Inhibitory Activity Research Articles

Targeting Epidermal Growth Factor Receptor with Ficus virens Metabolites to Manage Cancer Progression: Molecular Docking and ADME Study

Abstract Introduction: Targeting epidermal growth factor receptor (EGFR) has been used in the treatment of several cancer types where EGFR has a notable involvement in signalling pathways. Medicinal plants are the oldest and healthiest source of medication used in modern pharmacological therapy. Previous research indicates that the compounds found in Ficus virens stem bark have significant therapeutic properties against a range of illnesses, including cancer. Therefore, in this study, molecular docking research was conducted to determine the binding interactions and affinity of secondary metabolites predicted in F. virens methanolic extract with the target protein, EGFR. Methodology: Three-dimensional (3D) conformers of the secondary metabolism products and adenosine triphosphate (ATP) were collected from PubChem on 5 January 2024. The 3D structure of EGFR and its inhibitor was retrieved from the Protein Data Bank (PDB) databank and ligands and proteins were converted to AutoDock-compatible format and then the energy minimisation was performed by the Open Babel in PyRx. Finally, using PyRx-Python 0.8, molecular docking was done, and using Discovery Studio, visualisation was done as well. The grid box dimensions were specified at 30 Å ×30 Å ×25 Å, and the physiochemical property evaluation was done by the SwissADME online server. Results: In this study, molecular docking assessed 14 compounds, including phytochemicals and ATP, for their binding with EGFR (PDB Id: 1XKK). Redocking of lapatinib validated the results. Natural chemicals showed binding energies from −4.0 to −7.8 Kcal/mol, with oleic acid and iso-caryophyllene demonstrating promising interactions, sourced from F. virens. Despite some limitations, these compounds exhibit potential for EGFR-targeted drug development, despite one Lipinski’s rule violation. Conclusions: EGFR inhibitory activities of iso-caryophyllene and oleic acid, which were identified in the F. virens methanol extract, were remarkable and higher than that of the substrate; their potential opens up exciting new possibilities for moving forward with cancer treatment. It is encouraged to further investigate the in vivo effectiveness of iso-caryophyllene, by means of animal models and cell lines.

Cross-modal plasticity in children with cochlear implant: converging evidence from electroencephalography and functional near-infrared spectroscopy

Abstract Over the first years of life, the brain undergoes substantial organization in response to environmental stimulation. In a silent world, it may promote vision by 1) recruiting resources from the auditory cortex and 2) making the visual cortex more efficient. It is unclear when such changes occur and how adaptive they are, questions that children with cochlear implants can help address. Here, we examined 7 to 18 years old children: 50 had cochlear implants, with delayed or age-appropriate language abilities, and 25 had typical hearing and language. High-density electroencephalography and functional near-infrared spectroscopy were used to evaluate cortical responses to a low-level visual task. Evidence for a weaker visual cortex response and less synchronized or less inhibitory activity of auditory association areas in the implanted children with language delays suggests that cross-modal reorganization can be maladaptive and does not necessarily strengthen the dominant visual sense.

New piperazine derivatives helvamides B–C from the marine-derived fungus Penicillium velutinum ZK-14 uncovered by OSMAC (One Strain Many Compounds) strategy

Four extracts of the marine-derived fungus Penicillium velutinum J.F.H. Beyma were obtained via metal ions stress conditions based on the OSMAC (One Strain Many Compounds) strategy. Using a combination of modern approaches such as LC/UV, LC/MS and bioactivity data analysis, as well as in silico calculations, influence metal stress factors to change metabolite profiles Penicillium velutinum were analyzed. From the ethyl acetate extract of the P. velutinum were isolated two new piperazine derivatives helvamides B (1) and C (2) together with known saroclazin A (3) (4S,5R,7S)-4,11-dihydroxy-guaia-1(2),9(10)-dien (4). Their structures were established based on spectroscopic methods. The absolute configuration of helvamide B (1) as 2R,5R was determined by a combination of the X-ray analysis and by time-dependent density functional theory (TD-DFT) calculations of electronic circular dichroism (ECD) spectra. The cytotoxic activity of the isolated compounds against human prostate cancer PC-3 and human embryonic kidney HEK-293 cells and growth inhibition activity against yeast-like fungi Candida albicans were assayed.Graphical

