Influence of polyunsaturated fatty acids on the modulation of innate immune and antioxidant system of Astyanax lacustris males exposed to the anti-inflammatory diclofenac

• Grant number: 25/06655-6
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: December 01, 2025
• End date: December 31, 2028
• Field of knowledge: Biological Sciences - Physiology - General Physiology
• Principal Investigator: Renata Guimarães Moreira Whitton
• Grantee: Jennifer Lima de Oliveira
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 24/13478-0 - Faunal responses to anthropogenic environmental changes: contributions of conservation physiology, AP.TEM

Abstract

The rapid population and industrial growth in Brazil has led to serious negative impacts on water bodies, such as the increase of toxic substances and excess of nutrients, factors that contribute to eutrophication and water degradation. These processes can alter the availability of fatty acids (FAs), especially essential ones, which must be obtained through diet and play a crucial role in the physiology of aquatic organisms, including teleosts. Additionally, pharmaceuticals such as the anti-inflammatory diclofenac (DCF) have been frequently detected in surface waters around the world and may physiologically affect fish. In omnivorous teleosts with variable feeding patterns depending on their trophic level, such as Astyanax lacustris, these changes in water quality are even more concerning. Given this issue, the present study aims to understand how multiple environmental stressors, such as different nutritional scenarios (NSs) and the presence of DCF, affect the immune and antioxidant systems of male A. lacustris. The study will be divided into three phases: 1) Incorporation: The fish will be fed diets containing different FA profiles for 4 weeks. The incorporation of FAs from the NSs into their tissues will be assessed, as well as whether these FAs influence immune and antioxidant biomarkers; 2) Pharmaceutical exposure: After confirming the incorporation of dietary FAs, the fish will be exposed to DCF for 7 days to evaluate the combined impact of FAs and the drug on the FA profile in tissues, as well as on immune and antioxidant systems; 3) Immune challenge: The fish will undergo an immune challenge, and the response of their immune and antioxidant systems will be evaluated following bacterial stimulation.