Effects of interaction between synthetic and natural organophosphates on Oreochromis niloticus (Teleostei: Cichlidae)

• Grant number: 21/14239-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): April 01, 2022
• Effective date (End): February 28, 2026
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Science
• Principal Investigator: Ernani Pinto Junior
• Grantee: Larissa Souza Passos
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 13/07914-8 - FoRC - Food Research Center, AP.CEPID

Abstract

Aquatic ecosystems have been increasingly degraded due to human activities worldwide. The proliferation of toxic cyanobacteria, caused by the intensification of the eutrophication process generally coincides with pollution by pesticides, mainly due to runoff and leaching. In this way, aquatic organisms are directly exposed concomitantly to different contaminants. Therefore, this study will aim to evaluate the toxicity of the cyanobacteria Sphaerospermopsis torques-reginae (strain ITEP-024), producer of a natural organophosphate (guanitoxin), associated with synthetic organophosphate pesticides in specimens of Oreochromis niloticus (Nile tilapia). The main hypothesis is that the association of these contaminants will cause synergistic effects in these animals with physiological, biochemical, genotoxic, and molecular damage. For that, we will verify the exposure of O. niloticus for 96 hours to malathion and trichlorfon insecticides and the ITEP-024 strain, in doses previously evaluated, individually; and together: ITEP-024 + malathion and ITEP-024 + trichlorfon. To detect the deleterious effects on fish, distinct biomarkers will be analyzed, involving genotoxic, neurotoxic, oxidative stress, and bioaccumulation parameters in tissues, in addition to the main metabolites involved (global metabolomics). The transcriptome of O. niloticus will also be analyzed, and the differentially expressed genes will be validated. By carrying out the proposed analyses, it is expected that important information will be obtained to understand the toxic potential of the interaction between cyanobacteria and pesticides in fish and also the risk for human consumption since this species is widely used in aquaculture.