Search Results (498)

Background: Chronic obstructive pulmonary disease (COPD) is a heterogeneous syn-drome which leads to irreversible and progressive airflow limitation. Yufeining (YFN) is a Chinese herbal formula employed for treating COPD; however, the key ingredients and mechanisms are not fully defined. Methods: The key bioactive compounds and their corresponding targets of YFN were recognized using the network pharmacology method. The CIBERSORT algorithm was employed to identify the immune infiltration profiles in COPD and their correlation with the principal targets. Through the COPD mouse model, the effects of kaempferol on inflammation, oxidative damage, and apoptosis were evaluated. The BEAS-2B cells treated with cigarette smoke extract (CSE) were used to assess the protective effects of kaempferol against inflammation, oxidative stress, and apoptosis. Using flow cytometry, the anti-apoptosis effects of kaempferol were analyzed. Transcriptomic Analysis was performed to investigate the transcriptional changes in CSE-induced BEAS-2B cells. Results: Kaempferol is a key compound of YFN, and STAT3, TP53, and IL1B are predicted to be the core targets of YFN for COPD treatment. Immune infiltration analysis revealed a significant correlation between STAT3-TP53-IL1B signaling network and inflammatory cell infiltration. Kaempferol alleviated inflammation, oxidative damage, and apoptosis in the COPD mouse model. In CSE-induced BEAS-2B cells, kaempferol inhibited the inflammatory response, oxidative damage, and apoptosis. The transcriptome sequencing revealed a total of 223 differentially expressed genes. After treating with kaempferol, the transcriptional levels of STAT3 significantly increased, while those of TP53 and IL1B significantly decreased. Conclusions: Kaempferol can exert therapeutic effects against COPD by inhibiting inflammatory response and oxidative damage, and reducing cell apoptosis. Furthermore, this study indicated the therapeutic mechanism of YFN in COPD involves potentially targeting the STAT3-TP53-IL1B signaling network through kaempferol. Full article

Efficient charge separation and electron transfer in Photosystem II (PSII) depend on small inorganic cofactors that maintain redox balance and catalytic stability. Chloride facilitates water-oxidizing-complex turnover and minimizes charge recombination. Bicarbonate, coordinated to the non-heme iron, facilitates electron transfer between the plastoquinones Q_A and Q_B. This work investigates cooperativity between these cofactors across PSII in the hypercarbonate-requiring cyanobacterium Limnospira maxima. Bromide-for-chloride substitution induces a distinct kinetic limitation at the water oxidizing complex. While bicarbonate depletion inhibits electron transfer at the acceptor side, bromide-substituted cells maintain a measurable level of electron flow through the intersystem chain. The presence of bromide induces structural changes that allow partial electron transfer to continue even in the absence of the bicarbonate cofactor, which is not observed in the chloride system. However, this dual anion stress results in irreversible functional impairment in some centers, whereas full recovery of activity is observed with native chloride. When the donor side is restricted by bromide, the loss of bicarbonate, which is thought to function as a proton buffer for the donor side, compromises the overall stability of the reaction center. This leads to a permanent decrease in activity of the electron transfer chain, suggesting an interdependence between the roles of chloride and bicarbonate that is essential for protecting PSII during ionic stress. Full article

Metal ion-based chemo-immunotherapy is often limited by rigid intracellular metal homeostasis, insufficient reactive oxygen species (ROS) accumulation, and an immunosuppressive tumor microenvironment (TME). To overcome these limitations, we engineered an ATP-responsive, core–shell bimetallic nanoreactor (Cu/ZIF@PDA, termed CZP) featuring a precisely controlled ~25 nm biomimetic polydopamine (PDA) coating. Triggered by elevated tumoral ATP levels, CZP undergoes coordination-induced disassembly and promotes oxidative stress amplification. Specifically, the PDA shell acts as a superoxide dismutase (SOD) mimetic to continuously supply H₂O₂, fueling Cu²⁺-mediated Fenton-like reactions to unleash highly toxic hydroxyl radicals (•OH) while aggressively depleting the intracellular glutathione (GSH) pool. This irreversible oxidative damage, coupled with Zn²⁺-induced mitochondrial dysfunction, triggers profound mitochondrial DNA (mtDNA) leakage. Crucially, this cytosolic DNA robustly activates the cGAS-STING signaling axis, driving a massive surge in immunogenic cell death (ICD) and significantly promoting dendritic cell (DC) maturation. Furthermore, CZP markedly inhibited primary tumor growth in vivo and showed protection in a tumor re-challenge model, accompanied by enhanced dendritic cell maturation. These findings support the potential of this ATP-responsive bimetallic nanoplatform to promote antitumor immune activation. Full article

