SensoryGAN: AI-driven design of low-toxicity dairy flavor alternatives with integrated neurosensory and cellular safety validation.

Bronchiolitis obliterans (BO) is a destructive fibrotic lung disease, which can be partly induced by 2,3‑butanedione [also known as diacetyl (DA)]; however, the mechanism underlying the effects of DA on BO is not clear. In the present study, a bioinformatics analysis was performed using DA‑treated or untreated lung tissues of rats, and it was observed that cell proliferation regulating inhibitor of protein phosphatase 2A (CIP2A) was significantly increased in samples from the DA group. CIP2A is associated with inflammation and epithelial‑mesenchymal transition (EMT), and facilitates lung injury; however, its effect on DA‑induced BO and the underlying mechanism remain unknown. To solve these issues, DA‑treated models of BO were established in rats and cells, and ethoxysanguinarine (a CIP2A inhibitor) was administered to induce a decrease in CIP2A. The pathological changes were detected by hematoxylin and eosin, Masson and Giemsa staining. Reverse transcription‑quantitative PCR, western blotting, immunohistochemistry, immunofluorescence and enzyme‑linked immunosorbent assay were used to measure CIP2A expression and levels of pathology‑related markers. Notably, inhibition of CIP2A ameliorated the pathological features of BO, including reduced intraluminal occlusion, inflammatory infiltration and fibrosis. The expression of inflammation, fibrosis and EMT markers was also decreased in samples with CIP2A inhibition. Furthermore, CIP2A inhibition was revealed to work through the nuclear factor‑κB (NF‑κB) pathway; phosphorylation of NF‑κB inhibitor α and nuclear translocation of p65 were reduced. In summary, these results demonstrated that CIP2A may promote BO development by increasing inflammation, fibrosis and EMT through activating the NF‑κB signaling pathway. Therefore, inhibition of CIP2A may be considered a potential strategy for BO treatment.

IntroductionBronchiolitis obliterans (BO) is an irreversible, chronic obstructive pulmonary disease with inflammation and fibrosis causing bronchiolar narrowing. Inhaling diacetyl (DA) can result in BO in humans.MethodsWe aimed to investigate the relationship between fibrosis-related gene expression and ubiquitin C (UbC) regulation in a rat model of BO following a single DA instillation, by examining lung histopathology, UbC protein levels, and transcriptomic changes.ResultsAfter DA exposure, rat bronchioles exhibited marked inflammation, increased collagen deposition, airway fibrosis, and obstruction. These changes were confirmed by histology and semi-quantitative image analysis. UbC protein levels were significantly elevated in a time-dependent manner. RNA sequencing revealed significant alterations in gene expression and enrichment of multiple molecular functions and biological processes in BO rats compared with controls, including pathways related to fibrosis formation and ubiquitin dysregulation. Quantitative PCR (qPCR) validation further confirmed the transcriptomic results, showing significant upregulation of Ube2t and Fap and downregulation of Cyp1a1, consistent with enhanced ubiquitin activity, fibroblast activation, and impaired oxidative stress regulation.DiscussionThese findings indicate that DA instillation induces early BO-like changes, disrupts ubiquitin regulation, and increases UbC expression, potentially through oxidative stress–related mechanisms. A better understanding of ubiquitin regulation (particularly UbC) may provide novel molecular targets for therapeutic intervention in BO.

