Application of microwave-assisted micro-solid-phase extraction for determination of parabens in human ovarian cancer tissues

Parabens promotes invasive properties of multiple human cells: A potential cancer-associated adverse outcome pathway

Parabens are esters of p-hydroxybenzoic acid, which have been used as preservatives and considered safe for nearly a century, until the last two decades when concerns began to be raised about their association with cancers. Knowledge of the mode of action of parabens on the metastatic properties of different cancer cells is still very limited. In the present study, we investigated the effects of methylparaben (MP) and propylparaben (PP) on cell invasion and/or migration in multiple human cancerous and noncancerous cells, including hepatocellular carcinoma cells (HepG2), cervical carcinoma cells (HeLa), breast carcinoma cells (MCF-7), and human placental trophoblasts (HTR-8/SVneo). MP and PP at concentrations in a range of 5-500 μg/L significantly promoted the invasion of four cell lines, with a minimum effective concentration of 5 μg/L. MP and PP up-regulated the expression levels and enzymatic activities of matrix metalloproteinase 2 and 9 (MMP2 and MMP9), as well as altered the expression of the tissue inhibitors of metalloproteinase 1 and 2 (TIMP1 and TIMP2) in four cell lines, suggesting MMPs/TIMPs as potential key events (KEs) for paraben-induced cell invasion. Activation of the p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal protein kinases 1/2 (JNK1/2) signaling pathways was required for MP- and PP-promoted invasion of four cell lines, suggesting MAPK signaling pathways as candidates for KEs in cancer or noncancerous cells response to paraben exposure. This study showed for the first time that the two widely used parabens, MP and PP, promoted invasive capacity of multiple human cells through a common mode of action. This study provides evidence for the establishment of a potential cancer-associated AOP for parabens based on pathway-specific mechanism(s), which contributes towards assessing the health risks of these environmental chemicals.

The perturbation of parabens on the neuroendocrine system in zebrafish larvae

Parabens, as the synthetic preservatives, have caused universal environmental contamination and human exposure. Whether parabens could disturb neuroendocrine system was still ambiguous. In this study, the effects of four commonly-used parabens, i.e. methyl paraben (MeP), ethyl paraben (EtP), propyl paraben (PrP) and butyl paraben (BuP), were tested on the neuroendocrine system of zebrafish larvae by investigating the swimming behavior, the related hormones and biomarkers in the hypothalamic-pituitary-interrenal (HPI) axis. The results showed that all test chemicals significantly reduced the swimming distance and mean velocity of zebrafish larvae. The adrenocorticotropic hormone (ACTH) levels in zebrafish larvae were significantly increased, while the cortisol levels were obviously decreased by paraben exposure. The transcriptional analysis showed that the expressions of the target genes including gr, mr and crhr2 in the HPI axis were mostly down-regulated. The exploration of the initial molecular event showed that parabens could bind with the glucocorticoid receptor (GR) and trigger its transactivation, according to MDA-kb2 luciferase assay and molecular docking analysis. The interaction of parabens with the GR included the hydrogen bond and hydrophobic interaction. The findings herein revealed the potential deleterious effects of parabens on the neuroendocrine system of zebrafish larvae, thus accumulating the in vivo toxicological data on this kind of food preservatives.

Characterization of pregnant women exposure to halogenated parabens and bisphenols through water consumption

Exposure of pregnant women to endocrine disruptor compounds, such as parabens and bisphenol A is of concern for fetal transition. Their halogenated degradation products, mainly coming from water treatment plans, could be problematic as well, depending on their occurrence in drinking water in the first place. Thus, 25 halogenated compounds were synthesised in order to investigate 60 substances (Bisphenols, parabens and their degradation products) in 325 drinking water samples coming from a French cohort study of pregnant women. Analysis was performed by tandem mass spectrometry coupled to gas chromatography (GC-MS/MS) after SPE extraction and derivation of the contaminants. Results indicate that parabens (methylparaben, n-propylparaben, ethylparaben and n-butylparaben), bisphenols S, A and F, and their degradation product, 4-hydroxybenzoic acid, were detected up to several hundred ng/L in drinking water, with detection frequencies between 16% and 88%. Regarding halogenated degradation products, the highest detection frequencies were found for monochlorinated products (about 50% for 2-chlorobisphenol A), which were quantified up to several tens of ng/L. Such analytical approaches with broader spectrum of monitoring (i.e. chemical hazards and their degradation products) constitute in the beginning of a solution to exhaustively answer the questions related to the characterization of the human chemical exposome.

