Precise evaluation of plasma protein binding (PPB) (fu) is critical for predicting the pharmacokinetic behaviour of new chemical entities.In this study, we describe a rapid equilibrium dialysis (RED)-based flux dialysis approach for estimating PPB (fu) utilising pre-equilibration diffusion data.The empirical membrane permeability (Pmem) of the RED system was established using reference compounds spanning a wide range of binding affinities, including quinidine, imipramine, fluconazole and sertraline.The averaged Pmem value was subsequently applied to determine fu for test compounds such as efavirenz, mifepristone and warfarin, representing diverse physicochemical and binding properties.The current approach demonstrates immediate applicability for low- to moderately bound compounds, where reliable flux data can be obtained within a shorter timeframe.While early-phase diffusion provides useful kinetic information, accurate fu estimation for highly bound compounds requires extended sampling to obtain reliable flux measurements.Fu values obtained from the flux-based model showed close agreement with literature-reported equilibrium dialysis data, supporting the robustness and predictive validity of the approach.The results demonstrate proof-of-concept feasibility of a flux-based approach using RED device, while highlighting limitations related to signal sensitivity and assumptions associated with empirical permeability.
Plantamajoside was reported to possess blood pressure-lowering effects. This study explores how plantamajoside affects the pharmacokinetics of nifedipine, providing valuable insights for clinical drug use.This study examined the effect of plantamajoside on nifedipine pharmacokinetics. Sprague-Dawley rats (n = 6 per group) were administered nifedipine orally, either alone or after pre-treatment with plantamajoside. Blood concentrations of nifedipine were measured using liquid chromatography-tandem mass spectrometry. The effects of plantamajoside on nifedipine metabolic stability and cytochrome P450 3A (CYP3A) activity were evaluated in rat liver microsomes (RLMs).Co-administration of nifedipine with plantamajoside altered its pharmacokinetics, including elevated peak plasma concentration (Cmax), increased area under the concentration-time curve (AUC)(0-t), prolonged elimination half-life (t1/2), and reduced apparent clearance (CL/F). In vitro, plantamajoside enhanced the metabolic stability of nifedipine, extending its t1/2 and lowering intrinsic clearance. Plantamajoside also inhibited CYP3A activity in RLMs (half maximal inhibitory concentration, IC50 = 13.96 μM; inhibition constant, Ki = 7.10 μM).The increased nifedipine exposure in rats could be attributed to the inhibition of CYP3A-mediated metabolism by plantamajoside. Given the role of orthologous CYP3A4 in humans, this interaction may enhance antihypertensive efficacy but could also increase the risk of severe hypotension clinically.
Pharmacokinetic interactions between natural extracts and hepatic cytochrome P450 (CYP) enzymes are a concern in veterinary medicine. Lavender essential oil (LEO), containing linalool (LIN) and linalyl acetate (LINAc), may be coadministered with conventional medicines.This study examined the canine metabolism of LIN and LINAc by substrate depletion using pooled dog liver microsomes (pDLMs) and recombinant canine CYP enzymes (rCYPs). Inhibitory effects of LIN, LINAc, and LEO on CYP isoform-selective probe drug reactions were also evaluated.LINAc was hydrolysed to LIN by a heat-sensitive esterase activity in pDLMs. LIN depletion by pDLMs was NADPH-dependent, saturable with a Michaelis-Menten constant of 52 ± 11 µM, and induced by over 5-fold in liver microsomes from phenobarbital-treated dogs. Recombinant CYP2B11 showed the highest LIN depletion activity, followed by CYP2C21, while other CYPs tested did not show measurable substrate depletion. Inhibition experiments showed that LIN, LINAc, and LEO inhibited CYP2B11-mediated metabolism but not metabolism by CYP2C21, CYP2D15, or CYP3A12. IC50 values for LIN, LINAc, and LEO were 7.1, 2.7, and 2.5 µM for tramadol N-demethylation, and 13.9, 8.0, and 8.6 µM for methadone-N-demethylation, respectively. None of the terpenes were shown to directly inhibit recombinant CYP2B11 activity, suggesting that they exerted indirect inhibition via metabolites generated by other CYPs in pDLMs.These findings highlight CYP2B11 and CYP2C21 as key enzymes in LIN and LINAc metabolism and underscore the potential for herb-drug interactions when treating dogs with lavender essential oil.
