An Improved GC-MS Method for Malondialdehyde (MDA) Detection: Avoiding the Effects of Nitrite in Foods

Study on the Anti-Inflammatory Effect of Gentiana scabra Bunge Extract and Its Mechanism Using Zebrafish and RAW264.7 Cell Models

Gentiana scabra Bunge (Gentian) is a traditional medicinal plant valued for its anti-inflammatory and analgesic effects, with historical use in treating atopic dermatitis. Despite its therapeutic reputation, a comprehensive scientific analysis of its constituents is lacking. This study systematically evaluates the anti-inflammatory effects of Gentian extract and explores its molecular mechanisms. We characterized the chemical profile of Gentian extracts using HPLC and assessed their anti-inflammatory activity in zebrafish and cellular models. Gentian extract significantly reduced inflammation, as shown by decreased neutrophil migration in response to sodium lauryl sulfate (SLS), reduced tail wagging in zebrafish embryos, and alleviated lipopolysaccharide (LPS)-induced edema. It also lowered reactive oxygen species (ROS) and malondialdehyde (MDA) levels, indicating antioxidant properties, and downregulated pro-inflammatory cytokines and genes. In LPS-stimulated RAW264.7 cells, the extract upregulated IκBα and reduced p65 and STAT3 phosphorylation, inhibiting NF-κB and JAK-STAT pathways. This study is the first to systematically evaluate the anti-inflammatory mechanisms of Gentian extract in zebrafish and RAW264.7 cell models, enhancing its understanding and providing a scientific basis for its application in anti-inflammatory products.

Construction of Guanidinium-Functionalized Covalent Organic Frameworks via Phototriggered Click Reaction as a Dual-Mode Accurate Sensor for Malondialdehyde

Malondialdehyde (MDA) serves as a pivotal indicator to estimate the lipid peroxidation status and as a biomarker for the assessment of oxidative stress and screening of disease by people excretion. However, most of the existing analytical methods for MDA suffer from complicated derivation, leading to poor accuracy and inconvenience. In this work, the guanidinium-functionalized covalent organic framework (COF) was delicacy-designed and used to tune the modular structure by the building blocks with condensation, phototriggered click reaction, and further guanidylation process. A methoxy-group-containing linker in the skeleton was adopted to form lone-pair delocalized oxygen atoms, trigger the resonance effect, attenuate the polarization of the C═N bond linkages, and weaken the interlayer repulsion, supporting the stability of the guest gating COF. The available guanidino groups grew from the ordered pore walls of the COF and served as the customized talon with an enhanced interaction site density to rapidly grab the target guest by charge-assisted strong hydrogen bonds and electrostatic attraction forces. This distinctive feature significantly bolstered sensitive signal transduction, enabling rapid MDA sensing (within 120 s) without derivation treatment, and achieved a calculated limit of detection (LOD) as low as 0.08 μM. With the accessible image-data transmission process, the portable dual-channel sensing platform achieved sensitive and accurate MDA monitoring.

Separation, Analysis, and Degradation of Cembranoids in Flue-Cured Tobacco Leaves

Cembranoids are significant flavor precursors found in flue-cured tobacco leaves. The degradation products can serve as important aromatic compounds. In this study, 16 cembranoids were discovered in flue-cured tobacco leaves by liquid chromatography-mass spectrometry (MS), and 1 cembranoid featuring both oxidation and dehydrogenation from α/β-cembranoid was identified for the first time. α- and β-cembranoids were confirmed to be precursors to various degradation products. Additionally, β-cembranoid was prone to epimerize into α-cembranoid while simultaneously undergoing allylic rearrangement, with the hydroxyl group undergoing migration. During the aging and curing processes, cembranoids can easily add oxygen atoms to the carbon-carbon double bonds, whereas the hydroxyl group in the structure may form epoxides, oxidize into ketones, or undergo dehydration reactions. Additionally, the microwave plasma torch interfaced with an MS was used to create and detect the pyrolysis and oxidized products of cembranoids. More degradation products were discovered, including oxidation products with the addition of one to three oxygen atoms, as well as a series of aromatic compounds such as 1,3,5-heptatriene and its range of homologs. This research presented the different degradation pathways of cembranoids in flue-cured tobacco during aging and curing processes, offering valuable insights for the enhancement of tobacco production techniques and quality control.

The Efficiency of Chitosan Against Tert Butylhydroquinone (TBHQ)-Induced Neurobehavioral Changes and Toxicity Effects in Male Rats

BACKGROUND

We investigated chitosan's protective effects against tertiary butylhydroquinone (TBHQ)-induced toxicity in adult male rats, focusing on cognitive functions and oxidative stress in the brain, liver, and kidneys.

