Inhibition Of Alkaline Phosphatase Research Articles

Design of an Electrochemical Device for the Detection of Alkaline Phosphatase Inhibitors in Seawater

Design of an Electrochemical Device for the Detection of Alkaline Phosphatase Inhibitors in Seawater

Ectonucleotidase inhibitors: targeting signaling pathways for therapeutic advancement-an in-depth review.

Ectonucleotidase inhibitors are a family of pharmacological drugs that, by selectively targeting ectonucleotidases, are essential in altering purinergic signaling pathways. The hydrolysis of extracellular nucleotides and nucleosides is carried out by these enzymes, which include ectonucleoside triphosphate diphosphohydrolases (NTPDases) and ecto-5'-nucleotidase (CD73). Ectonucleotidase inhibitors can prevent the conversion of ATP and ADP into adenosine by blocking these enzymes and reduce extracellular adenosine. These molecules are essential for purinergic signaling, which is associated with a variability of physiological and pathological processes. By modifying extracellular nucleotide metabolism and improving purinergic signaling regulation, ectonucleotide pyrophosphatase/phosphodiesterase (ENPP) inhibitors have the potential to improve cancer treatment, inflammatory management, and immune response modulation. Purinergic signaling is affected by CD73 inhibitors because they prevent AMP from being converted to adenosine. These inhibitors are useful in cancer therapy and immunotherapy because they may improve chemotherapy effectiveness and alter immune responses. Purinergic signaling is controlled by NTPDase inhibitors, which specifically target enzymes involved in extracellular nucleotide breakdown. These inhibitors show promise in reducing immunological responses, thrombosis, and inflammation, perhaps assisting in the treatment of cardiovascular and autoimmune illnesses. Alkaline phosphatase (ALP) inhibitors alter the function of enzymes involved in dephosphorylation reactions, which has an impact on a variety of biological processes. By altering the body's phosphate levels, these inhibitors may be used to treat diseases including hyperphosphatemia and certain bone problems. This article provides a guide for researchers and clinicians looking to leverage the remedial capability of ectonucleotidase inhibitors in a variety of illness scenarios by illuminating their processes, advantages, and difficulties.

Alkaline phosphatase activatable near-infrared fluorescent probe for in-situ diagnosis of cholestatic liver injury

Cholestatic liver injury (CLI) is a clinical syndrome caused by impaired bile excretion and is almost asymptomatic in early-stage. If CLI is not recognized timely, it will elicit more severe liver diseases. Therefore, earlier diagnosis of CLI is urgently needed but remains challenging. On the basis of the consensus that elevation of serum alkaline phosphatase (ALP) is the most susceptible indicator of earlier cholestatic diseases. Herein, we conjugated dicyanoisophorone with hydroxyl-substituted coumarin derivative to afford an intramolecular charge transfer (ICT)-based fluorophore TX-OH, and successfully constructed an enzyme activatable fluorescent probe TX-PS, which enables specifically detecting ALP with near-infrared emission (720 nm), large stokes shift (198 nm) and excellent linear relationship (R2 = 0.9969) between fluorescence intensity and the concentrations of ALP (0–100 U/L). Moreover, TX-PS exhibits applicable for imaging of ALP activities in living cells and zebrafish with ignorable toxicity and shows great potential to visually screen ALP inhibitors. Importantly, the liver tissues from CLI mice displayed remarkably higher fluorescence intensity than that from normal mice, suggesting the valuable capability of TX-PS for evaluating CLI degree. Overall, this work affords a powerful tool for earlier diagnosis of CLI and high-throughput screening of ALP inhibitors or new drugs for CLI therapeutics.

Synthesis, Structural characterization, and Alkaline phosphatase inhibition studies of transition metal complexes of (e)-4-((3,5-dichlorophenyl) amino)-4-oxobut-2-enoic acid

Synthesis, Structural characterization, and Alkaline phosphatase inhibition studies of transition metal complexes of (e)-4-((3,5-dichlorophenyl) amino)-4-oxobut-2-enoic acid

Cardamonin inhibits osteogenic differentiation by downregulating Wnt/beta-catenin signaling and alleviates subchondral osteosclerosis in osteoarthritic mice.