Albifimbrins A and B, a pair of epimeric tetrahydrofuran-containing linear polyketide derivatives from the marine-derived fungus Albifimbria verrucaria CD1-4

A pair of new epimeric polyketides, named albifimbrins A and B (1 and 2), were isolated from the cultures of the shellfish-derived fungus Albifimbria verrucaria CD1–4. Their structures were determined by extensive spectroscopic analysis including HR-MS, 1D and 2D NMR data, together with the CD exciton chirality method. Compounds 1 and 2 possess unusual tetrahydrofuran moiety in their linear molecule structures. The antimicroalgal assay indicated that compounds 1 and 2 shown moderate inhibitory activities against marine harmful microalgae, Prorocentrum donghaiense, Amphidinium carterae and Heterocapsa circulariaquama.

Combination of betulinic acid and EGFR-TKIs exerts synergistic anti-tumor effects against wild-type EGFR NSCLC by inducing autophagy-related cell death via EGFR signaling pathway

BackgroundEpidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of lung cancer patients with mutated EGFR. However, the efficacy of EGFR-TKIs in wild-type EGFR tumors has been shown to be marginal. Methods that can sensitize EGFR-TKIs to EGFR wild-type NSCLC remain rare. Hence, we determined whether combination treatment can maximize the therapeutic efficacy of EGFR-TKIs.MethodsWe established a focused drug screening system to investigate candidates for overcoming the intrinsic resistance of wild-type EGFR NSCLC to EGFR-TKIs. Molecular docking assays and western blotting were used to identify the binding mode and blocking effect of the candidate compounds. Proliferation assays, analyses of drug interactions, colony formation assays, flow cytometry and nude mice xenograft models were used to determine the effects and investigate the molecular mechanism of the combination treatment.ResultsBetulinic acid (BA) is effective at targeting EGFR and synergizes with EGFR-TKIs (gefitinib and osimertinib) preferentially against wild-type EGFR. BA showed inhibitory activity due to its interaction with the ATP-binding pocket of EGFR and dramatically enhanced the suppressive effects of EGFR-TKIs by blocking EGFR and modulating the EGFR-ATK-mTOR axis. Mechanistic studies revealed that the combination strategy activated EGFR-induced autophagic cell death and that the EGFR-AKT-mTOR signaling pathway was essential for completing autophagy and cell cycle arrest. Activation of the mTOR pathway or blockade of autophagy by specific chemical agents markedly attenuated the effect of cell cycle arrest. In vivo administration of the combination treatment caused marked tumor regression in the A549 xenografts.ConclusionsBA is a potential wild-type EGFR inhibitor that plays a critical role in sensitizing EGFR-TKI activity. BA combined with an EGFR-TKI effectively suppressed the proliferation and survival of intrinsically resistant lung cancer cells via the inhibition of EGFR as well as the induction of autophagy-related cell death, indicating that BA combined with an EGFR-TKI may be a potential therapeutic strategy for overcoming the primary resistance of wild-type EGFR-positive lung cancers.Graphical abstract

Bioassay-guided isolation and identification of antibacterial compounds from Piper betle leaf with inhibitory activity against the Vibrio species in shrimp

Bioassay-guided isolation and identification of antibacterial compounds from <i>Piper betle</i> leaf with inhibitory activity against the <i>Vibrio</i> species in shrimp

Evaluation of Novel Spiro-pyrrolopyridazine Derivatives as Anticancer Compounds: In Vitro Selective Cytotoxicity, Induction of Apoptosis, EGFR Inhibitory Activity, and Molecular Docking Analysis

Evaluation of Novel Spiro-pyrrolopyridazine Derivatives as Anticancer Compounds: In Vitro Selective Cytotoxicity, Induction of Apoptosis, EGFR Inhibitory Activity, and Molecular Docking Analysis