Determination of α-Dicarbonyl compounds in traditional Chinese herbal medicines

Bronchiolitis obliterans (BO) is a devastating lung disease that can develop following inhalation exposure to certain chemicals. Diacetyl (DA) is one chemical commonly associated with BO development when inhaled at occupational levels. Previous studies in rats have shown that repetitive DA vapor exposures increased lung CD4+CD25+ T cells and bronchoalveolar (BAL) interleukin-17A (IL-17A) concentrations concurrent with the development of airway remodeling. We hypothesized that IL-17A neutralization would attenuate the severity of airway remodeling after repetitive DA vapor exposures. Sprague-Dawley rats were exposed to 200 parts-per-million DA vapor or filtered air (RA) for 6 h/day × 5 days and monitored for 2 wk postexposure. Treatment with IL-17A neutralization (αIL-17A) or IgG (control) began immediately following exposures and continued twice weekly until study's end. Lungs were harvested for histology, flow cytometry, and BAL analyses. Survival, oxygen saturations, and percent weight change decreased significantly in DA-exposed versus RA-exposed rats, but did not differ significantly between DA + αIL-17A versus DA + IgG. Similarly, the number nor severity of airway lesions did not differ significantly between DA + αIL-17A versus DA + IgG rats despite the percentage of lung regulatory T cells increasing with decreased BAL IL-17A concentrations. Ashcroft scoring of the distal lung parenchyma suggested worse parenchymal remodeling in DA + αIL-17A versus DA + IgG rats with increased expression of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and nuclear factor-kappa B (NF-κB). Collectively, IL-17A neutralization in DA-exposed rats failed to attenuate airway remodeling with increased expression of pro-inflammatory cytokines TNF-α, IL-1β, and NF-κB.NEW & NOTEWORTHY Interleukin-17A (IL-17A) neutralization has shown benefit previously in preclinical models of transplant-associated bronchiolitis obliterans (BO), yet it remains unknown whether IL-17A neutralization has similar benefit for other forms of BO. Here, IL-17A neutralization fails to prevent severe airway remodeling in rats exposed repetitively to the flavoring chemical diacetyl, and instead, promotes a proinflammatory microenvironment with increased expression of TNF-α, IL-1β, and NF-κB within the lung.

The use of e-cigarettes (ECs) has become increasingly popular worldwide, even though scientific results have not established their safety. Diacetyl (DA) and acetylpropionyl (AP), which can be present in ECs, are linked with lung diseases. Ethyl maltol (EM)—the most commonly used flavoring agent—can be present in toxic concentrations. Until now, there is no methodology for the determination of nicotine, propylene glycol (PG), vegetable glycerin (VG), EM, DA, and acetylpropionyl in e-liquids that can be used as a quality control procedure. Herein, gas chromatography coupled with mass spectrometry (GC-MS) was applied for the development of analytical methodologies for these substances. Two GC-MS methodologies were developed and fully validated, fulfilling the standards for the integration in a routine quality control procedure by manufacturers. As proof of applicability, the methodology was applied for the analysis of several e-liquids. Differences were observed between the labeled and the experimental levels of PG, VG, and nicotine. Three samples contained EM at higher concentrations compared to the other samples, while only one contained DA. These validated methodologies can be used for the quality control analysis of EC liquid samples regarding nicotine, PG, and VG amounts, as well as for the measurement of the EM.

Bronchiolitis obliterans (BO) is a debilitating disease of the small airways that can develop following exposure to toxic chemicals as well as respiratory tract infections. BO development is strongly associated with diacetyl (DA) inhalation exposures at occupationally relevant concentrations or severe influenza A viral (IAV) infections. However, it remains unclear whether lower dose exposures or more mild IAV infections can result in similar pathology. In the current work, we combined these two common environmental exposures, DA and IAV, to test whether shorter DA exposures followed by sublethal IAV infection would result in similar airways disease. Adult mice exposed to DA vapors 1 h/day for 5 consecutive days followed by infection with the airway-tropic IAV H3N2 (HKx31) resulted in increased mortality, increased bronchoalveolar lavage (BAL) neutrophil percentage, mixed obstruction and restriction by lung function, and subsequent airway remodeling. Exposure to DA or IAV alone failed to result in significant pathology, whereas mice exposed to DA + IAV showed increased α-smooth muscle actin (αSMA) and epithelial cells coexpressing the basal cell marker keratin 5 (KRT5) with the club cell marker SCGB1A1. To test whether DA exposure impairs epithelial repair after IAV infection, mice were infected first with IAV and then exposed to DA during airway epithelial repair. Mice exposed to IAV + DA developed similar airway remodeling with increased subepithelial αSMA and epithelial cells coexpressing KRT5 and SCGB1A1. Our findings reveal an underappreciated concept that common environmental insults while seemingly harmless by themselves can have catastrophic implications on lung function and long-term respiratory health when combined.

