Extremophilic microorganisms represent a unique source of novel natural products. Among them, cold adapted bacteria and particularly alpine microorganisms are still underexplored. Here, we describe the isolation and characterization of a novel Gram-positive, aerobic rod-shaped alpine bacterium (KRL4), isolated from sediments from the Karuola glacier in Tibet, China. Complete phenotypic analysis was performed revealing the great adaptability of the strain to a wide range of temperatures (5–40 °C), pHs (5.5–8.5), and salinities (0–15% w/v NaCl). Genome sequencing identified KRL4 as a member of the placeholder genus Exiguobacterium_A and annotation revealed that only half of the protein-encoding genes (1522 of 3079) could be assigned a putative function. An analysis of the secondary metabolite clusters revealed the presence of two uncharacterized phytoene synthase containing pathways and a novel siderophore pathway. Biological assays confirmed that the strain produces molecules with antioxidant and siderophore activities. Furthermore, intracellular extracts showed nematocidal activity towards C. elegans, suggesting that strain KRL4 is a source of anthelmintic compounds.

Postbiotics are commonly defined as preparations of inanimate probiotics and/or their cellular components and/or their metabolites/end products that confer health benefits on the host. They have been suggested as a promising strategy to limit infectious diseases. Emerging evidence support the efficacy of the postbiotic derived from cow’s milk fermentation with the probiotic Lacticaseibacillus paracasei CBAL74 (FM-CBAL74) in preventing pediatric infectious diseases. We aimed at reviewing the evidence available.

Fibrinogen (FIB), a key component of the coagulation cascade, is traditionally recognized for its role in hemostasis and tissue repair. However, due to its high plasma abundance and susceptibility to proteolytic cleavage during inflammation, it may also represent a previously unrecognized source of bioactive peptides. This study presents, for the first time, a comprehensive analysis of the antimicrobial, anti-inflammatory, and antiviral properties of six cationic antimicrobial peptides (AMPs) deriving from the C-terminal extremities of the three subunits of human fibrinogen (FIBα, FIBβ, and FIBγ), identified using a scoring function developed by our group. Antibacterial assays against Gram-positive and Gram-negative pathogens revealed different antimicrobial activity profile depending on their parent protein. Selected peptides displayed additive or synergistic effects when combined with conventional antibiotics or the thrombin-derived peptide (P)GKY20, highlighting their potential for combination therapies. Hemolytic assay confirmed the biocompatibility of fibrinogen-derived cryptic peptides with erythrocytes. Furthermore, the peptides significantly reduced LPS-induced nitric oxide release in murine macrophages Raw 264.7 cells, indicating anti-inflammatory activity. Notably, antiviral activity was observed against enveloped viruses (HCoV-229E and HSV-1) under various treatment conditions, while no activity was detected against the non-enveloped virus CVB3. Overall, these findings reveal human fibrinogen as a source of multifunctional cryptic peptides with broad-spectrum antimicrobial, antiviral, and immunomodulatory activities, supporting their potential as part of the innate immune system.

Background: The skin microbiota-derived metabolite butyrate plays a pivotal role in maintaining skin health. Unfortunately, unpleasant sensorial properties and unfavorable physicochemical properties strongly limit the butyrate use in dermatology clinical practice. This study investigates the effects of N-(1-carbamoyl-2-phenyl-ethyl) butyramide (FBA), a butyric acid releaser with neutral sensorial properties on skin keratinocyte function. Methods: Immortalized human keratinocyte cell line (HaCaT cells) was treated with FBA at various concentrations (0.001–1 mM) and time points (6–48 h). Cellular proliferation was assessed using MTT assays, while barrier integrity was evaluated by measuring tight junction proteins (occludin and ZO-1). Oxidative stress was analyzed using ROS assays and Western blot for Nrf2 and NF-κB expression. Markers of differentiation and extracellular matrix proteins were measured via quantitative PCR and wound-healing capability was assessed using a scratch assay. Results: FBA significantly enhanced keratinocyte proliferation at an optimal concentration of 0.1 mM. Tight junction protein expression increased, indicating improved barrier function. FBA reduced oxidative stress by upregulating Nrf2 and suppressing NF-κB activity. It also promoted the expression of differentiation markers (e.g., keratin-1, filaggrin) and extracellular matrix proteins (e.g., collagen type I and elastin). Furthermore, FBA accelerated wound closure, demonstrating its efficacy in enhancing the mechanisms of skin repair. Conclusions: Our results demonstrate that FBA enhances human keratinocyte cell differentiation, proliferation, and skin repair while protecting against oxidative stress. Its potential in cosmetics lies in delivering butyric acid benefits without organoleptic limitations, with possible applications in several skin condition characterized by deficient butyrate production and inflammation, such as atopic dermatitis.

