We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Effects of chronic exposure of naturally weathered microplastics on oxidative stress level, behaviour, and mitochondrial function of adult zebrafish (Danio rerio)
Summary
Researchers exposed adult zebrafish to naturally weathered microplastics for 21 days and assessed behavioral changes, oxidative stress, and mitochondrial function. The study found that weathered microplastics induced anxiety-like behavior, elevated oxidative stress markers, and disrupted mitochondrial function, suggesting that real-world weathered microplastics may pose different biological risks than pristine laboratory particles.
Microplastics (MPs) are a big and growing environmental concern, with studies showing sublethal to acute biological impacts on typical aquatic organisms. However, little is known about the biological effects of naturally weathered MPs, particularly focusing on mitochondria dysfunction as the key trigger of the biological effects. Therefore, in this study, naturally weathered MPs were produced from day-to-day life products, characterized, and chronically exposed (21 days) to adult zebrafish at the concentration of 0.1 and 1 mg/L. Locomotion and unconditioned anxiety-like behaviour was assessed. Mitochondrial respiration, membrane potential, mitochondrial complex activity and oxidative-related parameters were evaluated in the brain and liver. The results revealed the weathered MPs as a copolymer of propylene and ethylene that induced anxiety-like behaviour. There was an increase in brain catalase activity while the brain lactate dehydrogenase activity was inhibited after exposure to 1 mg/L. Brain glutathione levels were increased while their ratio was not affected. Mitochondrial respiratory chain complex Ⅱ and IV were also significantly decreased in the brain, although not compromising mitochondrial function. On the other hand, exposure to 1 mg/L caused a deficiency in liver mitochondrial respiration and decreased mitochondrial membrane potential, which were associated with the mitochondrial respiratory chain inhibition. An increase in hepatic superoxide dismutase and catalase activity was noticed, supporting the occurrence of ROS-induced ROS release as the potential trigger for the mitochondrial dysfunction. Overall, these findings highlight the potential indirect and cumulative environmental effects these particles may pose to aquatic ecosystems.
Sign in to start a discussion.
More Papers Like This
Toxic effects of naturally-aged microplastics on zebrafish juveniles: A more realistic approach to plastic pollution in freshwater ecosystems
Researchers exposed juvenile zebrafish to naturally aged polystyrene microplastics at environmentally relevant concentrations for five days. They found that the microplastics disrupted the fish's antioxidant defenses, indicating oxidative stress, and caused measurable cellular and neurological impacts. The study suggests that even short-term exposure to realistic levels of weathered microplastics can affect the health of freshwater organisms.
Photoaged microplastics induce neurotoxicity via oxidative stress and abnormal neurotransmission in zebrafish larvae (Danio rerio)
This study found that microplastics aged by sunlight were more toxic to zebrafish larvae than fresh microplastics, causing brain damage and abnormal behavior. The sun-aged particles triggered greater oxidative stress and disrupted neurotransmitter systems in the developing fish. This is concerning because most microplastics in the environment have been weathered by sunlight, meaning the real-world health risks may be greater than lab studies using fresh plastics suggest.
Impact of virgin and weathered microplastics on zebrafish: Bioaccumulation, developmental toxicity and molecular pathway disruptions
Researchers compared the effects of brand-new versus environmentally weathered microplastics on zebrafish larvae and found that weathered particles were far more toxic, causing 80% mortality compared to 20% for new plastics. The weathered microplastics triggered more severe disruptions to oxidative stress pathways, cell death signaling, and DNA repair mechanisms. The study emphasizes that laboratory tests using only pristine microplastics may significantly underestimate the real-world dangers of plastic pollution.
Toxicity evaluation of the combination of emerging pollutants with polyethylene microplastics in zebrafish: Perspective study of genotoxicity, mutagenicity, and redox unbalance
Researchers exposed adult zebrafish to polyethylene microplastics combined with a mixture of common water pollutants for 15 days and assessed DNA damage, mutation rates, and oxidative stress. They found that microplastics alone caused DNA damage and nuclear abnormalities as severe as those caused by the pollutant mixture, challenging the assumption that microplastics are less harmful than chemical contaminants. The study revealed that the fish's antioxidant defenses were overwhelmed across multiple organs, suggesting widespread oxidative damage from microplastic exposure.
Genotoxic and Oxidative Damage of Environmental Pollutant Microplastics on Zebrafish (Danio rerio)
Researchers exposed zebrafish to polystyrene and polyethylene microplastics at different concentrations for up to 21 days to measure oxidative stress and DNA damage. The study found that both types of microplastics disrupted the antioxidant system and caused measurable DNA damage, with effects depending on dosage and exposure time. These results suggest that microplastics in waterways could pose genetic and cellular risks to aquatic life.