The damaging effects of polyethylene microplastics exposure on juvenile carp and the ameliorative role of Opuntia Milpa alta extract

Abstract

In recent years, the pollution of microplastics (MPs) in water ecosystems has gained much attention. Polyethylene microplastics (PE-MPs) are stable and can accumulate in organisms, causing harm to fish and other aquatic life. This study used juvenile carp to examine the toxic effects of PE-MPs and the potential benefits of Opuntia Milpa alta extract. We optimized fluorescence labeling to prepare 30 μm PE-MPs and analyzed their distribution in juvenile carp. The results showed that they mainly accumulate in the liver and intestines, with some in the kidneys and gills. A 45-d exposure study revealed that PE-MPs caused liver cell damage, inflammation, and increased liver function biomarkers (AST, ALT, ALP) (P < 0.05). There was also a decrease in gut microbiota diversity and an increase in harmful bacteria like Desulfovibrionaceae. The intervention with Opuntia Milpa alta extract (0.50%, 1.00%, 2.00% in feed) significantly reduced AST and ALT levels (P < 0.05), improved liver health, and restored gut microbiota diversity. Analysis of the extract showed it contains bioactive substances like polysaccharides (23.15%) and alkaloids (55.96%). These components likely enhance liver function and balance gut health by modulating the gut-liver connection. This study offers new insights into ecotoxicological measures for microplastic pollution and suggests that natural plant extracts can help protect environmental health.

In recent years, the pollution of microplastics (MPs) in water ecosystems has gained much attention. Polyethylene microplastics (PE-MPs) are stable and can accumulate in organisms, causing harm to fish and other aquatic life. This study used juvenile carp to examine the toxic effects of PE-MPs and the potential benefits of Opuntia Milpa alta extract. We optimized fluorescence labeling to prepare 30 μm PE-MPs and analyzed their distribution in juvenile carp. The results showed that they mainly accumulate in the liver and intestines, with some in the kidneys and gills. A 45-d exposure study revealed that PE-MPs caused liver cell damage, inflammation, and increased liver function biomarkers (AST, ALT, ALP) (P < 0.05). There was also a decrease in gut microbiota diversity and an increase in harmful bacteria like Desulfovibrionaceae. The intervention with Opuntia Milpa alta extract (0.50%, 1.00%, 2.00% in feed) significantly reduced AST and ALT levels (P < 0.05), improved liver health, and restored gut microbiota diversity. Analysis of the extract showed it contains bioactive substances like polysaccharides (23.15%) and alkaloids (55.96%). These components likely enhance liver function and balance gut health by modulating the gut-liver connection. This study offers new insights into ecotoxicological measures for microplastic pollution and suggests that natural plant extracts can help protect environmental health.

Graphical abstract

Keywords

Polyethylene microplastics / Juvenile carp / Damaging effects / Opuntia Milpa alta extract / Intervention mechanism

Highlight

	● PE-MPs accumulate in juvenile carp liver/intestines, causing hepatocyte damage.
	● OMAE reduces liver enzymes (AST/ALT) and mitigates histopathological injuries.
	● OMAE restores gut microbiota diversity, suppressing harmful bacteria.
	● Polysaccharides and alkaloids in OMAE modulate gut-liver axis for detoxification.

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