A membrane-protected microsolid phase-extraction method based on molecular imprinting and its application to the determination of local anesthetics in cosmetics

As local anesthetics (LAs) that are illegally added into cosmetics are harmful to consumer health, it is necessary to establish an efficient method for detecting these substances. Herein, a molecularly imprinted polymer (bupivacaine) was prepared by bulk polymerization and packed into a hollow fiber for use as an extraction phase to fabricate a membrane-protected microsolid phase-extraction device. The optimal values of the influencing parameters for the microextraction process were as follows: a sample solution pH of 9.0, a loading and washing time of 2 h and an elution time of 32 min. A GC-MS method was established for determination of local anesthetics and coupled with the microextraction method to successfully detect local anesthetics in cosmetic samples. The calibration curve for the proposed method was linear in the range of 0.4∼50 mg/L and showed a good correlation coefficient (r² ). The LODs for local anesthetics were in the range of 0.01∼0.71 mg/L. The molecularly imprinted polymer exhibited good imprinting and selectivity, and the microsolid phase-extraction device was simple and inexpensive and fabrication was reproducible. The combination of molecular imprinting technology, membrane separation and microsolid phase-extraction methods used in this study can potentially be applied to pretreat local anesthetics in cosmetic samples. This article is protected by copyright. All rights reserved.

Research progress on the association between environmental pollutants and the resistance mechanism of PARP inhibitors in ovarian cancer

The occurrence and progression of ovarian cancer are closely related to genetics and environmental pollutants. Poly(ADP-ribose) polymerase (PARP) inhibitors have been a major breakthrough in the history of ovarian cancer treatment. PARP is an enzyme responsible for post-translational modification of proteins and repair of single-stranded DNA damage. PARP inhibitors can selectively inhibit PARP function, resulting in a synthetic lethal effect on tumor cells defective in homologous recombination repair. However, with large-scale application, drug resistance also inevitably appears. For PARP inhibitors, the diversity and complexity of drug resistance mechanisms have always been difficult problems in clinical treatment. Herein, we mainly summarized the research progress of DNA damage repair and drug resistance mechanisms related to PARP inhibitors and the impact of environmental pollutants on DNA damage repair to aid the development prospects and highlight urgent problems to be solved.

Analytical Chemistry in the 21st Century: Challenges, Solutions, and Future Perspectives of Complex Matrices Quantitative Analyses in Biological/Clinical Field

Nowadays, the challenges in analytical chemistry, and mostly in quantitative analysis, include the development and validation of new materials, strategies and procedures to meet the growing need for rapid, sensitive, selective and green methods. In this context, considering the constantly updated International Guidelines, constant innovation is mandatory both in the pre-treatment procedures and in the instrumental configurations to obtain reliable, true, and reproducible information. In this context, additionally to the classic plasma (or serum) matrices, biopsies, whole blood, and urine have seen an increase in the works that also consider non-conventional matrices. Obviously, all these studies have shown that there is a correlation between the blood levels and those found in the new matrix, in order to be able to correlate and compare the results in a robust way and reduce any bias problems. This review provides an update of the most recent developments currently in use in the sample pre-treatment and instrument configurations in the biological/clinical fields. Furthermore, the review concludes with a series of considerations regarding the role and future developments of Analytical Chemistry in light of the forthcoming challenges and new goals to be achieved.

Amended Safety Assessment of Parabens as Used in Cosmetics

The Expert Panel for Cosmetic Ingredient Safety (Panel) assessed the safety of 21 parabens as preservatives in cosmetic products. All of these ingredients are reported to function in cosmetics as preservatives; however, 5 are reported to also function as fragrance ingredients. The Panel reviewed relevant data relating to the safety of these ingredients under the reported conditions of use in cosmetic formulations. The Panel concluded that 20 of the 21 parabens included in this report are safe in cosmetics in the present practices of use and concentration described in this safety assessment when the sum of the total parabens in any given formulation does not exceed 0.8%. However, the available data are insufficient to support a conclusion of safety for benzylparaben in cosmetics.