The inhibition and metabolism kinetics of tetrahydropalmatine (THP), protopine (PRO), and dehydrocorydaline (DHC), three major biologically active components of Corydalis yanhusuo W. T. Wang, which has been used for thousands of years in China, were evaluated in human liver microsomes (HLMs) to determine their potential for drug-drug interactions.THP acted as a mechanism-based inhibitor of cytochrome P450 2D6 (CYP2D6), with a Kinact of 0.053 min⁻1 and a Ki of 0.26 µM. It was metabolised by HLMs with a Km of 7.62 μM, Vmax of 0.071 nmol/min/mg, and intrinsic clearance (CLint) of 9.27 × 10⁻6 L/min/mg. The oxidative metabolism of THP involved CYP2C19, CYP3A4, CYP1A2, and CYP2D6.PRO was a mixed inhibitor (both competitive and non-competitive) of CYP2D6, with Ki of 0.023 µM and Kis of 0.042 µM. HLMs metabolised PRO with a Km of 3.99 μM, Vmax of 0.033 nmol/min/mg protein, and CLint of 8.20 × 10⁻⁶ L/min/mg. Its oxidative metabolism involved CYP2C19, CYP2D6, and CYP3A4.DHC was a weakly competitive inhibitor of CYP2D6 (Ki = 20.1 µM) and was no longer metabolised by HLMs.These findings indicate that CYP2D6 is a potential target for drug-drug interaction involving THP and PRO, whereas DHC exhibits minimal interaction potential.
Xevinapant, an oral IAP (inhibitor of apoptosis protein) inhibitor, was clinically investigated for the treatment of various cancers. A novel metabolite of xevinapant, oxidated D-1143-MET1 (oxMET1), was identified in the human mass balance study, which had not been detected in previous non- and clinical studies but represented almost 10% of the total drug exposure after single-dose administration and was therefore pinpointed for its structural and initial nonclinical characterization.Using high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) spectroscopy after a semi-preparative isolation of oxMET1 it was possible to determine its definitive structure.OxMET1 exhibited only negligible inhibitory activity on cIAP1 in vitro, and thus, taking the low unbound fraction in human plasma into account, contribution to in vivo efficacy was considered low.In addition, coverage of human exposure could be shown in plasma samples from toxicity studies performed with preclinical species, so oxMET1, although likely major, was not a disproportionate circulating metabolite in humans. Based on these findings, this metabolite did not raise safety concerns according to the MIST guidelines, however it warrants further characterisation of its drug-drug interaction (DDI) potential. The integrated workflow presented here highlights the importance of metabolite characterization in drug development.
Chemotherapy resistance in ovarian cancer (OC) poses a significant challenge in clinical treatment. We aim to explore the inhibitory impact of the synergistic action of Cryptotanshinone and matrine on OC cells, along with its molecular mechanism, thereby providing a novel therapeutic strategy for OC management. Cell proliferation was assessed via the CCK-8 assay; apoptosis was analysed by flow cytometry; cell migration and invasion were evaluated using the Transwell assay; gene expression was measured with qRT-PCR. A nude mouse xenograft model was established to verify in vivo efficacy. The role of the PI3K/Akt/mTOR pathway was elucidated through rescue experiments. Cyptotanshinone and matrine inhibited OC cell proliferation in a dose- and time-dependent manner. Combination therapy synergistically enhanced the antiproliferative effects, inducing apoptosis, suppressing migration and invasion, and downregulating the expression of MMP2 and MMP9. In cisplatin-resistant cells, the combination reversed drug resistance and reduced P-gp expression. Mechanistically, the combination markedly downregulated transcription of key genes in the PI3K/Akt/mTOR pathway. Rescue experiments confirmed that pathway inhibition underpins the synergistic effect. Cryptotanshinone and matrine exert anti-OC effects through multiple mechanisms by inhibiting the PI3K/Akt/mTOR pathway, effectively reversing drug resistance.
