Microplastic Presence in the Digestive Tract of Pearly Razorfish Xyrichtys novacula Causes Oxidative Stress in Liver Tissue

Abstract

Plastic pollution in the oceans is a growing problem, with negative effects on exposed species and ecosystems. Xyrichtys novacula L. is a very important fish species both culturally and economically in the Balearic Islands. The aim of the present study was to detect and categorise the presence of microplastics (MPs) in the digestive tract of X. novacula, as well as the existence of oxidative stress in the liver. For this purpose, the fish were categorised into two groups based on the number of MPs observed in the digestive tracts: a group with no or low presence of MPs (0–3 items) and a group with a higher presence of MPs (4–28 items). MPs were found in 89% of the specimens analysed, with a dominance of fibre type and blue colour. Regarding the type of polymer, polycarbonate was the most abundant, followed by polypropylene and polyethylene. For the group with a greater presence of MPs, the activities of the antioxidant enzymes glutathione peroxidase and glutathione reductase, as well as the phase II detoxification enzyme glutathione s-transferase, were higher than the activities observed in fish with little to no presence of MPs. The activities of catalase and superoxide dismutase and the levels of malondialdehyde did not show significant differences between both groups. In conclusion, these results demonstrate the presence of MPs in the digestive tract of X. novacula and the existence of an antioxidant and detoxification response, mainly based on the glutathione-based enzymes.

Presence and Potential Effects of Microplastics in the Digestive Tract of Two Small Species of Shark from the Balearic Islands

“…In the present work, an increase in antioxidant defences, especially SOD and GSH, has been observed in those sharks with a greater presence of MPs in their digestive tract, while the increase is not significant for CAT. It is interesting to mention that there has been no evidence of an increase in MDA levels, as a marker of oxidative damage, which would indicate that antioxidant mechanisms are capable of protecting against oxidative damage [15,41,63]. Similar results have been observed in similar studies carried out on organisms captured from the natural environment.…”

Combined Toxicity of Polystyrene Nanoplastics and Pyriproxyfen to Daphnia magna

“…Aquatic organisms inadvertently ingest these plastics, leading to their accumulation within their bodies [6][7][8]. This perpetual accumulation triggers adverse effects at the cellular, subcellular, and tissue levels, encompassing tissue damage [9,10], oxidative stress [11][12][13][14][15], induced lipid accumulation [16][17][18][19], metabolic disorders [20], digestive tract obstruction or injury [21], and disruption in growth and reproduction [17,22]. NPs (<1000 nm), being several orders of magnitude smaller than MPs, are more prone to absorption and concentration within aquatic organisms [23,24].…”

Sources, Degradation, Ingestion and Effects of Microplastics on Humans: A Review

“…Since 1970, scientists have discovered that the oceans contain plastic debris (including shattered and disintegrated debris), where the synthetic polymers (such as macro-plastics (large fragments ranging in diameter from centimeters to several dozen meters) and MPs (1–5 mm plastics and nano plastics (NMPs) < 1 mm)) that pose emerging issues for the environment in terms of pollution, animal ingestion (accumulation of toxins), and being bound by plastics (ropes and bags), thus causing drowning, suffocation, or strangulation [ 22 , 23 , 25 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. This is also known as a biological invasion due to its known biological effects, as plastics can act as a carrier for the growth of hydrates, diatoms, and bacteria after being transported and drifting [ 28 ].…”