Exploring noninvasive matrices for assessing long-term exposure to phthalates: a scoping review.

The phthalic acid esters (PAEs) are one class of the most abundant and frequently studied pseudo-persistent organic pollutants. Noninvasive urine is an effective substrate for evaluating PAE exposure, but repeated sampling is needed to overcome this bias. This adds much work to on-site collection and the cost of detection increases exponentially. Therefore, the aim of this study was to conduct a scope review to describe the detection methods and validity of the use of other noninvasive matrices, such as nails and hair, for assessing long-term exposure to PAEs. The PubMed, Web of Science and China National Knowledge Infrastructure (CNKI), electronic databases were searched from 1 January 2000 to 3 April 2024, and 12 studies were included. Nine and three studies used hair and nails, respectively, as noninvasive matrices for detecting PAE exposure. Five articles compared the results of nail or hair and urine tests for validity of the assessment of PAE exposure. The preprocessing and detection methods for these noninvasive samples are also described. The results of this review suggest that, compared with nails, hair may be more suitable as a noninvasive alternative matrix for assessing long-term exposure to PAEs. However, sample handling procedures such as the extraction and purification of compounds from hair are not uniform in various studies; therefore, further exploration and optimization of this process, and additional research evidence to evaluate its effectiveness, are needed to provide a scientific basis for the promotion and application of hair detection methods for assessing long-term PAE exposure levels.

Health hazards of preconception phthalate exposure: A scoping review of epidemiology studies.

There is a close relationship between preconception health and maternal and child health outcomes, and the consequences may be passed down from generation to generation. In 2018, Lancet published three consecutive articles emphasizing the importance of the preconception period. Phthalic acid ester (PAE) exposure during this period may affect gametogenesis and epigenetic information in gametophytes, thereby affecting embryonic development and offspring health. Therefore, this article reviews the effects of parental preconception PAE exposure on reproductive/birth outcomes and offspring health, to provide new evidence on this topic. We searched Web of Science, MEDLINE (through PubMed), the China National Knowledge Infrastructure (CNKI), ScienceDirect, and the VIP Journal Library from the date of database establishment to July 3, 2024. Finally, 12 articles were included. Three studies investigated the health hazards (effects on birth weight, abortion, etc.) of women's preconception PAE exposure. Nine studies involved both parents. Nine studies considered the impacts of PAE preconception exposure on reproductive/birth outcomes, focusing on birth weight, pregnancy loss, preterm birth, embryo quality, and placental weight. Three studies considered the impacts of preconception PAE exposure on offspring behavior. The results of this review suggested that parental preconception PAE exposure may have an impact on reproductive/birth outcomes and offspring behavior, including birth weight, child behavior, and dietary behavior. However, studies on the health hazards of preconception PAE exposure are relatively scarce, and the outcomes of current studies are varied. It is necessary to use systematic reviews to verify an accurate research question to provide recommendations for public health policy making.

Affinity selection-based two-dimensional chromatography coupled with high-performance liquid chromatography-mass spectrometry for discovering xanthine oxidase inhibitors from Radix Salviae Miltiorrhizae.

Xanthine oxidase (XOD) is a key oxidative enzyme to the pathogenesis of hyperuricemia and certain diseases induced by excessive reactive oxygen species. XOD inhibitors could provide an important therapeutic approach to treat such diseases. A new method using affinity selection-based two-dimensional chromatography coupled with liquid chromatography-mass spectrometry was developed for the online screening of potential XOD inhibitors from Radix Salviae Miltiorrhizae. Based on our previous study, the two-dimensional, turbulent-flow chromatography (TFC) was changed to a mixed-mode anion-exchange/reversed-phase column and one reversed-phase column. The developed method was validated to be selective and sensitive for screening XOD-binding compounds, especially weak acidic ones, in the extracts. Three salvianolic acids were screened from the Radix Salviae Miltiorrhizae extract via the developed method. The XOD inhibitory activities of salvianolic acid C and salvianolic acid A were confirmed, and their inhibitory modes were measured. Salvianolic acid C exhibited potent XOD inhibitory activity with an IC(50) of 9.07 µM. This work demonstrated that the developed online, two-dimensional TFC/LC-MS method was effective in discovering the binding affinity of new compounds from natural extracts for target proteins, even at low concentrations.

Screening for selective inhibitors of xanthine oxidase from Flos Chrysanthemum using ultrafiltration LC-MS combined with enzyme channel blocking.

In this study, a new method based on ultrafiltration liquid chromatography-mass spectrometry (UF-LC-MS) combined with enzyme channel blocking (ECB) was developed to discover bioactive components from herbal medicines. Xanthine oxidase (XOD), a critical enzyme for treating gout, was employed as the target protein for screening. By comparing chromatographic profiles of the compounds binding to XOD before and after the ECB experiment, the selective ligands could be distinguished from the non-selective binders. In this experiment, febuxostat bound to the channel entering into the active site of the enzyme and prevented potential ligands from binding. Finally, four compounds, namely, luteolin-7-O-glucoside, apigenin-7-O-glucoside, luteolin and apigenin were screened and identified as the candidate XOD inhibitors based on the ultrafiltration chromatogram of Flos Chrysanthemum, a famous traditional Chinese medicine used in many prescriptions for gout treatment. To verify the compounds screened further, a microplate method was applied to evaluate their enzyme inhibitory activities. The IC50 values of the above 4 compounds were 23.61, 38.80, 1.54 and 1.96µM, respectively. The structure-function relationship was also estimated according to the in vitro assay. The results were in favor of the hypothesis that the Flos Chrysanthemum extract might be used for gout treatment by inhibiting XOD.