Optimization of Ultrasound-Assisted Extraction of Free Phenolic Compounds and In Vitro Biological Activity from Peach Fruit Using Response Surface Methodology

In this study, the ultrasonic extraction (UAE) of free phenolic compounds and relative biological activities of the Bulgarian peach variety “Filina” was optimized using chemometric techniques (response surface methodology). A Box–Behnken design was used to reveal the variation in the hydro module, temperature, duration, and extractant on the total phenolic content, total flavonoid content, antioxidant potential, and inhibitory activity on each yield. The results revealed that the optimal conditions included a hydro module of 20, a duration of 39.33 min, a temperature of 70 °C, and an extractant of 96.64% to retrieve the highest level of bioactive compounds. The calculated parameters were discovered to be following the projected values.

Potential drug targets for tumors identified through Mendelian randomization analysis.

According to the latest cancer research data, there are a significant number of new cancer cases and a substantial mortality rate each year. Although a substantial number of clinical patients are treated with existing cancer drugs each year, the efficacy is unsatisfactory. The incidence is still high and the effectiveness of most cancer drugs remains unsatisfactory. Therefore, we evaluated the human proteins for their causal relationship to for cancer risk and therefore also their potential as drug targets. We used summary tumors data from the FinnGen and cis protein quantitative trait loci (cis-pQTL) data from a genome-wide association study, and employed Mendelian randomization (MR) to explore the association between potential drug targets and nine tumors, including breast, colorectal, lung, liver, bladder, prostate, kidney, head and neck, pancreatic caners. Furthermore, we conducted MR analysis on external cohort. Moreover, Bidirectional MR, Steiger filtering, and colocalization were employed to validate the main results. The DrugBank database was used to discover potential drugs of tumors. Under the threshold of False discovery rate (FDR) < 0.05, results showed that S100A16 was protective protein and S100A14 was risk protein for human epidermal growth factor receptor 2-positive (HER-positive) breast cancer, phosphodiesterase 5A (PDE5A) was risk protein for colorectal cancer, and melanoma inhibitory activity (MIA) was protective protein for non-small cell lung carcinoma (NSCLC). And there was no reverse causal association between them. Colocalization analysis showed that S100A14 (PP.H4.abf = 0.920) and S100A16 (PP.H4.abf = 0.932) shared causal variation with HER-positive breast cancer, and PDE5A (PP.H4.abf = 0.857) shared causal variation with colorectal cancer (CRC). The MR results of all pQTL of PDE5A and MIA were consistent with main results. In addition, the MR results of MIA and external outcome cohort were consistent with main results. In this study, genetic predictions indicate that circulating S100 calcium binding protein A14 (S100A14) and S100 calcium binding protein A16 (S100A16) are associated with increase and decrease in the risk of HER-positive breast cancer, respectively. Circulating PDE5A is associated with increased risk of CRC, while circulating MIA is associated with decreased risk of NSCLC. These findings suggest that four proteins may serve as biomarkers for cancer prevention and as potential drug targets that could be expected for approval.

Novel Pyrido[4,3-d]pyrimidine Derivatives as Potential Sterol 14α-Demethylase Inhibitors: Design, Synthesis, Inhibitory Activity, and Molecular Modeling.

Thirty-four new pyrido[4,3-d]pyrimidine analogs were designed, synthesized, and characterized. The crystal structures for compounds 2c and 4f were measured by means of X-ray diffraction of single crystals. The bioassay results showed that most target compounds exhibited good fungicidal activities against Pyricularia oryzae, Rhizoctonia cerealis, Sclerotinia sclerotiorum, Botrytis cinerea, and Penicillium italicum at 16 μg/mL. Compounds 2l, 2m, 4f, and 4g possessed better fungicidal activities than the commercial fungicide epoxiconazole against B. cinerea. Their half maximal effective concentration (EC50) values were 0.191, 0.487, 0.369, 0.586, and 0.670 μg/mL, respectively. Furthermore, the inhibitory activities of the bioactive compounds were determined against sterol 14α-demethylase (CYP51). The results displayed that they had prominent activities. Compounds 2l, 2m, 4f, and 4g also showed better inhibitory activities than epoxiconazole against CYP51. Their half maximal inhibitory concentration (IC50) values were 0.219, 0.602, 0.422, 0.726, and 0.802 μg/mL, respectively. The results of molecular dynamics (MD) simulations exhibited that compounds 2l and 4f possessed a stronger affinity to CYP51 than epoxiconazole.

