Metabolism of okadaic acid by NADPH-dependent enzymes present in human or rat liver S9 fractions results in different toxic effects

Kolrep, Franziska; Rein, Kathleen S.; Lampen, Alfonso; Hessel-Pras, Stefanie

doi:10.1016/j.tiv.2017.04.009

Cited by 17 publications

(12 citation statements)

References 33 publications

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“…We used pooled human liver S9 fractions based upon previous findings that they are more representative of hepatocyte metabolism compared to microsomes and are more amenable for high-throughput screening applications compared to hepatocytes 14 . S9 fractions contain both microsomal and cytosolic subcellular fractions and include most phase I (cytochrome P450s, flavin monooxygenases, and aldehyde oxidases) and phase II (sulfotransferases, methyltransferases, glutathione S-transferases, N-acetyl transferases, and UDP-glucuronosyltransferases) biotransformation enzymes 15 – 21 . We prepared human liver S9 fractions with required cofactors in a 96-well plate format (Fig.…”

Section: Resultsmentioning

confidence: 99%

Large scale enzyme based xenobiotic identification for exposomics

et al. 2021

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Advances in genomics have revealed many of the genetic underpinnings of human disease, but exposomics methods are currently inadequate to obtain a similar level of understanding of environmental contributions to human disease. Exposomics methods are limited by low abundance of xenobiotic metabolites and lack of authentic standards, which precludes identification using solely mass spectrometry-based criteria. Here, we develop and validate a method for enzymatic generation of xenobiotic metabolites for use with high-resolution mass spectrometry (HRMS) for chemical identification. Generated xenobiotic metabolites were used to confirm identities of respective metabolites in mice and human samples based upon accurate mass, retention time and co-occurrence with related xenobiotic metabolites. The results establish a generally applicable enzyme-based identification (EBI) for mass spectrometry identification of xenobiotic metabolites and could complement existing criteria for chemical identification.

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Section: Resultsmentioning

confidence: 99%

Large scale enzyme based xenobiotic identification for exposomics

et al. 2021

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“…Therefore, the authors concluded that the transference of animal data on humans for risk assessment purposes should take into account the inter-species differences in the metabolism of OA. The hepatic metabolism of OA was also studied with S9 fractions from humans, rats, and rats with enzyme inducers in the absence or presence of NADPH [ 63 ]. LC–MS/MS was used to identify the metabolites produced during this experiment detecting metabolites differing in +16 (+O) and +14 (+O/−H 2 ) Da with OA.…”

Section: Mass Spectrometry To Identify Marine Biotoxins Metabolitesmentioning

confidence: 99%

Contribution of Mass Spectrometry to the Advances in Risk Characterization of Marine Biotoxins: Towards the Characterization of Metabolites Implied in Human Intoxications

Estevez

Gago-Martı́nez

2023

Toxins

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A significant spread and prevalence of algal toxins and, in particular, marine biotoxins have been observed worldwide over the last decades. Marine biotoxins are natural contaminants produced during harmful algal blooms being accumulated in seafood, thus representing a threat to human health. Significant progress has been made in the last few years in the development of analytical methods able to evaluate and characterize the different toxic analogs involved in the contamination, Liquid Chromatography coupled to different detection modes, including Mass Spectrometry, the method of choice due to its potential for separation, identification, quantitation and even confirmation of the different above-mentioned analogs. Despite this, the risk characterization in humans is still limited, due to several reasons, including the lack of reference materials or even the limited access to biological samples from humans intoxicated during these toxic events and episodes, which hampered the advances in the evaluation of the metabolites responsible for the toxicity in humans. Mass Spectrometry has been proven to be a very powerful tool for confirmation, and in fact, it is playing an important role in the characterization of the new biotoxins analogs. The toxin metabolization in humans is still uncertain in most cases and needs further research in which the implementation of Mass Spectrometric methods is critical. This review is focused on compiling the most relevant information available regarding the metabolization of several marine biotoxins groups, which were identified using Mass Spectrometry after the in vitro exposition of these toxins to liver microsomes and hepatocytes. Information about the presence of metabolites in human samples, such as human urine after intoxication, which could also be used as potential biomarkers for diagnostic purposes, is also presented.

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“…Fresh mouse liver also obtained from C57BL/6 male and female mice were pooled, homogenized in 0.15 M Potassium chloride (KCl), and centrifuged at 9000g. The supernatant represents liver homogenate (S9) fraction, which was mixed with other buffers to formulate the liver S9 mix, as previously described (39). Liver S9 mix were spiked with AIP to make a final concentration of 1 μg/ml (L-AIP, D-AIP, or sD-AIP, respectively) and incubated at 37 C. Just after the addition of NADPH, 100 μl aliquot which represents t = 0 samples were withdrawn, and others were sampled accordingly at predetermined time points.…”

Section: Ex-vivo Stability Studymentioning

confidence: 99%