Irreversible covalent enzyme inhibitors, including targeted covalent inhibitors (TCIs) and mechanism-based enzyme inhibitors (MBEIs), play an increasingly important role in drug discovery. Their pharmacological behavior is governed by intrinsic inactivation parameters, typically described by the inactivation constant K_I, the maximal inactivation rate constant k_inact, and their ratio k_inact/K_I. However, no consensus exists regarding how these parameters should be experimentally determined and interpreted, particularly in high-throughput screening environments where IC₅₀ values are often used as primary descriptors. This article presents a critical survey of the kinetic methodologies employed to characterize irreversible enzyme inhibition. Continuous progress-curve analysis, discontinuous end-point assays, IC₅₀-based estimation strategies, direct mass-spectrometric monitoring of covalent modification, and numerical approaches required by pre-incubation protocols are examined and compared. Attention is given to the statistical robustness of parameter estimation under realistic experimental error, including bootstrap-based uncertainty analysis. For mechanism-based enzyme inhibitors, the kinetic consequences of branching between productive turnover and irreversible inactivation are analyzed, and limitations of classical half-life-based linearization methods are discussed. Intrinsic inactivation parameters are distinguished from protocol-dependent observables, and experimental conditions that may compromise reliable parameter extraction are identified. The objective is to clarify how irreversible inhibitors should be kinetically characterized when the goal is mechanistic understanding and rational drug design. By bridging classical enzymology with current discovery practices, this review provides practical guidance on what experimental data can legitimately support and where caution is required. Full article

Recent evidence links lens epithelial cell (LEC) dysfunction and cellular senescence—an irreversible cell cycle arrest with a pro-inflammatory secretory phenotype—to age-related cataract (ARC) progression. This systematic review synthesizes current knowledge on LEC senescence, its molecular features, and laboratory methods for senescence assessment in the ARC. Following PRISMA guidelines, a comprehensive search of PubMed, Scopus and Cochrane databases retrieved 3417 records from inception to 9 February 2025, with 14 studies ultimately included (821 patients and multiple in vitro LEC models). The following multiple senescence expression pathways were identified: SA-β-gal activity, p53/p21 and p16INK4A pathway activation, mitochondrial dysfunction, oxidative stress, and secretion of senescence-associated secretory phenotype (SASP) factors. Notably, cortical cataract demonstrated direct association with local senescent cell accumulation, while nuclear cataract reflected cumulative oxidative damage from impaired LEC-mediated antioxidant defense. Senescence markers correlated positively with cataract severity across multiple studies. Several potential therapeutic targets emerged, including metformin (AMPK activation/autophagic restoration), circMRE11A silencing, NLRP3 inflammasome inhibition, and modulation of FYCO1/PAK1 and MMP2 pathways. This review establishes LEC senescence as a central process in ARC pathogenesis and highlights promising senotherapeutic approaches. Future research should prioritize human surgical samples, develop standardized senescence detection panels (SA-β-gal + p21/p16 + SASP factors), and conduct longitudinal studies to establish causal relationships between senescence accumulation and cataract progression. Full article

Background: Chronic kidney disease (CKD) is characterized by irreversible structural damage and functional deterioration of the kidneys. Esculetin (ES), with its anti-inflammatory, antioxidant, and immunomodulatory activities, shows potential in delaying renal function decline. This study aimed to investigate the protective effect of ES on adenine-induced CKD in mice and its underlying molecular mechanism, with a focus on its role in preventing the transition from acute kidney injury (AKI) to CKD. Methods: A AKI-to-CKD transition mice model was established by feeding mice a 0.2% adenine diet, and ES (30, 60 mg/kg) was co-administered for 4 weeks as a prophylactic intervention. Serum creatinine (SCr), blood urea nitrogen (BUN), and renal histopathology (HE, Masson, IHC) were evaluated to assess renal injury. Network pharmacology and transcriptomics were combined to screen the targets, and Western blot was used to verify the signaling pathways. Results: ES significantly reduced SCr and BUN levels in CKD mice and alleviated renal tubular dilation and inflammatory infiltration. ES decreased pro-inflammatory factors (IL-1β, IL-6, TNF-α) and MDA levels and enhanced SOD activity. Additionally, ES inhibited renal interstitial collagen deposition and reversed epithelial–mesenchymal transition (EMT) by upregulating E-cadherin and downregulating α-SMA levels. Mechanism studies confirmed that ES significantly inhibited the phosphorylation levels of p-EGFR, p-SRC, p-PI3K, p-AKT, and p-p65 in renal tissues. Conclusions: ES effectively inhibits inflammation, oxidative stress, and fibrosis by modulating the EGFR/SRC/PI3K/AKT/NF-κB signaling axis, thereby preventing the AKI-to-CKD transition in the adenine-induced renal injury model and alleviating the progression of chronic renal damage. Full article

