Search Results (204)

Hydrothermal synthesis is a bottom-up, liquid-phase synthesis method and a heterogeneous reaction, utilizing a water solvent at a temperature of >25 °C and a pressure of ≥1 atm to dissolve and to precipitate crystalline or amorphous materials or to get solutions by using a reflux, autoclave, or flow reactor. Microwave-assisted hydrothermal and supercritical flow reactors successfully reduced the synthesis times from hours or days to minutes and seconds. Substitutions for precursors, reductors, or stabilizer chemicals with plant extracts successfully created greener hydrothermal methods, but they still need relatively long times (hours) and high temperatures (>100 °C). The stronger critical perseptives include the inhibited standarization and reproducibility due to plant species variant, plant growth conditions, and plant extraction methods. The plant extract can’t substitute surfactant as mesoporous template or the organic solvents for water-organic sol-vent mixture, and it is possibly photodegraded by microwave. Strategies to reduce time and temperature by mechanical hydrothermal synthesis using plant extracts, with safety prioritized, utilizing non-toxic products, degradable products, and non-harmful reactants, are suggested for future research. One mechanistic question is still not resolved: how distiguish crystalization mechanism by using the temperature reduction method and by using temperature different method. Full article

Type 2 diabetes (T2D) remains a major public health challenge in Africa, where limited healthcare access and the high cost of conventional therapies sustain reliance on African traditional medicine (ATM). This systematic review and meta-analysis evaluated the efficacy, mechanisms of action, and safety of African polyherbal formulations for T2D management. This systematic review and meta-analysis was conducted in accordance with PRISMA 2020 guidelines, following a protocol registered with PROSPERO (CRD420251168831). We searched PubMed, Scopus, ScienceDirect, Web of Science, and Google Scholar for studies published between 1 January 2011 and 31 December 2024. Seventeen studies met the inclusion criteria. Polyherbal formulations consistently improved glycaemic control, insulin sensitivity, antioxidant status, and lipid profiles. Meta-analysis of 10 preclinical studies demonstrated a significant reduction in fasting blood glucose compared with that of diabetic controls (SMD = −5.22, 95% CI: −5.55 to −4.89; p < 0.001; I² = 93.88%). Proposed mechanisms included β-cell protection, stimulation of insulin secretion, inhibition of α-amylase and α-glucosidase, and attenuation of oxidative stress. Safety data were limited and inconsistently reported. Human evidence was limited to one quasi-experimental clinical study and one acute human OGTT study. African polyherbal formulations demonstrate promising antidiabetic potential; however, methodological heterogeneity, limited phytochemical characterisation, inadequate safety assessment, and scarce clinical evidence highlight the need for standardised preclinical studies and well-designed clinical trials to support evidence-based integration into healthcare. Full article

Product Shezi (PS) is a polyherbal African traditional medicine (ATM) formulated from six known South African medicinal plants and is used for treating cutaneous wounds. However, its ethnopharmacological properties have not been scientifically validated. This study aimed to evaluate the antioxidant, anti-inflammatory, and antimicrobial activities of PS in vitro. Aqueous and methanolic extracts were prepared and qualitatively screened for phytochemical constituents. Cytotoxicity in fibroblasts and macrophages was assessed using an ATP-based viability assay. Antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and a hydrogen peroxide (H₂O₂)-induced oxidative stress model. Anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated macrophages were measured using the Griess reagent system, a human prostaglandin E₂ (PGE₂) ELISA, and a bovine serum albumin (BSA) anti-denaturation assay. Antimicrobial activity was assessed by twofold serial broth microdilution, agar well diffusion, and a crystal violet biofilm assay. Phytochemical screening confirmed the presence of saponins, alkaloids, tannins, glycosides, terpenoids, flavonoids, and steroids. PS exhibited IC₁₀ values of 3 and 10 μg/mL in fibroblasts and macrophages, respectively. PS (1–5 μg/mL) showed 70% DPPH scavenging potential and potent H₂O₂ cytoprotection (p < 0.001). Nitric oxide inhibition was non-significant (p > 0.05) whilst PGE₂ decreased significantly (p < 0.05) compared to LPS-stimulated cells. BSA denaturation was inhibited in a dose-dependent manner (p < 0.05). Staphylococcus aureus and S. epidermidis were the only microorganisms susceptible to PS (MIC 650–5000 μg/mL) with low SI (SI ≈ 0.05–0.06), while others were resistant. PS showed no antibiofilm activity (crystal-violet assay). Overall, PS demonstrated antioxidant and anti-inflammatory activities and selective antibacterial effects against planktonic bacteria in vitro. However, further optimization of extraction methods, detailed mechanistic studies, and in vivo investigations are warranted to substantiate therapeutic relevance. Full article