Xevinapant, a drug previously under development for head and neck cancer, was investigated to determine its intrinsic clearance (CLint) in vitro and assess the involvement of CYP enzymes in its metabolism. Extensive in vitro studies showed very low turnover, necessitating advanced methodologies to accurately measure CLint values.Two novel in vitro assays, using a modified suspension hepatocyte protocol or 3D hepatocyte spheroid cultures, allowed measuring hepatic turnover of xevinapant with very low CLint values of 1.3 or 0.3 µL/min/106 cells, respectively. Reaction phenotyping using specific inhibitors, enabled by enhanced detection capabilities in spheroids, identified primarily CYP3A (> 50%) as contributor to the hepatic metabolism of xevinapant.In vitro-in vivo extrapolation, in combination with data from the human mass balance study, revealed that hepatic metabolism, primarily mediated by CYP3A, accounts for approximately 30% of the overall clearance. The remaining clearance is renal (∼20%) and metabolic, but potentially extrahepatic (∼50%).This research highlights the importance and benefits of utilising advanced in vitro techniques, such as human hepatocyte spheroids, to accurately characterise drug metabolism, providing valuable insights for pharmacokinetic evaluations and, ultimately, supporting the development of a PBPK model and understanding the DDI risk of xevinapant.
1. Senecio scandens Buch.-Ham. (SBH) is widely used in traditional Chinese medicine, yet its clinical application is constrained by hepatotoxic pyrrolizidine alkaloids (PAs). The relative toxic contributions of individual PAs in SBH and their in vivo metabolic consequences remain unclear. 2. This study sought to elucidate PAs-related hepatotoxicity of SBH by integrating network toxicology, LC-MS/MS fingerprinting, in vivo toxicity evaluation, and liver metabolomics. 3. Network toxicology and molecular docking were used to prioritise hepatotoxic PAs and their putative targets. LC-MS/MS fingerprints of major PAs in 12 SBH samples were established. Spectrum-toxicity correlation analysis and untargeted metabolomics were used to assess hepatotoxicity-related associations and SPL-induced metabolic perturbations. 4. SPL, senecionine, adonifoline, and senkirkine were prioritised as candidate hepatotoxic PAs, with CYP3A4/CYP2C9 and DNA adduct-related pathways highlighted as potentially relevant toxicological nodes. Considerable regional variation in PAs levels was observed across SBH samples. Acute SBH exposure caused marked liver injury, and spectrum-toxicity modelling indicated that SPL showed the strongest association with hepatotoxicity among the detected PAs. Metabolomic profiling further showed that SPL exposure was associated with alterations in lipid and bile acid metabolism, glutathione metabolism, and the pentose phosphate pathway, together with enrichment of xenobiotic metabolism by cytochrome P450 and chemical carcinogenesis-DNA adduct pathways. 5. SPL is closely associated with SBH-induced hepatotoxicity and produces a metabolic signature consistent with canonical PAs bioactivation. Although SPL appears to be the most influential PAs among those detected, definitive comparisons of toxic potency require further validation using equimolar pure-compound exposure models.
