Morphofunctional studies of cardiotoxicity induced by the pesticide chlorpyrifos

• Grant number: 23/04028-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2023
• End date: July 31, 2025
• Field of knowledge: Biological Sciences - Pharmacology - Toxicology
• Principal Investigator: Danilo Roman Campos
• Grantee: Aline Naomi Ito
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
• Associated research grant: 21/05584-7 - Assessment of acute and chronic toxicity of the heart and brain exposed to pesticides found in potable water in Brazil, AP.JP2

Abstract

The use of pesticides allows meeting the food demand of today's society, but some chemical residues can persist in the environment and reach non-target organisms, leading, for example, to cardiotoxicity. Additionally, pesticide residues are found in drinking water and food, a fact that favors the daily intake of these compounds by the population. Chlorpyrifos, a type of organophosphate, has its toxicity attributed mainly to the inhibition of the cholinesterase enzyme. Several studies have observed the toxicity of this pesticide related to the central and peripheral nervous system and the inhibition of red blood cell cholinesterase, but few are specific for the heart. In toxicology studies, an important parameter is the concentration at which no adverse effect is observed (No Observed Adverse Effect Level). For chlorpyrifos, in studies with oral administration in rats, the value of 0.1 mg/kg/day was established as the NOAEL, based on the red blood cell cholinesterase inhibition assay. It is known that cholinesterase is an enzyme also found in cardiac tissue, but it is not known whether in vivo exposure to the pesticide chlorpyrifos at a concentration of 0.1 mg/kg/day is capable of altering the electrical activity of the organ or making it more susceptible to arrhythmias. Therefore, we aimed to evaluate whether the morphology of the heart and the electrical activity of this organ in rats is altered during treatment for 28 days with 0.1 mg/kg/day of chlorpyrifos. The parameters to be evaluated will be: in vivo electrocardiogram and cardiac injury markers, measured by histological and biochemical techniques. At the end of our study, we will be able to state whether the current proposed NOAEL for chlorpyrifos also applies to cardiac tissue.