Tomoki Fukuyama

Chronic dietary exposure to low concentrations of deoxynivalenol (DON), a trichothecene mycotoxin found in cereal products, disrupts immune homeostasis and exacerbates allergic inflammation. Chlorella sorokiniana ( CS ) can adsorb DON and reduce its systemic absorption. However, whether this DON-binding activity protects against DON-induced immune dysregulation remains unclear. Here, we investigated the effects of CS on DON-induced toxicity and DON-exacerbated allergic dermatitis. In vitro, murine DC2.4 dendritic cells were exposed to DON in the presence or absence of CS -treated DON preparations. DON reduced cell viability and ATP-dependent luminescence while increasing IL-1β and TNFα production in a concentration-dependent manner. Pretreatment with CS attenuated these cytotoxic and pro-inflammatory effects. In vivo, chronic low-dose DON exposure aggravated toluene diisocyanate–induced allergic dermatitis, as demonstrated by increased ear swelling, scratching behavior, inflammatory cell infiltration, dermal edema, and cutaneous expression of Il4 , Il13 , and Il33 . DON also increased dendritic, activated CD4 ⁺ T, and IgE ⁺ B cell populations; type 2 cytokine production; and serum IgE levels. Oral CS administration attenuated local and systemic allergic responses. Contrastingly, CS exerted limited effects on allergic inflammation in mice not exposed to DON, indicating that its protective activity was primarily associated with the mitigation of DON toxicity rather than with nonspecific immunosuppression. Both conventional and pulverized CS reduced several DON-associated inflammatory responses. An in vitro binding assay confirmed that CS decreased residual DON concentrations. These findings demonstrate that CS reduces the bioavailability and immunotoxic effects of DON and may represent a functional dietary strategy for preventing the mycotoxin-associated exacerbation of allergic inflammation.

House dust mite extract derived from Dermatophagoides pteronyssinus (Der p) is a major cause of allergic asthma; however, effective preventive approaches remain limited. This study examined whether direct treatment of Der p extract with engineered water nanostructures (EWNS) reduces the detectable allergen signal and biological responses associated with Der p 1. Der p extracts were exposed to EWNS for 1–24 h, and the ELISA-detectable Der p 1 signal was measured. Dendritic cell activation induced by EWNS-treated or untreated Der p extract normalized to Der p 1 content was evaluated in DC2.4 cells. A Der p-induced allergic airway inflammation model was generated by repeated intranasal administration of EWNS-treated or untreated Der p extract normalized to Der p 1 content. EWNS exposure reduced the ELISA-detectable Der p 1 signal. Ca ²⁺ influx, MHC class II expression, inflammatory cytokine production, and immune-related gene expression were attenuated by EWNS-treated Der p extract. In vivo, EWNS-treated Der p extract significantly reduced Der p-induced allergic airway inflammation, as indicated by improved percutaneous oxygen saturation and decreased pro-inflammatory responses. These findings suggest that EWNS treatment may reduce the allergenic activity of Der p extract.

Japanese cedar pollen ( Cryptomeria japonica ) is a major cause of seasonal allergic rhinitis in Japan, and Cry j 1 has been identified as its principal allergen. Although current treatments provide symptomatic relief, they do not prevent sensitization, highlighting the need for novel preventive strategies. Nanosized electrostatically atomized water particles (NEAWPs) are nanometer-scale water droplets containing reactive oxygen species (ROS) that have demonstrated antimicrobial activity; however, their effects on airborne allergens remain unclear. Therefore, this study investigated whether NEAWPs could reduce the allergenicity of Cry j 1 in human bronchial epithelial cells (BEAS-2B) and monocytic antigen-presenting cells (THP-1). Briefly, Cry j 1 was exposed to NEAWPs for 24–48 h, and allergenicity was assessed by ELISA, calcium imaging, flow cytometry, and cytokine analyses. NEAWPs treatment markedly reduced Cry j 1 antigenicity in a time-dependent manner, achieving 98.6% reduction after 48 h. In BEAS-2B cells, untreated Cry j 1 induced significant Ca²⁺ influx and upregulated IL-8, TNF-α, and IL-6 expression, whereas NEAWP-treated Cry j 1 failed to elicit these responses. Similarly, in THP-1 cells, NEAWP-treated Cry j 1 decreased CD11c+CD86+ cells and inflammatory cytokine production. These results indicate that NEAWPs denature Cry j 1, preventing epithelial activation and antigen presentation, thereby attenuating downstream immune responses. This study provides the first evidence that NEAWPs can effectively reduce the allergenicity of Japanese cedar pollen, suggesting a potentially non-invasive, environmentally friendly approach for allergy prevention. Therefore, future studies are required to explore the molecular mechanisms, in vivo efficacy, and safety of NEAWPs exposure to establish its translational potential in managing pollinosis and other airborne allergies.