Two spectrin-sensitive relaxations have been reported in the RBC plasma membrane: β_s (1.4 MHz, related to the interface β-relaxation) and γ1_s (9 MHz, rotation alignment of spectrin-bound dipoles by penetrating electric field). Here, a third (α_s) relaxation type is reported within the frequency region of surface (α) relaxation. With low-ion-strength outside media, the adsorption of blood plasma immunoglobulins on RBCs was found to inhibit β_s and γ1_s relaxations, while α_s relaxation was enforced with strong inflammation. The three relaxations are represented by three consecutive segments on the Cole′s plots: Δε_rd″.ω against Δε_r′ and Δε_rd″/ω against Δε_r′. Here, ω is the frequency of the field and Δε_r* = Δε_r′ + j.Δε_rd″ is the change in the relative complex dielectric permittivity of RBC suspension at the denaturation temperature of spectrin. The β_s segment in Δε_rd″.ω against the Δε_r′ plot could be regarded as a vector (complex number) whose projection on the vertical axis (the irreversible loss in energy) could express the ability of the plasma membrane to deform (under the impact of shear stress). Full article

Malignant gliomas remain highly treatment-resistant brain tumors despite surgery and adjuvant therapies. Targeted toxin therapies represent a unique strategy that exploits receptor-mediated cellular internalization to deliver cytotoxic components that result in the irreversible inhibition of protein synthesis independent of DNA damage or cell-cycle status. Advances in molecular profiling, toxin engineering, and delivery development have refined components targeting IL4Rα, IL13Rα2, EGFR/EGFRvIII, uPAR, and the transferrin receptor. Early clinical studies demonstrated biological activity, acceptable safety, and durable responses in subsets of patients, validating the fundamental mechanism of this approach. However, late-phase trials failed to demonstrate a population-level survival benefit, largely due to variability in delivery, receptor heterogeneity, and limitations in trial design rather than insufficient cytotoxic potency. Recent progress has focused on multiple receptor-targeting and delivery systems capable of achieving reliable intratumoral distribution. MRI-guided convection-enhanced delivery, vector-mediated toxin expression, and blood–brain barrier penetrant nanocarriers now enable more precise tumor targeting. Emerging evidence also reveals that toxin-mediated cytotoxicity can enhance antitumor immune responses, supporting their integration with immunotherapy. These advances position targeted toxins as precision cytotoxic compounds whose success depends on coordinated molecular targeting, delivery optimization, and biologically stratified patient selection, establishing a translational pathway for future glioma therapy. Full article

Cancer is an alarming health concern and economic burden in both developed and developing countries. Recently, there has been a growing demand for new alternative medications with more effectiveness and fewer harmful effects. During the past decades, a set of chemotherapeutic agents has been developed to fight against a large spectrum of cancer types. Unfortunately, their use is associated with a high level of toxicity; they are expensive, also, and their deployment is restricted by the emergence of cellular resistance. Plant-based components are garnering attention due to their low toxicity, selectivity, efficiency, and ease of accessibility. Alkaloids are one of these targeted compounds. Indeed, they are a highly diverse group with basic heterocyclic nitrogen-containing alkaloids that exhibit potent anticancer effects against a large panel of solid and liquid tumors, such as lung, breast, leukemia, liver, and colon cancer. The main molecular mechanisms involved in alkaloids’ anticancer effect are the induction of apoptosis via the extrinsic and intrinsic pathways, DNA damage, and the inhibition of cell cycle progression. Amazingly, these auspicious compounds exhibited strenuous inhibitory effects against a whole range of key enzymes involved in cancer progression and metastasis, such as Cytochrome P450 (CYP450), Cyclooxygenase-2 (Cox-2), Lysine-Specific Demethylase 1 (LSD1), Poly [ADP-ribose] polymerase (PARP), and topoisomerase, mainly through two action modes, namely irreversible and reversible inhibition. Furthermore, several conventional extraction methods have been developed to extract bioactive compounds from natural matrices, such as Soxhlet and hot water extraction. However, these techniques have many drawbacks, as they require a large amount of organic solvents, which not only affect human health but also generate severe environmental issues. To overcome these limitations, multiple eco-extraction techniques have emerged as potential alternatives to traditional extraction methods such as ultrasonic extraction, microwave-assisted extraction, and supercritical fluid extraction. In fact, they are considered eco-friendly and efficient technologies with less time and solvent consumption. Overall, this review aims to provide an updated overview of the most prominent anticancer alkaloids that have not been well reviewed already, as well as the main green extraction techniques relevant to the extraction of antineoplastic alkaloids. Full article

