Search Results (744)

Background/Objectives:α-Mangostin, a natural product from Garcinia mangostana L, presents very strong antibacterial activity in plant flavonoids against Staphylococcus aureus. Recently, it was reported that the quinone pool is a key target of α-mangostin against Gram-positive bacteria. Here, the detail centering this action mechanism of α-mangostin killing S. aureus was further explored. Methods: The interactions between α-mangostin and type II NADH:quinone oxidoreductase (NDH-2), a key enzyme in the respiratory chain, were explored through the enzyme kinetic experiments, fluorescence analyses, and molecular simulation. Simultaneously, the effect of α-mangostin on membrane potential was also investigated as a possible non-enzymatic mechanism. Results: it was found that α-mangostin mainly competes the menaquinone-binding sites of NDH-2 with menaquinone, and the half-maximal inhibitory concentration (IC₅₀) of α-mangostin on NDH-2 is 4.95 μM. Fluorescence analyses indicated that α-mangostin can spontaneously bind to NDH-2 to form an α-mangostin–NDH-2 complex. Subsequently, molecular simulation further showed that α-mangostin can dock to the menaquinone-binding sites of NDH-2. In addition, non-enzymatic mechanism showed that α-mangostin can cause membrane potential depolarization and disrupt the proton motive force balance, thereby promoting the cell-membrane destruction of S. aureus. Conclusions: α-Mangostin can mainly interact with the amino acid residues at the menaquinone-binding pocket of NDH-2 to block the electron transfer at the quinone pool in the respiratory chain of S. aureus, which will hinder the energy supply and act synergistically with cell membrane damage, ultimately leading to the death of S. aureus. Simultaneously, it once again proves that the quinone pool is a key target of plant flavonoids against Gram-positive bacteria. Full article

Forsythia suspensa leaves black tea (FSLBT) is a fermented herbal tea traditionally consumed in Northern China, yet its bioactive constituents and antioxidant basis remain insufficiently understood. In this study, a phytochemical investigation of FSLBT led to the isolation and structural identification of nine compounds, including five lignans and four pentacyclic triterpenic acids, whose structures were elucidated by ¹H-NMR, ¹³C-NMR, and HRESIMS spectral analysis. Notably, epipinoresinol and pinoresinol monomethyl ether were isolated from Forsythia suspensa leaves (FSL) for the first time. Among the isolated lignans, phillygenin, epipinoresinol, pinoresinol monomethyl ether, and pinoresinol were further evaluated for antioxidant activity using DPPH•, ABTS•+, and FRAP assays. The four lignans exhibited concentration-dependent antioxidant activities, with IC₅₀ (half maximal inhibitory concentration) values ranging from 20.32 to 46.40 μg/mL for DPPH• scavenging and 37.29 to 72.71 μg/mL for ABTS•+ scavenging, while FRAP EC₅₀ (half maximal effective concentration) values ranged from 1.53 to 1.90 mg/mL. Quantitative HPLC analysis showed that the contents of phillygenin, epipinoresinol, pinoresinol monomethyl ether, and pinoresinol in FSLBT were 3.48 ± 1.12 wt%, 0.39 ± 0.21 wt%, 0.26 ± 0.20 wt%, and 0.18 ± 0.07 wt%, respectively. These results indicate that FSLBT is enriched in lignan aglycones, particularly phillygenin, and that these major lignans possess measurable chemical antioxidant activities, providing a phytochemical basis for further investigation of the functional properties of this fermented herbal tea. Full article

The introduction of amine groups into the four-membered central ring of squaraine dyes is expected to enhance the intrinsic cytotoxicity of this scaffold. In this study, the biological effects of eight benzothiazole-based aminosquaraine dyes were investigated by varying the length of the N-alkyl chains and the nature of the introduced amine. Biological activity was evaluated through different assays in several cell lines, including apoptosis and cell cycle analysis, as well as confocal microscopy studies. Overall, the incorporation of amino, methylamino, and ethanolamino groups significantly increased cytotoxicity, with the corresponding dyes displaying low half-maximal inhibitory concentration values, in some cases even lower than that of the positive control, 5-fluorouracil. In contrast, derivatives bearing diethanolamino or ethylenediamino groups exhibited lower cytotoxicity, particularly the dye containing N-decyl chain. For the dyes selected for further investigation, bearing a methylamino group and N-butyl or -hexyl chains, the induction of apoptosis was evident, especially for methylaminosquaraine dye 3. These dyes also exhibited antiproliferative effects, as evidenced by their ability to induce cell cycle arrest. Confocal microscopy revealed a predominantly cytoplasmic distribution, likely associated with cytoplasmic organelles, with limited penetration into the nucleus. Overall, although squaraines are widely recognized as promising photodynamic agents, the present results suggest that they may also be explored in chemotherapeutic approaches, particularly when exhibiting high intrinsic cytotoxicity. Full article

