Quantification of polyethylene in mussel hemolymph and its limited additive effect on immune function induced by bezafibrate

Bioaccumulation of waterborne pharmaceutical residuals may be influenced by the presence of microplastics in the surrounding water and therefore, this study investigated whether in vivo co-exposure to weathered polyethylene microplastics (PE) (nominal 1 mg/L) and bezafibrate (BZ) (500 ng/L) add-on effects on immune function in comparison to exposure to BZ alone, as it has been observed for other emergent contaminants. Mytilus galloprovincialis was used as model organism and the co-exposure study was carried out for 3 weeks. Pyrolysis¿gas chromatography mass spectrometry (Py-GC/MS) technique was used for quantifying PE concentration in hemolymph. Lysosomal membrane stability (LMS) and phagocytosis efficiency of hemocytes, extracellular lysozyme activity and production of oxyradicals were determined as endpoints of immune function after 10 and 20 days. PE concentration in hemolymph of mussels treated with PE and PE+BZ were similar and had a high variability (hundreds of nanograms per milliliters) but values were one order of magnitude higher than mussels treated only with BZ, representing the first quantitative estimation of microplastic concentration that can be reached in this tissue under in vivo exposure conditions. However, still It remains to be determined what fraction of plastic particles were present in the plasma and what fraction carried by hemocytes. Mussels exposed to BZ and co-exposed to BZ+PE had significantly higher phagocytic rate than control mussels after 10 days, but this induction was transitory as phagocytosis efficiency was rather similar between treatments and control after 20 days. Lysosomal destabilization was found only after 20 days of exposure to BZ and BZ+PE, but not after exposure to PE. Overall, results obtained in this in vivo study showed that the BZ+PE coexposure did not exert synergic immunotoxic impact on mussels and that effects of BZ on immune function prevailed over the effects caused by the PE microparticles itself.

Bibliographic Details

Main Authors:	Martínez-Gómez, C., Llorca, Marta, Oporto, T., Rapuano, S., García-Pimentel, M.M., Farré, Marinella
Format:	actas de congreso biblioteca
Published:	2022-09-26
Online Access:	http://hdl.handle.net/10261/309852
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