This investigation was planned to evaluate the mechanistic interactions of Imidacloprid (IM) and Chlorothalonil (CL), inducing toxicity after 28 days of oral administration. Male Wistar rats were divided into a control (CR) and three treatment groups, receiving IM (45 mg/kg), CL (300 mg/kg), and mixture of IM+CL.IM and CL,individually or in combination induced a hypothyroidstate with a sharp decline in insulin levels. Additionally, high plasma alanine transferase (ALT/SGPT) and aspartate transferase (AST/SGOT) levels, as well as alkaline phosphatase (Alk-P) and creatinine were recorded in all treated groups. Both IM and CL significantly compromised the antioxidant defense system by increasing the MDA level, and inhibiting the activity of CAT and SOD.A significant binding affinity of IM and CL to enzymes integral to the blood transport and receptor binding of THs like MCT8 and TSHR was observed. The MD simulations revealed the strong and stable interactions between IM, CL, MCT8, and TSH-R. MMGBSA energies showed that both pesticides compete with hormones at active sites, indicating their potential to modulate key enzymes involved in thyroid hormone transport and action.Therefore, it is anticipated that these resultswill provide beneficial knowledge for future therapeutic endeavors.
Erlotinib is an orally administered tyrosine kinase inhibitor used in the treatment of EGFR-positive non-small cell lung cancer. However, poor tolerability and suboptimal patient adherence often limit its clinical efficacy. Furthermore, lower doses are recommended for elderly patients, those with EGFR-sensitising mutations, and cutaneous toxicities. A PLGA-based long-acting injectable formulation may offer significant advantages for metastatic NSCLC by enhancing treatment compliance. This study aims to develop a physiologically based pharmacokinetic model to support dose selection, optimisation of release profiles, and dosage form design.The semimechanistic ERL PBPK model was first developed and validated for oral formulations and subsequently extended to intramuscular depots. The IM model was used to determine the optimal dose and release profile to maintain plasma drug concentrations above the IC50 and Css min targets.A monthly dose of 750 mg with an intermediate-release profile able to maintain the drug concentration above the Css, min. When targeting the IC50, the prototype formulations required a monthly dose of 300 mg and a three-month dose of 1200 mg, both with intermediate-release profiles.The semimechanistic PBPK model successfully predicted the optimal dose and release profile. The results provided valuable insights for polymer grade selection and drug-to-polymer ratio optimisation.
To investigate the protective mechanism of Astragaloside IV (AS-IV) in diabetic retinopathy(DR).A streptozotocin-induced diabetic rat model was established and divided in to three groups: control, DR, and DR + AS-IV. Retinal injury was assessed using optical coherence tomography (OCT). Retinal proteomes were profiled using 4D-DIA proteomics. Candidate genes were validated using quantitative PCR (qPCR).302 differentially expressed proteins were detected. Venn diagram analysis revealed three down-regulated proteins in the DR group: Gnal, Dennd1a, and Snx13, and two up-regulated proteins: Ogn and Mylpf. AS-IV treatment reversed the expression of Dennd1a and Gnal while downregulating Ogn, Mylpf, and Snx13. PPI analysis revealed limited direct connectivity among the five proteins but identified 10 additional interactors, including MYLK, ADCY9, and RAB35. GO analysis indicated involvement in muscle contraction, muscle myosin complex, and phosphatidylinositol phosphate binding and structural molecule activity. KEGG analysis highlighted calcium signalling as a key pathway. Molecular docking demonstrated stable interactions between AS-IV and Dennd1a, Ogn, and Snx13 proteins. qPCR confirmed significant regulation of Dennd1a and Ogn, while Snx13 and Mylpf changes were not significant.AS-IV exhibited protective effects against diabetic retinal injury by modulating Dennd1a and Ogn, implicating calcium signalling and structural pathways in its therapeutic mechanism.