Identification of DprE1 inhibitors for tuberculosis through integrated in-silico approaches.

Decaprenylphosphoryl-β-D-ribose-2'-epimerase (DprE1), a crucial enzyme in the process of arabinogalactan and lipoarabinomannan biosynthesis, has become the target of choice for anti-TB drug discovery in the recent past. The current study aims to find the potential DprE1 inhibitors through in-silico approaches. Here, we built the pharmacophore and 3D-QSAR model using the reported 40 azaindole derivatives of DprE1 inhibitors. The best pharmacophore hypothesis (ADRRR_1) was employed for the virtual screening of the chEMBL database. To identify prospective hits, molecules with good phase scores (> 2.000) were further evaluated by molecular docking studies for their ability to bind to the DprE1 enzyme (PDB: 4KW5). Based on their binding affinities (< -9.0kcal/mole), the best hits were subjected to the calculation of free-binding energies (Prime/MM-GBSA), pharmacokinetic, and druglikeness evaluations. The top 10 hits retrieved from these results were selected to predict their inhibitory activities via the developed 3D-QSAR model with a regression coefficient (R2) value of 0.9608 and predictive coefficient (Q2) value of 0.7313. The induced fit docking (IFD) studies and in-silico prediction of anti-TB sensitivity for these top 10 hits were also implemented. Molecular dynamics simulations (MDS) were performed for the top 5 hit molecules for 200ns to check the stability of the hits with DprE1. Based on their conformational stability throughout the 200ns simulation, hit 2 (chEMBL_SDF:357100) was identified as the best hit against DprE1 with an accepted safety profile. The MD results were also in accordance with the docking score, MM-GBSA value, and 3D-QSAR predicted activity. The hit 2 molecule, (N-(3-((2-(((1r,4r)-4-(dimethylamino)cyclohexyl)amino)-9-isopropyl-9H-purin-6-yl)amino)phenyl)acrylamide) could serve as a lead for the discovery of a novel DprE1 inhibiting anti-TB drug.

Uncommon EpoxyquinolsPyrrolocytosporinA and cytosporin E2from the Fungus Eutypella sp. D-1.

Two uncommon epoxyquinols, pyrrolocytosporin A (1) and cytosporin E2 (2), along with the known cytosporin Y1 (3), were isolated from the solid defined medium of the Arctic-derived fungus Eutypella sp. D-1. Their structures were established through comprehensive analyses of spectroscopic and electronic circular dichroism data. Structurally, compound 1 represented the first nitrogen-containing epoxyquinol characterized by a pyrrole fused cytosporin framework, while compound 2 contained an uncommon cyclic carbonate functionality. The antibacterial, immunosuppressive, anti-inflammatory, and cytotoxic activities of all compounds were evaluated. Among the three metabolites, only compound 1 exhibited inhibitory effects on nitric oxide production induced by lipopolysaccharide with an IC50 value of 6.55 μM. Additionally, only compound 2 displayed inhibitory activity against ConA-induced T-cell proliferation with an IC50 value of 9.85 μM.

