Gallic acid pretreatment mitigates parathyroid ischemia-reperfusion injury through signaling pathway modulation.

Thyroid surgery often results in ischemia-reperfusion injury (IRI) to the parathyroid glands, yet the mechanisms underlying this and how to ameliorate IRI remain incompletely explored. Our study identifies a polyphenolic herbal extract-gallic acid (GA)-with antioxidative properties against IRI. Through flow cytometry and CCK8 assays, we investigate the protective effects of GA pretreatment on a parathyroid IRI model and decode its potential mechanisms via RNA-seq and bioinformatics analysis. Results reveal increased apoptosis, pronounced G1 phase arrest, and significantly reduced cell proliferation in the hypoxia/reoxygenation group compared to the hypoxia group, which GA pretreatment mitigates. RNA-seq and bioinformatics analysis indicate GA's modulation of various signaling pathways, including IL-17, AMPK, MAPK, transient receptor potential channels, cAMP, and Rap1. In summary, GA pretreatment demonstrates potential in protecting parathyroid cells from IRI by influencing various genes and signaling pathways. These findings offer a promising therapeutic strategy for hypoparathyroidism treatment.

Engineering cascade biocatalysis in whole cells for syringic acid bioproduction.

BACKGROUND: Syringic acid (SA) is a high-value natural compound with diverse biological activities and wide applications, commonly found in fruits, vegetables, and herbs. SA is primarily produced through chemical synthesis, nonetheless, these chemical methods have many drawbacks, such as considerable equipment requirements, harsh reaction conditions, expensive catalysts, and numerous by-products. Therefore, in this study, a novel biotransformation route for SA production was designed and developed by using engineered whole cells. RESULTS: An O-methyltransferase from Desulfuromonas acetoxidans (DesAOMT), which preferentially catalyzes a methyl transfer reaction on the meta-hydroxyl group of catechol analogues, was identified. The whole cells expressing DesAOMT can transform gallic acid (GA) into SA when S-adenosyl methionine (SAM) is used as a methyl donor. We constructed a multi-enzyme cascade reaction in Escherichia coli, containing an endogenous shikimate kinase (AroL) and a chorismate lyase (UbiC), along with a p-hydroxybenzoate hydroxylase mutant (PobA**) from Pseudomonas fluorescens, and DesAOMT; SA was biosynthesized from shikimic acid (SHA) by using whole cells catalysis. The metabolic system of chassis cells also affected the efficiency of SA biosynthesis, blocking the chorismate metabolism pathway improved SA production. When the supply of the cofactor NADPH was optimized, the titer of SA reached 133 µM (26.2 mg/L). CONCLUSION: Overall, we designed a multi-enzyme cascade in E. coli for SA biosynthesis by using resting or growing whole cells. This work identified an O-methyltransferase (DesAOMT), which can catalyze the methylation of GA to produce SA. The multi-enzyme cascade containing four enzymes expressed in an engineered E. coli for synthesizing of SA from SHA. The metabolic system of the strain and biotransformation conditions influenced catalytic efficiency. This study provides a new green route for SA biosynthesis.

Syringic acid attenuates acute lung injury by modulating macrophage polarization in LPS-induced mice.

