Search Results (16,648)

Equinin B (GQCQRKCLGHCSKKCPKHPQCRKRCIRRCFGYCL), a marine peptide from Actinia equina exhibits antibacterial activity against both Gram-positive and Gram-negative bacteria. To identify a smaller active region and explore tunable properties, three peptide fragments were synthesized: GQCQRKCLGHCS (EB1), KKCPKHPQCRK (EB2), and RCIRRCFGYCL (EB3), yielding peptides with key AMP-like properties, including the most positively charged and most hydrophobic regions. Only the 11-residue C-terminal fragment showed selective activity against Gram-positive bacteria, including Staphylococcus epidermidis, Bacillus subtilis, and Enterococcus hirae, while remaining inactive against Escherichia coli. Peptide modifications, achieved by replacing cysteine residues with arginine, generally did not enhance activity, but in the C-terminal fragment EB3 they reduced hemolytic activity and increased bacterial specificity. Membrane depolarization assays confirmed that the unmodified fragment EB3 strongly disrupts bacterial membranes, whereas the modified variant showed minimal depolarization, highlighting its markedly reduced membrane-disruptive potential. In silico modelling revealed that the EB3 can adopt multiple membrane-disruption modes, from transient shallow pores to carpet-like mechanisms, while the cysteine-to-arginine variant interacts mainly via partial insertion anchored by arginine residues. Phenylalanine appears to interact with the membrane, and reducing hydrophobicity by its removal abolished antibacterial activity. These findings highlight the 11-residue C-terminal fragment as a tunable, membrane-targeting motif with mechanistic novelty, offering a blueprint for developing safer, selective antimicrobial peptides with reduced cytotoxicity. Full article

Background/Objectives: Malaria remains a major global health burden, increasingly complicated by resistance to artemisinin-based therapies. Because artemisinin activation depends on heme and porphyrin chemistry, we sought to exploit host red blood cell (RBC) heme metabolism as a therapeutic vulnerability. This study aims to develop and evaluate a host-directed “bait-and-kill” strategy that selectively sensitizes malaria-infected RBCs to artemisinin. Methods: We integrated quantitative proteomics, erythropoiesis transcriptomic analyses, flow cytometry, and in vitro malaria culture assays to characterize heme metabolism in mature RBCs and Plasmodium falciparum-infected RBCs (iRBCs). The heme precursor 5-aminolevulinic acid (ALA) was used to induce porphyrin accumulation, and dihydroartemisinin (DHA) was applied as the killing agent. Drug synergy, porphyrin accumulation, reactive oxygen species (ROS) induction, and parasite survival were assessed, including ring-stage survival assays using artemisinin-resistant clinical isolates. Results: Mature RBCs retain a truncated heme biosynthesis pathway capable of accumulating porphyrin intermediates, while uninfected RBCs are impermeable to ALA. In contrast, iRBCs exhibit increased membrane permeability, allowing selective ALA uptake and porphyrin accumulation. ALA alone did not induce cytotoxicity or ROS, whereas DHA induced ROS and parasite killing. The ALA + DHA combination resulted in synergistic parasite elimination, including complete clearance of artemisinin-resistant P. falciparum isolates from the Greater Mekong Subregion, with no recrudescence observed over three weeks of culture. Evidence supports a predominant role for host-derived heme metabolites in mediating this synergy. Conclusions: The bait-and-kill strategy selectively exploits host RBC heme metabolism to restore and enhance artemisinin efficacy while sparing uninfected cells. Using clinically safe compounds, this host-directed approach provides a promising, resistance-bypassing framework for malaria treatment and combination drug development. Full article

Non-alcoholic fatty liver disease (NAFLD), often associated with obesity, has become a serious public health matter. NAFLD is characterized by an excessive lipid accumulation in hepatocytes, mainly stored as triglycerides. The marine microalga Phaeodactylum tricornutum is well known for its richness of bioactive compounds, particularly lipids. Therefore, different natural lipid extracts from P. tricornutum are deciphered to jugulate or prevent obesity leading to NAFLD. In this study, the main focus was on the effects of purified neutral and polar lipid extracts from P. tricornutum in a cellular model of NAFLD. Human HepG2 cells were used and exposed for 24 h to 250 μM palmitate to induce NAFLD with or without microalgal lipid extracts. Data showed that neutral lipid extract presented lower viability and cytotoxic activities on HepG2 at 75 µg/mL. The impact on apoptosis was around 5% and below the threshold. Nevertheless, the use of neutral lipid at 50 µg/mL induced a decrease in the number and size of lipid droplets, and so, preventing NAFLD. On the contrary, the polar lipid extract had no effect on the accumulation of triglycerides in HepG2 cells. To conclude, neutral lipid extract seemed to be a good candidate to prevent NAFLD. Full article