The therapeutic potential of pharmacologically targeting kinases involved in regulating the DNA damage response (DDR) has been investigated for over two decades. Inhibitors of ATM, ATR, CHK1, CHK2 and WEE1 have been developed with the aim of subverting cell cycle checkpoint function in cancer cells, promoting cell death. The DNA repair pathway non-homologous end-joining can also be targeted through DNA-PK inhibition. However, despite extensive preclinical and clinical studies, none of the many candidate inhibitors have yet made it through to clinical approval. Emerging evidence for tumour biomarkers associated with enhanced sensitivity to DDR kinase inhibition may provide a way through this impasse. Clinical testing in appropriately stratified cohorts is now becoming increasingly common, with some promising results. Building on results obtained with small-molecule inhibitors, targeted protein degradation (TPD) utilising proteolysis-targeting chimaeras (PROTACs) or molecular glues for degradation of DDR kinases is a rapidly developing strategy. This review discusses the current ATM, ATR, DNA-PK, CHK1, CHK2 and WEE1 inhibitors that show the most promise as monotherapies and combination treatments in solid tumours, as well as the potential benefits of using TPD technology over small-molecule inhibitors. Established and emerging biomarkers that can be applied to patient selection are also discussed. Full article

Background/Objectives: Though PARP inhibition has improved the management of advanced prostate cancer, patient outcomes may be modest and disease progression on treatment is common. We sought to improve understanding of tumor cell response to PARP inhibition to support development of novel strategies to enhance and/or prolong PARP inhibitor (PARPi) efficacy. Methods: Cell viability assays and microscopy were used for initial characterization of PARPi response in models of advanced prostate cancer. RNA sequencing was performed to investigate time-dependent transcriptomic changes induced by PARP inhibition. Western blots, flow cytometry, and both additional viability assays and microscopy were used to validate RNA sequencing results and test potential therapeutic strategies. Results: Characterization of responses to PARP inhibition reveals time-dependent changes which may be targeted to improve treatment efficacy. In line with the expected PARPi mechanism of action, short-term treatment is largely associated with activation of ATM and the DNA damage response and cell cycle checkpoint signaling. Targeting ATM with clinical stage inhibitors significantly enhances reduction of tumor cell viability by PARP inhibition. Tumor cells exposed to longer-term treatment exhibit SLUG-dependent epithelial–mesenchymal transition (EMT) and evidence for altered fatty acid metabolism, both of which may be targeted to enhance PARPi anti-tumor cell effects. Conclusions: This study provides insight into both short and longer-term cellular response to PARPi treatment and provides a foundation for additional efforts to explore effective strategies to maximize the utility of PARP inhibition for managing prostate cancer. Full article

