Integrative Insights Into Pesticide Toxicity: Evidence From Gene Expression and Histopathology in Liver

Aquatic ecosystems are gradually being threatened by intensive agricultural practices, especially the extensive application of pesticides. Although pesticides such as organophosphates, carbamates, pyrethroids, phenylpyrazoles, and neonicotinoids are extensively used in agriculture for pest control, their entry into aquatic environments through runoff, leaching, and atmospheric deposition poses significant risks to nontarget organisms, including fish. This study provides a comprehensive understanding of pesticide-induced toxicity in fish, with particular emphasis on histopathological modifications and genetic alterations in the liver as critical biomarkers of cellular dysfunction, tissue injury, and toxicological responses. At the molecular level, the principal pathways affected included apoptosis (bcl2, caspase 3, 8, and 9), necroptosis (mlkl, ripk1, and ripk3), autophagy (atg and lc3), inflammation (cyp19a, nfκb, tnfα, and nox4), and DNA damage response pathways (atm, atr, tp53, and mdm2) indicating severe cellular stress, genomic instability, and tissue dysfunction induced by pesticide exposure. The major histopathological alterations observed in the liver included vacuolization, hemorrhage, vascular congestion, pyknotic nuclei, and inflammatory cell infiltration. This review highlights an integrated understanding of the association between hepatic histopathological manifestations and molecular responses in fish exposed to pesticides, providing insights into the mechanisms of hepatotoxicity and recognizing possible biomarkers for environmental monitoring and ecotoxicological risk assessment. These biomarkers play a crucial role in assessing the extent of aquatic contamination and understanding the implications of pesticide exposure on fish health, biodiversity, and ecosystem stability. Furthermore, this review underscores the urgent need for effective monitoring and mitigation strategies to safeguard aquatic life and maintain environmental integrity.