The plague, caused by Yersinia pestis, has resulted in significant mortality over the past century. Despite advances in antimicrobial therapy, plague remains a re-emerging infectious disease with ongoing outbreaks and increasing concerns regarding antimicrobial resistance. Today, plague cases are still being reported, and the loss of effectiveness of treatment methods remains a major challenge. Therefore, effective treatment strategies are needed. In this study, we aimed to develop aptamers specific to Yersinia outer protein M (YopM), a key immunosuppressive protein that is essential for virulence. Our goal was to develop an aptamer that binds to YopM and inhibits its interaction with the human DEAD-box helicase 3 (DDX3) protein. YopM-DDX3 protein interaction was targeted because of its key role in nucleocytoplasmic shuttling of YopM. To achieve this, we developed the YopM16 aptamer using magnetic bead-based (Systematic Evolution of Ligands by Exponential Enrichment) (SELEX). The selected YopM16 aptamer exhibited a half-maximal inhibitory concentration(IC₅₀) value of 103.3 ± 2 nM and effectively inhibited the interaction between YopM and DDX3. The inhibitory effect of the aptamer on protein interaction was confirmed using a pull-down assay and colorimetric test. Given that protein–protein interaction surfaces are considered undruggable, YopM16 is a promising inhibitor with the potential to serve as a molecular tool to investigate the virulence mechanism of YopM, as well as a novel antibacterial agent upon validation of its inhibition in cellular models. Full article

Phenolic acids and flavonoids remain attractive redox-active scaffolds in medicinal chemistry, where they are widely used for early-stage prioritization and intrinsic reactivity ranking. However, direct comparisons under harmonized conditions remain scarce, limiting structure-based assessment. Here, a structurally diverse panel of hydroxybenzoic acids, hydroxycinnamic acids, flavonoids, a flavanone, and synthetic comparators was profiled using Folin–Ciocalteu response, ABTS radical cation scavenging, DPPH radical scavenging, and reducing power assays. The data reveal pronounced assay dependence alongside clear structure–activity trends. Gallic acid showed the strongest DPPH scavenging (half-maximal inhibitory concentration, IC₅₀ = 4.45 µmol/L) and reducing power (17.26 µmol TE/mg), while quercetin was consistently active across all four endpoints. Eriocitrin (IC₅₀ = 2.47 µmol/L) and rutin (IC₅₀ = 2.66 µmol/L) were particularly effective in the ABTS assay, showing that glycosylation does not abolish cation-radical scavenging. Lipinski’s Rule of Five and Veber oral-bioavailability criteria place these findings within a drug-likeness context. The results also highlight the limitations of the Folin–Ciocalteu assay as a standalone measure of total phenolic content, since its response depends strongly on hydroxylation density. Rather than asserting therapeutic efficacy, this work provides a harmonized comparative dataset identifying phenolic substructures with the strongest and most consistent redox activity, together with the structural drivers underlying these patterns. Full article