Environment-sensitive fluorophores are very valuable tools in the study of molecular and cellular processes. When used to label proteins and peptides, they allow for the monitoring of even small variations in the local microenvironment, thus acting as reporters of conformational variations and binding events. Luciferin and aminoluciferin, well known substrates of firefly luciferase, are environment-sensitive fluorophores with unusual and still-unexploited properties. Both fluorophores show strong solvatochromism. Moreover, luciferin fluorescence is influenced by pH and water abundance. These features allow to detect local variations of pH, solvent polarity and local water concentration, even when they occur simultaneously, by analyzing excitation and emission spectra. Here, we describe the characterization of (amino)luciferin-labeled derivatives of four bioactive peptides: the antimicrobial peptides GKY20 and ApoB_L, the antitumor peptide p53pAnt and the integrin-binding peptide RGD. The two probes allowed for the study of the interaction of the peptides with model membranes, SDS micelles, lipopolysaccharide micelles and Escherichia coli cells. K_d values and binding stoichiometries for lipopolysaccharide were also determined. Aminoluciferin also proved to be very well-suited to confocal laser scanning microscopy. Overall, the characterization of the labeled peptides demonstrates that luciferin and aminoluciferin are previously neglected environment-sensitive labels with widespread potential applications in the study of proteins and peptides.

Background and aim. Acute rhinitis (AR) is a common condition in children, primarily of viral origin, causing nasal congestion, rhinorrhea, and discomfort, with a significant impact on quality of life and economic burden. Current treatments are limited to symptomatic relief, with nasal irrigation being the primary non-pharmacological intervention. This study aimed at evaluating the efficacy and safety of Elysium Naso-gola—an isotonic saline solution enriched with mullein (Verbascum thapsus), thyme (Thymus vulgaris), propolis, and long-chain polyphosphates—in reducing symptom severity and duration in pediatric AR. Methods. A randomized, double-blind, placebo-controlled pilot trial was conducted on 60 children (aged 4–14 years) with AR. Participants were randomized into two groups: the active group received Elysium Naso-gola, while the placebo group received a sterile isotonic saline solution, both administered as nasal sprays four times daily for seven days. Symptom severity was assessed at baseline (T0), day 5 (T1), and day 10 (T2) using the I-NOSE questionnaire and Visual Analog Scale (VAS). The primary outcome was symptom reduction at T1, while secondary outcomes included nasal obstruction improvement and complete symptom resolution at T2. Results. At baseline, both groups exhibited comparable symptoms severity. At T1, the active group showed a significant reduction in I-NOSE scores compared to placebo group (p < 0.05), with a marked decrease in nasal obstruction severity. VAS scores also indicated a greater improvement in nasal breathing in the active group. At T2, complete symptom resolution was achieved in 60% of patients treated with Elysium Naso-gola, compared to only 5.3% in the placebo group (p < 0.01). No adverse events were reported, and treatment adherence was high in both groups. Conclusions. The findings suggest that Elysium Naso-gola is a safe and effective non-pharmacological treatment for pediatric AR, providing faster symptom relief and higher resolution rates. Larger multicenter trials are warranted to confirm these preliminary results and further explore its role in pediatric respiratory care.