0
Article ? AI-assigned paper type based on the abstract. Classification may not be perfect — flag errors using the feedback button. Tier 2 ? Original research — experimental, observational, or case-control study. Direct primary evidence. Environmental Sources Food & Water Gut & Microbiome Human Health Effects Marine & Wildlife Nanoplastics Sign in to save

Polystyrene Nanoplastics Induce Multi-Organ Toxicity in the Rainbow Trout (Oncorhynchus mykiss): An Integrated Assessment of Physiological, Immunological, and Molecular Responses

2025 Score: 48 ? 0–100 AI score estimating relevance to the microplastics field. Papers below 30 are filtered from public browse.
Melika Mirzaei Nashtoroudi, Mahboobeh Afrand, Kamran Rezaei Tavabe, Amirreza Abed‐Elmdoust, Gholamreza Rafiee, Hassan Rahimian

Summary

Rainbow trout were exposed to polystyrene nanoplastics at three concentrations for 28 days and assessed for physiological, immunological, and molecular responses across multiple organs. NPs accumulated in liver, spleen, and intestine, causing dose-dependent oxidative stress, immune dysregulation, and altered gene expression, demonstrating multi-organ toxicity in a commercially important fish species.

Abstract Plastics constitute a major category of waste in aquatic ecosystems, significantly exacerbating environmental pollution and endangering marine organisms. Examining plastic pollution in these ecosystems is essential for understanding its effects and formulating appropriate strategies for their protection. This study investigated the toxicity resulting from 28-days of exposure to different concentrations of polystyrene nanoplastics (PS-NPs; average size 73 nm; T1–0.1, T2–10, and T3–100 mg/kg of diet). After a 28-day exposure to PS-NPs, the growth performance, hematological and immunological indices, antioxidant parameters, plasma cortisol levels, tissue histopathology, and gene expression in Oncorhynchus mykiss liver and spleen were examined. Examining plastic pollution in aquatic ecosystems is essential for understanding its impact and formulating appropriate strategies to safeguard their health. Our findings indicate that PS-NPs significantly affected the physiology and histopathology of O. mykiss , with the severity of effects being dose-dependent. The survival rate of the fish decreased significantly, and most immuno-hematological parameters, as well as electrolyte levels (sodium and potassium), showed a marked decline compared to the control group; however, lymphocyte counts increased. The activity of the antioxidant enzyme SOD exhibited a decreasing trend, whereas ROS activity and the relative expression levels of HSP-70 and TNF-α (in both tissues), as well as SOD (in the liver), increased, and IL-10 (in both tissues) decreased with higher concentrations of PS-NPs. Moreover, blood glucose and cortisol levels exhibited significant dose-dependent reductions. Histopathological analysis indicated moderate to severe changes in the liver, spleen, and intestinal tissue of the group subjected to a dietary exposure of 100 mg/kg of PS-NPs. The findings demonstrate that PS-NPs negatively impacted the physiology, immune response, and gene expression in the rainbow trout. This indicates that particulate plastic pollution adversely affects aquatic organisms and may also threaten human health via the food chain and the chemical toxicity of these particles.

Sign in to start a discussion.

More Papers Like This

Article Tier 2

Sub-chronic nanoplastic toxicity in Etroplus suratensis (Pisces, Cichilidae): Insights into tissue accumulation, stress and metabolic disruption

Researchers exposed pearl spot fish to polystyrene nanoplastics at different concentrations for 14 days and found that the particles accumulated in multiple organs with concentration-dependent distribution patterns. The nanoplastics caused elevated glucose and cholesterol levels, suppressed antioxidant defenses, and increased markers of oxidative damage and stress. Gene expression changes in stress response and growth-related genes suggest that nanoplastic exposure may impair both immune function and normal development in fish.

Article Tier 2

Polystyrene microparticles can affect the health status of freshwater fish – Threat of oral microplastics intake

Researchers fed juvenile rainbow trout polystyrene microplastics at three dietary concentrations for six weeks and assessed multiple health parameters. They found that the highest concentration triggered immune responses, liver and gill damage, disrupted antioxidant balance, and reduced plasma proteins. The study demonstrates that oral microplastic intake can negatively affect the health of freshwater fish across multiple organ systems.

Article Tier 2

Ecotoxicological effects of polystyrene nanoplastics on common carp: Insights into blood parameters, DNA damage, and gene expression

Exposing common carp to polystyrene nanoplastics caused significant DNA damage in blood and brain cells, along with changes in genes related to immune function and stress response. Higher concentrations led to more severe effects, and the nanoplastics also disrupted liver antioxidant defenses. Since carp are widely consumed fish, these findings raise questions about the safety of fish from nanoplastic-contaminated waters for human consumption.

Article Tier 2

Polystyrene nanoplastics target lysosomes and affect lipid metabolism in RTgutGC and head kidney macrophages from Oncorhynchus mykiss

Researchers investigated the subcellular targets of polystyrene nanoplastics in rainbow trout intestinal cells and head kidney macrophages, finding that PS-NPs co-localized with lysosomes but not mitochondria and did not trigger reactive oxygen species production or alter oxidative metabolism. RNASeq analysis further revealed effects on lipid metabolism pathways, indicating that lysosomal targeting and lipid disruption are key mechanisms of nanoplastic toxicity in fish cells.

Article Tier 2

Bioaccumulation and homeostatic alterations in trout exposed to a sublethal dose of polystyrene nanoplastics

Researchers orally exposed rainbow trout to polystyrene nanoplastics and found the particles accumulated mainly in the gut and blood — not the liver — causing subtle immune and metabolic changes without visible tissue damage after 96 hours. These findings suggest nanoplastics selectively distribute in fish tissues and trigger mild biological responses even at sublethal doses.

Share this paper