In Vitro Alpha-Glucosidase Inhibitory Effect of Etlingera Elatior Ethanol Extract Growing in Gayo Highland, Aceh Province, Indonesia

Background The prevalence of diabetes mellitus (DM) is increasing overtime, potentially leading to various severe health complications and mortality. Despite therapeutic agents have currently been developed, unexpected adverse effects are inevitable. Hence, safe and effective medications such as those of plant origin are critical to prevent unexpected complication in DM sufferers. Etlingera elatior has been widely used as spice and traditional medicine to treat diabetes in Aceh Province, Indonesia. However, study regarding α-glucosidase inhibitory effect of E. elatior growing in Gayo highlands, Aceh, Indonesia, is completely lacking. The aim of this study was to evaluate in vitro α-glucosidase inhibitory effect of E. elatior ethanol extracts (EEEE) growing in Gayo highlands, Aceh Province, Indonesia. Methods Antioxidant activity was determined using DPPH procedure, whereas α-glucosidase inhibition assay was carried out using spectrophotometric method. Data analysis was performed using One-Way Analysis of Variance (ANOVA), followed by Duncan’s multiple range test at α=0.05. Results Phytochemical analysis revealed the presence of total phenolic (TPC), total flavonoid (TFC), and total tannin (TTC) content in all E. elatior plant parts, in which the highest TPC was found in the stem (158.38 GAE/g), whereas the highest TFC and TTC was obtained in the rhizome extracts. The extract of fruit showed the strongest antioxidant activities, followed by the stem and leaf, with IC50 of 2.381 μg/mL, 6.966 μg/mL, and 19.365 μg/mL, respectively. All E. elatior extracts revealed a significant inhibitory activity against α-glucosidase at the concentration of 500 μg/mL, in which the stem extract showed the most effective α-glucosidase inhibitory effect with IC50 value of 5.15 μg/mL, suggesting its promising potential as antidiabetic agent. Conclusions This study highlights E. elatior potency as a novel source of antioxidant and natural antidiabetic compounds that are useful for the prevention and treatment of diabetes.

Identification of Hyperuricemia Alleviating Peptides from Yellow Tuna Thunnus albacares.

The development of food-derived antihyperuricemic substances is important for alleviating hyperuricemia (HUA) and associated inflammation. Here, novel peptides fromThunnus albacares (TAP) with strong antihyperuricemic activity were prepared. TAP was prepared by alkaline protease (molecular weight <1000 Da), with an IC50 value of xanthine oxidase inhibitory activity of 2.498 mg/mL, and 5 mg/mL TAP could reduce uric acid (UA) by 33.62% in human kidney-2 (HK-2) cells (P < 0.01). Mice were fed a high-purine diet and injected with potassium oxonate to induce HUA. Oral administration of TAP (600 mg/kg/d) reduced serum UA significantly by 42.22% and increased urine UA by 79.02% (P < 0.01) via regulating urate transporters GLUT9, organic anion transporter 1, and ATP-binding cassette subfamily G2. Meantime, TAP exhibited hepatoprotective and nephroprotective effects, according to histological analysis. Besides, HUA mice treated with TAP showed anti-inflammatory activity by decreasing the levels of toll-like receptor 4, nuclear factors-κB p65, NLRP3, ASC, and Caspase-1 in the kidneys (P < 0.01). According to serum non-targeted metabolomics, 91 differential metabolites between the MC and TAP groups were identified, and purine metabolism was considered to be the main pathway for TAP alleviating HUA. In a word, TAP exhibited strong antihyperuricemic activity both in vitro and in vivo.

Two peptides LLRLTDL and GYALPCDCL inhibit foam cell formation through activating PPAR-γ/LXR-α signaling pathway in oxLDL-treated RAW264.7 macrophages.