Osteosarcoma is the most common primary malignant bone tumour in adolescents, with a poor prognosis and high rates of recurrence and metastasis. Ferroptosis, a form of regulated cell death associated with iron overload and lipid peroxidation, and mitochondrial dysfunction have been recognised as potential therapeutic targets in cancer. α-Hederin, a natural triterpenoid saponin, has shown antitumor effects in several cancers, but its role in osteosarcoma remains unclear. This study aimed to investigate the pharmacological effects and mechanisms of α-hederin on osteosarcoma. We integrated network pharmacology and molecular docking to identify potential targets and pathways, and validated the findings using in vitro experiments in 143B osteosarcoma cells. Network pharmacology analysis revealed 27 overlapping targets between α-hederin and osteosarcoma, with significant enrichment in the PI3K/AKT and ferroptosis pathways. Molecular docking confirmed strong binding affinity between α-hederin and key targets. Functional assays demonstrated that α-hederin inhibited cell proliferation and migration, increased intracellular Fe2+ and lipid reactive oxygen species levels, disrupted mitochondrial membrane potential and ATP production, and downregulated mitochondrial biogenesis proteins. Transmission electron microscopy further revealed typical mitochondrial morphological changes associated with ferroptosis. Western blotting showed decreased expression of GPX4 and SLC7A11, increased ACSL4 levels, and suppressed activation of the PI3K/AKT pathway. Moreover, these effects were partially reversed by the ferroptosis inhibitor Ferrostatin-1. Collectively, these results indicate that α-hederin exerts antitumor effects against osteosarcoma by inducing ferroptosis and impairing mitochondrial function, partly through inhibition of the PI3K/AKT signalling pathway, providing a potential therapeutic strategy for osteosarcoma.
Alicyclic amines are ubiquitous compounds with manifold uses in medicinal chemistry. Unfortunately, they are subject to metabolic activation to form reactive intermediates. Alicyclic amines were observed to form direct cysteine (Cys) or cysteinylglycine (CysGly) conjugates across a large GSK GSH trapping dataset. These results suggest that hard electrophilic intermediates were generated from the alicyclic amines (e.g. piperidine) and trapped as Cys and/or CysGly conjugates. This is unusual since there is a general consensus that alicyclic amine biotransformation forms hard electrophiles typically require hard nucleophile trapping agents and cannot be trapped by soft nucleophiles.Compound A and tofacitinib, both containing a piperidine group, were used as alicyclic amine examples to explore the bioactivation pathways generating hard electrophiles in GSH trapping studies. Direct Cys and CysGly conjugates on the piperidine ring were observed for Compound A and tofacitinib in GSH trapping experiments. Both were proposed to be the thioethers resulting from reactions with hard electrophile iminium intermediates. Aldehyde intermediates formed through piperidine ring-opening were also captured by Cys and CysGly. Therefore, the aforementioned hard electrophiles created through bioactivation of alicyclic amines can be screened in drug discovery GSH trapping studies.
Zanthoxylum rhetsa (ZR) is a medicinal plant native to Southeast Asia, widely used in traditional medicine. Despite its medicinal importance, systematic documentation of isolated bioactive constituents and their therapeutic relevance remains scarce. This systematic review aimed to compile phytochemical profile of ZR and summarise evidence on its bioactive/drug-like phytoconstituents and compound-specific biological activities, highlighting its potential as source of natural therapeutics. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic search of PubMed, Scopus, and Web of Science was conducted, and duplicates were removed using Rayyan software. Compounds isolated from ZR were found to confer significant cytotoxic, antimicrobial, anti-inflammatory, antioxidant, anti-photaging, antispasmodic, and antidiarrheal effects. Mechanistic investigations revealed that several compounds exhibited selective cytotoxicity against cancer only, inhibited microbial proliferation through membrane disruption, and modulated signalling pathways associated with inflammation and oxidative stress. Additionally, absorption, distribution, metabolism, excretion (ADME) analysis highlighted nitidine, dihydrochelerythrine, and hesperidin isolated from ZR as promising drug leads with favourable pharmacokinetic and safety profiles. ZR constitutes a chemically diverse reservoir of bioactive metabolites, highlighting its significance as promising natural source of drug-like compounds and emphasising the need for comprehensive mechanistic, pharmacological, and clinical investigations to evaluate therapeutic translation.
