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.

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.

References

[1] Abdullah A , Ramli R , Ridzuan M S M , Murni M , Hashim S , Sudirwan F , Abdullah S Z , Mansor N N , Amira S , Saad M Z . et al. (2017). The presence of Vibrionaceae, Betanodavirus and Iridovirus in marine cage-cultured fish: role of fish size, water physicochemical parameters and relationships among the pathogens. Aquaculture Reports, 7: 57–65

[2] Aruwa C E , Amoo S O , Kudanga T . (2018). Opuntia (Cactaceae) plant compounds, biological activities and prospects: a comprehensive review. Food Research International, 112: 328–344

[3] Barnes D K A , Galgani F , Thompson R C , Barlaz M . (2009). Accumulation and fragmentation of plastic debris in global environments. Philosophical Transactions of the Royal Society B: Biological Sciences, 364(1526): 1985–1998

[4] Bojarski B , Witeska M , Kondera E . (2025). Blood biochemical biomarkers in fish toxicology-a review. Animals, 15(7): 965

[5] Božić G , Rašković B , Stanković M , Poleksić V , Marković Z . (2021). Effects of different feeds on growth performance parameters, histology of liver, distal intestine, and erythrocytes morphology of common carp (Cyprinus carpio L.). Biologia, 76(12): 3769–3779

[6] Cámara-Ruiz M , Cerezo I M , Guardiola F A , García-Beltrán J M , Balebona M C , Moriñigo M Á , Esteban M Á . (2021). Alteration of the immune response and the microbiota of the skin during a natural infection by Vibrio harveyi in European seabass (Dicentrarchus labrax). Microorganisms, 9(5): 964

[7] Cao J W , Xu R , Wang F H , Geng Y , Xu T C , Zhu M R , Lv H L , Xu S W , Guo M Y . (2023). Polyethylene microplastics trigger cell apoptosis and inflammation via inducing oxidative stress and activation of the NLRP3 inflammasome in carp gills. Fish & Shellfish Immunology, 132: 108470

[8] Chang Y T , Huang W T , Wu P L , Kumar R , Wang H C , Lu H P . (2024). Low salinity stress increases the risk of Vibrio parahaemolyticus infection and gut microbiota dysbiosis in Pacific white shrimp. BMC Microbiology, 24(1): 275

[9] Chen J J , Rao C Y , Yuan R J , Sun D D , Guo S Q , Li L L , Yang S , Qian D D , Lu R H , Cao X L . (2022). Long-term exposure to polyethylene microplastics and glyphosate interferes with the behavior, intestinal microbial homeostasis, and metabolites of the common carp (Cyprinus carpio L.). Science of the Total Environment, 814: 152681

[10] Cui J , Zhang Y H , Liu L , Zhang Q R , Xu S W , Guo M Y . (2023). Polystyrene microplastics induced inflammation with activating the TLR2 signal by excessive accumulation of ROS in hepatopancreas of carp (Cyprinus carpio). Ecotoxicology and Environmental Safety, 251: 114539

[11] Dai Y H , Zhao J , Sun C X , Li D Y , Liu X , Wang Z Y , Yue T T , Xing B S . (2022). Interaction and combined toxicity of microplastics and per- and polyfluoroalkyl substances in aquatic environment. Frontiers of Environmental Science & Engineering, 16(10): 136

[12] Das A , Ruhal R . (2025). Potential of plants-based alkaloids, terpenoids and flavonoids as antibacterial agents: an update. Process Biochemistry, 150: 94–120

[13] Dong R , Zhou C L , Wang S Y , Yan Y S , Jiang Q . (2022). Probiotics ameliorate polyethylene microplastics-induced liver injury by inhibition of oxidative stress in Nile tilapia (Oreochromis niloticus). Fish & Shellfish Immunology, 130: 261–272

[14] Gewert B , Plassmann M M , MacLeod M . (2015). Pathways for degradation of plastic polymers floating in the marine environment. Environmental Science: Processes & Impacts, 17(9): 1513–1521

[15] Ghosh T . (2025). Microplastics bioaccumulation in fish: Its potential toxic effects on hematology, immune response, neurotoxicity, oxidative stress, growth, and reproductive dysfunction. Toxicology Reports, 14: 101854

[16] González-Silvera D , Cuesta A , Esteban M Á . (2021). Immune defence mechanisms presented in liver homogenates and bile of gilthead seabream (Sparus aurata). Journal of Fish Biology, 99(6): 1958–1967

[17] Green G B H , Williams M B , Brandom J L , Chehade S B , Fay C X , Morrow C D , Lawrence A L , Bej A K , Watts S A . (2024). A bacterial-sourced protein diet induces beneficial shifts in the gut Microbiome of the Zebrafish, Danio rerio. Current Deve-lopments in Nutrition, 8(2): 102077

[18] Guo J L , Zhou Y L , Zhao H , Chen W Y , Chen Y J , Lin S M . (2019). Effect of dietary lipid level on growth, lipid metabolism and oxidative status of largemouth bass, Micropterus salmoides. Aquaculture, 506: 394–400

