Effects of Di-Isononyl Phthalate (DiNP) on Follicular Atresia in Zebrafish Ovary

Abstract

Di-isononyl phthalate (DiNP) is a plasticizer reported to elicit hormone-like activity and disrupt metabolism and reproduction in fish and other vertebrates. In general, phthalates have been used at high concentrations beyond reported environmental levels to assess their adverse effects on fish gonadal physiology. The present study exposed adult female zebrafish to a wide range of DiNP concentrations [0.42 µg L−1 (10−9 M), 4.2 µg L−1 (10−8 M), and 42 µg L−1 (10−7 M)] for 21 days. We evaluated gene expression profiles related to apoptosis, autophagy, and oxidative stress; DNA fragmentation (TUNEL assay: terminal deoxynucleotidyl transferase dUTP nick end labeling) and caspase activity (CAS3) were also examined. Exposure to 0.42 and 4.2 µg L−1 upregulated the genes coding for tnfa and baxa, sod1, prkaa1, respectively. CAS3 immunohistochemistry revealed a higher number of positive vitellogenic oocytes in ovaries exposed to 0.42 µg L−1. Subsequently, we examined the relationship between CAS3 signaling and DNA fragmentation. Accordingly, DNA fragmentation was observed in vitellogenic follicles of fish exposed to 0.42 and 4.2 μg L−1. Our results demonstrate that follicular atresia can occur after exposure to environmental levels of DiNP for 21 days, which may adversely affect the reproductive performance of female zebrafish in a non-monotonic manner.

Plastic additives in commercial fish of Aegean and Ionian Seas and potential hazard to human health

“…Higher concentrations of DINP in the GIT, in comparison to the other fish tissues examined, have also been cited for fish samples from the Tyrrhenian Sea (Squillante et al, 2023) and the Catania market (Salvaggio et al, 2019). Both DIDP and DINP presence has been found to impair the reproduction system and alter the behavioral patterns of the fish (e.g., Forner-Piquer et al, 2019;Poopal et al, 2020;Godoi et al, 2021), while unlike to DEHP that is monitored in the seawater due to legislative enforcement (EU, 2000), DIDP and DINP presence is only regulated for food contact materials (Hidalgo-Serrano et al, 2022). DBP was detected only in a part of the samples, specifically in M.barbatus from IOS and S.pilchardus, and B.boops from NAS, with the latter having the highest mean concentration.…”

Are New Phthalate Ester Substitutes Safer than Traditional DBP and DiBP? Comparative Endocrine-Disrupting Analyses on Zebrafish Using In Vivo, Transcriptome, and In Silico Approaches

“…The results showed that “benzoic acid-free” GTA and DINCH are two promising alternatives. Our results suggest that “benzoic acid-containing” PAEs, such as DBP, DiBP, DINP, and GTA, as well as their endocrine-disrupting effects, especially thyroid- and androgen/estrogen-disrupting activity, on human health warrant further investigation. − It should be noted that small chemical data sets with similar structural features may introduce potential biases, such as the “activity cliff” problem. − The toxicological fragment presented here offers a solution for the development of in silico methods for the endocrine-disrupting assessment of PAEs and new alternatives, although further validation is required. Furthermore, the range of critical hormones tested, such as more active androgens [5α-dihydrotestosterone (DHT) and 11-KT], thyroid hormones (T 4 ), and corticosterone, should be expanded in the future. ,, In the end, this study raises concerns about the safety of new alternatives and the current toxicological evaluation for endocrine disruption assessment.…”

High-Temperature Stress Induces Autophagy in Rainbow Trout Skeletal Muscle

“…Autophagy is triggered by various stimuli, including lack of nutrients, reactive oxygen species (ROS), endoplasmic reticulum stress, and the presence of microorganisms [35]. Although various reports in teleosts have investigated autophagy in processes such as reproduction [36][37][38], hepatic metabolism [13,39,40], and immune response to infections [41,42], there is limited evidence of the role of autophagy in skeletal muscle catabolism. Studies of fine flounder (Paralichthys adspersus) have shown that stress induced by high-density farming can upregulate the expression of genes involved in the autophagy process, which is believed to be protective mechanism against apoptosis regulated by the ubiquitin-proteasome pathway [43].…”