The remarkable evolution of oncological therapies has dramatically improved cancer survival rates but has simultaneously introduced a significant burden of cardiovascular complications. Cardio-oncology has emerged as a critical multidisciplinary field focused on mitigating the “collateral damage” of life-saving anticancer treatments, ranging from traditional chemotherapeutics to novel immunotherapies. This review provides a comprehensive analysis of the pathophysiological mechanisms, clinical phenotypes, and evolving management strategies for cancer therapy-related cardiac dysfunction (CTRCD). An extensive synthesis of the current literature was conducted, focusing on the molecular pathways of cardiotoxicity, including Topoisomerase IIβ inhibition by anthracyclines, HER2 signaling disruption by targeted agents, and immune-mediated myocarditis triggered by checkpoint inhibitors (ICIs). Cardiotoxicity is increasingly recognized as a spectrum of phenotypes. Heart failure with reduced ejection fraction (HFrEF) remains a primary concern with cytotoxic agents, while heart failure with preserved ejection fraction (HFpEF) is emerging as a critical complication of radiation therapy and tyrosine kinase inhibitors (TKIs). The integration of advanced diagnostic tools—specifically Global Longitudinal Strain (GLS) and Cardiac Magnetic Resonance (CMR) mapping—has shifted the clinical focus toward subclinical detection. Furthermore, pivotal clinical trials such as PRADA and SUCCOUR have validated early pharmacological prophylaxis and strain-guided interventions. Emerging challenges, including the management of CAR-T cell-induced cytokine release syndrome and the specific cardiovascular needs of pediatric and geriatric populations, are also explored. The future of cardio-oncology lies in precision medicine, leveraging genomic profiling and artificial intelligence to identify high-risk individuals. A proactive, multidisciplinary approach is essential to ensure that the success of modern oncology is not compromised by irreversible cardiovascular morbidity. Full article

Retinal ischemia–reperfusion (I/R) injury results in irreversible vision loss largely through retinal ganglion cell (RGC) death, with ferroptosis being a key mechanism. This study evaluated the therapeutic potential of the ferroptosis inhibitor Liproxstatin-1 (Lip-1) and deciphered its underlying mechanism. Using a mouse retinal I/R model and primary RGC cultures subjected to oxygen–glucose deprivation/reoxygenation (OGD/R), we demonstrated that Lip-1 effectively inhibits ferroptosis. Lip-1 treatment preserved retinal architecture (as assessed by H&E staining and SD-OCT) and partially restored visual function (as measured by electroretinography). Integrated molecular analyses—including immunofluorescence, Western blotting, and RNA sequencing—showed that Lip-1 downregulates early growth response 1 (EGR1), thereby inhibiting p53 and consequently restoring solute carrier family 7 member 11 (xCT) expression. Crucially, lentivirus-mediated EGR1 knockdown attenuated OGD/R-induced ferroptosis, confirming its pivotal role. Our work defines a coherent EGR1–p53–xCT signaling axis driving ferroptosis in retinal I/R injury and identifies Lip-1 as a neuroprotective agent targeting this pathway. These findings establish a druggable ferroptotic cascade and provide a mechanistic rationale for targeting EGR1 in the treatment of ischemic retinopathies. Full article

Background/Objectives: The increasing prevalence of antimicrobial-resistant bacteria highlights the need for improved methodologies to evaluate antimicrobial activity beyond conventional minimum inhibitory concentration testing. While resazurin-based assays are widely used for minimum inhibitory concentration determination due to their simplicity and sensitivity, minimum bactericidal concentration assessment still relies on labor-intensive colony-forming unit counting. The objective of this study was to develop and validate a resazurin-based microwell assay capable of determining both the minimum inhibitory concentration and the minimum bactericidal concentration without routine plate counting, thereby simplifying bactericidal evaluation. Methods: A two-step resazurin-based fluorescence assay was designed and performed in microplates. After determining the minimum inhibitory concentration using resazurin as a metabolic indicator, well-showing inhibited bacterial growths were subjected to a regrowth phase by transferring aliquots into fresh antimicrobial-free medium containing resazurin. This additional step allowed discrimination between reversible metabolic inhibition and irreversible bacterial death. The method was evaluated using ciprofloxacin and chloramphenicol against four bacterial species: Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Minimum bactericidal concentration values obtained using this assay were compared with those obtained through conventional colony counting on agar plates. Results: Minimum bactericidal concentration values obtained using the two-step fluorescence assay were fully concordant with the conventional colony-forming unit counting method for all tested antibiotics and bacterial species. Conclusions: The proposed two-step resazurin-based microwell assay represents a rapid, reliable, and less labor-intensive alternative for the determination of both the minimum inhibitory concentration and the minimum bactericidal concentration, with potential applications in clinical and industrial microbiology laboratories. Full article

