Developmental toxicity of two trimethylbenzene isomers, mesitylene and pseudocumene, in rats following inhalation exposure

The presence and physico-chemical properties of microplastics in seawater, sediment, and several organs of the spotted scat fish (Scatophagus argus, Linnaeus, 1766) collected from different locations along the East Java coast in Indonesia

A comprehensive study was undertaken to examine the contamination of spotted scat fish (Scatophagus argus) with microplastics (MP) in various locations along the East Java coast of Indonesia. The purpose of this study was to collect detailed information regarding the abundance, color, shape, size, type of polymer, and chemical components of the MP. The findings of this study indicated that MP exhibiting distinct attributes-including a specific fiber type, black coloration, and a size range of 1000- <5000 μm-was most abundant in the gill, stomach, and intestines of spotted scat fish of varying lengths. And MP with a size range of 100-<500 μm was prevalent in the sediment. MP with black fragments measuring less than 100 μm in diameter were found primarily in seawater. A positive correlation was identified between fish length and MP abundance in the intestines, as indicated by the Spearman correlation coefficient. Conversely, a negative correlation was detected between fish length and MP abundance in the gills. The findings of the Fourier transform infrared spectroscopy and Gas chromatography-mass spectrometry analyses, which indicate the presence of various polymers and chemical substances including plasticizers (e.g., diethyl phthalate, decane, and eicosane), stabilizers (2-piperidinone, hexadecanoic acid, mesitylene, and 2,4-Di-tert-butylphenol), and flame retardant (cyclododecene), in fish, are of the utmost importance. These substances have the potential to endanger the health of both animals and humans if they are ingested through the food chain.

Foodomics for agroecology: Differentiation of volatile profile in mint (Mentha × gracilis Sole) from permaculture, organic and conventional agricultural systems using HS-SPME/GC-MS

In the present study, foodomics approach was employed to investigate changes in the metabolism from the volatile terpenoids profile of mint(Mentha × gracillis Sole)from conventional, organic and permaculture (a type of agroecological agriculture system) farms using headspace solid-phase microextraction (HS-SPME) associated to gas chromatography coupled to mass spectrometry (GC-MS) and chemometric tools. The discrimination among the three types of mint was successfully achieved and demonstrated evidence of ecological interaction impact in the food metabolism. The agroecological mint presented as differential compounds: α-terpineol, bornyl formate, cis-carvyl propionate, cis-carveol, camphor, dihydrocarvyl acetate, dihydrocarveol, karahanaenone, nonanal, 3-octyl acetate, and trans-3-hexenyl-2 methylbutyrate. While organic and conventional mint presented as differential compounds: α-cedrene, β -pinene, γ-muurolene, δ-cadinene, germacrene, terpinolene, and elemol. The majority of differential metabolites from agroecological mint are oxygenated monoterpenes, which have more intense flavor and biological activities than hydrocarbons monoterpenes and sesquiterpenes found in organic and conventional mint. Furthermore, the discrimination between organic and conventional mint was effectively performed, which demonstrated different terpenoid profiles though without implying benefits for one or another agriculture system.

Nickel Oxide-Carbon Soot-Cellulose Acetate Nanocomposite for the Detection of Mesitylene Vapour: Investigating the Sensing Mechanism Using an LCR Meter Coupled to an FTIR Spectrometer

Nanocomposite sensors were prepared using carbon soot (CNPs), nickel oxide nanoparticles (NiO-NPs), and cellulose acetate (CA), which was used to detect and study the sensing mechanism of mesitylene vapour at room temperature. Synthesised materials were characterised using high-resolution transmission electron microscopy (HR-TEM), powder x-ray diffraction (PXRD), Raman spectroscopy, and nitrogen sorption at 77 K. Various sensors were prepared using individual nanomaterials (NiO-NPs, CNPs, and CA), binary combinations of the nanomaterials (CNPs-NiO, CNPs-CA, and NiO-CA), and ternary composites (NiO-CNPs-CA). Among all of the prepared and tested sensors, the ternary nanocomposites (NiO-CNPs-CA) were found to be the most sensitive for the detection of mesitylene, with acceptable response recovery times. Fourier-transform infrared (FTIR) spectroscopy coupled with an LCR meter revealed that the mesitylene decomposes into carbon dioxide.

