Bisphenols and Oxidative Stress Biomarkers—Associations Found in Human Studies, Evaluation of Methods Used, and Strengths and Weaknesses of the Biomarkers

• Main Authors: Inger-Lise Steffensen, Hubert Dirven, Stephan Couderq, Arthur David, Shereen Cynthia D’Cruz, Mariana F Fernández, Vicente Mustieles, Andrea Rodríguez-Carillo, Tim Hofer
• Format: Article
• Language: English
• Published: MDPI AG 2020-05-01
• Series: International Journal of Environmental Research and Public Health
• Subjects: adverse outcome pathway (AOP); analytical methods; antioxidant; bisphenol F (BPF); bisphenol S (BPS); effect biomarker
• Online Access: https://www.mdpi.com/1660-4601/17/10/3609

<b> </b>Bisphenols, particularly bisphenol A (4,4′-(hexafluoroisopropylidene)-diphenol) (BPA), are suspected of inducing oxidative stress in humans, which may be associated with adverse health outcomes. We investigated the associations between exposure to bisphenols and biomarkers of oxidative stress in human studies over the last 12 years (2008‒2019) related to six health endpoints and evaluated their suitability as effect biomarkers. <i>PubMed</i> database searches identified 27 relevant articles that were used for data extraction. In all studies, BPA exposure was reported, whereas some studies also reported other bisphenols. More than a dozen different biomarkers were measured. The most frequently measured biomarkers were 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-OHdG), 8-iso-prostaglandin F2α (8-isoprostane) and malondialdehyde (MDA), which almost always were positively associated with BPA. Methodological issues were reported for MDA, mainly the need to handle samples with caution to avoid artefact formation and its measurements using a chromatographic step to distinguish it from similar aldehydes, making some of the MDA results less reliable. Urinary 8-OHdG and 8-isoprostane can be considered the most reliable biomarkers of oxidative stress associated with BPA exposure. Although none of the biomarkers are considered BPA- or organ-specific, the biomarkers can be assessed repeatedly and non-invasively in urine and could help to understand causal relationships.