Background/Objectives: Bladder cancer treatment is frequently hindered by chemoresistance to agents such as cisplatin, a process in which autophagy is hypothesized to play a cytoprotective role. This study aimed to investigate the time-dependent transcriptional dynamics of autophagy-related genes in response to cisplatin in bladder cancer cell lines to better elucidate the molecular underpinnings of this resistance. Methods: Two human bladder cancer cell lines, T24 and 5637, were exposed to varying concentrations of cisplatin. Cell viability and half-maximal inhibitory concentration (IC₅₀) values were determined at 24 and 48 h using the MTS assay. Subsequently, the relative mRNA expression levels of key autophagy-related genes (ULK1, BECN1, ATG5, ATG7, LC3B, SQSTM1/p62, LAMP1, and TFEB) were quantitatively analyzed via RT-qPCR at 0, 6, 24, and 48 h intervals. Results: Cisplatin exerted a dose- and time-dependent cytotoxic effect, with 5637 cells exhibiting significantly greater sensitivity compared to T24 cells. Transcriptional analysis revealed a dynamic, multiphasic modulation of the autophagic pathway: an early-phase upregulation of initiation genes (ULK1, BECN1), a mid-phase increase in autophagosome formation genes (ATG5, ATG7), and a late-phase alteration in lysosomal regulation genes (LAMP1, TFEB). Notably, the more chemoresistant T24 cells mounted a robust and sustained autophagic transcriptional response, whereas the sensitive 5637 cells demonstrated a more limited and transient reaction. Conclusions: Cisplatin modulates the autophagic pathway at the transcriptional level in a highly dynamic, time-dependent, and cell-line-specific manner. Interpreted alongside established functional evidence in the literature, the sustained autophagic gene expression observed in the resistant cells is consistent with a potential cytoprotective role, warranting further functional validation at the protein level. These findings map the temporal genetic landscape of cisplatin-induced autophagy, providing a theoretical framework for optimizing the timing of autophagy-targeted combination therapies in bladder cancer. Full article

Sea buckthorn leaves are a relatively underutilised component of sea buckthorn processed products; however, various studies have indicated that they possess hypoglycaemic potential. Under alkaline solubilisation and acid-precipitation conditions, the extraction yield of sea buckthorn leaf protein (SLP) reached 19.33%. Trypsin was selected as the hydrolysing enzyme to extract SLPPs-T, with half-maximal inhibitory concentrations (IC₅₀) against α-glucosidase and DPP-IV of 0.1361 ± 0.017 mg/mL and 0.1286 ± 0.012 mg/mL, respectively. UV spectroscopy, Fourier transform infrared spectroscopy, circular dichroism spectroscopy and particle size analysis indicated that the secondary and microstructures of SLP underwent changes following its hydrolysis to SLPPs-T; following separation, purification, sequence identification and computer screening, two novel peptides, PM-8 and VG-11, were obtained; molecular docking, solid-phase synthesis and in vitro experiments confirmed that VG-11 exhibited superior inhibitory activity, with half-maximal inhibitory concentrations (IC₅₀) against α-glucosidase and DPP-IV of 0.3885 ± 0.015 mM and 0.2611 ± 0.021 mM, respectively. In summary, this study explored the potential of sea buckthorn leaf protein as a natural hypoglycaemic product through a combination of computational modelling and experimental methods, thereby significantly enhancing the value of sea buckthorn resources. Full article

Background and Objectives: The integration of chemotherapy (ChT) and immune checkpoint inhibitors (ICIs) has become a standard approach in oncology. Although the addition of ICIs to double-agent ChT regimens has demonstrated clinical benefit in multiple studies, other trials have reported no significant improvement. ChT is hypothesized to potentiate the effects of ICIs through multiple mechanisms, including tumor antigen release and modulation of the tumor microenvironment. This study aimed to evaluate whether nivolumab enhances the cytotoxic effects of cisplatin or paclitaxel in lung adenocarcinoma (A549) cell lines under immune-independent conditions. Materials and Methods: A549 lung alveolar carcinoma cell lines were treated with varying concentrations of nivolumab, cisplatin, and paclitaxel, individually and in combinations. Cytotoxicity and apoptosis were assessed using mitochondrial membrane potential analysis, cell viability assays, and morphological evaluation of cellular and nuclear alterations characteristic of apoptotic cell death. Results: Nivolumab alone exhibited no cytotoxic activity. The combination of cisplatin at its IC₅₀ (half-maximal inhibitory concentration) (3 µg/mL) with 13 µg/mL nivolumab yielded the most pronounced cytotoxicity (89%) compared to cisplatin alone (49%, p < 0.001). Paclitaxel combined with nivolumab increased cytotoxicity to 69% versus 51% for paclitaxel alone (p < 0.05). The enhancement effect was greater with cisplatin than with paclitaxel. Notably, adding nivolumab to the cisplatin–paclitaxel combination reduced cytotoxicity from 73% to 64%. Mechanistic analysis revealed a significant reduction in Rhodamine 123 fluorescence intensity in drug-treated groups versus controls (p < 0.001), indicating loss of mitochondrial membrane potential, a hallmark of intrinsic apoptotic activation, suggesting apoptotic priming. Conclusions: Nivolumab potentiates the cytotoxic effects of cisplatin and paclitaxel in A549 lung adenocarcinoma cells, with a more pronounced effect observed in combination with cisplatin. This enhancement is associated with mitochondrial membrane potential loss, supporting mitochondrial apoptotic priming as a potential underlying mechanism of drug synergy. Full article