Ram semen is highly susceptible to cold shock, which induces irreversible damage to the integrity and fluidity of membranes. Chilled semen is commonly used within 24 h of collection. However, while its storage at 5 °C extends semen lifespan, it is often accompanied by quality deterioration due to accumulation of reactive oxygen species (ROS). This study evaluated the potential of crocin, a carotenoid with antioxidant properties, to improve the quality of chilled ram semen stored at 5 °C for up to three days in a soybean lecithin–based extender supplemented with two crocin concentrations (0.5 and 1 mM). Sperm motility, viability, glutathione levels, the expression of proteins involved in the heat stress response (HSR), and apoptosis were assessed at 24 h intervals. Crocin preserved motility (up to Day 1), viability (up to Day 2,) and kinematic parameters (up to Day 3). In addition, crocin enhanced intracellular glutathione and Hsp70 levels and inhibited apoptotic levels dose-dependently, indicating the antioxidant and cytoprotective role of crocin. Despite 0.5 mM being effective up to Day 1, 1 mM crocin augmented antioxidant capacity, modulated stress response mechanisms, and preserved sperm quality during chilled storage up to Day 3, highlighting its potential as a valuable additive of ram semen extenders. Full article

Sensorineural hearing loss (SNHL), the predominant form of global hearing impairment, stems from the irreversible loss of inner ear sensory cells and neurons. Since mammalian cochlea lacks regenerative capacity, cell death represents a final common pathway for diverse insults. Current therapies are merely compensatory, underscoring an urgent need for mechanistic, targeted interventions. Autophagy, a critical homeostatic process, plays complex and dynamic roles in the cochleae. This review synthesizes current evidence on its regulation, highlighting its stage-specific and dual roles in SNHL. We emphasize mitophagy and its context-dependent effects on cell survival. Critically, we discuss an emerging therapeutic paradigm: a dual-phase autophagy modulation strategy. This approach proposes enhancing cytoprotective autophagy in early stages to maintain homeostasis, while inhibiting excessive autophagic flux later to prevent catastrophic cell death. This precision-targeting framework holds significant promise for guiding novel drug development and future clinical translation, moving beyond symptomatic management towards transformative treatment. Full article

Salicylic acid (SA) is a key signaling molecule regulating secondary metabolism and stress responses in plants, but its preharvest role as a low-cost elicitor in cannabis remains underexplored. This study evaluated the effects of preharvest foliar SA application at different concentrations and application intervals on pigments, antioxidants, and cannabinoids in Cannabis sativa L. leaves and inflorescences. In leaves, moderate SA (0.1 M) significantly enhanced total phenolic content, total flavonoid content, and antioxidant activity (%DPPH inhibition), while higher concentrations suppressed these responses, reflecting a regulated metabolic trade-off rather than irreversible tissue damage. A significant interaction between SA concentration and preharvest time was observed for chlorophyll a (p < 0.01), whereas chlorophyll b and total chlorophyll were not significantly influenced by the interaction. In inflorescences, short-term application of 0.1 M SA (1 h preharvest) maximized phenolics, flavonoids, antioxidant capacity, and pigment accumulation, whereas the untreated controls showed the lowest levels. Cannabinoids exhibited distinct responses: Δ⁹-tetrahydrocannabinol (Δ⁹-THC), total tetrahydrocannabinol (Total THC), and tetrahydrocannabinolic acid (THCA) peaked at 0.1 M SA applied 1 h preharvest, while cannabidiol (CBD) was less concentration-dependent, with maximum accumulation observed at 1.0 M SA applied 24 h preharvest. Preharvest SA elicitation strongly modulated cannabis secondary metabolism. Short-term application of moderate SA promoted total phenolic, total flavonoid, antioxidant, pigment, and THC-group cannabinoid accumulation, while CBD displayed broader tolerance to concentration and application timing. These findings highlighted the potential of SA as a preharvest elicitor to improve cannabis phytochemical quality. Full article