METHODS

Rats were divided into four groups (n = 8/group): (1) Control, (2) Chitosan only, (3) TBHQ only, and (4) Chitosan + TBHQ.

RESULTS

TBHQ exposure led to significant cognitive impairments and increased oxidative stress, marked by elevated malondialdehyde (MDA) and decreased superoxide dismutase (SOD) and glutathione (GSH) levels. Behavioral tests, including the Morris Water Maze (MWM) as well as Passive Avoidance Learning (PAL) tasks, confirmed memory and learning deficits in the TBHQ group. Histopathological analysis showed damage in the brain, liver, and kidney tissues of TBHQ-exposed rats. Chitosan treatment significantly mitigated these effects, reducing oxidative stress markers and preserving tissue integrity. These findings suggest that chitosan's antioxidant properties may provide a therapeutic benefit against TBHQ-induced neurotoxicity and organ damage.

CONCLUSIONS

These findings suggest that chitosan exerts potent neuroprotective effects, potentially through its antioxidant and anti-inflammatory properties, and could serve as a therapeutic agent against TBHQ-induced toxicity.

Chrysin mitigates neuronal apoptosis and impaired hippocampal neurogenesis in male rats subjected to D-galactose-induced brain aging

Oxidative stress-induced neuronal apoptosis is primarily involved in brain aging and impaired hippocampal neurogenesis. Long-term D-galactose administration increases oxidative stress related to brain aging. Chrysin, a subtype of flavonoids, exhibits neuroprotective effects, particularly its antioxidant properties. To elucidate the neuroprotection of chrysin on neuronal apoptosis and an impaired hippocampal neurogenesis relevant to oxidative damage in D-galactose-induced brain aging, male Sprague Dawley rats were allocated into vehicle control, D-galactose, chrysin, and cotreated rats. The rats received their respective treatments daily for 8 weeks. The reactions of scavenging enzymes, protein regulating endogenous antioxidant defense, and anti-apoptotic protein expression were significantly reduced in the hippocampus and prefrontal cortex of the animals receiving D-galactose. Conversely, product of oxidative damage and apoptotic protein expressions were significantly elevated in both cortical areas of the D-galactose group. In hippocampal neurogenesis, significant upregulation of cell cycle arrest and decrease in differentiated protein expression were detected after D-galactose administration. Nevertheless, chrysin supplementation significantly mitigated all negative effects in animals receiving D-galactose. This study demonstrates that chrysin likely attenuates brain aging induced by D-galactose by enhancing scavenging enzyme activities and reducing oxidative stress, neuronal apoptosis, and the impaired hippocampal neurogenesis.

Possible role of high calcium concentrations in rat neocortical neurons in inducing hyper excitatory behavior during emergence from sevoflurane: a proposed pathophysiology

Sevoflurane has been shown to increase the incidence of emergence delirium in children; however, the mechanism remains unclear. Sevoflurane increases cytoplasmic calcium concentration which in turn may play a role in emergence delirium. This study aimed to investigate the level of intracellular calcium in rats experiencing hyperexcitatory behavior after exposure to sevoflurane, as well as the role of magnesium in preventing this phenomenon. After ethical approval, 2-5-week-old Sprague-Dawley rats (n = 34) were insufflated with sevoflurane in a modified anesthesia chamber. One group received magnesium sulphate intraperitoneally. After termination of sevoflurane exposure, the occurrence of hyperexcitation was observed. Brain tissue samples from the rats were studied for intracellular calcium levels under a two-channel laser scanning confocal microscope and were quantitatively calculated using ratiometric calculation. The presence of inflammation or oxidative stress reaction was assessed using nuclear factor κB and malondialdehyde. The incidence of hyperexcitatory behavior post sevoflurane exposure was 9 in 16 rats in the observation group and none in the magnesium group. Tests for inflammation and oxidative stress were within normal limits in both groups. The rats showing hyperexcitation had a higher level of cytosol calcium concentration compared to the other groups. To conclude, the calcium concentration of neocortical neurons in Sprague-Dawley rats with hyperexcitatory behavior is increased after exposure to sevoflurane. Administration of magnesium sulphate can prevent the occurrence of hyperexcitation in experimental animals.