Melamine, a nitrogen-rich industrial chemical, has raised increasing concern as an emerging environmental contaminant with potential reproductive toxicity. While its nephrotoxic effects are well established, the direct impact of melamine on human sperm remains poorly defined. In this study, we investigated the in vitro effects of melamine on human sperm, under both capacitating and non-capacitating conditions. Functional analyses revealed that the exposure to 0.8 mM melamine, the highest non-cytotoxic concentration in vitro, significantly compromised sperm motility and disrupted key capacitation processes, including tyrosine phosphorylation patterns, cholesterol efflux, and the acrosome reaction. Molecular assessments demonstrated melamine-induced mitochondrial dysfunction, characterized by COX4I1 downregulation, reduced mitochondrial membrane potential, and altered reactive oxygen species production. In parallel, gene expression analyses revealed the activation of apoptotic pathways, with the upregulation of BAX and downregulation of BCL2, changes that were more pronounced during capacitation. Furthermore, melamine exposure significantly increased sperm DNA fragmentation and denaturation, indicating genotoxic stress. Collectively, these findings demonstrate that even low, non-cytotoxic concentrations of melamine compromise sperm function by disrupting capacitation, mitochondrial activity, and genomic integrity. This study identifies capacitation as a critical window of vulnerability and underscores the need to consider melamine as a potential environmental risk factor for male reproductive health. Full article

Adipose tissue thermogenesis is a promising strategy to counter obesity and metabolic disease, but sustained activation of thermogenic adipocytes elevates oxidative and lipid-peroxidation stress, increasing susceptibility to ferroptotic cell death. Existing models often treat redox buffering, hypoxia signaling and ferroptosis as separate processes, which cannot explain why similar interventions—such as antioxidants, β-adrenergic agonists or iron modulators—alternately enhance thermogenesis or precipitate tissue failure. Here, we propose the Redox–Thermogenesis–Ferroptosis Compass (RTF-Compass) as a framework that maps adipose depots within a space defined by ferroptosis resistance capacity (FRC), ferroptosis signaling intensity (FSI) and HIF-1α-dependent hypoxic tone. Within this space, thermogenic output follows a hormetic, inverted-U trajectory, with a Thermogenic Ferroptosis Window (TFW) bounded by two failure states: a Reductive-Blunted state with excessive antioxidant buffering and weak signaling, and a Cytotoxic state with high ferroptotic pressure and inadequate defense. We use this model to reinterpret genetic, nutritional and pharmacological studies as state-dependent vectors that move depots through FRC–FSI–HIF space and to outline principles for precision redox medicine. Although the TFW is represented as coordinates in FRC–FSI–HIF space, we use ‘Compass’ to denote a coordinate framework in which perturbations act as vectors that orient depots toward thermogenic or cytotoxic outcomes. Finally, we highlight priorities for testing the model in vivo, including defining lipid species that encode ferroptotic tone, resolving spatial heterogeneity within depots and determining how metabolic memory constrains reversibility of pathological states. Full article

Chimeric antigen receptor (CAR) T cell therapy has demonstrated clinical success in hematologic malignancies but has limited efficacy in solid tumors due to tumor microenvironment (TME) barriers that impede CAR T cell recognition, infiltration, and sustained function. Traditional 2D assays inadequately recapitulate these constraints, necessitating improved in vitro models. This study validated a 3D tumor spheroid platform using an agarose microwell system to generate uniform B7-H3-positive spheroids from multiple solid tumor cell lines, enabling the evaluation of CAR T cell activity. TME-relevant immune modulation under 3D conditions was analyzed by flow cytometry for B7-H3, MHC I/II, and antigen processing machinery (APM), followed by co-culture with B7-H3 CAR T cells to assess cytotoxicity, spheroid integrity, tumor viability, and CAR T cell activation, exhaustion, and cytokine production. Two human cancer-cell-line-derived spheroids, DU 145 (prostate cancer) and SUM159 (breast cancer), retained B7-H3 expression, while MC38 (mouse colon cancer)-derived spheroids served as a B7-H3 negative control. Under 3D culture conditions, DU 145 and SUM159 spheroids acquire TME-like immune evasion characteristics and specifically downregulated MHC-I and APM (TAP1, TAP2, LMP7) with concurrent upregulation of MHC-II and calreticulin. Co-culture showed effective spheroid infiltration, cytotoxicity, and structural disruption, with infiltrating CAR T cells displaying higher CD4⁺ fraction, activation, exhaustion, effector/terminal differentiation, and IFN-γ/TNF-α production. This 3D platform recapitulates critical TME constraints and provides a cost-effective, feasible preclinical tool to assess CAR T therapies beyond conventional 2D assays. Full article