Pancreatic lipase (PL) inhibition is a promising dietary strategy for obesity management. In this study, the inhibitory mechanisms and structural basis of polyphenols extracted from different sugarcane fractions were investigated using in vitro enzyme assays, spectroscopy, and molecular docking analyses. PL inhibitory activity was evaluated using p-nitrophenyl laurate (pNPL) as the substrate, with all assays performed in triplicate and results statistically analyzed. Among the extracts, sugarcane peel polyphenols (SP) exhibited the strongest inhibition, with a half-maximal inhibitory concentration (IC₅₀) of 31.56 mg/mL, significantly lower than that of sugarcane juice polyphenols (SJ, 55.86 mg/mL) and sugarcane bagasse polyphenols (SB, 65.31 mg/mL). Enzyme kinetic analyses revealed a reversible mixed-type inhibition mechanism. In contrast to crude extracts, individual phenolic monomers showed substantially lower IC₅₀ values (0.13–1.33 mg/mL), highlighting the intrinsic dilution. Compositional analysis identified ferulic acid, gallic acid, chlorogenic acid, and schaftoside as key contributors to PL inhibition. Fourier transform infrared (FTIR) and fluorescence spectroscopy demonstrated that polyphenols altered PL secondary structure by modulating α-helix and β-sheet contents and perturbed the microenvironment of tryptophan (Trp) and tyrosine (Tyr) residues. Molecular docking further indicated that these compounds bind within or near the substrate-binding channel via hydrogen bonding and hydrophobic interactions, engaging critical residues including Ser152, His263, and Phe77, and potentially influencing conformational elements involved in active-site accessibility. Collectively, these results suggest that sugarcane, particularly its peel, represents a valuable natural source of PL inhibitors. Despite the relatively high IC₅₀ values of crude extracts, their inhibitory activity arises from multicomponent contributions and supports their potential application as dietary modulators of fat digestion rather than as pharmaceutical lipase inhibitors. Full article

The emergence of chloroquine-resistant Plasmodium falciparum in the 1950s posed a global threat to malaria control. Ceasing chloroquine use restored chloroquine-sensitive strains in many African countries. To assess whether chloroquine sensitivity re-emerged in Lambaréné, Gabon, we compiled published and new data on P. falciparum ex vivo chloroquine susceptibility, quantified as half-maximal inhibitory concentration (IC₅₀), from four time points between 2004 and 2024. We then assessed the prevalence of pfcrt and pfmdr1 polymorphisms associated with chloroquine resistance via real-time PCR and Sanger sequencing, respectively, at six different time points between 2009 and 2024. Ex vivo chloroquine susceptibility data revealed a stepwise decrease in the median chloroquine IC₅₀ from 2004 (113.8 nM; IQR: 79.6–163.5 nM, n = 42), 2009 (46.7 nM; IQR: 27.4–76.9 nM, n = 26), and 2017–2018 (15.6 nM; IQR: 6.1–40.9 nM, n = 46) to 2024 (2.1 nM; IQR: 0.8–6.1 nM, n = 39). The chloroquine-sensitive pfcrt haplotype CVMNK increased from 3.6% (1/28) in 2009 to 98.2% (56/57) in 2024, as well as the wild-type pfmdr1 N86 (23.1% (6/16), 2009; 100% (19/19), 2024). Paired molecular and ex vivo analyses revealed an association between IC₅₀ values and CVMNK pfcrt and pfmdr1 N86. Our data provide evidence for the reestablishment of chloroquine-sensitive P. falciparum in Lambaréné, Gabon. Full article

