Analysis of the oxidative profile of synovial fluid samples from equines subjected to experimental synovitis and the effect of treatment with hyaluronic acid on oxidative stress

• Grant number: 24/20584-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2025
• End date: December 31, 2025
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
• Principal Investigator: Ana Liz Garcia Alves
• Grantee: Victória Ferreira Alexandre
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Synovial fluid is an important compound of synovial joints. It is a fluid with viscoelastic properties due to the high concentration of high-molecular-weight hyaluronic acid in its composition. The hyaluronic acid grants a damping and lubricating function to the joints, reducing friction between the cartilage surfaces. The inflammation of a joint component can involve the synovial membrane (synovitis), resulting in the release of inflammatory factors in the synovial fluid. It is reported an increase in oxidative stress when the inflammation starts, which accelerates the degradation process of hyaluronic acid and leads to a reduction in the viscoelasticity of the synovial fluid, consequently diminishing its lubricating function. Thus, the present project will evaluate the oxidative profile of synovial fluid in horses subjected to experimental synovitis and treated with hyaluronic acid. Sixteen animals were divided in two groups: eight of them in the control group and the remaining in the treated group. Synovial fluid was collected from the horses, stored in a freezer at -80°C, followed by the induction of synovitis. After twelve hours from the initial synovial fluid collection, intra-articular administration of Phosphate Buffered Saline (PBS) was conducted in one of the groups and 1% sodium hyaluronate in the other group. Synovial fluid from all animals were collected 12h, 24h, 48h, 168h, and 336h post-treatment. These samples will be analyzed using the TBARS method to assess of oxidative stress products. The results will undergo statistical analysis through normality test and the Shapiro-Wilk test, followed by an analysis of variance for the treatments with repeated measures over time, and Tukey's test for multiple comparisons of means at different time points.