Background: Hair loss (alopecia) is primarily driven by the premature transition of hair follicles from the anagen (growth) to the catagen (regression) phase. Intracellular calcium signaling is implicated in hair follicle biology, including the regulation of Wnt/β-catenin activity and the modulation of catagen-associated factors such as TGF-β2. Cyclic ADP-ribose (cADPR), a calcium-mobilizing second messenger synthesized by CD38, has recently emerged as a potential modulator of intracellular calcium dynamics. This study investigated whether cADPR is associated with changes in intracellular calcium retention and anagen-associated signaling pathways in human hair follicle dermal papilla cells (HHDPCs). Methods: HHDPCs were treated with cADPR (0.001–0.5 ppm) and analyzed for cell viability, intracellular calcium retention, β-catenin-dependent transcription, and the gene expression of LEF-1 and TGF-β2. Cell viability was evaluated using the MTT assay, intracellular calcium content was quantified by ICP–OES, β-catenin activation was assessed using a TOPFlash luciferase assay, and gene expression was measured by qRT-PCR. Results: cADPR did not induce marked cytotoxicity, maintaining more than 98% cell viability across all concentrations. The highest response was observed at 0.05 ppm, at which intracellular calcium content remained elevated for up to six hours as assessed by ICP–OES. At this concentration, β-catenin-dependent transcription increased by approximately 2.3-fold relative to control, LEF-1 expression was significantly upregulated (~2.5-fold), and TGF-β2 expression was significantly downregulated (~0.3-fold). These responses showed an overall concentration-dependent trend across assays. Conclusions: These findings indicate an association between cADPR treatment and modulation of intracellular calcium retention and anagen-related signaling readouts in HHDPCs, supporting the need for further studies to establish mechanistic causality and physiological relevance. Full article

This study addresses the critical need for advanced biomedical materials that possess both potent antimicrobial properties and high biocompatibility to prevent device-related infections and promote healing. To this end, we demonstrate the successful development and comprehensive characterization of functional composite materials based on a photopolymerizable acrylate resin modified with laser-ablated copper nanoparticles (Cu NPs). The synthesized Cu NPs exhibited a monomodal size distribution with a peak at 47 nm, a high zeta potential of −33 mV, and a spherical morphology. Incorporation of Cu NPs into the polymer matrix via Masked Stereolithography (MSLA) enabled the fabrication of complex structures that maintained high surface quality and optical transparency after polishing. Modification of photopolymer resin with Cu NPs significantly increased the strength of the resulting products and caused dose-dependent formation of reactive oxygen species (ROS). The resulting composite materials exhibited strong antibacterial activity against E. coli. Crucially, despite their potent antimicrobial efficacy, the materials showed no cytotoxicity towards human fibroblast cultures. These results highlight the potential of these composites for a new generation of biomedical applications, such as implantable devices and wound coatings, which combine programmable antimicrobial activity with high biocompatibility. Full article

In this work, kaolin/chitin (K/Ch) composite aerogels with different mass ratios were successfully fabricated via a freeze–drying approach. The influence of kaolin content on the microstructure, properties and hemostatic performance of the composite aerogels was systematically investigated. The results demonstrated that the incorporation of kaolin endowed the chitin-based aerogels with tunable porous structures, excellent water absorption capacity (up to 4282% for K_0.25/Ch₂), and enhanced water retention (73.7% for K₂/Ch₂ at 60 min). Moreover, the K/Ch composite aerogels exhibited good biodegradability, no cytotoxicity (cell viability > 91.9%), and no hemolysis (hemolysis rate < 1.5% at all test concentrations). In vitro hemostatic evaluations revealed that the composite aerogels exhibited rapid blood coagulation (blood clotting time of 16 s for K₂/Ch₂) with a blood coagulation index (BCI) as low as 0.5%, which was attributed to the synergistic effect of the physical adsorption of chitin and the coagulation cascade activation by kaolin. These findings indicated that the K/Ch composite aerogels could be used as novel natural hemostatic materials for potential effective and rapid hemostasis. Full article

