Exploring the influence of polystyrene-nanoplastics on two distinct in vitro systems in farm animals: A pilot study

The harmful effects of micro- and nanoplastics (MNPs) on the aquatic ecosystem are already well established, and several studies have demonstrated that MNPs can contaminate the soil. However, the impact of MNPs on farm animals, whose products are intended for human consumption, as well as the accumulation and translocation of these particles in their bodies, is less investigated and not well understood. To address this issue, we evaluated the cellular uptake and the effects of three different concentrations (5, 25, and 75 μg/mL) of 100 nm polystyrene nanoplastics (PS-NPs) on ovarian bovine granulosa cells (GCs) and porcine myoblasts derived from skeletal muscle satellite cells as in vitro primary cell culture models. The uptake of PS-NPs was shown for all the concentrations tested, both for GCs and for myoblasts. The results for GCs reported a significant decrease in cell viability (P < 0.05) for all concentrations of nanoplastics tested compared to the control. However, steroid hormone production and the mRNA expression of GC physiology marker genes were not affected. The results for myoblasts showed a significant decrease in the mean confluence (P < 0.05) after exposure to a concentration of 75 μg/mL of nanoplastics compared to the control. This may be indicative of an initial inhibition of muscle fibre formation. However, cell viability, proliferative capacity, and the mRNA expression of myogenesis-associated genes were not affected. As there is currently no standard method for assessing the quantity of particles that overcome the anatomical barriers and accumulate in various parts of the body, recognizing the implications of exposure to MNPs in farm animals can help us to better comprehend the potential risks to human health. This knowledge is critical for developing informed treatment and avoidance strategies, ensuring the safety of both the food we consume and the environment in which it is produced.