Ultrasound assisted solvent extraction of porous membrane-packed samples followed by liquid chromatography-tandem mass spectrometry for determination of BADGE, BFDGE and their derivatives in packed vegetables

The problem of the presence of trace organic pollutants in food is of growing importance due to increasing awareness about their impact on newborns, infants and adults of reproductive age. Despite the fact that packaged food products offer many advantages, packaging can be a source of contamination for stored food. Thus, monitoring such pollution in food is of high importance. In this work, a novel methodology based on the solvent extraction of porous membrane-packed samples followed by liquid chromatography-tandem mass spectrometry was applied for the determination of bisphenol A diglycidyl ether (BADGE), bisphenol F diglycidyl ether (BFDGE) and their derivatives in packed vegetables. Several parameters of the extraction process were optimized, including the volume and type of extraction solvent as well as the sonication time. Due to advantages such as simplicity of use, short analysis time, and a reduction in the required amount solvent, the developed procedure can be considered green. In addition, the developed methodology was characterized by good validation parameters. Limit if quantitation (LOQ) was found to be in the range of 0.8 to 1.5 ng/g. The obtained recoveries varied from 78.3% to 111.2%. The repeatability of the extraction ranged between 0.6% and 5.8% (RSD). The proposed method was successfully applied to determine the presence of BADGE, BFDGE and their derivative compounds in the vegetable samples stored in different types of containers. The obtained data indicate that the majority of investigated samples were contaminated by chlorinated and hydroxyl derivatives of BADGE.

In-situ preparation of porous monolithic polymer inside hollow fiber as a micro-solid phase extraction device for glucocorticoids in cosmetics

Glucocorticoids have a certain whitening effect on the skin. However, frequent and long-term use of cosmetics including glucocorticoids is harmful to health. Herein, we proposed a novel micro-solid phase extraction method for the detection of prednisolone acetate, prednisone, and prednisolone in cosmetics coupled with high-performance liquid chromatography. In this method, porous monolithic polymer micro-extraction bars were prepared by "one-step, one-pot" in situ photopolymerization combined with sacrificial support in hollow fiber under water atmosphere. The crucial factors such as pH of sample solution, extraction, and elution times that influence micro-extraction were optimized and found to be 9.0, 2 h, and 32 min, respectively. Under the optimum experimental conditions, the linear range of the calibration curves were from 5.0 to 2000 µg/L with correlation coefficients (R² ) between 0.9922 and 0.9996. The limit of detection and limit of quantification were 1.5 µg/L and 5.0 µg/L, respectively, and the recoveries were found to be in range of 69.0-113.3%. The analysis of precision for intraday and interday were less than 10.40 and 10.59%. The device has been successfully achieved photopolymerization under water atmosphere. The results indicated that this method is simple, accurate, and satisfactory for the pretreatment and determination of glucocorticoids in complex cosmetics samples.

Organic Acids and Polyphenols Determination in Polish Wines by Ultrasound-Assisted Solvent Extraction of Porous Membrane-Packed Liquid Samples

In the near future, Poland is going to have more and more favorable conditions for viticulture. Organic acids and polyphenols are among the most commonly analyzed compounds due to their beneficial properties for human health and their importance in the winemaking process. In this work, a new technique involving ultrasound-assisted solvent extraction of porous membrane-packed liquid samples (UASE-PMLS) was for the first time described and applied for real samples. The methodology based on UASE-PMLS for organic acids and polyphenols in wine samples was optimized and validated. Using the new technique coupled to GC–MS, organic acids and polyphenols were evaluated in Polish wine samples. Extraction solvent, extraction temperature, derivatization time and sample pH were optimized. Chemometric tools were used for data treatment. Good linearity was obtained for the concentration ranges evaluated with r values between 0.9852 and 0.9993. All parameters of method validation (intra- and inter-day precision and matrix effect) were over 80% with coefficient of variation (CV) up to 17%. Recovery was between (92.0 ± 8.5)% and (113 ± 16)%. Finally, green assessment was evaluated using Analytical Eco-Scale and Green Analytical Procedure Index (GAPI). The UASE-PMLS is characterized by many advantages, e.g., the extraction process is fast and easy coupled to GC–MS. Regarding other extraction techniques, the amount of used solvent is minimum, and no waste is generated. Therefore, it is an environmentally friendly technique.