The ecdysteroid receptor (EcR) plays a crucial role in insect development and metamorphosis, making it a promising target for the design of novel biorational compounds. This study investigated the cytotoxicity, as well as the EcR agonist and antagonist activities, of three synthetic molecules analogous to tebufenozide and extracts from nine plant species using the dipteran S2 cell line which originates from the insect model of the fruit fly Drosophila melanogaster. Cytotoxicity assays were performed to determine appropriate concentrations of the synthetic molecules and plant extracts for cell transfection. EcR agonist and antagonist activities were evaluated using 20-hydroxyecdysone (20E) as the control hormone. The synthetic molecules analogous to tebufenozide did not activate EcR in S2 cells. In contrast, the plant extract of Neoblechnum brasiliense, commonly known as Brazilian dwarf tree fern, exhibited significant antagonistic activity at 100 µM, reducing receptor activity by 92%, likely due to its phytosteroid content, and without inducing cytotoxic effects. These findings demonstrate that certain plant extracts, particularly N. brasiliense, act as effective EcR antagonists and may represent promising natural leads for the development of environmentally compatible biorational compounds to control economically important dipteran pests, such as fruit flies and mosquitoes. Full article

This study investigated the effects of thermal processing and extraction solvents on the phytochemical composition, antioxidant potential, and cytotoxic activity of Sukhothai fragrant rice (Oryza sativa L.). Rice subjected to three processing methods, unprocessed (raw), popped/puffed and steam-cooked, was extracted using hot water or 70% (v/v) ethanol, yielding six extracts. Trans-ferulic acid, γ-oryzanol and anthocyanins were quantified using HPLC-DAD and HPLC-ESI-MS, while total phenolic and flavonoid contents, and antioxidant activities were evaluated using Folin–Ciocalteu, aluminium chloride, DPPH and ABTS assays. Cytotoxicity was assessed in Huh7 hepatocellular carcinoma cells. Water extracts consistently produced higher yields and contained greater total phenolic, flavonoid and anthocyanin contents, resulting in stronger antioxidant activity. Unprocessed rice water extract exhibited the highest trans-ferulic acid recovery and antioxidant capacity. Thermal processing, particularly steamed cooking, markedly reduced phytochemical contents, likely due to heat-induced degradation. In contrast, ethanolic extracts yielded lower quantities but higher concentrations of less polar bioactive compounds and exhibited greater cytotoxic effects. Overall, minimal thermal processing combined with aqueous extraction best preserved antioxidant compounds, while ethanolic extraction enhanced biological potency. These findings highlight the importance of processing intensity and solvent polarity in optimizing the nutraceutical and functional potential of black rice. Full article

The development of eco-friendly antimicrobial materials is essential for addressing antibiotic resistance, while reducing environmental impact. In this study, bio-derived anionic and cationic cellulose nanofibers (a-CNF and c-CNF) were employed as templating matrices for the in situ hydrothermal synthesis of cellulose/ZnO nanohybrids. Physicochemical characterization confirmed efficient cellulose functionalization and high-quality nanofibrillation, as well as the formation of uniformly dispersed ZnO nanoparticles (≈10–20 nm) strongly integrated within the cellulose network. The ZnO content was 30 and 20 wt. % for a-CNF/ZnO and c-CNF/ZnO, respectively. Antibacterial evaluation against Escherichia coli and Staphylococcus aureus revealed enhanced activity for both hybrids, with c-CNF/ZnO displaying the lowest MIC/MBC values (50/100 μg/mL). Antiviral assays revealed complete feline calicivirus inactivation at 100 μg/mL for c-CNF/ZnO, while moderate activity was observed against bovine coronavirus, highlighting the role of surface charge. Cytotoxicity assays on mammalian cells demonstrated high biocompatibility at antimicrobial concentrations. Life cycle assessment showed that c-CNF/ZnO exhibits a lower overall environmental burden than a-CNF/ZnO, with electricity demand being the main contributor, indicating clear opportunities for further reductions through process optimization and scale-up. Overall, these results demonstrate that CNF/ZnO nanohybrids effectively combine renewable biopolymers with ZnO antimicrobial functionality, offering a sustainable and safe platform for biomedical and environmental applications. Full article