Foam cell formation plays a pivotal role in atherosclerosis-associated cardiovascular diseases. Bioactive peptides generated from marine sources have been found to provide multifunctional health advantages. In the present study, we investigated the anti-atherosclerotic effects of LLRLTDL (Bu1) and GYALPCDCL (Bu2) peptides, isolated from ark shell protein hydrolysates by assessing their inhibitory effect on oxidized LDL (oxLDL)-induced foam cell formation. The two peptides showed a promising anti-atherosclerotic effect by inhibiting foam cell formation, which was evidenced by inhibiting lipid accumulation in oxLDL-treated RAW264.7 macrophages and oxLDL-treated primary human aortic smooth muscle cells (HASMC). Two peptides effectively reduced total cholesterol, free cholesterol, cholesterol ester, and triglyceride levels by upregulating cholesterol efflux and downregulating cholesterol influx. Expression of cholesterol influx-related proteins such as SR-A1 and CD36 were reduced, whereas cholesterol efflux-related proteins such as ATP-binding cassette transporter ABCA-1 and ABCG-1 were highly expressed. In addition, Bu1 and Bu2 peptides increased PPAR-γ and LXR-α expression. However, PPAR-γ siRNA transfection reversed the foam cell formation inhibitory activity of Bu1 and Bu2 peptides. Furthermore, the synergistic effect of Bu1 and Bu2 peptides on foam cell formation inhibition was observed with PPAR-γ agonist thiazolidinediones, indicating that PPAR-γ signaling pathway plays a key role in foam cell formation of macrophages. Beyond their impact on foam cell formation, Bu1 and Bu2 peptides demonstrated anti-inflammatory potential by inhibiting the generation of pro-inflammatory cytokines and nitric oxide and NF-κB nuclear activation. Taken together, these results suggest that Bu1 and Bu2 peptides may be useful for atherosclerosis and associated anti-inflammatory therapies.

Aqueous humor perturbations in chronic smokers: a proteomic study

The detrimental effects of smoking are multisystemic and its effects on the eye health are significant. Smoking is a strong risk factor for age-related nuclear cataract, age-related macular degeneration, glaucoma, delayed corneal epithelial healing and increased risk of cystoid macular edema in patients with intermediate uveitis among others. We aimed to characterize the aqueous humor (AH) proteome in chronic smokers to gain insight into its perturbations and to identify potential biomarkers for smoking-associated ocular pathologies. Compared to the control group, chronic smokers displayed 67 (37 upregulated, 30 downregulated) differentially expressed proteins (DEPs). Analysis of DEPs from the biological point of view revealed that they were proteins involved in complement activation, lymphocyte mediated immunity, innate immune response, cellular oxidant detoxification, bicarbonate transport and platelet degranulation. From the molecular function point of view, DEPs were involved in oxygen binding, oxygen carrier activity, hemoglobin binding, peptidase/endopeptidase/cysteine-type endopeptidase inhibitory activity. Several of the upregulated proteins were acute phase reactant proteins such as clusterin, alpha-2-HS-glycoprotein, fibrinogen, alpha-1-antitrypsin, C4b-binding protein and serum amyloid A-2. Further research should confirm if these proteins might serve as biomarkers or therapeutic target for smoking-associated ocular diseases.

Selected Chromatographic Methods for Determining the Biological Activity of Substances

This paper presents various aspects of the use of chromatography to determine the biological activity of substances. On the one hand, the use of chromatography to determine the lipophilicity of a substance, a property that affects all LADME steps in various biomimetic systems, is presented, using various descriptors such as the retention factor in pure water (or buffer with physiological plasma pH), the CHI value, and Chrom logD. The use of chromatography in biomimetic systems to determine the interaction of substances with phospholipids (IAM stationary phases) and transport proteins (stationary phases with immobilised proteins) is also discussed. On the basis of the retention data obtained in these systems, the volume of distribution of the substance and the degree of binding of the substance with the proteins in question can be determined. Chromatography is also a method used to determine the interaction of substances with specific membrane receptors at their site of action using membrane chromatography (MCM). Thanks to biological detection, chromatography can also be used to determine the antimicrobial activity (bioautography) of substances and the effect of substances on biochemical reactions taking place in organisms, such as antioxidant properties and the inhibitory activity of various enzymes (biological assay).

Synthesis of α-Hydroxy-1,2,3-Triazole-linked Sialyltransferase Inhibitors and Evaluation of Selectivity Towards ST3GAL1, ST6GAL1 and ST8SIA2.