Membrane-Protected Molecularly Imprinted Polymer for the Microextraction of Indole-3-butyric Acid in Mung Bean Sprouts

Based on the hollow fiber protected molecularly imprinted polymer, a micro-solid-phase extraction (μ-SPE) method was developed and applied for the analysis of indole-3-butyric acid in mung bean sprouts by high-performance liquid chromatography. The extraction conditions of the μ-SPE method were optimized using L⁹(3⁴) orthogonal, and optimum conditions were found as follows: pH of sample solution was 2.0, chloroform was the organic solvent for embedding the μ-SPE bars, and acetonitrile was the desorption solvent. In addition, the extraction time was 80 min, desorption time was 5 min, stirring speed was 800 rpm, and concentration of NaCl was 10%. Under the optimum conditions, a standard curve was established for IBA, with a correlation coefficient of 0.9999. After extraction with phosphate buffer solution (pH = 9.0), successful pretreatment of mung bean sprouts was achieved by the μ-SPE method. The limit of detection was 0.075 mg/kg, and the recoveries were found to be in the range of 88.9-106.4%. This method is simple, environmentally friendly, and can be used for the determination of indole auxin contents in green bean sprouts quickly and accurately.

Traces of intact paraben molecules in endometrial carcinoma

Endometrial carcinoma is the most commonly encountered gynecological cancer in women worldwide and is also one of the popular models of the hormone-dependent carcinomas. This study was aimed to evaluate and compare the concentrations of five paraben molecules (methylparaben, ethylparaben, N-propylparaben, benzylparaben, isobutylparaben + N-butylparaben) in the endometrial and myometrial tissue samples of patients diagnosed with endometrial carcinoma and benign gynecologic diseases. A total of 88 patients were included in the study and chemical analysis was performed on 176 tissue samples. The study group comprised of 33 patients with endometrial carcinoma and 6 patients with endometrial intraepithelial neoplasia. The control group comprised of 49 patients. One endometrial and one myometrial tissue samples were collected from each patient. The analyses were performed using ultrahigh-performance liquid chromatography and tandem mass spectrometry (UHPLC-MS/MS). At least one type of paraben molecule was detected in 23.07% (9/39) of the patients in the study group, and in 2.04% (1/49) of the patients in the control group; this difference between the groups was statistically significant (p = .002). N-Propylparaben and isobutyl + N-butylparaben were the most frequently detected (in 7/10 of the samples) paraben molecules in the study. Tumor characteristics (tumor diameter, myometrial invasion, architectural grade, nuclear grade, lymphovascular space invasion, and tumor stage) were comparable between the two groups of endometrial carcinoma (paraben-detected and paraben-undetected groups). In conclusion, paraben molecules were more frequently detected in the endometrial carcinoma tissue samples than in the normal endometrium.

A New Sensor for Methyl Paraben Using an Electrode Made of a Cellulose Nanocrystal-Reduced Graphene Oxide Nanocomposite

A new cellulose nanocrystal-reduced graphene oxide (CNC-rGO) nanocomposite was successfully used for mediatorless electrochemical sensing of methyl paraben (MP). Fourier-transform infrared spectroscopy (FTIR) and field-emission scanning electron microscopy (FESEM) studies confirmed the formation of the CNC-rGO nanocomposite. Cyclic voltammetry (CV) studies of the nanocomposite showed quasi-reversible redox behavior. Differential pulse voltammetry (DPV) was employed for the sensor optimization. Under optimized conditions, the sensor demonstrated a linear calibration curve in the range of 2 × 10^-4-9 × 10^-4 M with a limit of detection (LOD) of 1 × 10^-4 M. The MP sensor showed good reproducibility with a relative standard deviation (RSD) of about 8.20%. The sensor also exhibited good stability and repeatability toward MP determinations. Analysis of MP in cream samples showed recovery percentages between 83% and 106%. Advantages of this sensor are the possibility for the determination of higher concentrations of MP when compared with most other reported sensors for MP. The CNC-rGO nanocomposite-based sensor also depicted good reproducibility and reusability compared to the rGO-based sensor. Furthermore, the CNC-rGO nanocomposite sensor showed good selectivity toward MP with little interference from easily oxidizable species such as ascorbic acid.