Volatile organic compounds (VOCs) are increasingly implicated in systemic diseases, but their contribution to skin disorders such as atopic dermatitis (AD) remains unclear. This study assessed VOC concentrations in medical environments, their effects on AD development, and the efficacy of VOC removal using chemical filters. Total VOC levels were monitored in 3 types of veterinary hospitals. AD-like lesions were induced in female NC/Nga mice by repeated dermal application of toluene diisocyanate or house dust mite ointment, with or without topical exposure to a VOC mixture (10 μg/ml). Clinical parameters, including dermatitis scores, transepidermal water loss, and skin thickness, were measured weekly, and immunological and histological analyses were performed. VOC monitoring revealed that 1 hospital exhibited concentrations exceeding 400 μg/m³. In the mouse model, direct VOC exposure significantly aggravated keratinocyte inflammation and worsened AD symptoms. Application of chemical filtering systems effectively reduced VOC levels in real clinical settings, and their use in the experimental model suppressed AD development. However, therapeutic application of VOC removal showed only limited effects on systemic immunological markers. These findings suggest that VOCs present in healthcare environments may contribute to the onset and progression of AD. Incorporating VOC-removing filters into air-conditioning systems could serve as a preventive strategy to improve the management of allergic skin diseases.

Bentonite, a naturally occurring clay mineral, is widely used for detoxifying mycotoxins and chemical contaminants, yet its potential interactions with microorganisms remain poorly characterized. Staphylococci, including Staphylococcus aureus in humans and Staphylococcus pseudintermedius in dogs, are major contributors to impetigo or pyoderma and other skin diseases, with rising antibiotic resistance underscoring the need for novel preventive strategies. This study investigated whether sodium bentonite directly modulates staphylococcal growth and associated inflammatory responses in vitro and in vivo . In bacterial culture assays, sodium bentonite showed a strong binding affinity for staphylococci, leading to significant reductions in viable colony counts. Pre-treatment of S. aureus and S. pseudintermedius with bentonite attenuated keratinocyte injury and markedly suppressed pro-inflammatory cytokine secretion, including IL-6, IL-8, and CCL2. In a murine pyoderma model, bentonite pre-treatment of S. pseudintermedius prevented lesion development, reduced bacterial burden, and downregulated cutaneous expression of TNFα, IL-1β, and IL-13, findings that were corroborated by histological improvements. Importantly, these effects extended to methicillin-resistant strains, highlighting a potential application against drug-resistant staphylococcal infections. By contrast, direct topical administration of bentonite gel in a murine atopic dermatitis model produced only modest benefits: ear swelling was reduced, but transepidermal water loss and clinical scores remained unchanged, suggesting limited therapeutic value in established chronic inflammatory conditions. Overall, sodium bentonite does not exhibit intrinsic bactericidal or anti-inflammatory properties but exerts protective effects through direct bacterial binding and subsequent inhibition of staphylococcus-induced cytotoxicity and inflammation. These findings identify sodium bentonite as a safe, non-antibiotic preventive option for staphylococci-associated skin diseases, particularly pyoderma, in both humans and companion animals. Future studies should further explore formulation strategies and delivery methods to optimize its clinical utility.