Characterisation of plasmatic B-esterases in bottlenose dolphins (Tursiops truncatus) and their potential as biomarkers of xenobiotic chemical exposures

Sensitivity of cholinesterases and carboxylesterases to pharmaceutical products in Tinca tinca

“…In vitro exposures of microsomal fractions of the liver with other lipid regulators such as fenofibrate and simvastatin (100 μM) evidenced weak inhibitions on CbE activity in B. meridionalis , Squalius laietanus , S. solea , Scyliorhinus canicular , Engraulis encrasicolus , and S. pilchardus 4–6,65 and moderate inhibitions of this enzymatic activity in D. labrax , Trachyrhynchus scabrus , A. rostratus , Cataetix laticeps , and S. aurata 6,7 as also Ribalta et al 66 observed in humans. Solé et al 60 also documented slight inhibitions (<10% vs. control) on plasma CbE of dolphins after in vitro exposure to these compounds. Fenofibrate was the exception since this compound produced a stimulation of the hepatic CbE activity in S. aurata 7 .…”

“…However, the clofibric acid, carbamazepine, EE 2 , and antipyrine produced slight inductions in brain, muscle, liver, and kidney AChE activities (Figure 2). A recent study in dolphins ( Tursiops truncatus ) also reported this effect (slight inductions, <10% vs. control) on plasma AChE activity after in vitro exposure at 50 μM of fenofibrate that belongs to the same therapeutic group of clofibric acid 60 . In any case, an increase in AChE activity has no relevance from an ecotoxicological point of view because currently, inhibition of AChE activity is the only used in vitro endpoint for specific neurotoxicity 61 …”

“…A recent study in dolphins (Tursiops truncatus) also reported this effect (slight inductions, <10% vs. control) on plasma AChE activity after in vitro exposure at 50 μM of fenofibrate that belongs to the same therapeutic group of clofibric acid. 60 In any case, an increase in AChE activity has no relevance from an ecotoxicological point of view because currently, inhibition of AChE activity is the only used in vitro endpoint for specific neurotoxicity. 61 Our results are in line with evidence from in silico studies, particularly ligand-based linear and nonlinear modeling together with structure-based toxicophore modeling and molecular docking simulations, that have established high binding affinities and interactions between some pharmaceuticals (EE 2 , norfloxacin, ibuprophen, acetaminophen, carbamazepine, clofibric acid, and nicotine) and the active site of the AChE enzyme.…”

“…Engraulis encrasicolus, and S. pilchardus[4][5][6]65 and moderate inhibitions of this enzymatic activity in D. labrax, Trachyrhynchus scabrus, A. rostratus, Cataetix laticeps, and S. aurata 6,7 as also Ribalta et al66 observed in humans. Solé et al60 also documented slight inhibitions (<10% vs. control) on plasma CbE of dolphins after in vitro exposure to these compounds. Fenofibrate was the exception since this compound produced a stimulation of the hepatic CbE activity in S. aurata 7.…”

Characterisation of ChE in Solea solea and exposure of isoflavones in juveniles of commercial flatfish (Solea solea and Solea senegalensis)

“…Also, other compounds, such as detergents, surfactants and metals, are able to act by inhibiting the enzymatic activity of cholinesterases, as confirmed by a study carried out on Poecilia reticulata by Guilhermino et al (2000) or in Puntius javanicus (Sabullah et al, 2014). In a study by Solé et al (2022), in in vitro samples of dolphin plasma exposed to pesticides and plastic additives, acetylcholinesterase activity (AChE) showed differences compared to the control. The above findings reflect the variety and quantity of compounds that affect the enzymatic activity of cholinesterases, showing the importance of studies with new compounds such as isoflavones.…”