Background: Head and neck squamous cell carcinoma (HNSCC) remains a highly aggressive malignancy with poor clinical outcomes. Although poly(ADP-ribose) polymerase (PARP) inhibitors have shown promising activity in tumors with homologous recombination deficiency, their efficacy in BRCA wild-type HNSCC remains limited. Reactive oxygen species (ROS)-induced DNA damage may increase cellular dependence on DNA repair pathways and thereby enhance sensitivity to PARP inhibition. This study investigated whether ROS-mediated DNA damage could sensitize BRCA wild-type HNSCC cells to the PARP inhibitor olaparib. Methods: BRCA wild-type HSC-3 and SCC-25 HNSCC cell lines were exposed to H₂O₂ to induce oxidative stress. Intracellular ROS levels were quantified using DCFDA assays, DNA double-strand breaks were evaluated by γ-H2AX ELISA, PARP activity was assessed by ELISA, and cell viability was determined using MTT assays. Expression levels of DNA repair genes (PARP1, PARP2, BRCA1, BRCA2, RAD51, and MLH1), checkpoint kinases (ATM, ATR, and CHK1), the homologous recombination regulator FANCD2, and redox defense genes (NQO1, GPX4, and SLC7A11) were analyzed by qRT-PCR. Therapeutic selectivity was assessed using HGF-1 normal human gingival fibroblasts as a normal cell control. Apoptosis was measured through caspase-3/7 activity assays, and drug interactions were evaluated using the Chou–Talalay method. Results: H₂O₂ treatment increased intracellular ROS levels in both cell lines, accompanied by significant induction of DNA damage as demonstrated by elevated γ-H2AX levels. ROS induction markedly enhanced olaparib sensitivity, significantly reducing IC₅₀ values in both HSC-3 and SCC-25 cells. Combined H₂O₂ and olaparib treatment produced strong synergistic cytotoxicity, suppressed DNA repair, checkpoint kinase, and redox defense gene expression, and increased caspase-3/7 activity compared with control cells. Importantly, the combination demonstrated selective cytotoxicity toward cancer cells, with normal HGF-1 cells retaining significantly higher viability. Conclusions: ROS-induced DNA damage significantly enhances the anti-tumor activity of olaparib in BRCA wild-type HNSCC cells through a functional synthetic lethal-like interaction involving the simultaneous collapse of DNA repair capacity, checkpoint activation, and oxidative stress buffering, culminating in apoptosis induction. These findings support the rationale for combining ROS-generating therapies with PARP inhibitors in HNSCC treatment. Full article

An undescribed seco-kaurane diterpenoid, benincaside A (BA), was isolated from the seeds of Benincasa hispida. The seeds of B. hispida have been traditionally used in folk medicine and previous studies have reported anti-tumor potential in B. hispida seed extracts. Accordingly, we investigated the cytotoxicity and underlying mechanisms of BA in colorectal cancer cells. BA inhibited growth in HT29, Colo205, HCT116, and CT26 colorectal cancer cells, as determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, while showing no toxicity toward normal human umbilical vein endothelial cells (HUVEC) and human fibroblast WS-1 cells. In HCT116 cells, BA-induced deoxyribonucleic acid (DNA) damage and apoptosis, as evidenced by morphological changes, 4,6-diamidino-2-phenylindole dihydrochloride (DAPI) staining, and assays of caspase-8 and caspase-3 activities. BA triggered apoptotic cell death via the extrinsic pathway, as indicated by elevated caspase-8 and caspase-3 activities. Intracellular reactive oxygen species (ROS) generation was observed in BA-treated HCT116 cells. The growth-inhibitory effects were significantly attenuated by pretreatment with N-acetylcysteine (NAC, an antioxidant), caffeine (an ATM kinase inhibitor), z-VAD-fmk (pan-caspase inhibitor), or z-IETD-fmk (caspase-8-specific inhibitor). Colorimetric assays confirmed increased caspase-8 and caspase-3 activities in BA-treated cells. This study is the first to report ROS-dependent signaling as a key mechanism underlying BA-induced cell death in HCT116 human colorectal cancer cells. Full article