Green infant formula analysis: Optimizing headspace solid-phase microextraction of carbonyl compounds associated with lipid peroxidation using GC-MS and pentafluorophenylhydrazine derivatization

The refinement and optimization of a method combining headspace solid-phase microextraction (HS-SPME) with gas chromatography-mass spectrometry (GC-MS) was successfully performed for the first time to determine seven carbonyl and dicarbonyl compounds, including glyoxal, methylglyoxal, dimethylglyoxal, and malondialdehyde in infant formulae, related to lipid peroxidation. HS-SPME was utilized for simultaneous extraction and derivatization with pentafluorophenylhydrazine (PFPH). Critical parameters such as temperature, pH, extractive phase, and salting-out were meticulously investigated and fine-tuned by an asymmetrical 2232//9 screening design to ensure the method's efficacy and reliability. Optimal conditions included a PFPH concentration of 5 g/L, pH 5.0, head-space extraction at 60 °C within 10 min, utilizing a DVB/CAR/PDMS coating, and a 20% w/w salting-out. The analytical validation of this method, compliant with FDA guidelines, demonstrated exceptional linearity, sensitivity, specificity, precision (RSD ≤13.8%), and accuracy (84.8% ≤ recovery ≤111.5%). The metric approach AGREEprep confirms its eco-friendliness, marking a significant step towards an environmentally conscious approach in infant formula analysis. An occurrence study conducted on 25 infant formula samples revealed widespread carbonyl and dicarbonyl compounds in both powdered and liquid variants. ANOVA results exhibited variations in compound concentrations among different sample groups. Clustering analyses delineated distinct groups based on carbonyl content, indicating the potential of these compounds as markers for lipid peroxidation and food quality assessment. This method serves as a valuable tool for evaluating infant formula quality, stability towards oxidation, and safety.

Integration of Ultrathin Bubble Walls and Electrochemistry: Innovation in Microsensing for Forensic Nitrite Detection and Microscale Metallic Film Deposition

We present a strategy for electrochemical measurements using a durable minute bubble wall with a thickness of 27 μm (D = 1.8 cm) as an innovative electrochemical medium. The composition, thickness, and volume of the tiny bubble film were investigated and estimated using the spectroscopic method and the Beer-Lambert law. A carbon microelectrode (D = 10 μm) was then employed as the working electrode, inserted through the bubble wall to function as the solution interface. First, the potential of this method for microelectrodeposition of metallic Ag and Pd films in a tiny bubble was investigated. Interestingly, microscopic images of the deposited film clearly demonstrated that the bubble thickness determines and confines the electrochemical deposition zone. In other words, innovative template-free microelectrodeposition was achieved. In the second phase of our work, microelectroanalysis of trace levels of nitrite ions was performed within the bubble wall and on a foam-covered hand, between the fingers directly, with a low limit of detection of 28 μM. This technique holds significance in criminal investigations, as the presence of NO2- ions on the hand indicates the potential presence of gunshot residue and aids in identifying suspects. In comparison to current methods, this approach is rapid, simple, cost-effective, and amenable to on-site applications, eliminating the need for sample treatment. Ultimately, the utilization of a bubble wall as a novel electrochemical microreactor can open new ways in microelectrochemical analysis, presenting novel opportunities and applications in the field of electrochemical sensors.

Ameliorative effect of Odontonema cuspidatum extract against testicular damage induced by sodium nitrite in rats

Background

Sodium nitrite (NaNO2) is a chemical substance used to enhance taste, add color, and keep food products fit for consumption for a longer time. NaNO2 gives rise to a negative adverse effect on male reproductive function. Odontonema cuspidatum (OC) is a natural plant that possesses antioxidant capacity.

Aim

Our research evaluates the potential beneficial effect of OC extract on the harmful effects caused by NaNO2 on the testicular tissue and sperm characteristics of male rats.

Methods

Four groups with a total of forty rats: the control, the NaNO2-received group, the OC-administered group, and the fourth group received both NaNO2 and OC. All groups were administered daily for two months. Sperm characteristics, testicular antioxidant status, qRT-PCR, and histopathological changes were evaluated.

Results

Coadministration of NaNO2 and OC, in comparison with NaNO2 alone, contributed to a notable enhancement in acrosomal integrity, decreasing sperm abnormalities and restoring serum testosterone levels. Moreover, such coadministration reduced the oxidative stress marker, malondialdehyde (MDA), and increased superoxide dismutase (SOD) in testicular tissue, lowering TNF-α gene expression, and increasing the expression of P450scc and StAR genes. In addition, the NaNO2 and OC combination decreased the testicular histopathological changes and the Caspase-3 and Proliferating cell nuclear antigen (PCNA) immunoexpression in seminiferous tubules compared with the NaNO2 group.

Conclusion

The extract of OC exhibited the ability to decrease oxidative stress and ameliorate the detrimental effects caused by NaNO2.

