Fusarium solani (F. solani) and Alternaria solani (A. solani) are among the most destructive pathogenic fungi affecting potatoes, causing significant crop losses in both field and post-harvest conditions. Current control relies heavily on synthetic fungicides which pose serious environmental and health risks. Therefore, there is a growing need to find efficient and environmentally friendly alternatives to combat fungal infections in potatoes. This study offers chitosan (CS) and zinc oxide (ZnO) nanoparticles (NPs) as potential fungicides against A. solani and F. solani. We evaluated their antifungal properties and elucidated the mechanism underlining their activity. Our results revealed that both CS and ZnO NPs exhibited pronounced antifungal activity against the two pathogenic strains by effectively inhibiting the mycelium growth. Furthermore, we discovered that the activity of the NPs involved the induction of oxidative stress in fungal cells and changes in the molecular organization of their membranes.

Oxidative stress induces lipid peroxidation within the membrane bilayer, thereby compromising membrane integrity. Polyphenols (PPs), renowned for their antioxidant properties, have been shown to mitigate oxidative damage. Here, we investigated the structural and antioxidant effects of PPs—specifically flavonoid glycosides (FGs) and phenolic acids (PAs)—extracted from Inula oculus-christi using steady-state fluorescence spectroscopy in both model and cell membranes. Membrane lipid order was evaluated using DPH and Laurdan spectroscopy, while DPH-TEMPO fluorescence quenching was employed to quantify raft-like domain formation in model systems. The antioxidant capacity of the PP extracts was assessed via fluorescence quenching of cis-parinaric acid. Both FGs and PAs conferred approximately 2-fold antioxidant protection, with FGs showing a 1.13-fold greater effect than PAs. In addition, both PP classes promoted lipid raft formation, particularly in cholesterol-rich membranes. PPs increased order in the liquid-disordered (L_d) phase while inducing disorder in the liquid-ordered (L_o) phase, depending on the lipid-to-PP ratio. Notably, FGs enhanced membrane fluidity more strongly in A549 than in MDCKII cells, as reflected by a ~5.7-fold decrease in Laurdan GP in A549 (from 0.04 to −0.17) versus a ~1.4-fold decrease in MDCKII at 200 μg/mL. These findings highlight the dual structural and antioxidative roles of FGs and PAs in preserving membrane integrity under oxidative stress.

Urticaria, also known as Hives, is a prevalent skin condition characterized by the activation of mast cells and basophils. Currently, anti-IgE therapy is one of the most effective and utilized treatments for managing the disease. The relation between skin atopy and cross-reactivity to various antigens in urticaria is still unclear and requires elucidation. This study investigates the relationship between food and aeroallergic sensitization (cross-reactivity) in patients with chronic immediate urticaria who do not have other clinically apparent allergic diseases. Serological tests were conducted on 54 antigens using the immunoblot method in 80 patients with ongoing CU, comprising 60% women and 40% men, with an average age of 29.3 years for women and 34.89 years for men. Sixty percent of the individuals in the studied group tested positive for food and/or inhalant allergens. A strong correlation (r = 0.891; p = 0.01) was established between the quantitative values of specific IgE to g12 and IgE antibodies for food allergens in the sensitized patients. The correlation coefficients for specific groups were as follows: r = 0.93 (p = 0.01) for group g3, r = 0.77 (p = 0.01) for group g1, and r = 0.91 (p = 0.01) for group g6.

Dendrimers, 4-dimethylamino-1,8-naphthalimide (DAB) and its halogenated analog 3-bromo-4-dimethylamino-1,8-naphthalimide (DAB-Br), were evaluated on eukaryotic cells, human HFF-1 fibroblast cells, and five fungal species. Although both dendrimers have demonstrated antibacterial and antiviral potential, thus far, their effects on eukaryotic cells, particularly human and fungal cells, have not been investigated. For this purpose, their cytotoxicity, mechanisms of cellular entry, and antifungal activity were studied. Dynamic light scattering measurements revealed that both dendrimers exhibited positive surface charges (+28 to +35 mV), good colloidal stability, and nanoscale dimensions (117–234 nm), facilitating interactions with target cells. The MTT assay showed that DAB was more cytotoxic toward HFF-1 cells (IC₅₀ = 27 µg/mL) compared to DAB-Br (IC₅₀ = 68 µg/mL). In contrast, the resazurin-based antifungal assay demonstrated that DAB-Br had superior antifungal activity, achieving a lower minimum inhibitory concentration (0.148 µg/µL), compared to DAB (0.295 µg/µL). A trypan blue exclusion test revealed that both dendrimers entered cells through membrane permeabilization, either temporarily or permanently, depending on the concentration and exposure time. At concentrations above 30 µg/mL, irreversible permeabilization was observed within two hours of treatment, accompanied by a decrease in membrane lipid order, indicating altered membrane integrity and permeability. Conversely, at lower concentrations (7.5–15 µg/mL), dendrimers induced only temporary membrane permeabilization, with membranes remaining intact, suggesting a reversible interaction with the lipid bilayer. Conducting thorough and systematic research to fully explore their biological activities could provide valuable insight for future applications.