Background/Objectives: Pancreatic ductal adenocarcinomas (PDACs) are lethal tumors exhibiting resistance to most cancer therapeutics, particularly DNA-damaging agents. The KRAS oncogene drives PDACs, and many of these tumors are addicted to it and its downstream effectors. One such effector is Rac1, a small GTPase involved in actin cytoskeleton remodeling and regulation of the DNA damage response. We previously showed that Rac1 inhibition blocks activation of ATM/Chk2 and ATR/Chk1 pathways in response to gamma rays, sensitizing PDAC cells to radiation. Methods: Western blot analyses were used to assess the impacts of Rac1 inhibition on the components of the ATR/Chk1 cascade. Results: Here, we show that Rac1 inhibition disrupts ATR/Chk1 signaling by promoting degradation of Claspin, a key component of the fork protection complex needed for the Ser345-phosphorylation of Chk1 by ATR. In PDACs and normal pancreatic ductal cells, Rac1 inhibition (via inhibitors or siRNA) decreased Claspin protein levels without affecting its mRNA, reflecting a >3-fold reduction in Claspin’s half-life. Claspin contains a phosphodegron recognized by SCF^βTrCP E3 ubiquitin ligase when phosphorylated at Ser30/Ser34, a process involving PLK1 kinase. In PDAC cells, Claspin degradation upon Rac1 inhibition required the proteasome and βTrCP1/2 proteins, and was blocked by the mutagenesis of Ser30/Ser34, but occurred independently of PLK1 activity. Although Rac1 inhibitors reduced Claspin in both normal and cancer cells, PDAC cells may be uniquely vulnerable due to elevated replication stress and greater reliance on ATR/Chk1. Accordingly, Claspin depletion sensitized PDAC cells but not normal cells to gamma rays, inducing apoptosis only in cancer cells. Conclusions: These findings identify Rac1 as a critical regulator of ATR/Chk1 signaling through stabilization of the fork protection protein Claspin. Rac1 inhibition promotes the βTrCP-dependent, proteasome-mediated degradation of Claspin via its phosphodegron, thereby impairing Chk1 activation in response to DNA damage. Full article

Cervical cancer constitutes a major global health burden with a high incidence rate. Despite its well-established role in genome stability and cell cycle regulation, its specific anti-tumor mechanism involving the induction of a senescence-like state remains unclear. To determine whether Mg²⁺ impedes cervical cancer progression through the induction of a senescence-like phenotype via the ATM/CHK2/p21 pathway, HeLa cells were used in this study. Cell proliferation, migration, and invasion were measured using CCK-8, EdU, wound-healing, and Transwell assays, while SA-β-gal staining and western blotting served to examine both senescence-related markers and pathway protein expression. A BALB/c nude mouse xenograft model was established to evaluate tumor growth and safety following intratumoral Mg²⁺ injection. The results showed that Mg²⁺ inhibited proliferation, migration, and invasion in a concentration-dependent manner. Treatment with 20 mM Mg²⁺ increased SA-β-gal positivity, decreased Lamin B1 expression, and activated the ATM/CHK2/p21 pathway; moreover, this upregulation of p21 was reversed by an ATM inhibitor. ELISA revealed that 10 mM Mg²⁺ enhanced IL-6 and TNF-α secretion, confirming effective induction of the senescence-associated secretory phenotype, while higher concentrations diminished this effect, which may be partly attributed to the reduction in cell viability. In vivo experiments showed that Mg²⁺ inhibited tumor growth without notable alterations in body weight, liver and kidney function, or serum magnesium levels. In summary, the localized high concentration of magnesium ions induces cells to enter a senescence-like state via the ATM/CHK2/p21 pathway, thereby selectively suppressing malignant cellular behaviors. Notably, its in vivo efficacy and safety profile in vivo are favorable. It is also worth noting that these findings should be interpreted within the context of a preclinical, high-dose local Mg²⁺ model. Full article

Background/Objectives: Combinations of PARP inhibitors (PARPi) and androgen receptor pathway inhibitors (ARPi) have led to clinical success in treating advanced prostate cancer. However, it is unclear where in the clinical paradigm these combinations will fare best, and their mechanism of action remains unclear. We sought to address open questions and explore alternative strategies to enhance PARPi efficacy. Methods: Viability and morphology were assessed in response to (1) abiraterone, olaparib, or combination and (2) enzalutamide, talazoparib, or combination in castration-resistant C4-2B cells and abiraterone- or enzalutamide-resistant derivative cell models (ARPi-resistant). The efficacy of the ATM inhibitor lartesertib with and without a PARPi was also determined. Western blots and RNA-sequencing were used to interrogate the mechanistic effects of treatment. Results: PARPi and ARPi combinations were effective in all models but provided the most benefit in ARPi-sensitive C4-2B cells. Mechanistically, ARPi was not found to affect homologous recombination repair gene expression but may increase PARP activity. Prolonged PARP inhibition was found to increase the expression of AR target genes, and PARPi pre-treatment increased sensitivity to enzalutamide. ATM inhibition significantly increases PARPi efficacy and appears to outperform ARPi-containing combinations in ARPi-resistant models. Conclusions: PARPi and ARPi combinations are effective in ARPi-resistant models, but efficacy appears stronger in ARPi-sensitive CRPC cells. Presented findings support a novel hypothesis that PARP inhibition may increase ARPi sensitivity with increasing AR activity. Additionally, ATM inhibition may provide more benefit than an ARPi in combination with a PARPi in ARPi-resistant settings. These findings support continued PARPi development for improving patient outcomes. Full article

