Enzymatic, morphological, and genotoxic effects of benzo[a]pyrene in rainbow trout (Oncorhynchus mykiss)

Abstract

Fish have defense systems that are capable of repairing damages caused by xenobiotics like benzo[a]pyrene (BaP), so the aims of this study were to identify BaP toxicity in melanomacrophages (MMs) cytoskeleton, evaluate the melanin area in MMs and analyze genotoxicity. Rainbow trout juveniles (n = 24) were split in 48h and 7d treatments that received 2 mg/kg of BaP. After the experiment, blood samples were collected and liver was removed, to proceed with the analysis: EROD activity, MMs melanin area quanti cation, melanosomes movements, and a genotoxicity test. The results revealed increased in EROD activity after 48h and 7d BaP exposure. The group 7d displayed a reduction in MMs pigmented area, melanosomes aggregation, in addition to an increased frequency of micronuclei. By means of the EROD assay, it was possible to con rm the activation of BaP biotransformation system. The impairment of the melanosomes' movements possibly by an inactivation of the protein responsible for the pigment dispersion consequently affects the melanin area and thus might negatively impact the MMs detoxi cation capacity. In addition to this cytotoxicity, the increased frequency of micronucleus might also indicate the genotoxicity of BaP in this important sh species.

Benzo[a]pyrene—Environmental Occurrence, Human Exposure, and Mechanisms of Toxicity

“…Genotoxicity of B[ a ]P in Rainbow Trout was assessed by Fanali et al [ 131 ]. Young Rainbow Trouts were tested after exposure to B[ a ]P at 2 mg/kg.…”

Integration of Genotoxic Biomarkers in Environmental Biomonitoring Analysis Using a Multi-Biomarker Approach in Three-Spined Stickleback (Gasterosteus aculeatus Linnaeus, 1758)

“…In addition, four phytosanitary substances (aclonifene, cypermethrine, chlorpyrifos, bifenox) were measured, which are classified as priorities by the WFD. Notably, some of these molecules are potentially genotoxic substances, according to the literature [ 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 ]. Courrières , with high fish mortality, seemed to be the most degraded.…”