BACKGROUND: Acute lung injury (ALI) is a continuum of lung changes caused by multiple lung injuries, characterized by a syndrome of uncontrolled systemic inflammation that often leads to significant morbidity and death. Anti-inflammatory is one of its treatment methods, but there is no safe and available drug therapy. Syringic acid (SA) is a natural organic compound commonly found in a variety of plants, especially in certain woody plants and fruits. In modern pharmacological studies, SA has anti-inflammatory effects and therefore may be a potentially safe and available compound for the treatment of acute lung injury. PURPOSE: This study attempts to reveal the protective mechanism of SA against ALI by affecting the polarization of macrophages and the activation of NF-κB signaling pathway. Trying to find a safer and more effective drug therapy for clinical use. METHODS: We constructed the ALI model using C57BL/6 mice by intratracheal instillation of LPS (10 mg/kg). Histological analysis was performed with hematoxylin and eosin (H&E). The wet-dry ratio of the whole lung was measured to evaluate pulmonary edema. The effect of SA on macrophage M1-type was detected by flow cytometry. BCA protein quantification method was used to determine the total protein concentration in bronchoalveolar lavage fluid (BALF). The levels of Interleukin (IL)-6, IL-1ß, and tumor necrosis factor (TNF)-α in BALF were determined by the ELISA kits, and RT-qPCR was used to detect the expression levels of IL-6, IL-1ß and TNF-α mRNA of lung tissue. Western blot was used to detect the expression levels of iNOS and COX-2 and the phosphorylation of p65 and IκBα in the NF-κB pathway in lung tissue. In vitro experiments were conducted with RAW267.4 cell inflammation model induced by 100 ng/ml LPS and A549 cell inflammation model induced by 10 µg/ml LPS. The effects of SA on M1-type and M2-type macrophages of RAW267.4 macrophages induced by LPS were detected by flow cytometry. The toxicity of compound SA to A549 cells was detected by MTT method which to determine the safe dose of SA. The expressions of COX-2 and the phosphorylation of p65 and IκBα protein in NF-κB pathway were detected by Western blot. RESULTS: We found that the pre-treatment of SA significantly reduced the degree of lung injury, and the infiltration of neutrophils in the lung interstitium and alveolar space of the lung. The formation of transparent membrane in lung tissue and thickening of alveolar septum were significantly reduced compared with the model group, and the wet-dry ratio of the lung was also reduced. ELISA and RT-qPCR results showed that SA could significantly inhibit the production of IL-6, IL-1ß, TNF-α. At the same time, SA could significantly inhibit the expression of iNOS and COX-2 proteins, and could inhibit the phosphorylation of p65 and IκBα proteins. in a dose-dependent manner. In vitro experiments, we found that flow cytometry showed that SA could significantly inhibit the polarization of macrophages from M0 type macrophages to M1-type macrophages, while SA could promote the polarization of M1-type macrophages to M2-type macrophages. The results of MTT assay showed that SA had no obvious cytotoxicity to A549 cells when the concentration was not higher than 80 µM, while LPS could promote the proliferation of A549 cells. In the study of anti-inflammatory effect, SA can significantly inhibit the expression of COX-2 and the phosphorylation of p65 and IκBα proteins in LPS-induced A549 cells. CONCLUSION: SA has possessed a crucial anti-ALI role in LPS-induced mice. The mechanism was elucidated, suggesting that the inhibition of macrophage polarization to M1-type and the promotion of macrophage polarization to M2-type, as well as the inhibition of NF-κB pathway by SA may be the reasons for its anti-ALI. This finding provides important molecular evidence for the further application of SA in the clinical treatment of ALI.

Advancing Photodynamic Antimicrobial Strategy: Sustainable Fabrication of Novel Lauryl Gallate-Chitosan Hydrophobic Films with Rapid Bacterial Capture and Biofilms Elimination Capabilities for Promoting Wound Healing.

Bioinspired photoactive composites, in terms of photodynamic inactivation, cost-effectiveness, and biosafety, are promising alternatives to antibiotics for combating bacterial infections while avoiding antibacterial resistance. However, the weak bacterial membrane affinity of the photoactive substrate and the lack of synergistic antibacterial effect remain crucial shortcomings for their antibacterial applications. Herein, we developed a hydrophobic film from food antioxidant lauryl gallate covalently functionalized chitosan (LG-g-CS conjugates) through a green radical-induced grafting reaction that utilizes synergistic bacteria capture, contact-killing, and photodynamic inactivation activities to achieve enhanced bactericidal and biofilm elimination capabilities. Besides, the grafting reaction mechanism between LG and CS in the ascorbic acid (AA)/H2O2 redox system was further proposed. The LG-g-CS films feature hydrophobic side chains and photoactive phenolic hydroxyl groups, facilitating dual bactericidal activities through bacteria capture and contact-killing via strong hydrophobic and electrostatic interactions with bacterial membranes as well as blue light (BL)-driven photodynamic bacterial eradication through the enhanced generation of reactive oxygen species. As a result, the LG-g-CS films efficiently capture and immobilize bacteria and exhibit excellent photodynamic antibacterial activity against model bacteria (Escherichia coli and Staphylococcus aureus) and their biofilms under BL irradiation. Moreover, LG-g-CS films could significantly promote the healing process of S. aureus-infected wounds. This research demonstrates a new strategy for designing and fabricating sustainable bactericidal and biofilm-removing materials with a high bacterial membrane affinity and photodynamic activity.