Saline-alkaline (SA) soils pose a serious threat to soybean production worldwide. Although severe saline-alkaline stress can reduce yield by up to 30%, the mechanisms underlying saline-alkaline-induced inhibition of root growth remain unclear. In this study, two soybean cultivars with contrasting tolerance, Chang Nong 26 (CN26) and Jiyu 441 (JY441), were exposed to saline-alkaline stress induced by NaHCO₃ and Na₂CO₃ at Na⁺ concentrations of 0, 21, and 45 mmol·L⁻¹. The effects on seed germination, early seedling growth, antioxidant responses, and root DNA damage were systematically examined. High-level saline-alkaline stress significantly inhibited germination and root elongation in both cultivars. Superoxide dismutase (SOD) and peroxidase (POD) activities increased markedly under stress, indicating activation of antioxidant defenses. Catalase (CAT) and ascorbate peroxidase (APX) to scavenge ROS and maintain cellular redox balance. Nevertheless, oxygen-free radicals (OFRs) accumulated to a significantly greater extent in the root tips of CN 26 than in JY441, suggesting lower tolerance in CN 26. Random amplified polymorphic DNA (RAPD) analysis revealed pronounced DNA damage in root tips under saline-alkaline stress, with more polymorphic bands detected in CN 26 than in JY441. Furthermore, qRT-PCR analysis demonstrated that the expression of DNA damage repair-related genes (RAD51, OGG1, RAD4, and ATM) was downregulated in CN 26 roots under stress, whereas E2FA and WEE1 expression was upregulated. In contrast, these DNA repair genes in JY441 were significantly induced during the early stage of stress exposure and subsequently declined. Collectively, this study demonstrates that saline-alkaline stress inhibits soybean growth through the induction of oxidative DNA damage and cell cycle arrest in roots. The reduced capacity for DNA repair in CN 26 likely contributes to its greater sensitivity to saline-alkaline stress. This study provides mechanistic insights into saline-alkaline stress-induced growth inhibition in soybean and offers a theoretical basis for breeding stress-tolerant cultivars. Full article

Cellular senescence (CSEN) is caused by a variety of factors that trigger complex molecular pathways. These include telomere shortening, oncogene activation and replicative stress, as well as DNA damage caused by genotoxic anticancer drugs and endogenous and exogenous genotoxins. Here, we review the induction of CSEN by exogenous genotoxic insults resulting from food and environmental exposures. The available data show that genotoxins/carcinogens in tobacco smoke and smokeless tobacco, in the environment, in food, beverages and life-style products induce CNS. The exposures include N-nitroso compounds, polycyclic aromatic hydrocarbons, heterocyclic aromatic amines, acrylamide, heavy metals, fine dust, mycotoxins, phytotoxins, and phycotoxins. Also, heme in red meat contributes to CSEN as it catalyzes the formation of genotoxic species in the colon. Induction of CSEN by external genotoxins/carcinogens is bound on the DNA damage response pathway (DDR), which relies on activation of the ATM/ATR-CHK2/CHK1-p53-p21 axis and the p53-independent p16/p14 axis, eliciting cyclin-dependent kinase inhibition and permanent cell cycle arrest. Other factors that can be involved are DREAM, MAPK, cGAS/Sting, and NF-κB. The accumulation of non-repaired DNA damage triggering CSEN following external genotoxic exposures may contribute significantly to the amelioration of senescent cells and organ failure with age in humans. Senescent cells drive, via the senescence-associated secretory phenotype (SASP), inflammation that is involved in many diseases, including cancer. Although most of the studies were performed with in vitro cell systems, the consequences of CSEN induction by genotoxic nutritional components and environmental exposures seem to be underestimated. Since CSEN correlates with aging, it is reasonable to conclude that exogenous genotoxic pollutants contribute significantly to the aging process through CSEN induction. In light of these findings, it is deduced that reducing genotoxin exposures and using “rejuvenation” supplements (senotherapeutics) are reasonable strategies to counteract cellular senescence and the aging process. Full article

