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Propylparaben (PrP) and dichloropropylparaben (diClPrP) are found in soil worldwide, mainly due to the incorporation of urban sludge in crop soils and the use of non-raw wastewater for irrigation. Studies on the adverse effects of PrP on plants are incipient and not found for diClPrP. PrP and diClPrP were evaluated at concentrations 4, 40, and 400 µg/L for their phytotoxic potential to seeds of Allium cepa (onion), Cucumis sativus (cucumber), Lycopersicum sculentum (tomato), and Lactuca sativa (lettuce), and cytotoxic, genotoxic potential, and for generating oxygen-reactive substances in root meristems of A. cepa bulbs. PrP and diClPrP caused a significant reduction in seed root elongation in all four species. In A. cepa bulb roots, PrP and diClPrP resulted in a high prophase index; in addition, PrP at 400 µg/L and diClPrP at the three concentrations significantly decreased cell proliferation and caused alterations in a significant number of cells. Furthermore, diClPrP concentrations induced the development of hooked roots in onion bulbs. The two chemical compounds caused significant changes in the modulation of catalase, ascorbate peroxidase, and guaiacol peroxidase, disarming the root meristems against hydroxyl radicals and superoxides. Therefore, PrP and diClPrP were phytotoxic and cytogenotoxic to the species tested, proving dangerous to plants.

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In this study, UiO-67 (Zr)/g-C3N4 composites (U67N) were synthesized at wt.% ratios of 05:95, 15:85, and 30:70 using the solvothermal method at 80 °C for 24 h followed by calcination at 350 °C. The composites were characterized using UV-Vis diffuse reflectance spectroscopy, Fourier-transform infrared spectroscopy, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy-energy-dispersive X-ray spectroscopy, transmission electron microscopy, and nitrogen physisorption analysis. In addition, thermal stability analysis of UiO-67 was conducted using thermogravimetric analysis. The photocatalytic performance of the composites was assessed during the degradation and mineralization of a mixture of methylparaben (MeP) and propylparaben (PrP) under simulated sunlight. The adsorption process of U67N 15:85 was characterized through kinetic studies and adsorption capacity experiments, which were modeled using pseudo-first-order and pseudo-second-order kinetics and Langmuir and Freundlich isotherms, respectively. The influence of pH levels 3, 5, and 7 on the photocatalytic degradation of the mixture was investigated, revealing enhanced degradation and mineralization at pH 3. The U67N composite exhibited dual capability in removing contaminants through adsorption and photocatalytic processes. Among the prepared composites, U67N 15:85 demonstrated the highest photocatalytic activity, achieving removal efficiencies of 96.8% for MeP, 92.5% for PrP, and 45.7% for total organic carbon in 300 kJ/m2 accumulated energy (3 h of reaction time). The detoxification of the effluent was confirmed through acute toxicity evaluation using the Vibrio fischeri method. The oxidation mechanism of the heterojunction formed between UiO-67 (Zr) and g-C3N4 was proposed based on PL analysis, photoelectrochemistry studies (including photocurrent response, Nyquist, and Mott-Schottky analyses), and scavenger assays.

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Exposure to phenols and parabens may contribute to increased maternal inflammation and adverse birth outcomes, but these effects are not well-studied in humans. This study aimed to investigate relationships between concentrations of 8 phenols and 4 parabens with 6 inflammatory biomarkers (C-reactive protein (CRP); matrix metalloproteinases (MMP) 1, 2, and 9; intercellular adhesion molecule-1 (ICAM-1); and vascular cell adhesion molecule-1 (VCAM-1)) measured at two time points in pregnancy in the PROTECT birth cohort in Puerto Rico. Linear mixed models were used, adjusting for covariates of interest. Results are expressed as the percent change in outcome per interquartile range (IQR) increase in exposure. Particularly among phenols, numerous significant negative associations were found, for example, between benzophenone-3 and CRP (-11.21 %, 95 % CI: -17.82, -4.07) and triclocarban and MMP2 (-9.87 %, 95 % CI: -14.05, -5.5). However, significant positive associations were also detected, for instance, between bisphenol-A (BPA) and CRP (9.77 %, 95 % CI: 0.67, 19.68) and methyl-paraben and MMP1 (10.78 %, 95 % CI: 2.17, 20.11). Significant interactions with female fetal sex and the later study visit (at 24-28 weeks gestation) showed more positive associations compared to male fetal sex and the earlier study visit (16-20 weeks gestation). Our results suggest that phenols and parabens may disrupt inflammatory processes pertaining to uterine remodeling and endothelial function, with important implications for pregnancy outcomes. More research is needed to further understand maternal inflammatory status in an effort to improve reproductive and developmental outcomes.