Neuroinflammation, a major component of many CNS disorders, has been suggested to be associated with diacetyl (DA) exposure. DA is commonly used as a food flavoring additive and condiment. Lately, silymarin (Sily) has shown protective and therapeutic effects on neuronal inflammation. The study aimed to explore the role of Sily in protecting and/or treating DA-induced neuroinflammation. Neuroinflammation was induced in rats by administering DA (25 mg/kg) orally. Results revealed that Sily (50 mg/kg) obviously maintained cognitive and behavioral functions, alleviated brain antioxidant status, and inhibited microglial activation. Sily enhanced IL-10, GDNF and Dyn levels, reduced IFN-γ, TNFα, and IL-1β levels, and down-regulated the MAPK pathway. Immunohistochemical investigation of EGFR and GFAP declared that Sily could conserve neurons from inflammatory damage. However, with continuing DA exposure during Sily treatment, oxidative stress and neuroinflammation were less mitigated. These findings point to a novel mechanism involving the Dyn/GDNF and MAPK pathway through which Sily might prevent and treat DA-induced neuroinflammation.

Comparison of pyrazines formation in methionine/glucose and corresponding Amadori rearrangement product model

Diacetyl (DA) is a highly reactive alpha diketone associated with flavoring-related lung disease. In rodents, acute DA vapor exposure can initiate an airway-centric, inflammatory response. However, this immune response has yet to be fully characterized in the context of flavoring-related lung disease progression. The following studies were designed to characterize the different T cell populations within the lung following repetitive DA vapor exposures. Sprague-Dawley rats were exposed to 200 parts-per-million DA vapor for 5 consecutive days × 6 h/day. Lung tissue and bronchoalveolar lavage fluid (BALF) were analyzed for changes in histology by H&E and Trichrome stain, T cell markers by flow cytometry, total BALF cell counts and differentials, BALF IL17a and total protein immediately, 1 and 2 weeks post-exposure. Lung histology and BALF cell composition demonstrated mixed, granulocytic lung inflammation with bronchial lymphoid aggregates at all time points in DA-exposed lungs compared to air controls. While no significant change was seen in percent lung CD3+, CD4+, or CD8+ T cells, a significant increase in lung CD4+CD25+ T cells developed at 1 week that persisted at 2 weeks post-exposure. Further characterization of this CD4+CD25+ T cell population identified Foxp3+ T cells at 1 week that failed to persist at 2 weeks. Conversely, BALF IL-17a increased significantly at 2 weeks in DA-exposed rats compared to air controls. Lung CD4+CD25+ T cells and BALF IL17a correlated directly with BALF total protein and inversely with rat oxygen saturations. Repetitive DA vapor exposure at occupationally relevant concentrations induced mixed, granulocytic lung inflammation with increased CD4+CD25+ T cells in the rat lung.

Analysis of α-dicarbonyl compounds and 4-methylimidazole in coffee made with various roasting and brewing conditions