Tumour-derived sialoglycans, bearing the charged nonulosonic sugar sialic acid at their termini, play a critical role in tumour cell adhesion and invasion, as well as evading cell death and immune surveillance. Sialyltransferases (ST), the enzymes responsible for the biosynthesis of sialylated glycans, are highly upregulated in cancer, with tumour hypersialylation strongly correlated with tumour growth, metastasis and drug resistance. As a result, desialylation of the tumour cell surface using either targeted delivery of a pan-ST inhibitor (or sialidase) or systemic delivery of a non-toxic selective ST inhibitors are being pursued as potential new anti-metastatic strategies against multiple cancers including pancreatic, ovarian, breast, melanoma and lung cancer. Herein, we have employed molecular modelling to give insights into the selectivity observed in a series of selective ST inhibitors that incorporate a uridyl ring in place of the cytidine of the natural donor (CMP-Neu5Ac) and replace the charged phosphodiester linker of classical ST inhibitors with a neutral a-hydroxy-1,2,3-triazole linker. The inhibitory activities of the nascent compounds were determined against recombinant human ST enzymes (ST3GAL1, ST6GAL1, ST8SIA2) showing promising activity and selectivity towards specific ST sub-types. Our ST inhibitors are non-toxic and show improved synthetic accessibility and drug-likeness compared to earlier nucleoside-based ST inhibitors.

Mycobacterium tuberculosis suppresses host antimicrobial peptides by dehydrogenating L-alanine

Antimicrobial peptides (AMPs), ancient scavengers of bacteria, are very poorly induced in macrophages infected by Mycobacterium tuberculosis (M. tuberculosis), but the underlying mechanism remains unknown. Here, we report that L-alanine interacts with PRSS1 and unfreezes the inhibitory effect of PRSS1 on the activation of NF-κB pathway to induce the expression of AMPs, but mycobacterial alanine dehydrogenase (Ald) Rv2780 hydrolyzes L-alanine and reduces the level of L-alanine in macrophages, thereby suppressing the expression of AMPs to facilitate survival of mycobacteria. Mechanistically, PRSS1 associates with TAK1 and disruptes the formation of TAK1/TAB1 complex to inhibit TAK1-mediated activation of NF-κB pathway, but interaction of L-alanine with PRSS1, disables PRSS1-mediated impairment on TAK1/TAB1 complex formation, thereby triggering the activation of NF-κB pathway to induce expression of AMPs. Moreover, deletion of antimicrobial peptide gene β-defensin 4 (Defb4) impairs the virulence by Rv2780 during infection in mice. Both L-alanine and the Rv2780 inhibitor, GWP-042, exhibits excellent inhibitory activity against M. tuberculosis infection in vivo. Our findings identify a previously unrecognized mechanism that M. tuberculosis uses its own alanine dehydrogenase to suppress host immunity, and provide insights relevant to the development of effective immunomodulators that target M. tuberculosis.

Effects of different extraction methods on the structure and function of blackberry seed polysaccharides

SummaryThe different extraction methods including hot‐water extraction, ultrasound‐assisted extraction, and microwave‐assisted extraction, enzyme‐assisted extraction, ultrasound and microwave‐assisted extraction, and ultrasound and enzyme‐assisted extraction (UEE) methods were carried out to extract blackberry seed polysaccharides (BSPs). The extraction yield, structure, antioxidant capacity, and glucometabolic enzyme inhibition activities of BSPs were determined in this work. Extraction methods have no influence on the monosaccharide composition of BSPs but affected the molar ratio of monosaccharides. Fourier transform infrared spectroscopy and X‐ray diffraction results showed that the extraction method cannot effect on the functional groups and crystal forms of BSPs. The findings also revealed that UEE led to the highest BSP extraction yield (4.56%), highest antioxidant capacities, and highest α‐amylase (48.49%) and α‐glucosidase (67.33%) inhibitory rates, which may because of the dispersed molecular weight distribution and loose microstructure of BSPs. These results suggest that UEE may be used in the industry to obtain BSPs with high functional activities.