[19] Hamed M , Monteiro C E , Sayed A E D H . (2022). Investigation of the impact caused by different sizes of polyethylene plastics (Nano, micro, and macro) in common carp juveniles, Cyprinus carpio L., using multi-biomarkers. Science of the Total Environment, 803: 149921

[20] Hernández Díaz M , Galar Martínez M , García Medina S , Cortés López A , Ruiz Lara K , Cano Viveros S , García Medina A L , Pérez-Pastén Borja R , Rosales Pérez K E , Gómez Oliván L M . et al. (2024). Polluted water from a storage dam (Villa Victoria, méxico) induces oxidative damage, AChE activity, embry-otoxicity, and behavioral changes in Cyprinus carpio larvae. Environmental Research, 258: 119282

[21] Hilal B , Khan M M , Fariduddin Q . (2024). Recent advancements in deciphering the therapeutic properties of plant secondary metabolites: phenolics, terpenes, and alkaloids. Plant Physiology and Biochemistry, 211: 108674

[22] Holeček M . (2024). Origin and roles of alanine and glutamine in gluconeogenesis in the liver, kidneys, and small intestine under physiological and pathological conditions. International Journal of Molecular Sciences, 25(13): 7037

[23] Holman B W B , Bailes K L , Meyer R G , Hopkins D L . (2019). Effect of modified Soxhlet (Soxtec) and Folch extraction method selection on the total lipid determination of aged beef. Journal of Food Science and Technology, 56(8): 3957–3961

[24] Kim D G , Lee S J , Lee J M , Lee E W , Jang W J . (2023). Changes in the gut microbiota composition of juvenile olive flounder (Paralichthys olivaceus) caused by pathogenic bacterial infection. Fishes, 8(6): 294

[25] Li H H , Isaac N , Shen K X , Cheng J , Xiang J , Bao L S , Zhu X , Pan Y X , Chu W Y , Luo Q H . et al. (2024). Dietary lipid-induced changes in antioxidant status, lipid metabolism and flesh quality of juvenile rice flower carp (Cyprinus carpio). Aquaculture Reports, 35: 101967

[26] Li Z ZZhang X XAweya J JWang S QHu ZLi S KWen X B (2019). Formulated diet alters gut microbiota compositions in marine fish Nibea coibor and Nibea diacanthus. Aquaculture Research, 50(1): 126–138

[27] Liu T J , Yang J , Wu J W , Sun X R , Gao X J . (2024). Polyethylene microplastics induced inflammation via the miR-21/IRAK4/NF-κB axis resulting to endoplasmic reticulum stress and apoptosis in muscle of carp. Fish & Shellfish Immunology, 145: 109375

[28] Liu Z , Shen J S , Zhu W Y . (2017). Interaction between microflora and nitrogen nutrients in large intestine and its impacts on host health. Acta Microbiologica Sinica, 57(1): 8–14

[29] Lu L , Luo T , Zhao Y , Cai C H , Fu Z W , Jin Y X . (2019). Interaction between microplastics and microorganism as well as gut microbiota: a consideration on environmental animal and human health. Science of the Total Environment, 667: 94–100

[30] Ma L M , Cai H M , Liang X M , You F , Jiang A X , Yang G K , Zhang X D , Chang X L , Zhang Y M , Meng X L . (2022). Community structure analysis of intestinal sulfate-reduction bacteria of Cyprinus carpio L. in aquaculture pond. Freshwater Fisheries, 52(6): 3–9

[31] Mohamad N , Mustafa M , Amal M N A , Saad M Z , Md Yasin I S , Al-Saari N . (2019). Environmental factors associated with the presence of vibrionaceae in tropical cage-cultured marine fishes. Journal of Aquatic Animal Health, 31(2): 154–167

[32] Najahi H , Banni M , Nakad M , Abboud R , Assaf J C , Operato L , Belhassen M , Gomes L , Hamd W . (2025). Plastic pollution in food packaging systems: impact on human health, socioeconomic considerations and regulatory framework. Journal of Hazardous Materials Advances, 18: 100667

[33] Ndrepepa G . (2021). Aspartate aminotransferase and cardiovascular disease: a narrative review. Journal of Laboratory and Precision Medicine, 6: 6

[34] Pan Q , Zhou Y , Wang Y , Xu B C , Li P J , Chen C G . (2024). Effects of ultrasound-assisted dry-curing on water holding capacity and tenderness of reduced-sodium pork by modifying salt-soluble proteins. Food Chemistry, 453: 139704

[35] Rodríguez-Mendoza C A , González Campos R E , Lorenzo-Leal A C , Bautista Rodríguez E , Paredes Juárez G A , El Kassis E G , Hernández L R , Juárez Z N , Bach H . (2022). Phytochemical screening and bioactivities of cactaceae family members endemic to Mexico. Plants, 11(21): 2856

