Resumen:
Current and thorough information on the ecotoxicological consequences of pharmaceuticals is accessible globally.
However, there remains a substantial gap in knowledge concerning the potentially toxic effects of COVID-19
used drugs, individually and combined, on aquatic organisms. Given the factors above, our investigation assumes
pivotal importance in elucidating whether or not paracetamol, dexamethasone, metformin, and their tertiary
mixtures might prompt histological impairment, oxidative stress, and apoptosis in the liver of zebrafish. The
findings indicated that all treatments, except paracetamol, augmented the antioxidant activity of superoxide
dismutase (SOD) and catalase (CAD), along with elevating the levels of oxidative biomarkers such as lipid
peroxidation (LPX), hydroperoxides (HPC), and protein carbonyl content (PCC). Paracetamol prompted a
reduction in the activities SOD and CAT and exhibited the most pronounced toxic response when compared to
the other treatments. The gene expression patterns paralleled those of oxidative stress, with all treatments
demonstrating overexpression of bax, bcl2, and p53. The above suggested a probable apoptotic response in the
liver of the fish. Nevertheless, our histological examinations revealed that none of the treatments induced an
apoptotic or inflammatory response in the hepatocytes. Instead, the observed tissue alterations encompassed
leukocyte infiltration, sinusoidal dilatation, pyknosis, fatty degeneration, diffuse congestion, and vacuolization.
In summary, the hepatic toxicity elicited by COVID-19 drugs in zebrafish was less pronounced than anticipated.
This attenuation could be attributed to metformin’s antioxidant and hormetic effects.