Assessment of the Effect of Leonurine Hydrochloride in a Mouse Model of PCOS by Gene Expression Profiling.

Polycystic ovary syndrome (PCOS) is an endocrine disease commonly associated with metabolic disorders in females. Leonurine hydrochloride (Leo) plays an important role in regulating immunity, tumours, uterine smooth muscle, and ovarian function. However, the effect of Leo on PCOS has not been reported. Here, we used dehydroepiandrosterone to establish a mouse model of PCOS, and some mice were then treated with Leo by gavage. We found that Leo could improve the irregular oestros cycle of PCOS mice, reverse the significantly greater serum testosterone (T) and luteinising hormone (LH) levels, significantly reduce the follicle-stimulating hormone (FSH) level, and significantly increase the LH/FSH ratio of PCOS mice. Leo could also change the phenomenon of ovaries in PCOS mice presented with cystic follicular multiplication and a lacking corpus luteum. Transcriptome analysis identified 177 differentially expressed genes related to follicular development between the model and Leo groups. Notably, the cAMP signalling pathway, neuroactive ligand-receptor interactions, the calcium signalling pathway, the ovarian steroidogenesis pathway, and the Lhcgr, Star, Cyp11a, Hsd17b7, Camk2b, Calml4, and Phkg1 genes may be most related to improvements in hormone levels and the numbers of ovarian cystic follicles and corpora lutea in PCOS mice treated by Leo, which provides a reference for further study of the mechanism of Leo.

Repurposing of Antifungal Drug Flucytosine/Flucytosine Cocrystals for Anticancer Activity against Prostate Cancer Targeting Apoptosis and Inflammatory Signaling Pathways.

This study aimed to repurpose the antifungal drug flucytosine (FCN) for anticancer activity together with cocrystals of nutraceutical coformers sinapic acid (SNP) and syringic acid (SYA). The cocrystal screening experiments with SNP resulted in three cocrystal hydrate forms in which two are polymorphs, namely, FCN-SNP F-I and FCN-SNP F-II, and the third one with different stoichiometry in the asymmetric unit (1:2:1 ratio of FCN:SNP:H2O, FCN-SNP F-III). Cocrystallization with SYA resulted in two hydrated cocrystal polymorphs, namely, FCN-SYA F-I and FCN-SYA F-II. All the cocrystal polymorphs were obtained concomitantly during the slow evaporation method, and one of the polymorphs of each system was produced in bulk by the slurry method. The interaction energy and lattice energies of all cocrystal polymorphs were established using solid-state DFT calculations, and the outcomes correlated with the experimental results. Further, the in vitro cytotoxic activity of the cocrystals was determined against DU145 prostate cancer and the results showed that the FCN-based cocrystals (FCN-SNP F-III and FCN-SYA F-I) have excellent growth inhibitory activity at lower concentrations compared with parent FCN molecules. The prepared cocrystals induce apoptosis by generating oxidative stress and causing nuclear damage in prostate cancer cells. The Western blot analysis also depicted that the cocrystals downregulate the inflammatory markers such as NLRP3 and caspase-1 and upregulate the intrinsic apoptosis signaling pathway marker proteins, such as Bax, p53, and caspase-3. These findings suggest that the antifungal drug FCN can be repurposed for anticancer activity.

Ascorbic acid potentiates photodynamic inactivation mediated by octyl gallate and blue light for rapid eradication of planktonic bacteria and biofilms.