[36] Salehi M , Rashidinejad A . (2025). Multifaceted roles of plant-derived bioactive polysaccharides: a review of their biological functions, delivery, bioavailability, and applications within the food and pharmaceutical sectors. International Journal of Biological Macromolecules, 290: 138855

[37] Sun H , Wang L X , Chen F Y , Meng X Y , Zheng W B , Peng H , Hao H , Chen H Y , Wang K J . (2024a). The modulation of intestinal commensal bacteria possibly contributes to the growth and immunity promotion in Epinephelus akaara after feeding the antimicrobial peptide Scy-hepc. Animal Microbiome, 6(1): 54

[38] Sun Y , Deng Q F , Zhang Q R , Zhou X , Chen R H , Li S Y , Wu Q , Chen H G . (2024b). Hazards of microplastics exposure to liver function in fishes: a systematic review and meta-analysis. Marine Environmental Research, 196: 106423

[39] Sun YDeng Q FZhang Q RZhou XChen R HLi S YWu QChen H G (2024b). Hazards of microplastics exposure to liver function in fishes: a systematic review and meta-analysis. Marine Environmental Research, 196: 106423

[40] Thompson R C, Courtene-Jones W, Boucher J, Pahl S, Raubenheimer K, Koelmans A A (2024). Twenty years of microplastic pollution research: What have we learned? Science, 386(6720): eadl2746

[41] Ting H , Adolph T E , Trauner M . (2022). Gut-liver axis: pathophysiological concepts and clinical implications. Cell Metabolism, 34(11): 1700–1718

[42] Wang J Q , Wu F , Dong S Q , Wang X S , Ai S H , Liu Z T , Wang X N . (2024a). Meta-analysis of the effects of microplastic on fish: insights into growth, survival, reproduction, oxidative stress, and gut microbiota diversity. Water Research, 267: 122493

[43] Wang L , Wang L R , Liu C , Feng D , Huang J T , Jin Z , Ma F R , Xu J X , Xu Y Y , Zhang M . et al. (2025). Effects of water flow treatment on muscle quality, nutrient composition and volatile compounds in common carp (Cyprinus carpio). Food Chemistry: X, 26: 102257

[44] Wang Z , Chen S B , He Y W , Liang L , Jiang Z G . (2024b). Fish guts possess higher priority in assessing ecological risk of microplastics in both fish bodies and aquatic environments. Ecological Indicators, 168: 112792

[45] Wu J , Lu J , Wu J . (2022). Effect of gastric fluid on adsorption and desorption of endocrine disrupting chemicals on microplastics. Frontiers of Environmental Science & Engineering, 16(8): 104

[46] Xie M X , Zhou W , Xie Y D , Li Y , Zhang Z , Yang Y L , Olsen R E , Ran C , Zhou Z G . (2021). Effects of Cetobacterium somerae fermentation product on gut and liver health of common carp (Cyprinus carpio) fed diet supplemented with ultra-micro ground mixed plant proteins. Aquaculture, 543: 736943

[47] Yan D , Xu W J , Yu Q Q , You J , Gao R C , Bao Y L . (2024). Pre-rigor salting improves gel strength and water-holding of surimi gel made from snakehead fish (Channa argus): the role of protein oxidation. Food Chemistry, 450: 139269

[48] Yang Y (2023). Study on selective extraction and bioactivities evaluation of polysaccharides from Opuntia Milpa Alta. Master Degree Thesis. Guizhou Normal University, Guizhou, China

[49] Yin L Y , Chen B J , Xia B , Shi X T , Qu K M . (2018). Polystyrene microplastics alter the behavior, energy reserve and nutritional composition of marine jacopever (Sebastes schlegelii). Journal of Hazardous Materials, 360: 97–105

[50] Zhang Y , Wen B , Meng L J , Gao J Z , Chen Z Z . (2021). Dynamic changes of gut microbiota of discus fish (Symphysodon haraldi) at different feeding stages. Aquaculture, 531: 735912

[51] Zhang Z Y (2023). Isolation, identification and preliminary study on the nutritional function of a strain of genus Cetobacterium, the core microbiota in the gut of Nile tilapia (Oreochromis niloticus). Master Degree Thesis. Guangdong Ocean University, Zhanjiang, China

[52] Zhu M R , Wang H R , Han F X , Cai Z L , Wang J J , Guo M Y . (2023). Polyethylene microplastics cause apoptosis via the MiR-132/CAPN axis and inflammation in carp ovarian. Aquatic Toxicology, 265: 106780

[53] Zhu N L , Li Z M , Yu Y , Liu Z Y , Liang X J , Wang W , Zhao J T . (2025a). Fate of microplastics in soil-water systems: view from free radicals driven by global climate change. Ecotoxicology and Environmental Safety, 295: 118138

[54] Zhu Y Y , Tian M , Lu S Y , Qin Y L , Zhao T , Shi H L , Li Z F , Qin D D . (2025b). The antioxidant role of aromatic plant extracts in managing neurodegenerative diseases: a comprehensive review. Brain Research Bulletin, 222: 111253

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