Urinary hippuric acid level as a biological indicator of toluene exposure on batik workers

Meta-analysis guided development of a standard artificial urine

In this study, we present the first meta-analysis of human urine reported in the literature, drawing data from a total of 35 articles with a combined participant count of 14,021. Through this analysis, we have developed an artificial urine (AU) composition that can be adjusted within typical physiological parameters for in vitro applications. Our findings demonstrate the utility of this AU in determining the solubility of nitrofurantoin, particularly in the context of crystalluria. Notably, we observe that in saline, nitrofurantoin solubility, within the framework of its urinary pharmacokinetics, suggests a risk of crystalluria. However, in AU, this risk is mitigated due to complexation with urea. More broadly, we anticipate that our developed formulation will serve as a foundation for translational studies across biomedical and pharmaceutical sciences.

Metabolomic biomarkers in liquid biopsy: accurate cancer diagnosis and prognosis monitoring

Liquid biopsy, a novel detection method, has recently become an active research area in clinical cancer owing to its unique advantages. Studies on circulating free DNA, circulating tumor cells, and exosomes obtained by liquid biopsy have shown great advances and they have entered clinical practice as new cancer biomarkers. The metabolism of the body is dynamic as cancer originates and progresses. Metabolic abnormalities caused by cancer can be detected in the blood, sputum, urine, and other biological fluids via systemic or local circulation. A considerable number of recent studies have focused on the roles of metabolic molecules in cancer. The purpose of this review is to provide an overview of metabolic markers from various biological fluids in the latest clinical studies, which may contribute to cancer screening and diagnosis, differentiation of cancer typing, grading and staging, and prediction of therapeutic response and prognosis.

Deciphering the human urine matrix: a new approach to simultaneously quantify the main ions and organic compounds by ion chromatography/mass spectrometry (IC-MS)

Analyzing the composition of (human) urine plays a major role in the fields of biology and medicine. Organic molecules (such as urea, creatine) and ions (such as chloride, sulfate) are the major compounds present in urine, the quantification of which allows for the diagnosis of a subject's health condition. Various analytical methods have been reported for studying urine components and validated on the basis of known and referenced compounds. The present work introduces a new method able to simultaneously determine both major organic molecules and ions contained in urine, by combining ion chromatography using a conductimetric detector with mass spectroscopy. The analysis of organic and ionized compounds (anionic and cationic) was achieved in double injections. For quantification, the standard addition method was used. Human urine samples were pre-treated (diluted and filtered) for IC-CD/MS analysis. The analytes were separated in 35 min. Calibration ranges (0-20 mg.L-1) and correlation coefficients (> 99.3%) as well as detection (LODs < 0.75 mg.L-1) and quantification (LOQs < 2.59 mg.L-1) limits were obtained for the main organic molecules (lactic, hippuric, citric, uric, oxalic acids, urea, creatine, and creatinine) and ions (chloride, sulfate, phosphate, sodium, ammonium, potassium, calcium, and magnesium) contained in urine. The intra- and inter-day accuracies of the analytes consistently ranged from 0.1 to 5.0%, and the precision was within 4.0%. For all analytes, no significant matrix effects were observed, and recoveries ranged from 94.9 to 102.6%. Finally, quantitative results of analytes were obtained from 10 different human urine samples.

Kinetic Profile of Urine Metabolites after Acute Intake of a Phenolic Compounds-Rich Juice of Juçara (Euterpe edulis Mart.) and Antioxidant Capacity in Serum and Erythrocytes: A Human Study

The juçara palm tree produces a small spherical and black-purple fruit similar to açaí. It is rich in phenolic compounds, especially anthocyanins. A clinical trial evaluated the absorption and excretion of the main bioactive compounds in urine and the antioxidant capacity in serum and erythrocytes of 10 healthy subjects after juçara juice intake. Blood samples were collected before (0.0 h) and 0.5 h, 1 h, 2 h, and 4 h after a single dose (400 mL) of juçara juice, while urine was collected at baseline and 0-3 and 3-6 h after juice intake. Seven phenolic acids and conjugated phenolic acids were identified in urine deriving from the degradation of anthocyanins: protocatechuic acid, vanillic acid, vanillic acid glucuronide, hippuric acid, hydroxybenzoic acid, hydroxyphenylacetic acid, and ferulic acid derivative. In addition, kaempferol glucuronide was also found in urine as a metabolite of the parent compound in juçara juice. Juçara juice caused a decrease in the total oxidant status of serum after 0.5 h in comparison to baseline values (p < 0.05) and increased the phenolic acid metabolites excretion. This study shows the relationship between the production of metabolites of juçara juice and the total antioxidant status in human serum, indicating evidence of its antioxidant capacity.

Magnetic layered double hydroxides for the sensitive dispersive solid phase microextraction of hippuric acid in urine samples prior to HPLC-UV analysis

The core- shell structural layered double hydroxide (Fe₃O₄-SiO₂-EN@Zn-Al-LDH) was successfully synthesized and applied as a solid sorbent in the magnetic dispersive micro solid-phase-extraction (M-DµSPE) method. It was combined with high-performance liquid chromatography for the trace analysis of hippuric acid (HA) from urine samples. The obtained magnetic layered double hydroxides (LDHs) were characterized by XRD, FT-IR, VSM, FE-SEM, and BET techniques. The characterization analysis indicated that Fe₃O₄- SiO₂- EN@ Zn-Al-LDH has a sufficient surface area and good saturation magnetism. The affecting variables on the extraction of HA by the proposed method were optimized. Excellent adsorption capacity (127.8 mg g^-1), wide linearity dynamic range (0.015-500 µg mL^-1), and satisfactory limits of detection and quantification (0.055 and 0.014 µg mL^-1, respectively) could be obtained under optimum conditions. The good repeatability and low relative standard deviation (7.2 %), low carry-over (2.7%), good matrix effect (93.6%), high reusability (up to 19 times), and an acceptable percent recovery value (97.2%) proved the selectivity and applicability of the proposed method for the extraction of the trace levels of HA in real urine samples.