This study reported for the first time that Ascorbic acid (AA) could appreciably boost the efficiency of Octyl gallate (OG)-mediated photodynamic inactivation (PDI) on Escherichia coli and Staphylococcus aureus in planktonic and biofilm states. The combination of OG (0.075 mM) and AA (200 mM) with 420 nm blue light (212 mW/cm2) led to a >6 Log killing within only 5 min for E. coli and S. aureus and rapid eradication of biofilms. The mechanism of action appears to be the generation of highly toxic hydroxyl radicals (•OH) via photochemical pathways. OG was exposed to BL irradiation to generate various reactive oxygen radicals (ROS) and the addition of AA could transform singlet oxygen (1O2) into hydrogen peroxide (H2O2), which could further react with AA to generate enormous •OH. These ROS jeopardized bacteria and biofilms by nonspecifically attacking various biomacromolecules. Overall, this PDI strategy provides a powerful microbiological decontamination modality to guarantee safe food products.

Syringic acid guards against indomethacin-induced gastric ulcer by alleviating inflammation, oxidative stress and apoptosis.

The purpose of this study was to evaluate the effects of syringic acid, an anti-oxidant, on indomethacin induced gastric ulcers in rats. Experimental groups were control, ulcer, ulcer treated with 20 mg/kg esomeprazole (a proton pump inhibitor that reduces acid secretion), and ulcer treated with 100 mg/kg syringic acid. Rats were pretreated with esomeprazole or syringic acid two weeks before ulcer induction. Our histopathological observations showed that either syringic acid or esomeprazole attenuated the severity of gastric mucosal damage. Moreover, syringic acid and esomeprazole pretreatments alleviated indomethacin-induced damage by regulating oxidative stress, inflammatory response, the level of transforming growth factor-ß (TGF-ß), expressions of COX and prostaglandin E2, cell proliferation, apoptosis and regulation of the NF-κB signaling pathway. We conclude that either esomeprazole or syringic acid administration protected the gastric mucosa from harmful effects of indomethacin. Syringic acid might, therefore be a potential therapeutic agent for preventing and treating indomethacin-induced gastric damage.

Discovery of digallic acid as XOD/URAT1 dual target inhibitor for the treatment of hyperuricemia.

The development of XOD/URAT1 dual target inhibitors has emerged as a promising therapeutic strategy for the management of hyperuricemia. Here, through virtual screening, we have identified digallic acid as a novel dual target inhibitor of XOD/URAT1 and subsequently evaluated its pharmacological properties, pharmacokinetics, and toxicities. Digallic acid inhibited URAT1 with an IC50 of 5.34 ± 0.65 µM, which is less potent than benzbromarone (2.01 ± 0.36 µM) but more potent than lesinurad (10.36 ± 1.23 µM). Docking and mutation analysis indicated that residues S35, F241 and R477 of URAT1 confer a high affinity for digallic acid. Digallic acid inhibited XOD with an IC50 of 1.04 ± 0.23 µM. Its metabolic product, gallic acid, inhibited XOD with an IC50 of 0.91 ± 0.14 µM. Enzyme kinetic studies indicated that both digallic acid and gallic acid act as mixed-type XOD inhibitors. It shares the same binding mode as digallic acid, and residues E802, R880, F914, T1010, N768 and F1009 contribute to their high affinity. The anion group (carboxyl) of digallic acid contribute significantly to its inhibition activity on both XOD and URAT1 as indicated by docking analysis. Remarkably, at a dosage of 10 mg/kg in vivo, digallic acid exhibited a stronger urate-lowering and uricosuric effect compared to the positive drug benzbromarone and lesinurad. Pharmacokinetic study indicated that digallic acid can be hydrolyzed into gallic acid in vivo and has a t1/2 of 0.77 ± 0.10 h. Further toxicity evaluation indicated that digallic acid exhibited no obvious renal toxicity, as reflected by CCK-8, biochemical analysis (CR and BUN) and HE examination. The findings of our study can provide valuable insights for the development of XOD/URAT1 dual target inhibitors, and digallic acid deserves further investigation as a potential anti-hyperuricemic drug.