Oxidative stress and inflammation are key drivers in the pathogenesis of various chronic diseases, including cardiovascular disease, neurodegenerative disorders, chronic kidney disease, and diabetes. This study evaluated the antioxidant and anti-inflammatory activities of SHE, CME, and FCME, all cultivated in northern Thailand. Human embryonic kidney cells (HEK293) were exposed to FeSO₄ to induce oxidative stress and to LPS to stimulate inflammation. Cell viability was assessed using the MTT assay, while intracellular ROS production was measured using the DCFH-DA. Lipid peroxidation was quantified using the thiobarbituric acid reactive substances assay, and the interleukin-6 (IL-6) release was determined by ELISAs. All extracts demonstrated low cytotoxicity; however, cell death increased at 48 h compared to 24 h. At 200 µg/mL, SHE, CME, and FCME significantly reduced the H₂O₂-induced ROS generation, with the combined treatment of SHE and FCME producing a more pronounced reduction than the individual treatments. Furthermore, the combination of SHE and FCME markedly decreased malondialdehyde (MDA) and IL-6 levels compared with other groups. These findings suggest that shallot and cha-miang extracts, particularly in combination, exhibit promising antioxidant and anti-inflammatory properties in kidney cell models. This combination could therefore be explored as a nutraceutical strategy for the prevention and management of chronic kidney disease, in which oxidative stress and inflammation play pivotal roles. Overall, our finding highlight the potential of the combined use of SHE and FCME as a functional ingredients in the food and pharmaceutical industries. Full article

Type 2 diabetes mellitus (T2DM) can be traditionally treated by edible and medicinal species rich in flavonoids and triterpenoids known for their metabolic benefits. Cucumis prophetarum L. has shown antioxidant and antidiabetic properties in decoction extracts. Since solvent polarity strongly influences the extraction of secondary metabolites, this study investigated the hydroalcoholic extracts of C. prophetarum L. to explore their chemical composition and insulin-sensitizing potential. Hydroalcoholic extracts from the leaf, stem, and root of C. prophetarum L. were analyzed by UV-Vis spectroscopy, ATR-FTIR, and UHPLC-ESI-QqTOF–MS/MS to profile their secondary metabolites. The insulin-sensitizing potential of each extract was assessed using an in vitro model of palmitic-acid-induced insulin resistance in L6 skeletal muscle cells, followed by Western blot analysis of key insulin-signaling proteins. Flavonoid glycosides such as apigenin-C,O-dihexoside, apigenin-malonylhexoside, and luteolin-C,O-dihexoside were abundant in leaf and stem extracts, while cucurbitacins predominated in the root. MTT assay confirmed that hydroalcoholic stem and root extracts of C. prophetarum L. were non-cytotoxic to L6 myotubes, whereas the leaf extract reduced viability only at higher concentrations. Oil Red O staining revealed a pronounced decrease in lipid accumulation following stem and root extract treatment. Consistently, the stem extract enhanced insulin signaling through the activation of the IRS-1/PI3K/Akt pathway, while the root extract primarily modulated the AMPK–mTOR pathway. Importantly, both extracts promoted GLUT4 translocation to the plasma membrane, highlighting their complementary mechanisms in restoring insulin sensitivity. Hydroalcoholic extracts of C. prophetarum L. alleviate insulin resistance through multiple molecular mechanisms, with bioactivity and composition differing markedly from previously reported in the decoctions, which highlight a promising source of insulin-sensitizing phytochemicals and underscore the importance of solvent selection in maximizing therapeutic potential. Full article

Thrombotic cardiovascular diseases are frequent side effects of cancer therapy with cytotoxic drugs such as Doxorubicin. Endothelial cell senescence is emerging as a critical mechanism underlying endothelial dysfunction in this context. Senescent cells, although unable to proliferate, secrete bioactive molecules that alter the tissue microenvironment, a feature known as the senescence-associated secretory phenotype (SASP). Besides soluble molecules, senescent cells also release extracellular vesicles (EVs). Previous studies indicate that senescent endothelial cells produce a secretome that promotes platelet activation; however, the contribution of EVs remains unclear. Here, we show that human microvascular endothelial cells (HMEC-1) exposed to Doxorubicin undergo senescence, display endothelial dysfunction, and release EVs. We found no differences in the concentration or size distribution of EVs from senescent and non-senescent cells. Nevertheless, EVs from senescent HMEC-1 promoted platelet activation more strongly than EVs from control cells. Notably, EVs alone did not induce platelet aggregation, suggesting that soluble factors are also required to support platelet-dependent hemostasis. These findings reveal that EVs from senescent endothelial cells contribute to platelet activation, a process that may favor thrombosis in patients receiving Doxorubicin-based chemotherapy. Full article