This study explores a dual-action approach for hypertension management based on a co-formulated suspension containing Candesartan cilexetil (CC) - Bisoprolol fumarate (BF) system, combining FTIR characterisation with computational modelling to evaluate molecular compatibility, binding behaviour, and pharmacokinetic properties.Direct in situ FTIR-ATR spectral analysis confirmed the successful interfacial wetting and co-dispersion of both drugs within the surfactant matrix, driven by robust hydrophobic interactions and cooperative hydrogen bonding. Hirshfeld surface analysis revealed complementary intermolecular interaction patterns between BF and CC, with BF exhibiting flexible hydrogen-bond networks and CC showing directional hydrogen bonding, π-π stacking, and electrostatic interactions.These distinct yet complementary profiles suggest favourable molecular packing and potential co-formulation. Molecular docking further demonstrated balanced binding of the dual system to both β1 and AT1 receptors, with binding energies of -5.19 and -4.88 kcal/mol, respectively. Furthermore, ADMET results indicate poor gastrointestinal absorption and low oral bioavailability, mainly due to high lipophilicity, which may limit in vivo efficacy, although the compound shows an overall acceptable safety profile.In summary, while the CC-BF system appears promising as a dual-target antihypertensive strategy, further formulation improvements and experimental in vitro and in vivo validation are required to confirm its therapeutic potential.
This study aimed to prepare and evaluate berberine micelles for improving the oral bioavailability and therapeutic effect against skin injury in hyperglycaemic mice. Berberine micelles were fabricated using the film dispersion method with PLGA-PEG-PLGA and glycyrrhizic acid monoamine salt, followed by orthogonal optimisation.The optimised berberine micelles exhibited a particle size of 112.55 ± 2.48 nm, polydispersity index of 0.217 ± 0.005, zeta potential of -31.60 ± 0.23 mV, encapsulation efficiency of 95.57 ± 1.36% (w/w), and drug loading capacity of 7.06 ± 0.25% (w/w). In vitro release of berberine from micelles was higher than that of free berberine across all tested media.Pharmacokinetic studies in rats showed that berberine micelles prolonged the half-life from 5.77 h to 12.19 h and extended the mean retention time from 20.74 h to 143.31 h, with a relative bioavailability 2.64‑fold greater than that of free berberine.In a streptozotocin‑induced hyperglycaemic mouse skin injury model, the high‑dose berberine micelle group significantly accelerated wound closure compared to the free drug group on days 6 and 9, and histopathological analysis of skin, liver, spleen, and pancreas revealed superior tissue recovery. These findings suggest that berberine micelles effectively enhance the anti‑hyperglycaemic and skin‑repairing efficacy of berberine.
Case reports of adverse event and loss of efficacy in individuals are the primary source of natural product drug interactions (NPDIs). Given the fundamental constraints, there is clear need for prospective and systematic study as foolproof methodology to understand NPDIs. Although human trials are confirmatory, an integrative physiologically-based pharmacokinetic (PBPK) modelling approach can be considered, despite challenges associated with NP data availability, variability and complexity.To explore the applicability of this approach, glycyrrhizin (GL) and its active metabolite glycyrrhetinic acid (GA) were identified as an NP with numerous pharmacological benefits and a potential likelihood of concomitant administration with narrow therapeutic antipsychotic drug quetiapine. Numerous serious case reports of quetiapine toxicity in combination with NPs support the proposed hypothesis.Simcyp® simulator was used to develop and validate quetiapine PBPK model followed by its utilisation for the evaluation of NPDI risk. PBPK modelling data indicated ∼ three-fold increase in quetiapine area under the curve (AUC) and peak plasma concentration (Cmax) in the presence of GA, signifying moderate increase in exposure which implies the need for further clinical assessment. This study successfully demonstrated the translation of in vitro information into helpful risk predictions for in vivo NPDIs by PBPK modelling.