Interrelations between the plasma membrane and cytoskeleton are of crucial importance for essential cellular processes such as endocytosis, formation of intercellular junctions, cell morphology, etc. Many studies validate the beneficial effects of polyphenols as antioxidant and protective agents, but a molecular mechanism of their interaction and transition through the plasma membranes of different cell lines is still missing. In this study, we examined the affinity of fractions enriched in flavonoid glycosides (FGs) and caffeoylquinic acids (CQAs), obtained from the methanol extract of the medicinal plant Inula oculus-christi L., to reorganize the plasma membrane structure and actin cytoskeleton by using confocal microscopy. Assessment of the degree of membrane ordering aiming to distinguish the ordered from disordered regions of the cellular membranes was performed using the fluorescent dye Di-4-ANEPPDHQ, and visualization of F-actin was by TRITC-phalloidin. Two epithelial cell lines with clear differences in their origin and plasma membrane organization were chosen: the non-malignant MDCK II and the cancerous A549. Our results showed that flavonoid glycosides exhibited an ordering effect on plasma membranes of cancerous cells and fluidized one on non-malignant cells. Different patterns of actin reorganization were observed for both cell lines after treatment. Our results indicate the potential of plant-derived polyphenols as modulators of the membrane’s structural organization, offering valuable insights for the development of membrane-targeted therapeutic strategies.

Petasin, a lipophilic sesquiterpene ester isolated from Petasites hybridus, exhibits well-documented anti-inflammatory and anti-allergic activities, although its molecular mechanisms of action remain incompletely understood. Here, we investigated its direct effects on membrane organization using biomimetic large unilamellar vesicles (LUVs) modeling resting and activated mast cell plasma membranes. The models comprised phosphatidylcholines (EggPC, PAPC), sphingomyelin (SM), ganglioside GD3, and cholesterol (Chol), with phosphatidylserine (PS) additionally incorporated into the activated membrane model. Simplified liquid-disordered (L_d) and liquid-ordered (L_o) lipid systems were used to resolve phase-dependent effects. Membrane properties were assessed by Laurdan generalized polarization, DPH fluorescence anisotropy, DPH-TEMPO fluorescence quenching, di-8-ANEPPS dipole potential measurements, and dynamic light scattering (DLS). Petasin exerted phase- and composition-dependent effects on membrane organization. It increased lipid order in relatively disordered membrane environments, while producing only minor changes in highly ordered L_o membranes, revealing a clear dependence of its effects on the initial lipid phase state. In heterogeneous mast cell membrane models exhibiting L_o/L_d phase coexistence, DPH-TEMPO quenching indicated a concentration-dependent increase in the estimated size of ordered lipid nanodomains. In parallel, petasin decreased membrane dipole potential in a concentration-dependent manner, demonstrating modulation of membrane interfacial electrostatic properties. These findings indicate coordinated modulation of lipid packing, lateral membrane organization, and interfacial electrostatics, with the membrane response influenced by lipid composition. DLS measurements showed no evidence of vesicle aggregation or major alterations in vesicle size distribution. Overall, these findings identify petasin as a membrane-active modulator capable of fine-tuning lipid order, lateral membrane organization, and interfacial electrostatics in a phase- and composition-dependent manner. Given the importance of membrane organization and lipid raft dynamics in FcεRI clustering and mast cell activation, these membrane effects may represent an additional biophysical mechanism of the anti-inflammatory and anti-allergic actions of petasin. More broadly, our findings highlight membrane physicochemical organization as a relevant factor in the regulation of mast cell function and provide a basis for further investigation of membrane-mediated mechanisms in allergic and mast cell-associated inflammatory responses.