Cancer remains a leading cause of morbidity and mortality globally, with current therapies often limited by toxicity, drug resistance, and reduced efficacy in advanced stages. Medicinal plants represent important sources of bioactive compounds (BACs) with anticancer and chemopreventive potential; however, their successful application is strongly influenced by extraction strategies that determine phytochemical recovery and downstream biological activity. This review evaluates solvent-based extraction techniques used to extract BACs from medicinal plants with reported anticancer properties, synthesizing peer-reviewed articles from PubMed and Google Scholar published between 2020 and 2025. Solvent-based methods, including Soxhlet and maceration, were most widely applied due to their operational simplicity and the preservation of structurally diverse metabolites while percolation, decoction, infusion, and hydro-distillation were sparsely utilized. Extraction strategy and solvent polarity emerged as primary factors shaping phytochemical profiles, with phenolics, flavonoids, alkaloids, and terpenoids identified as dominant classes. Reported half maximal inhibitory concentration (IC₅₀) ranged from highly potent (0.12 µg/mL) to weak (30,000 µg/mL), reflecting variability driven by extraction parameters and plant matrix complexity. Anticancer mechanisms commonly involved apoptosis induction, cell-cycle arrest, reactive oxygen species-mediated cytotoxicity, and inhibition of proliferative signaling pathways across breast, cervical, colon, lung, liver, and prostate cancer models. Although solvent-based extraction approaches remain widely used, their context-dependent nature and lack of standardization limit reproducibility. Overall, anticancer and chemotherapeutic efficacy is primarily governed by BAC composition, while extraction methods act as upstream modulators. Future progress requires phytochemical-informed, standardized workflows supported by hybrid extraction systems, AI-assisted optimization, and advanced bioavailability and delivery systems to enable reproducible and clinically relevant translation of plant-derived chemotherapeutics. Full article

Background/Objectives: Head and neck squamous cell carcinoma (HNSCC) often exhibits limited clinical response to targeted therapies, such as Cetuximab. Identifying key drivers of tumor progression and elucidating the factors that modulate therapeutic sensitivity are essential for improving clinical outcomes. In this study, we aimed to investigate the role of CAV2 in HNSCC proliferation and its impact on Cetuximab sensitivity. Methods: Prognosis-associated genes in HNSCC were screened using the The Cancer Genome Atlas (TCGA) database. The functional role of Caveolin-2 (CAV2) in cell proliferation and apoptosis was assessed via Cell Counting Kit-8 (CCK-8), colony formation, and flow cytometry assays. Mechanistic insights were obtained through co-immunoprecipitation, ubiquitination assays, and proteomic analysis. The impact of CAV2 on Cetuximab sensitivity was evaluated both in vitro and in a xenograft mouse model. Results: Clinical analysis of 43 pairs of HNSCC tumor and adjacent normal tissues revealed that elevated CAV2 expression was significantly associated with poor prognosis in HNSCC patients (95%CI: 1.197–1.7518, p = 1.33 × 10⁻¹³). In vitro, knockdown of CAV2 suppressed cell proliferation and significantly increased apoptosis rates (from 5.1% to 10.8%, p = 0.004). Mechanistically, CAV2 interacted with the PACT protein and disrupted the PACT-PKR axis via the ubiquitin–proteasome pathway. Notably, CAV2 deficiency synergized with Cetuximab treatment, reducing the the half maximal inhibitory concentration (IC₅₀) value by 6-fold compared with control cells and suppressing tumor growth by 48.41% in xenograft models compared to Cetuximab monotherapy (p < 0.0001). Conclusions: In conclusion, these findings establish CAV2 as a critical regulator of HNSCC progression and Cetuximab sensitivity via post-translational modulation of the PACT–PKR axis. Targeting the CAV2/PACT/PKR axis may therefore represent a promising therapeutic strategy to potentiate the efficacy of EGFR-targeted therapy in patients with HNSCC. Full article