Novel insights into the protective effects of leonurine against acute kidney injury: Inhibition of ER stress-associated ferroptosis via regulating ATF4/CHOP/ACSL4 pathway.

Acute kidney injury (AKI) is a common and serious global health problem with high risks of mortality and the development of chronic kidney diseases. Leonurine is a unique bioactive component from Leonurus japonicus Houtt. and exerts antioxidant, antiapoptotic or anti-inflammatory properties. This study aimed to explore the benefits of leonurine on AKI and the possible mechanisms involved, with a particular foc on the regulation of ferroptosis and endoplasmic reticulum (ER) stress. Our results showed that leonurine exhibited prominent protective effects against AKI, as evidenced by the amelioration of histopathological alterations and reduction of renal dysfunction. In addition, leonurine significantly suppressed ferroptosis in AKI both in vivo and in vitro by effectively restoring ultrastructural abnormalities in mitochondria, decreasing ASCL4 and 4-HNE levels, scavenging reactive oxygen species (ROS), as well as increasing GPX4 and GSH levels. In parallel, leonurine also markedly mitigated ER stress via down-regulating PERK, eIF-2α, ATF4, CHOP and CHAC1. Further studies suggested that ER stress was closely involved in erastin-induced ferroptosis, and leonurine protected tubular epithelial cells in vitro by inhibiting ER stress-associated ferroptosis via regulating ATF4/CHOP/ASCL4 signalling pathway. Mechanistically, ATF4 silencing in vitro regulated CHOP and ACSL4 expressions, ultimately weakening both ER stress and ferroptosis. Notably, analyses of single-cell RNA sequencing data revealed that ATF4, CHOP and ASCL4 in renal tubular cells were all abnormally upregulated in patients with AKI compared to healthy controls, suggesting their contributions to the pathogenesis of AKI. Altogether, these findings suggest that leonurine alleviates AKI by inhibiting ER stress-associated ferroptosis via regulating ATF4/CHOP/ASCL4 signalling pathway, thus providing novel mechanisms for AKI treatment.

Leonurine alleviates vancomycin nephrotoxicity via activating PPARγ and inhibiting the TLR4/NF-κB/TNF-α pathway.

Vancomycin (VCM) is the first-line antibiotic for severe infections, but nephrotoxicity limits its use. Leonurine (Leo) has shown protective effects against kidney damage. However, the effect and mechanism of Leo on VCM nephrotoxicity remain unclear. In this study, mice and HK-2 cells exposed to VCM were treated with Leo. Biochemical and pathological analysis and fluorescence probe methods were performed to examine the role of Leo in VCM nephrotoxicity. Immunohistochemistry, q-PCR, western blot, FACS, and Autodock software were used to verify the mechanism. The present results indicate that Leo significantly alleviates VCM-induced renal injury, morphological damage, and oxidative stress. Increased intracellular and mitochondrial ROS in HK-2 cells and decreased mitochondrial numbers in mouse renal tubular epithelial cells were reversed in Leo-administrated groups. In addition, molecular docking analysis using Autodock software revealed that Leo binds to the PPARγ protein with high affinity. Mechanistic exploration indicated that Leo inhibited VCM nephrotoxicity via activating PPARγ and inhibiting the TLR4/NF-κB/TNF-α inflammation pathway. Taken together, our results indicate that the PPARγ inhibition and inflammation reactions were implicated in the VCM nephrotoxicity and provide a promising therapeutic strategy for renal injury.

Effects of Leonurine on oocyte maturation and parthenogenetic embryo development in sheep.

