Evaluation of oxidative stress in healthy horses undergoing ozone therapy by rectal insufflation at fixed doses

• Grant number: 21/09632-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2021
• End date: October 31, 2022
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
• Principal Investigator: Breno Fernando Martins de Almeida
• Grantee: Yasmin Cunha Duarte
• Host Institution: Centro Universitário Faculdades Integradas de Ourinhos. Fundação Educacional Miguel Mofarrej. Ourinhos , SP, Brazil

Abstract

Ozone therapy induces a controlled oxidative stress in the organism, which would induce an antioxidant response, improving systems such as the immune and circulatory, helping in infectious and inflammatory processes, according to previous reports. However, very little is known about how ozone therapy affects the oxidative stress parameters, especially in horses. This type of assessment is necessary to understand the pathophysiological mechanisms that ozone therapy causes in the body, an initial item for this therapy to be recommended as a safe and effective treatment. In this context, this project will aim to evaluate the oxidative stress parameters of healthy horses undergoing ozone therapy by rectal insufflation, in addition to the evaluation of clinical, hematological and biochemical parameters. For this purpose, 10 healthy adult mares will undergo 8 applications of ozone by rectal insufflation twice a week at a dose of 0.125 mg of ozone/kg, with sample collection for assessment of oxidative stress, blood count and biochemicals up to 10 weeks after the beginning of the therapy. Additionally, another 10 healthy horses will constitute the control group and will have blood samples taken at the same times as the treated group. Oxidative stress will be determined by total antioxidant capacity (TAC) by four methods: by reduction of ABTS cation (TAC-ABTS), reduction of ABTS cation associated with peroxidase (TAC-ABTS+HRP), iron reduction (TAC-FRAP) and cupric reduction (TAC-CUPRAC); in addition to the determination of total oxidizing capacity (TOC), lipid peroxidation by thiobarbituric acid reactive substances (TBARS) and uric acid and albumin antioxidants. Clinical hematological and biochemical analyzes will be performed in an automated veterinary cell counter and in a semi-automated photocolorimeter using a set of commercial reagents, respectively. The variables will be tested for normality and homoscedasticity and the differences between moments will be verified by ANOVA with repeated measures with Tukey's post-test or Friedmann with Dunn's post-test, while the differences between the groups at each moment will be verified by the unpaired t test or Mann-Whitney test, being considered significant when p<0.05. (AU)