In this study, the Box–Behnken Design (BBD) was adopted to optimize the ultrasound-assisted extraction (UAE) conditions of polyphenols from Hericium erinaceus (H. erinaceus) on the basis of single-factor experiments, with extraction time, solid–liquid ratio and ethanol concentration as the key investigation factors. The optimal extraction parameters were determined as follows: extraction time of 56.85 min, solid–liquid ratio of 1:56.71 g/mL and ethanol concentration of 44.64%, under which the actual yield of the total polyphenol crude extract (TPCE) reached 0.9985 ± 0.03%, which was highly consistent with the theoretical predicted value of 0.9960%, verifying the good fitting degree of the established model. Taking L-ascorbic acid as the positive control, the antioxidant activity of TPCE was evaluated by determining its scavenging capacity against ABTS·⁺, ·OH and DPPH· free radicals, and the half-maximal effective concentration (EC₅₀) values were measured to be 0.8850, 0.9490 and 4.198 mg/mL, respectively. With acarbose as the reference drug, the inhibitory effects of TPCE on α-amylase and α-glucosidase related to carbohydrate metabolism were assayed, and the corresponding half-maximal inhibitory concentration (IC₅₀) values were 0.0135 and 130.3 mg/mL, respectively. Furthermore, ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) was employed for the tentative identification of bioactive components in TPCE, and a total of 48 and 64 chemical constituents were characterized in negative and positive ion modes, respectively, providing a chemical basis for the biological activities of TPCE. This study confirmed that UAE is an efficient and feasible technology for extracting polyphenols from H. erinaceus, which lays a theoretical foundation for the development and utilization of its polyphenols, and also provides novel insights into the development of natural functional ingredients and potential therapeutic agents for the intervention of type 2 diabetes. Additionally, the findings further validate edible fungi as a valuable reservoir of natural bioactive substances, with promising application prospects in the research and development of functional foods and pharmaceuticals targeting metabolic diseases. Full article

Fufang Yinhua Jiedu Granules (FFYHG) is usually applied to treat influenza and the common cold. However, there is no available report concerning the effects of chemical constituents in FFYHG on antiviral activity. In our study, four new terpenoid derivatives (1–4) and seventeen known compounds were isolated from FFYHG. Their structures and absolute configurations were determined by various techniques, including high-resolution mass spectrometry analysis, 1/2-dimensional (1D/2D) nuclear magnetic resonance (NMR) analysis, comparative electronic circular dichroism (ECD) studies (experiment vs. calculation), and acid hydrolysis. In addition, the inhibitory effects of twenty-one isolated compounds against influenza A viruses (H1N1) including A/California/07/2009 (CA07) and A/WSN/1933 (WSN) strains were evaluated in vitro, and compound 4 exhibited a moderate inhibitory effect on CA07 strain, with a half maximal inhibitory concentration (IC₅₀) value of 37.10 ± 1.35 μM. This study enhanced the understanding of the active ingredients in FFYHG against influenza virus, providing a foundation for further research on the material basis and quality control of FFYHG. Full article

Impatiens hawkeri W. Bull (I. hawkeri) is popular among consumers due to its diverse flower colors and year-round blooming. However, changes in ecological conditions, cultivation methods, and planting scale have led to increased disease incidence and diversity, particularly the widespread and destructive leaf spot disease. Currently, studies addressing the pathogen species and its biological characteristics remain limited. In this study, a highly pathogenic strain (IH-4) was selected from previously isolated fungi associated with leaf spot in I. hawkeri. Its taxonomic status was confirmed using upright fluorescence microscope analysis, internal transcribed spacer (ITS)/large subunit (LSU)/RNA polymerase II second largest subunit (rpb2)/β-tubulin (tub2) rRNA gene sequencing, and phylogenetic tree construction. Additionally, the biological characteristics of the pathogen and its sensitivity to 8 chemical fungicides were assessed. Strain IH-4 was identified as Ectophoma multirostrata (E. multirostrata) through combined morphological and molecular approaches. Optimal growth conditions included a temperature of 25 °C, a pH of 7, Potato Dextrose Agar (PDA) medium, fructose as the optimal carbon source, and urea as the optimal nitrogen source, with the fastest growth observed under a semi-light photoperiod (12 h light/12 h dark). Fungicide sensitivity assays indicated that 25% azoxystrobin exhibited the lowest half-maximal effective concentration (EC₅₀, 0.0724 μg/mL) and the steepest virulence regression slope (1.7), demonstrating the strongest inhibitory activity and highest sensitivity. Microscopic observations revealed that IH-4 hyphae penetrate I. hawkeri leaf tissues via stomata, colonize internally, and consequently cause host damage. This study provides a theoretical foundation for the timely and effective management of leaf spot disease in I. hawkeri. Full article