Leonurine (LEO), an alkaloid isolated from Leonurus spp., has anti-oxidant, anti-inflammatory and anti-apoptotic effects and can prevent damage caused by reactive oxygen species (ROS). These properties suggest that it can improve the maturation rate of oocytes and developmental ability of embryos, which are key parameters in animal breeding. In this study, the effects of LEO on in vitro maturation and early embryonic development in sheep oocytes were evaluated. Among various doses examined (0, 10, 20 and 40 µM), a dose of 20 µM was optimal with respect to the oocyte maturation rate. Compared with estimates in the control group, GSH levels and mitochondrial membrane potential of sheep oocytes treated with 20 µM LEO were significantly higher, and 40 µM LEO would affect oocyte maturation. Additionally, ROS levels were significantly lower, expression levels of the antioxidant genes CAT and SOD1 were significantly higher, and there was no significant difference in GPX3 expression. The Bax/Bcl-2 ratio and Caspase-3 expression were significantly reduced in the 20 µM LEO group. During early embryonic development in vitro, the cleavage rate and blastocyst rate were significantly higher in the 20 µM LEO treatment group compared to other groups. GSH levels and mitochondrial membrane potential were significantly higher, while ROS levels were significantly lower, and expression levels of the antioxidant genes CAT, GPX3 and SOD1 were significantly higher in eight-cell embryos treated with 20 µM LEO than in the control group. The Bax/Bcl-2 ratio and Caspase-3 levels were significantly decreased. In summary, LEO can reduce the effect of oxidative stress, improve the oocyte maturation rate and enhance embryonic development.

Targeted inhibition of gut bacterial ß-glucuronidases by octyl gallate alleviates mycophenolate mofetil-induced gastrointestinal toxicity.

Mycophenolate mofetil (MMF) is a viable therapeutic option against various immune disorders as a chemotherapeutic agent. Nevertheless, its application has been undermined by the gastrotoxic metabolites (mycophenolic acid glucuronide, MPAG) produced by microbiome-associated ß-glucuronidase (ßGUS). Therefore, controlling microbiota-produced ßGUS underlines the potential strategy to improve MMF efficacy by overcoming the dosage limitation. In this study, the octyl gallate (OG) was identified with promising inhibitory activity on hydrolysis of PNPG in our high throughput screening based on a chemical collection of approximately 2000 natural products. Furthermore, OG was also found to inhibit a broad spectrum of BGUSs, including mini-Loop1, Loop 2, mini-Loop 2, and mini-Loop1,2. The further in vivo experiments demonstrated that administration of 20 mg/kg OG resulted in predominant reduction in the activity of BGUSs while displayed no impact on the overall fecal microbiome in mice. Furthermore, in the MMF-induced colitis model, the administration of OG at a dosage of 20 mg/kg effectively mitigated the gastrointestinal toxicity, and systematically reverted the colitis phenotypes. These findings indicate that the OG holds promising clinical potential for the prevention of MMF-induced gastrointestinal toxicity by inhibition of BGUSs and could be developed as a combinatorial therapy with MFF for better clinical outcomes.

Dry-air roasting impact on physicochemical, functional, antioxidant properties, phenolic profile and Maillard reaction products of flaxseed flour and cake flour.

The study investigated and compared physicochemical, functional, antioxidant properties, phenolic profile and Maillard reaction products (MRP) of flaxseed flour (FF) and flaxseed cake flour (FCF) upon dry-air roasting (DaR) of flaxseeds at 140, 160 and 180 °C for 5 and 10 min. This information on FF and FCF is limited and has considerable gaps. The raw FF exhibited higher fat, ash, antioxidant and functional properties while lower protein than the FCF. Upon increasing DaR conditions, the ash and protein increased in FCF and decreased in FF. DaR at 180 °C for 10 min augmented water solubility index, ΔE, MRP, free rutin and syringic acid, bound epicatechin, gallic acid and syringic acid while lowered moisture, L*, b*, hue, chroma, potassium, iron, selenium, emulsion indexes, caffeic acid, flavonoids and free resveratrol in FF and FCF. In conclusion, DaR improves phenolic profile, antioxidant properties, MRP, water solubility and oil absorption capacity of FF and FCF.

Methyl gallate from Camellia nitidissima Chi flowers reduces quorum sensing related virulence and biofilm formation against Aeromonas hydrophila.

