Variables will be tested for normality (Shapiro-Wilk test) and differences between groups will be verified by unpaired t or Mann-Whitney tests. All statistical analyzes will be performed in a computer program (GraphPad Prism, v.6.00 for Windows, GraphPad Software, La Jolla, CA, USA, www.graphpad.com), being considered significant when p<0.05.