Effects of short-term exposure to environmentally relevant pesticides mixture on morphological alterations, oxidative-nitrative stress biomarkers, cellular apoptosis, and antioxidant expression in kidneys of goldfish

Abstract

Chemical stressors are pervasive, affecting both terrestrial and aquatic environments. The continual influx of these toxins is damaging ecosystems and the organisms that inhabit them. The abundance of environmental toxins makes aquatic habitats inhospitable for aquatic life. These chemical stressors consistently disrupt the life processes of aquatic organisms, particularly their physiological functions. This study examined on the effects of environmentally relevant pesticides mixture (low-dose and high-dose: S-metolachlor: 2.4 go/L, 12 μg/L; linuron: 2.0 μg/L, 10 μg/L; isoproturon: 1.2 μg/L, 6.0 μg/L; tebucanozole: 1.2 μg/L, 6.0 μg/L; aclonifen: 0.8 μg/L, 4.0 μg/L; atrazine: 0.4 μg/L, 2.0 μg/L; pendimethalin: 0.4 μg/L, 2.0 μg/L, and azinphos-methyl: 0.8 μg/L, 4.0 μg/L) on tissue morphology, cellular apoptosis, and nitrotyrosine protein (NTP), dinitrophenyl protein (DNP), renin, superoxide dismutase (SOD), and catalase (CAT) expression in the kidneys of goldfish (Carassius auratus) exposed for one week under controlled laboratory conditions. Histopathological analysis revealed severe tissue damage in the kidneys, while silver staining identified melano-macrophage centers, and immunohistochemistry and real-time PCR shed light on the expression of molecular biomarkers in these tissues. Exposure to pesticide mixtures caused fish to exhibit glomerular shrinkage, enlargement of Bowman's space, and degradation of glomerular cells. Moreover, the expression of renin, DNP, NTP, SOD, and apoptotic nuclei increased in kidney tissues, while CAT expression decreased. Overall, our findings indicate that exposure of goldfish to an environmentally relevant pesticide mixture leads to increased cellular damage and altered osmoregulatory and antioxidant enzyme expressions, which may impair physiological functions, including growth, reproduction, and development in teleost fish.