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Parabens, a group of preservatives with a wide industrial range, threaten human and aquatic biota health due to their toxicity and endocrine disruption potential. As conventional wastewater treatment may not be enough to keep natural environments safe, toxicity studies are useful tools for supporting ecological risk assessments. Here, we focused on assessing ethylparaben's, one of the most common kinds of paraben, toxicity in the cladocerans Daphnia similis and Ceriodaphnia silvestrii. The EC50 sensitivity for D. similis and C. silvestrii was 24 (21-28) mg L- 1 and 25 (19-33) mg L- 1, respectively. Inhibition of reproduction and late development of females were observed in C. silvestrii exposed to 8 mg L- 1. Furthermore, species sensitivity distribution was used to assess ecological risk, and ethylparaben demonstrated low potential risk for aquatic biota.

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Parabens are classified as endocrine-disrupting chemicals (EDCs) capable of interfering with the normal functioning of the thyroid, affecting the proper regulation of the biosynthesis of thyroid hormones (THs), which is controlled by the hypothalamic-pituitary-thyroid axis (HPT). Given the crucial role of these hormones in health and the growing evidence of diseases related to thyroid dysfunction, this review looks at the effects of paraben exposure on the thyroid. In this study, we considered research carried out in vitro and in vivo and epidemiological studies published between 1951 and 2023, which demonstrated an association between exposure to parabens and dysfunctions of the HPT axis. In humans, exposure to parabens increases thyroid-stimulating hormone (TSH) levels, while exposure decreases TSH levels in rodents. The effects on THs levels are also poorly described, as well as peripheral metabolism. Regardless, recent studies have shown different actions between different subtypes of parabens on the HPT axis, which allows us to speculate that the mechanism of action of these parabens is different. Furthermore, studies of exposure to parabens are more evident in women than in men. Therefore, future studies are needed to clarify the effects of exposure to parabens and their mechanisms of action on this axis.

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Background: New hybrid compounds were synthesized by linking the valproic acid (VPA) structure with other anticonvulsant/anti-inflammatory scaffolds. Materials & methods: The chemistry involved the incorporation of the linker oxymethyl ester into VPA, followed by reaction with the second scaffold. The antiseizure effects were investigated by the maximal electroshock seizure test, and the most active compound was additionally evaluated in the 6 Hz test and pentylenetetrazol test in mice. Results: The compounds showed protection against seizures. The hybrid structure with the butylparaben scaffold exhibited an ED50 of 8.265 mg/kg (0.0236 mmol/Kg) in the maximal electroshock seizure test and 50.00 mg/kg (0.147 mmol/kg) in the 6 Hz test. Conclusion: The antiseizure activity of the synthesized compounds highlighted the potential of hybrid structures to treat multifactorial diseases such as epilepsy.

This article focuses on the design of new anticonvulsant compounds that combine the chemical structure of valproic acid with other interesting scaffolds with anticonvulsant or anti-inflammatory properties. These compounds protected against in vivo acute seizure models (mice). The results revealed the capacity of combining known scaffolds into a single structure to generate new active compounds with multitarget purposes.

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Parabens and phthalates are commonly found as contaminants in human fluids and are able to provoke reproductive toxicity, being considered endocrine disruptors. To evaluate the effects of phthalate and paraben, alone or in combination, on reproductive development of the offspring, female pregnant Wistar rats were allocated in six experimental groups: Three control groups (gavage [CG], subcutaneous [CS], and gavage + subcutaneous) received corn oil as vehicle, and the remaining groups were exposed to di(2-ethylhexyl)phthalate (DEHP) (500 mg/kg, gavage), butyl paraben (BP) (100 mg/kg, subcutaneously), or MIX (DEHP + BP), from Gestational Day 12 until Postnatal Day (PND) 21. The following parameters were assessed on the offspring: anogenital distance and weight at PND 1, nipple counting at PND 13, puberty onset, estrous cycle, weights of reproductive and detoxifying organs, histological evaluation of reproductive organs, and sperm evaluations (counts, morphology, and motility). Female pups from MIX group presented reduced body weight at PND 1, lower AGD, and decreased endometrium thickness. Male animals showed decreased body weight at PND 1 and lower number of Sertoli cells on DEHP and MIX groups, MIX group revealed increase of abnormal seminiferous tubules, DEHP animals presented delayed preputial separation and higher percentage of immotile sperms, and BP males presented diminished number of Leydig cells. In conclusion, the male offspring was more susceptible to DEHP toxicity; even when mixed to paraben, the main negative effects observed seem to be due to antiandrogenic phthalate action. On the other hand, DEHP seems to be necessary to improve the effects of BP on reducing estrogen-dependent and increasing androgen-dependent events.