Disentangling the Complexity of Nutrition, Frailty and Gut Microbial Pathways during Aging: A Focus on Hippuric Acid

Hippuric acid (HA) is a metabolite resulting from the hepatic glycine conjugation of benzoic acid (BA) or from the gut bacterial metabolism of phenylalanine. BA is generally produced by gut microbial metabolic pathways after the ingestion of foods of vegetal origin rich in polyphenolic compounds, namely, chlorogenic acids or epicatechins. It can also be present in foods, either naturally or artificially added as a preservative. The plasma and urine HA levels have been used in nutritional research for estimating the habitual fruit and vegetable intake, especially in children and in patients with metabolic diseases. HA has also been proposed as a biomarker of aging, since its levels in the plasma and urine can be influenced by the presence of several age-related conditions, including frailty, sarcopenia and cognitive impairment. Subjects with physical frailty generally exhibit reduced plasma and urine levels of HA, despite the fact that HA excretion tends to increase with aging. Conversely, subjects with chronic kidney disease exhibit reduced HA clearance, with HA retention that may exert toxic effects on the circulation, brain and kidneys. With regard to older patients with frailty and multimorbidity, interpreting the HA levels in the plasma and urine may result particularly challenging because HA is at the crossroads between diet, gut microbiota, liver and kidney function. Although these considerations may not make HA the ideal biomarker of aging trajectories, the study of its metabolism and clearance in older subjects may provide valuable information for disentangling the complex interaction between diet, gut microbiota, frailty and multimorbidity.

Eu(III)-Functionalized MOF-Based Dual-Emission Ratiometric Sensor Integrated with Logic Gate Operation for Efficient Detection of Hippuric Acid in Urine and Serum

With the introduction of Eu³⁺ ions as the secondary fluorescent signal reporter and sensing active sites, a dual-emission ratiometric sensor of Eu³⁺@NiMOF (Eu³⁺ functional NiMOF) for hippuric acid (HA) detection in urine and serum was fabricated via the postsynthetic encapsulating strategy. Based on the two emission signals at 441 nm (turn-on) and 628 nm (turn-off), the produced Eu³⁺@NiMOF ratiometric sensor provided enhanced sensitivity, higher selectivity, and 9.7 times lower limits of detection (LOD) for the detection of HA (2.38 μM, 0.42 μg·mL^-1) than that of the pristine NiMOF. Considering the high sensitivity and visualization results, further exploration of intelligent applications in the HA sensing process was carried out by constructing a tandem combinational logic gate to improve the practicability and convenience with the help of a smartphone. This work provides a promising approach for developing MOF-based ratiometric sensors to detect biomarkers.

Exposure assessment of wastewater treatment plant employees to BTEX: a biological monitoring approach

To monitor employees' work safety and exposure against air contaminants, Trans, trans-muconic acid, Hippuric acid, Methyl hippuric acid, Mandelic acid and Phenylglyoxylic acid can be used as reliable biomarkers of exposure to benzene, toluene, ethylbenzene, and xylene (BTEX) compounds. This study aims to determine the level of urinary metabolites of BTEX compounds using biological monitoring in the employees of a wastewater treatment plant (WWTP) in the south of Iran. The study was performed on 56 employees of the WWTP of one of the southern cities of Iran in 2020. Urine samples (n total = 112) consisting of 60 samples of employees working in the operation section (exposed group) and 52 samples of employees working in the administrative section (control group) in the WWTP were collected before and at the end of their shift. The mean concentration of urinary metabolites of BTEX of both groups ranged from 546.43 (μg/g cr) for trans, trans-muconic acid to 0.006 (μg/g cr) for methyl hippuric acid, which indicates that most of the evaluated metabolites showed a higher concentration than their occupational threshold limit value urine (p < 0.05). Regression analysis results showed a significant correlation (p < 0.05) between age and utilization of flame heaters with changes in the measured BTEX metabolites in the urine. The results of this study illustrate that WWTPs should be considered as one of the workplaces with potential sources of BTEX exposure for employees. Future investigations are recommended to perform itemized appraisals of BTEX intake sources, particularly in employees of the operational sections of WWTP.

Investigation of Dermal Exposure to Heavy Metals (Cu, Zn, Ni, Al, Fe and Pb) in Traditional Batik Industry Workers

Batik is an Indonesian cultural heritage that has been designated by UNESCO. Batik industry is one of the industries that applies the synthetic dyes, beside natural ones which have long been used in producing Batik particularly in the modern production. The purpose of this research investigated heavy metals on workers in batik industry, which focuses on dermal detection as portal of entry. Samples of dermal intake of workers were examined with cross-sectional approach, while non-worker samples of resident living surrounding the industry were used as control. Dermal intake on workers and non-workers were examined using Patch Filter. Heavy metals content of the synthetic dyes used in the batik production and those in the patch filter which was attached to worker's skin during sampling period were analyzed using X-Ray Fluorescence (XRF) method. The XRF measurement result of the synthetic dyes shows a detection of several heavy metals including Cu and Zn as the highest detected concentration, while the XRF measurement of the patch filter detects several heavy metal contents, which include Cu, Zn, Ni, Al, Fe and Pb. The highest detected heavy metal concentration found in the patch filter were Cu, Zn and Ni. Meanwhile, the highest detected heavy metal concentration of Pb was found in workers in the stamping process. The result indicates that highest Hazard Quotient (HQ) values for Cu, Zn, Mn, and Fe were found in workers of dyeing process compared to those in other processing stages.