Interactive toxicity of non-/biodegradable NPs and butyl methoxydibenzoyl methane on intestinal health and metabolism of zebrafish

Biodegradable plastics have been widely used to reduce pollution from conventional plastics, but the harsh conditions of their degradation make them equally capable of generating nanoplastics (NPs) pollution and producing interactive ecotoxicity by coexisting with various pollutants. In this paper, the interactive toxicity of polystyrene (PS)-NPs and polylactic acid (PLA)-NPs with the typical Organic UV filters butyl methoxydibenzoyl methane (BM-DBM) on the intestinal health and metabolism of zebrafish (Danio rerio) was investigated at the tissue and molecular levels using wild AB zebrafish as a model organism. The results showed that both NPs and BM-DBM exposure alone or in combination induced different degrees of inflammatory symptoms in the zebrafish intestine, where PS and PS+B exposure groups also induced an imbalance of the zebrafish intestinal flora, causing a more severe intestinal inflammatory response than PLA and PLA+B. PS and PS+B also induced more metabolic pathways or differential metabolite alterations than PLA and PLA+B, respectively. The results of liver-related factor response showed that all exposure groups except PLA alone induced oxidative stress in liver tissue, and hepatic metabolic factors were also interfered with to varying degrees, with more severe organismal metabolic abnormalities induced in the PS and PS+B groups. The above reflected the liver friendliness of PLA, while highlighting the risk of hepatotoxicity of PS. Pearson correlation analysis proved that abnormal changes in metabolites such as lipids and lipid-like molecules due to changes in intestinal flora are most likely an important mechanism and cause of the abnormal response of intestinal and hepatic molecular indicators. We hope that our study will provide a basis for the ecological risk assessment of non-/biodegradable NPs and provide data support for the promotion of biodegradable plastics.