Green Synthesis of Au Magnetic Nanocomposites Using Waste Chestnut Skins and Their Application as a Peroxidase Mimic Nanozyme Electrochemical Sensing Platform for Sodium Nitrite

An electrochemical sensor with high sensitivity for the detection of sodium nitrite was constructed based on the peroxidase-like activity of Au magnetic nanocomposites (Au@Fe3O4). The Au@Fe3O4 composite nanoparticles were green-synthesized via the reduction of gold nanoparticles (AuNPs) from waste chestnut skins combined with the sonochemical method. The nanoparticles have both the recoverability of Fe3O4 and the advantage of being able to amplify electrical signals. Furthermore, the synergistic effect of green reduction and sonochemical synthesis provides a functional approach for the preparation of Au@Fe3O4 with significant peroxidase-like activities. The physicochemical properties were characterized using transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), the Brunauer-Emmett-Teller (BET) method, and Fourier transform infrared spectroscopy (FT-IR). The electrochemical properties of sodium nitrite were determined with cyclic voltammetry (CV) and chronoamperometry (i-t). The results revealed that Au@Fe3O4 acted as a peroxidase mimic to decompose hydrogen peroxide to produce free radicals, while ·OH was the primary free radical that promoted the oxidation of sodium nitrite. With the optimal detection system, the constructed electrochemical sensor had a high sensitivity for sodium nitrite detection. In addition, the current response had a good linear relationship with the sodium nitrite concentration in the range of 0.01-100 mmol/L. The regression equation of the working curve was y = 1.0752x + 4.4728 (R2 = 0.9949), and the LOD was 0.867 μmol/L (S/N = 3). Meanwhile, the constructed detection system was outstanding in terms of recovery and anti-interference and had a good detection stability of more than 96.59%. The sensor has been successfully applied to a variety of real samples. In view of this, the proposed novel electrochemical analysis method has great prospects for application in the fields of food quality and environmental testing.

Ameliorative effect of Nigella sativa conjugated silver nanoparticles against chromium-induced hepatotoxicity and renal toxicity in mice

Hexavalent chromium induces oxidative stress in the liver and kidney. Therefore an in vivo study was designed to investigate the modulatory effect of biosynthesized AgNP against Cr (VI) induced hepatotoxicity and nephrotoxicity. The organs index, serum level of ALT, AST, ALP, MDA, total protein and creatinine were measured. The histopathology and micrometry of the liver and kidney were examined. The liver index was significantly increased (0.098 ± 0.13 g) with slight increase in kidney index in Cr exposed group. The serum level of ALT (163.0 ± 5.5 U/L), AST (484.0 ± 10.7 U/L), ALP (337.6 ± 9.6 U/L), MDA (641.2 ± 29.2 U/L), and creatinine (2.9 ± 0.2 mg/dL) were significantly increased (P ≤ 0.05) with significant decrease in total protein level (2.9 ± 0.2 g/dL) (P ≤ 0.05) in chromium treated group. In histopathology, distorted hepatic cords, necrosis, damaged glomerulus and Bowman's capsule were observed. Micrometric studies of the liver and kidney showed significant increase in size of hepatocytes (1188.2 ± 467.7 µ²) and their nuclei (456.4 ± 206.7 µ²), ACSA of Bowman's capsule (11835.5 ± 336.7 µ²) and glomerulus (9051.8 ± 249.8 µ²⁾ in Cr (VI) treated group. The size of brush border (10.1 ± 3.0 µ) was significantly reduced in Cr (VI) treated group however the ACSA of lumen was not significantly changed. With the administration of NSSE and Nigella sativa AgNPs, decreased the oxidative damage caused by Cr (V).

Transcriptomics and metabolomics analysis reveal the anti-oxidation and immune boosting effects of mulberry leaves in growing mutton sheep

Introduction

Currently, the anti-oxidation of active ingredients in mulberry leaves (MLs) and their forage utilization is receiving increasing attention. Here, we propose that MLs supplementation improves oxidative resistance and immunity.

Methods

We conducted a trial including three groups of growing mutton sheep, each receiving fermented mulberry leaves (FMLs) feeding, dried mulberry leaves (DMLs) feeding or normal control feeding without MLs.

Results

Transcriptomic and metabolomic analyses revealed that promoting anti-oxidation and enhancing disease resistance of MLs is attributed to improved tryptophan metabolic pathways and reduced peroxidation of polyunsaturated fatty acids (PUFAs). Furthermore, immunity was markedly increased after FMLs treatment by regulating glycolysis and mannose-6-phosphate pathways. Additionally, there was better average daily gain in the MLs treatment groups.

Conclusion

These findings provide new insights for understanding the beneficial effects of MLs in animal husbandry and provide a theoretical support for extensive application of MLs in improving nutrition and health care values.