Toxicological responses of BEAS-2B cells to repeated exposures to benzene, toluene, m-xylene, and mesitylene using air-liquid interface method

In order to reduce exposure to toxic chemicals, the European REACH regulation (1907/2006) recommends substituting toxic molecules with compounds that are less harmful to human health and the environment. Toluene is one of the most frequently used solvents in industries despite its toxicity. The objective of this study is to better understand and compare the toxicity of toluene and its homologues in a bronchial cell model. Thus, human bronchial BEAS-2B cells were exposed to steams of toluene, m-xylene, mesitylene (1,3,5-trimethylbenzene), and benzene (20 and 100 ppm). Exposure was carried out using an air-liquid interface (ALI) system (Vitrocell) during 1 h/day for 1, 3, or 5 days. Cytotoxicity, xenobiotic metabolism enzyme gene expression, and inflammatory response were evaluated following cell exposures. BEAS-2B cell exposure to toluene and its homologues revealed the involvement of major (CYP2E1) and minor metabolic pathways (CYP1A1). A late induction of genes (EPHX1, DHDH, ALDH2, and ALDH3B1) was measured from Day 3 and can be linked to the formation of metabolites. An increase in the secretion level of inflammatory markers (TNF-α, IL-6, IL-8, MCP-1, and GM-CSF) was also observed. In parallel, regulation between inflammatory mediators and the expression of transmembrane glycoprotein mucin MUC1 was also studied. This in vitro approach with ALI system points out the relevance of conducting repeated exposures to detect potential late effects. The difference recorded after cell exposure to toluene and its homologues highlights the importance of substitution principle.

Abortifacient efficacy of aqueous-acetone extracts of Adenopus breviflorus Benth seed in female albino rats

The present study evaluated the abortifacient potential of aqueous-acetone extract of Adenopus breviflorus Benth Seed on the reproductive health of matured female albino rats by monitoring the indices of dysfunctions in reproductive system. Prior to the conduction of the fertility studies, the oral acute toxicity of the seed extract was evaluated for autonomic, behavioral and neurological changes, within 24 h to determine the LD50.The influence of aqueous-acetone extract of Adenopus breviflorus Benth Seed was evaluated for antioxidant, reproductive hormones and histology of uteri tissues primarily to monitor effects in female fertility. Female rats exhibiting thick clump of spermatozoa in their vaginal smear were randomly selected and used for the study to determine the abortifacient activity of the seed extract. Parameters such as number of live and dead fetuses, anogenital distance (AGD) and crown rump length (CRL), and the variation in birth weight of liters and gestation period between control and experimental animals were determined. The phytochemical composition of the seed extract was characterized by Gas Chromatography and Mass Spectrophotometry for the identification of phytochemical of toxic or therapeutic effects. Symptoms similar to clinical toxicity such as salivation, respiratory distress, weight loss and change in appearance of hair were noticed at concentrations above 1600 mg/kg BWT, there was no maternal mortality at any period of the experiment. There were changes in the behavioural, neurological and autonomic profile in groups with doses greater than 1600 mg/kg BWT. The LD50 evaluation showed that the aqueous-acetone extract of the seed was safe at dose of 5000 mg/kg BWT. The GC-MS characterization of the aqueous-acetone seed revealed isomeric derivatives of benzene-mesitylene and pseudocumene 4.28 g/100 g of sample) and 5.85 g/100 g of sample respectively as most predominant phytochemicals in the seed extract which demonstrated maternal toxicity. The effects on the female reproductive hormones of the treated animals revealed that FSH, LH and prolactin were significantly reduced (p < 0.05) in all the treated groups by the extract. Progesterone (PH) and estrogen (EH) were also reduced significantly. The study revealed scientific evidence in support of the abortifacient activity of seed extract that was significantly corresponding to the discovered phytochemical compounds.

Adsorption of mesitylene via mesoporous adsorbents

Mesitylene (or 1,3,5-trimethylbenzene) is a volatile organic compound emitted from various industrial processes, e.g., spray coating. Its emissions have become a critical issue because mesitylene is toxic and cannot be removed using traditional adsorbents, e.g., zeolite (H-ZSM-5; the diameter of mesitylene molecules is greater than the pore size of H-ZSM-5). Hence, an adsorbent with a large pore size, MCM-41, is used in this study to investigate its adsorption capacity for mesitylene and compare with that of H-ZSM-5. Experimental results reveal that MCM-41 without Al₂O₃ exhibits a good adsorption capacity (184 mg/g) for the gas stream containing 100 ppm of mesitylene at a relative humidity of 10%. The adsorption kinetics is well described by the Freundlich isotherm. Furthermore, experimental results reveal that MCM-41 is effective for the adsorption of low concentrations (10 ppm) of mesitylene. In addition, adsorption-desorption tests revealed that the sample MCM-41-AS is stable to sustain the adsorption capacity after 10 adsorption-desorption cycles. After 10 adsorption-desorption cycles, MCM-41-AS retains 92.4% of its initial adsorption capacity (170 vs. 184 mg/g). Finally, MCM-41 and H-ZSM-5 in series are effective for the simultaneous removal of mesitylene and toluene in the gas stream.

IMPLICATIONS

This study aims to improve the performance of adsorbent for mesitylene, which is typically applied in the spray-coating industry. The zeolite MCM-41-AS is selected as a candidate for the investigation. Experimental results reveal that MCM-41-AS exhibits a good adsorption capacity for mesitylene and that it can be integrated with H-ZSM-5-25 for the simultaneous adsorption of mesitylene and toluene.