In this study, an analytical method for the determination of α-dicarbonyl compounds (α-DCs), including glyoxal (GO), methylglyoxal (MGO) and diacetyl (DA), in soy sauce was validated using gas chromatography-nitrogen-phosphorus detection. Through Maillard reaction various α-DCs, including GO, MGO and DA have been found in fermented food, dairy products and beverages. The analysis of α-DC was carried out by a derivatisation with o-phenylenediamine. The limit of detection and limit of quantitation were 0.04 and 0.12μg/kg for GO, 0.04 and 0.13μg/kg for MGO, and 0.07 and 0.22μg/kg for DA. The intra- and inter-day accuracy ranged from 92.8 to 109% for GO, from 99.5 to 113% for MGO and from 93.6 to 102% for DA. The intra- and inter-day precision ranged from 3.38 to 12.1% for GO, from 0.67 to 7.65% for MGO and from 1.27 to 9.35% for DA. In 20 commercial soy sauces, α-DCs were found in concentration ranges of 5.60-31.7μg/mL for GO, 14.4-116μg/mL for MGO and 0.47-5.48μg/mL for DA. The developed analytical method could be applied for the determination of α-DCs in soy sauce and motivate investigations related to reducing the content of α-DCs in soy sauce.

Diacetyl (DA), a food flavorant, is linked with occupational lung disease. Our in vitro experiments described the formation of a covalent adduct by DA with Arg5 of the Aβ1-42 peptide, which resulted in only a transient increase in neurotoxicity in SH-SY5Y cells. However, in vivo implications of these effects on Alzheimer's disease (AD) pathogenesis and the underlying mechanisms remain poorly understood. In the APP/PS1 transgenic AD mouse model, DA treatment did not exacerbate learning and memory deficits in the Morris water maze test. Moreover, DA increased the Aβ1-42 plaque burden and decreased neuronal inflammation in the transgenic AD mice. Additionally, cognitive impairment induced by intracerebroventricular Aβ1-42 was restored by the DA treatment, as assessed by the T-maze test. A corresponding mitigation of neuronal inflammation was also observed in the hippocampus of these nontransgenic mice due to the acceleration of Aβ1-42 aggregation by DA into nontoxic plaques. The data from SDS-PAGE, dot-blot, and TEM in vitro experiments corroborated the acceleration of the Aβ1-42 aggregation observed in vivo in AD animal models and characterized the DA-induced formation of Aβ1-42 fibrils. Such Aβ1-42-DA fibrils were unstable in the presence of detergent and amenable to detection by the thioflavin T reagent, thus underscoring the distinct assembly of these fibrils compared to that of the fibrils of the native Aβ1-42. Taken together, the results of this study present for the first time the in vivo implications of the DA-induced acceleration of Aβ1-42 and may provide a strategy for the rational design of Aβ1-42 aggregation accelerators as AD therapeutics that promote oligomer-free Aβ1-42 fibril formation.

α-Dicarbonyl compounds related to antimicrobial and antioxidant activity of maillard reaction products derived from xylose, cysteine and corn peptide hydrolysate

Pentose is involved in the browning through the Maillard reaction of food derived of plant origin. During research on the Maillard reaction between xylose (Xyl) and lysine (Lys), we detected 4-hydroxy-5-methyl-3(2H)-furanone (HMFO) as a major decomposition product of Xyl. To clarify the chemical pathway of the browning of pentose system, the formation and decomposition of dicarbonyls from HMFO and Xyl were examined. In the HMFO system, HMFO was oxidatively hydrolyzed to form 2-hydroxy-3,4-dioxopentanal, which leads to the formation of methylglyoxal (MGO) and then diacetyl (DA). In the Xyl system, MGO was also the major dicarbonyl degradation product from 1-deoxyxylosone (1-DX). Among Xyl, HMFO, MGO, and DA, MGO turned brown most rapidly in the presence of Lys and formed melanoidin-like brown pigments. In the Xyl system, MGO derived from HMFO and 1-DX most contributed to the browning, although some low-molecular-weight pigments, a colorless polymer, and fluorescent substances were also formed.