Cefotaxime is a third-generation cephalosporin that is used to treat susceptible bacterial infections. This systematic review provides an in-depth analysis of all pharmacokinetic (PK) and pharmacodynamic (PD) parameters of cefotaxime in humans.A systematic search was conducted using the search engines Google Scholar, PubMed, Science Direct, and Cochrane Library to identify the relevant articles on the PK of cefotaxime.The healthy populations have shown a linear increase in area under the plasma concentration vs. time curve from zero to infinity (AUC0-∞) after receiving doses ranging from 250-2000 mg. One study has reported a decrease in cefotaxime clearance (CL) in patients with renal insufficiency compared to healthy participants, i.e. 129.8 ± 9.3 ml/min vs. 272.8 ± 43.9 ml/min. Moreover, a slight increase in the maximum plasma concentration (Cmax) of about 5.6% was observed when cefotaxime is co-administered with tazobactam. Therefore, cefotaxime depicts time-dependent killing above the minimum inhibitory concentration (MIC < 2 ug/ml), this property makes it suitable for managing infections caused by susceptible pathogens.This review compiles all the relevant PK and PD parameters of cefotaxime in healthy subjects. These data may assist health practitioners in adjusting the cefotaxime dose among renal failure patients to avoid toxicity.
Sodium 2-mercaptoethanesulfonate (MESNA) is widely used as a uroprotective agent to prevent haemorrhagic cystitis (HC) associated with oxazaphosphorine chemotherapy; however, emerging evidence suggests broader cytoprotective potential beyond the urinary system.This review systematically compiles and evaluates preclinical and clinical evidence on the multi-organ protective effects of MESNA, including its roles in mitigating nephrotoxicity, hepatotoxicity, cardiotoxicity, neurotoxicity, pulmonary injury, gastrointestinal damage, and reproductive toxicity.The protective mechanisms of MESNA are primarily attributed to its thiol-mediated detoxification, antioxidant activity, and anti-inflammatory effects, including scavenging of reactive oxygen species (ROS), reduction of lipid peroxidation, modulation of cytokine responses, and maintenance of cellular redox balance.In addition to its established clinical use in oncology, MESNA demonstrates potential applications in surgical procedures, ischemia-reperfusion injury, and combination therapies, although current clinical evidence supporting its systemic protective effects remains limited.Despite its promising therapeutic profile, factors such as short plasma half-life, limited systemic bioavailability, and variability in clinical outcomes highlight the need for further mechanistic studies and well-designed clinical trials to establish its role as a multi-organ cytoprotective agent.
Zinc oxide (ZnO) nanomaterials, acting as engineered xenobiotic-like agents, can induce complex cellular stress and defense responses. This study reports a novel green synthesis of ZnO nanoflowers using Camellia sinensis leaf extract, resulting in a biocompatible nanostructure with a distinctive flower-like morphology.The C. sinensis-mediated synthesis provides a sustainable and reproducible approach for producing stable ZnO nanoflowers. The nanoparticles were thoroughly characterised (hydrodynamic assembly size: 259.3 nm; zeta potential: -32.35 mV; individual nanostructure physical dimensions: ∼38.8 × 138.7 nm), and their biological interactions were evaluated in L929 fibroblasts to assess xenobiotic-like cellular responses.Cytotoxicity was dose- and time-dependent (IC50 = 52.3 µg/mL at 24 h, 14.1 µg/mL at 48 h, and 10.5 µg/mL at 72 h). At a non-toxic IC50 concentration, the nanoflowers induced a transient adaptive stress response, characterised by significant yet reversible upregulation of inflammatory cytokines (IL-1β, IL-10) and key apoptotic regulators (Bax, Bcl-2, and p53).Collectively, this study demonstrates that green-synthesised ZnO nanoflowers trigger moderate, self-resolving apoptotic and inflammatory signalling consistent with a xenobiotic-like adaptive cellular response. These findings highlight the potential of plant-mediated synthesis to engineer ZnO nanostructures with controlled bioactivity, supporting their safer application in biomedical contexts.