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Parabens are compounds used as chemical preservatives in cosmetics, drugs, and food. Some can cause adverse effects on human health. In this study, a square wave voltammetric method using a glassy carbon electrode was developed for simultaneous determination of methyl, ethyl, propyl, and butyl parabens in sweeteners. To overcome the strong overlap of voltammetric signals caused by calibrated and uncalibrated constituents, unfolded partial least squares with residual bilinearization (U-PLS/RBL) was used. The U-PLS/RBL calibration model was constructed and evaluated using a validation set obtained using a Taguchi design. Satisfactory and unbiased results were obtained with a linear response in the range of 0.78-4.48 µmol L-1 and recoveries from 82.64% to 121.77%. As far as the authors know, a voltammetric method that simultaneously determines four parabens in complex samples such as sweeteners without any previous pretreatment has not yet been reported in the literature.

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Objective: To summarize evidence regarding the toxic potential of administering parabenscontaining cosmetics in humans. Methods: The systematic review followed the methodology proposed in Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA). Electronic searches of the PubMed, Virtual Health Library (BVS), and Science Direct databases were performed between October 1st and 31st, 2018. No language restriction was determined. Original articles reporting observational, in vitro and in silico studies of toxicity caused by parabens in human or human cells were considered for eligibility. Two independent reviewers performed data extraction and assessed the methodological quality and risk of bias of articles by using the Downs & Black Scale. Score levels greater than 70% were assumed to reflect good methodological quality. The Kappa coefficient was calculated. Results: A total of 254 studies were found. Following the eligibility evaluation, 22 studies were included for the qualitative synthesis. The concordance between the reviewers was substantial (Kappa coefficient = 0.650). The meaningful reported outcomes were: high concentrations of parabens in the body; apoptosis damage to sperm DNA; oxidative stress; DNA damage; irritative potential; interference in the control of adipogenesis; estrogenic activity; genotoxicity; necrosis; role in carcinogenesis of breast cancer; harmful effects on human skin when exposed to the sun; stimulation of oncogenes expression; and interference with DNA transcription. Despite most included articles presenting appreciable methodological quality, remarkable limitations were observed and the mechanisms by which parabens exert toxicity on humans remained unclear. Conclusions: The accumulation of parabens in the human organism following repeated cosmetics administration on the skin is noteworthy. However overall, the evidence so far does not make it possible to determine whether, and in what extent, the use of paraben-containing cosmetics can disturb human health. Further investigations are still required for clarifying these issues.

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Parabens (PBs) are compounds widely used in industry for food and personal care products as antimicrobials and preservatives. Their indiscriminate use has resulted in their detection in different ecosystems so that humans and other organisms are highly exposed. Methylparaben (MePB), compared with other PBs, is mostly detected in food, personal care and baby care products. PBs could be linked to the generation of hormonal disorders and fertility impairment since their recent classification as endocrine disruptors. The knowledge of the effects that MePB can exert is of great importance as, in terms of reproduction, information is limited. Therefore, the objective of the present study was to evaluate the effect of MePB on porcine oocyte viability and in vitro maturation (IVM), as well as to determine the lethal concentration at 50% (LC50 ) and the maturation inhibition concentration at 50% (MIC50 ). Oocytes were exposed to different MePB concentrations 0 (control), 50, 100, 500, 750 and 1000 µm during 44 h of IVM. Cytoplasmic alterations and reduced cumulus cell expansion were observed in oocytes exposed to MePB; however, viability was not affected. In addition, oocyte maturation decreased in a concentration-dependent manner after exposure to MePB. The estimated LC50 was 2028.38 µm, whereas MIC50 was 780.31 µm. To our knowledge, this is the first study that demonstrates that MePB altered porcine oocyte morphology, and caused a reduction in cumulus cell expansion, both of which resulted in decreased oocyte maturation. Therefore, MePB exposure may be one of the factors involved in fertility impairment in mammals, including that of humans.

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