Identification and characterization of a novel 2R,3R-Butanediol dehydrogenase from Bacillus sp. DL01

Analysis of α-dicarbonyl compounds in coffee (Coffea arabica) prepared under various roasting and brewing methods

Bronchiolitis obliterans is a fatal respiratory disease characterized by the obliteration of small airways. Mesenchymal stem cells (MSCs) is a promising candidate for cell-based therapy. To evaluate the therapeutic effect of human umbilical cord-derived mesenchymal stem cells (HUC-MSCs) on a murine model of bronchiolitis obliterans like injury (BOLI). The murine model of BOLI was established by administrating of diacetyl (DA) via intratracheal instillation. Treatment of HUC-MSCs or HUC-MSCs culture medium (HUC-MSCs-CM) was conducted in the BOLI model. The pathogenic manifestations, lung function, and the number of neutrophils were similar between the oropharyngeal inhalation DA group (OPI-DA), intratracheal instillation group (ITI-DA); however, less reduction of weight and higher survival rate were observed in ITI-DA groups. Compared with the control groups, the trend of weight loss was significantly reduced (p < .05), and the pulmonary function was significantly improved (p < .05) in HUC-MSCs and HUC-MSCs-CM groups. Masson staining and hematoxylin and eosin staining showed that the deposition of collagen around bronchioles and blood vessels is less and airway epithelial cells and basal cells in lung tissue repaired better in HUC-MSCs and HUC-MSCs-CM groups compared with the control groups. Immunofluorescence shows the expression of E-cadherin and cytokeratin 5 (CK-5) were significantly higher in HUC-MSCs and HUC-MSCs-CM groups compared with control groups, while HUC-MSCs themselves did not express E-cadherin or CK-5. The DiI label showed HUC-MSCs gradually reduced after 2 days in the bronchus and 4 days in bronchiole. HUC-MSCs could help to repair airway epithelial cells in a murine model of BOLI. It might be related to paracrine factors of HUC-MSCs.

Present study was aimed to determine the changes and the best consumption time of kefir samples made from cow and goat milk using starter culture during the storage at the refrigerator (+4°C for 35 days). It was found that goat kefir (GK) samples had higher pH and lipolysis values during storage while cow kefir (CK) samples had higher values of viscosity. The counts of lactococci, lactobacilli, leuconostoc, total mesophilic aerobic bacteria, acetic acid bacteria and yeast decreased during the storage. Amounts of lactic, acetic, citric, pyruvic and oxalic acids were higher in GK samples. Acetaldehyde, diacetyl and acetoin contents were higher in CK samples. The highest sensory scores were obtained for CK samples on 14th day and for GC sample on 21th day of the storage.

Exposure to diacetyl (DA) has been linked to the respiratory condition bronchiolitis obliterans. Previous research has demonstrated that DA and other α-dicarbonyl compounds can be detected in both the e-liquids and aerosols of e-vapor products (EVPs). While some EVP manufacturers may add these compounds as flavor ingredients, the primary objective of this work was to determine the potential for the formation of α-dicarbonyl compounds during the generation of aerosols from EVPs where no DA or other α-dicarbonyl compounds are added to the e-liquid. A novel ultraperformance liquid chromatography-mass spectrometry-based analytical method for the determination of DA, acetyl propionyl, glyoxal, and methylglyoxal was developed and validated. Next, eight commercially available cig-a-like-type EVPs were evaluated for α-dicarbonyl formation. Increased levels of α-dicarbonyls were observed in the aerosols of all evaluated EVPs compared to their respective e-liquids. Mechanistic studies were conducted using a model microwave reaction system to identify key reaction precursors for DA generated from propylene glycol (PG) and carbon-13-labeled glycerin (GLY). These studies, along with the corresponding retrosynthetic analysis, resulted in the proposed formation pathway where hydroxyacetone is generated from PG and/or GLY. Hydroxyacetone then participates in an aldol condensation with formaldehyde where formaldehyde can also be generated from PG and/or GLY; the resultant product then dehydrates to form DA. This proposed pathway was further investigated through in situ synthetic organic experiments within the model microwave reaction system. This work establishes that DA is formed in the aerosol generation process of the EVPs tested though at levels below toxicological concern.