The hepatitis C virus (HCV) Core activates the ATM-Chk2 pathway, leading to phosphorylation of p53 at Ser-15, which inhibits mouse double minute 2 (MDM2)-mediated proteasomal degradation. This study reveals that HCV Core also promotes E6-associated protein (E6AP)-mediated degradation of p53 during HCV replication. In the presence of HCV Core, E6AP expression induced p53 ubiquitination, reduced its stability, and decreased p53 levels, whereas E6AP knockdown increased p53 levels. The E3 ubiquitin ligase activity of E6AP was critical for this process, as demonstrated using the E6AP C833A mutant and the E3 ligase inhibitor Heclin. Proteasomal inhibition with MG132 confirmed that HCV Core and E6AP act together to regulate p53 levels via the proteasome. Importantly, HCV Core-induced p53 phosphorylation was essential for E6AP-mediated degradation, as shown by the impairment of degradation in the presence of the ATM inhibitor KU-55933. E6AP also targeted p53 phosphorylated at Ser-15 by etoposide, as well as phosphomimetic mutants such as p53 S15D, but not non-phosphorylatable mutants such as p53 S15A. These findings suggest that HCV Core-induced p53 phosphorylation enhances E6AP-mediated degradation while preventing MDM2 from targeting p53, thereby maintaining p53 levels that support cell survival, viral replication, and potentially oncogenesis in human hepatocytes. Full article

Pancreatic cancer (PC) remains a highly lethal malignancy with limited treatment options and poor survival. Targeting DNA damage response (DDR) pathways has emerged as a promising therapeutic strategy, particularly the ATR-CHK1 and ATM-CHK2 axes. Preclinical studies demonstrate that ATR inhibition disrupts replication stress tolerance, impairs homologous recombination, and disables checkpoint control, enhancing cytotoxicity from standard therapies including gemcitabine, FOLFIRINOX, fluoropyrimidines, and radiotherapy. Synergistic effects have also been observed with other DDR-targeted agents, such as PARP and WEE1 inhibitors. Genomic contexts, including ATM deficiency, ARID1A alterations, and oncogene-driven replication stress, refine therapeutic sensitivity, supporting precision patient stratification. Early-phase clinical trials of ATR inhibitors (ART0380, AZD6738, BBI-355) alone or in combination show promising safety, tolerability, and preliminary efficacy. In this review, we summarize current literature on targeting the ATM-CHK2 and ATR-CHK1 pathways in PC, highlighting preclinical evidence, clinical developments, and strategies for biomarker-driven, precision oncology approaches. Full article

Ammonia (NH₃) is a zero-carbon fuel and an attractive hydrogen (H₂) carrier for gas turbine power generation due to its high energy density, ease of storage, and transportation. This study numerically investigates NH₃/air combustion using a hybrid Well-Stirred Reactor (WSR) and Plug Flow Reactor (PFR) model in Cantera at pressures of 1–20 atm, temperatures of 1850–2150 K, and equivalence ratios (ϕ) of 0.7–1.2. The effects of pressure, equivalence ratio, and temperature on NH₃ conversion and NO formation are examined. Results show that NH₃ exhibits a non-monotonic conversion curve with pressure after the WSR, reaching a minimum near 5 atm, whereas NO formation decreases monotonically from 1 to 20 atm. Equivalence ratio sweeps show that NO decreases steeply as ϕ increases from 0.7 to ~1.1 as nitrogen is redirected toward N₂ and oxidizer availability declines; residual NH₃ increases rapidly for ϕ > 1.0, especially at high pressure. Increasing temperature accelerates NH₃ oxidation and raises NO formation, most strongly at low pressure where thermal and NH/OH pathways are least inhibited. These results indicate that co-tuning pressure and equivalence ratio near rich operation enables low-NO_x ammonia combustion suitable for advanced gas turbine applications. Full article