Determination of volatile organic compounds exhaled by cell lines derived from hematological malignancies

Background: The gas human exhaled contains many volatile organic compounds (VOCs), which is related to the health status of body. Analysis of VOCs has been proposed as a noninvasive diagnostic tool for certain cancers. Detailed research on the VOCs in gas exhaled by cell can characterize cell type specific metabolites and may be helpful to detect the cancer markers in clinical practice.

Methods: Solid-phase microextraction (SPME) gas chromatography–mass spectrometry was used to detect VOCs in the headspace of tissue culture flask in non-Hodgkin’s lymphoma (NHL) cell line JEKO and acute mononuclear leukemia cell line SHI-1, to elaborate the characteristic gaseous biomarkers of hematological malignancies. While macrophage cells and lymphocytic cells were acted as control. The blank group was only the RPMI 1640 medium containing 10% fetal calf serum that without cells.

Results: Comparing with control group, the concentration of dimethyl sulfide, 2,4-dimethylheptane, methylbenzene, o-xylene, dodecane, and 1,3-di-tert-butylbenzene in JEKO cells was relatively higher, while the concentration of ethanol, hexanal, and benzaldehyde was lower. In SHI-1 cells, the levels of 2,4-dimethylheptane, benzene, 4-methyldecane, chloroform, 3,7-dimethyl dodecane, and hexadecane were significantly elevated, but the levels of hexanol and cyclohexanol were distinctly reduced.

Conclusions: This pilot study revealed that the malignant hematological cells could change the components of VOCs in the cell culture flask in a cell type-specific pattern. The traits of VOCs in our setting offered new strategy for hematological malignancies tracing, and would act as potential biomarkers in diagnosis of malignant hematological diseases.

Porous membrane protected micro-solid-phase extraction: A review of features, advancements and applications

Membrane protected micro-solid-phase extraction (μ-SPE) was introduced in 2006 as an alternative to multistep SPE. μ-SPE is based on packing of very small amount of sorbent inside the porous membrane sheet whose edges are heat sealed to fabricate a μ-SPE device. This device performs clean up, extraction, and pre-concentration in a single step. It suits best for extraction of complex samples as sorbent is effectively protected inside the membrane and extraneous matter cannot adsorb over it. This review summarizes most important aspects of μ-SPE including basic principles, extraction procedure, different formats, sorbents employed and affecting parameters. The article also provides a brief account on modified μ-SPE procedures where μ-SPE was either combined with other techniques or some major changes were introduced in original procedure. Finally, the applications of μ-SPE in environmental, food and biological analysis are described. At the end, advantages and pitfalls of μ-SPE are critically appraised.

Porous extraction paddle: a solid-phase extraction technique for studying the urine metabolome

RATIONALE

A method was needed to accomplish solid-phase extraction of a large urine volume in a convenient way where resources are limited, towards a goal of metabolome and xenobiotic exposome analysis at another, distant location.

METHODS

A porous extraction paddle (PEP) was set up, comprising a porous nylon bag containing extraction particles that is flattened and immobilized between two stainless steel meshes. Stirring the PEP after attachment to a shaft of a motor mounted on the lid of the jar containing the urine accomplishes extraction. The bag contained a mixture of nonpolar and partly nonpolar particles to extract a diversity of corresponding compounds.

RESULTS

Elution of a urine-exposed, water-washed PEP with aqueous methanol containing triethylammonium acetate (conditions intended to give a complete elution), followed by MALDI-TOF/TOF-MS, demonstrated that a diversity of compounds had been extracted ranging from uric acid to peptides.

CONCLUSIONS

The PEP allows the user to extract a large liquid sample in a jar simply by turning on a motor. The technique will be helpful in conducting metabolomics and xenobiotic exposome studies of urine, encouraging the extraction of large volumes to set up a convenient repository sample (e.g. 2 g of exposed adsorbent in a cryovial) for shipment and re-analysis in various ways in the future, including scaled-up isolation of unknown chemicals for identification. Copyright © 2016 John Wiley & Sons, Ltd.