Aeromonas hydrophila, a Gram-negative zoonotic bacterium, causes high mortality in fish farming and immunocompromised patients. This study aimed to extract methyl gallate (MG) from the flowers of Camellia nitidissima Chi and evaluate its potential as a quorum sensing inhibitor (QSI) against Aeromonas hydrophila SHAe 115. MG reduced QS-associated virulence factors, including hemolysis, protease, and lipase, while impairing swimming motility and biofilm formation. Additionally, MG down-regulated positive regulatory genes (ahyR, fleQ) and up-regulated negative regulators (litR, fleN). This highlights MG's promise as a potent QSI for A. hydrophila SHAe 115, advancing strategies against infections in aquaculture and human health.

Octadecyl Gallate and Lipid-Modified MnSe2 Nanoparticles Enhance Radiosensitivity in Esophageal Squamous Cell Carcinoma and Promote Radioprotection in Normal Tissues.

Radiotherapy, a widely used therapeutic strategy for esophageal squamous cell carcinoma (ESCC), is always limited by radioresistance of tumor tissues and side-effects on normal tissues. Herein, a signature based on four core genes of cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway, is developed to predict prognosis and assess immune cell infiltration, indicating that the cGAS-STING pathway and radiotherapy efficacy are closely intertwined in ESCC. A novel lipid-modified manganese diselenide nanoparticle (MnSe2-lipid) with extraordinarily uniform sphere morphology and tumor microenvironment (TME) responsiveness is developed to simultaneously overcome radioresistance and reduce side-effects of radiation. The uniform MnSe2 encapsulated lipid effectively achieves tumor accumulation. Octadecyl gallate on surface of MnSe2 forming pH-responsive metal-phenolic covalent realizes rapid degradation in TME. The released Mn2+ promotes radiosensitivity by generating reactive oxygen species induced by Fenton-like reaction and activating cGAS-STING pathway. Spontaneously, selenium strengthens immune response by promoting secretion of cytokines and increasing white blood cells, and performs antioxidant activity to reduce side-effects of radiotherapy. Overall, this multifunctional remedy which is responsive to TME is capable of providing radiosensitivity by cGAS-STING pathway-mediated immunostimulation and chemodynamic therapy, and radioprotection of normal tissues, is highlighted here to optimize ESCC treatment.

Theoretical insights into the mechanism underlying aflatoxin B1 transformation by the BsCotA-methyl syringate system.

Global concern exists regarding the contamination of food and animal feed with aflatoxin B1 (AFB1), which poses a threat to the health of both humans and animals. Previously, we found that a laccase from Bacillus subtilis (BsCotA) effectively detoxified AFB1 in a reaction mediated by methyl syringate (MS), although the underlying mechanism has not been determined. Therefore, our primary objective of this study was to explore the detoxification mechanism employed by BsCotA. First, the enzyme and mediator dependence of AFB1 transformation were studied using the BsCotA-MS system, which revealed the importance of MS radical formation during the oxidation process. Aflatoxin Q1 (AFQ1) resulting from the direct oxidation of AFB1 by BsCotA, was identified using ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results of UPLC-MS/MS and density functional theory calculations indicated that the products included AFQ1, AFB1-, and AFD1-MS-coupled products in the BsCotA-MS system. The toxicity evaluations revealed that the substances derived from the transformation of AFB1 through the BsCotA-MS mechanism exhibited markedly reduced toxicity compared to AFB1. Finally, we proposed a set of different AFB1-transformation pathways generated by the BsCotA-MS system based on the identified products. These findings greatly enhance the understanding of the AFB1-transformation mechanism of the laccase-mediator system.

Octyl gallate has potent anti-inflammasome activity by directly binding to NLRP3 LRR domain.

