Polystyrene Microplastics of Varying Sizes and Shapes Induce Distinct Redox and Mitochondrial Stress Responses in a Caco-2 Monolayer.

Currently, we lack crucial knowledge on how the physicochemical properties of particles affect cellular health, resulting in an important gap in our understanding of the human toxicity of microplastics (MPs). Our aim was to evaluate the impact of the size and the shape of MPs on uptake and the intracellular effects in a human epithelial colorectal adenocarcinoma (Caco-2) cell line. Spherical (200 nm and 2 µm) and fibre-/fragment-shaped (8.9 ± 10.1 µm by 1.14 ± 0.97 µm) polystyrene microplastics (PS-MPs) were used to study their uptake and the potential to induce redox and mitochondrial stress responses after 24 h of exposure. We demonstrated the cellular uptake of both spherical and fibre-/fragment-shaped MPs in a size-dependent manner. In response to 2 µm spheres, we observed differential expressions of redox-related genes, including HMOX1, CAT, and GPX1. All PS-MPs decreased the intracellular H2O2 levels, which can be attributed to mitochondrial stress responses, such as increased mitochondrial DNA content, footprint, and morphology. Altogether, we demonstrated uptakes and changes in redox and mitochondrial parameters for all PS-MPs, with the 200 nm spheres showing the most profound effects. This suggests that the induction of defensive responses in Caco-2 cells mainly correlates with the number of particles taken up.

Microplastics in coastal areas and seafood: implications for food safety.

Microplastics have become ubiquitous in the marine environment. Microplastics have been detected in many coastal environments and species, including commercial seafood. This triggers concern about potential economic impacts and the risks of dietary exposure, especially for coastal communities. However, data regarding the levels of microplastics in coastal seafood and their toxicological effects are still limited. Accordingly, the dietary risk is still poorly explored. This review summarizes and discusses recent scientific findings on (i) the presence of microplastics in coastal waters, (ii) the occurrence of microplastics in coastal seafood and the likelihood of trophic transfer, and (iii) the effects of microplastics on coastal fish and shellfish species. Human toxicity data are also reviewed, but the risks for human health are difficult to determine due to limited data. Based on available worldwide data, the estimation of microplastics intake through seafood consumption shows a huge variation. Additionally, a lack of standardized analytical methods complicates the comparison of results between studies and therefore seriously affects the reliability of risk assessments. It is concluded that more exposure and toxicity data are needed properly to assess human health risks of microplastics in coastal seafood, and the lack of data currently impede the derivation of a risk-based food safety standard. The pros and cons of an interim solution, i.e. setting a provisional action level, are being discussed.

Practices and health perception of preparation of Brassica vegetables: translating survey data to technological and nutritional implications.

Food preparation practices are known to have large nutritional implications on the final product. This article describes survey data on preparation practices of Brassica vegetables and the translation of these data into technological and nutritional implications using knowledge on the mechanisms of changes in the content of phytochemicals. The survey on preparation practices was performed with food service establishments (n = 123) and households (n = 477) in Semarang, Indonesia, and assessed the food handlers' perception of the health benefits of these vegetables. Boiling and stir-frying are the most frequently applied techniques to prepare Brassicas. The respondents perceive that steaming, boiling, and stir-frying result in vegetables with a high health benefit. White cabbage and choysum are the most frequently prepared Brassicas. However, broccoli is perceived as the healthiest. The consequences of the various applied preparation techniques on the content of alleged health promoting phytochemicals (glucosinolates) in dishes containing Brassica vegetables are discussed.