The NOD-, LRR-, and Pyrin domain-containing protein 3 (NLRP3) inflammasome plays key roles in regulating inflammation. Numerous studies show that the abnormal activation of NLRP3 associates with the initiation and progression of various diseases. Hence, the NLRP3 inflammasome may be a promising therapeutic target for these diseases. Octyl gallate (OG) is a small molecule with antioxidant, antimicrobial, antifungal, and anti-inflammatory activities; however, the mechanism underlying its anti-inflammatory activity is still unclear. Here, we developed a screening system for NLRP3-inflammasome inhibitors. A total of 3287 small molecules were screened for inhibitors of nigericin-induced NLRP3 oligomerization. OG was identified as a novel inhibitor. We show that OG directly targets the LRR domain of NLRP3 and thereby blocks the inflammatory cascade of the NLRP3 inflammasome. This contrasts with the mode-of-action of other direct NLRP3 inhibitors, which all bind to the NACHT domain of NLRP3. Interestingly, OG also inhibits the priming step by downregulating the Raf-MEK1/2-ERK1/2 axis. Thus, OG inhibits the NLRP3 inflammasome by two distinct mechanisms. Importantly, OG injection ameliorated the inflammation in mouse models of foot gout and sepsis. Our study identifies OG as a potential therapeutic agent for NLRP3-associated diseases.

The substitution sites of hydroxyl and galloyl groups determine the inhibitory activity of human pancreatic α-amylase in twelve tea polyphenol monomers.

Tea polyphenols have been reported as potential α-amylase inhibitors. However, the quantitative structure-activity relationship (QSAR) between tea polyphenols and human pancreas α-amylase (HPA) is not well understood. Herein, the inhibitory effect of twelve tea polyphenol monomers on HPA was investigated in terms of inhibitory activity, as well as QSAR analysis and interaction mechanism. The results revealed that the HPA inhibitory activity of theaflavins (TFs), especially theaflavin-3'-gallate (TF-3'-G, IC50: 0.313 mg/mL), was much stronger than that of catechins (IC50: 18.387-458.932 mg/mL). The QSAR analysis demonstrated that the determinant for the inhibitory activity of HPA was not the number of hydroxyl and galloyl groups in tea polyphenol monomers, while the substitution sites of these groups potentially might play a more important role in modulating the inhibitory activity. The inhibition kinetics and molecular docking revealed that TF-3'-G as a mixed-type inhibitor had the lowest inhibition constant and bound to the active sites of HPA with the lowest binding energy (-7.74 kcal/mol). These findings could provide valuable insights into the structures-activity relationships between tea polyphenols and the HPA inhibitors.

In Silico and In vitro Analysis of Phenolic Acids for Identification of Potential DHFR Inhibitors as Antimicrobial and Anticancer Agents.

BACKGROUND: DHFR is an indispensable enzyme required for the survival of almost all prokaryotic and eukaryotic cells, making it an attractive molecular target for drug design. OBJECTIVE: In this study, a combined in silico and in vitro approach was utilized to screen out potential anticancer and antimicrobial agents by using DHFR PDB ID 2W9S (for antimicrobial) and 1U72 (for anticancer). METHODS: Computational work was performed using Maestro Schrodinger Glide software. The DHFR inhibitory activity of the selected compounds was assessed using the DHFR test kit (CS0340-Sigma- Aldrich). RESULTS: Exhaustive analysis of in silico results revealed that some natural phenolic acids have a good docking score when compared to standards, i.e., trimethoprim and methotrexate, and have astonishing interactions with crucial amino acid residues available in the binding pocket of DHFR, such as Phe 92, Asp 27, Ser 49, Asn 18, and Tyr 98. In particular, digallic acid and chlorogenic acid have amazing interactions with docking scores of -9.9 kcal/mol and -9.6 kcal/mol, respectively, for the targeted protein 2W9S. Docking scores of -10.3 kcal/mol and -10.2 kcal/mol, respectively, for targeted protein 1U72. The best hits were then tested in vitro to evaluate the DHFR inhibitory activity of the compounds. DHFR inhibition activity results are in correlation with molecular docking results. CONCLUSION: In silico and in vitro results confirmed the good binding and inhibitory activity of some phenolic acids to the modeled target proteins. Among all the studied natural phenolic acids, chlorogenic acid, digallic acid, and rosmarinic acid appeared to be the most potential leads for future chemical alteration. This study can provide significant speculative guidance for the design and development of potent DHFR inhibitors in the future by using these compounds as leads.