Osteoarthritis (OA) is a common degenerative joint disease, and subchondral osteosclerosis is an important pathological change that occurs in its late stages. Cardamonin (CD) is a natural flavonoid isolated from Alpinia katsumadai that has anti-inflammatory activity. The objectives of this study were to investigate the therapeutic effects and potential mechanism of CD in regulating OA subchondral osteosclerosis at in vivo and in vitro settings. Eight-week-old male C57BL/6J mice were randomly divided into four groups: sham operation, anterior cruciate ligament transection (ACLT)-induced OA model, low-dose and high-dose CD treated ACLT-OA model groups. Histological assessment and immunohistochemical examinations for chondrocyte metabolism-related markers metalloproteinase-13, ADAMTS-4, Col II, and Sox-9 were performed. Microcomputed tomography was used to assess the sclerosis indicators in subchondral bone. Further, MC3T3-E1 (a mouse calvarial preosteoblast cell line) cells were treated with various concentrations of CD to reveal the influence and potential molecular pathways of CD in osteogenic differentiations. Animal studies suggested that CD alleviated the pathological changes in OA mice such as maintaining integrity and increasing the thickness of hyaline cartilage, decreasing the thickness of calcified cartilage, decreasing the Osteoarthritis Research Society International score, regulating articular cartilage metabolism, and inhibiting subchondral osteosclerosis. In vitro investigation indicated that CD inhibited alkaline phosphatase expression and production of calcium nodules during osteogenic differentiation of MC3T3-E1 cells. In addition, CD inhibited the expression of osteogenic differentiation-related indicators and Wnt/β-catenin pathway-related proteins. In conclusion, CD inhibits osteogenic differentiation by downregulating Wnt/β-catenin signaling and alleviating subchondral osteosclerosis in a mouse model of OA.

Label-free and sensitive assay for ICP-MS determination of alkaline phosphatase activity via manganese target

As an essential and universal enzyme, alkaline phosphatase (ALP) has been identified as an important biomarker of various diseases, thus highly sensitive assay of ALP activity is of great significance. Herein, a label-free and sensitive ICP-MS based assay was developed for ALP activity detection using MnO2 nanosheets (MnO2 NS) as the element target source. ALP triggered the hydrolysis of ascorbic acid-2-phosphate (AAP) to produce reductive ascorbic acid (AA), followed with the decomposition of MnO2 NS to Mn2+ ions, which were quantified directly by ICP-MS after selective separation of MnO2 NS and Mn2+ ions simply by filtration, and no further elemental labelling was needed. Under the selected conditions, the limit of detection (LOD) was 0.007 U L-1 for ALP. Additionally, this assay was also extended to investigate the inhibition effect of ALP inhibitor (Na3VO4) with reasonable results. To our knowledge, this is the first endeavor for ALP activity detection using ICP-MS, which holds great promise for the early clinical diagnosis and biomedical research on ALP.

Exploration of newly synthesized azo-thiohydantoins as the potential alkaline phosphatase inhibitors via advanced biochemical characterization and molecular modeling approaches

In the current study, Azo-Thiohydantoins derivatives were synthesized and characterized by using various spectroscopic techniques including FTIR, 1H-NMR, 13C-NMR, elemental and HRMS analysis. The compounds were evaluated for alkaline phosphatase activity and it was observed that among all the synthesized compounds, derivative 7e exhibited substantial inhibitory activity (IC50 = 0.308 ± 0.065 µM), surpassing the standard inhibitor (L–Phenyl alanine, IC50 = 80.2 ± 1.1 µM). Along with this, these derivatives were comprehensively examined regarding the electronic properties and reactivity of the synthesized compounds using Density Functional Theory (DFT) calculations, where the results were found very promising and the synthesized compound were found stable. After that, SwissADME evaluations highlighted compounds for their favorable physicochemical properties, including solubility and drug-likeness. Molecular docking exhibited the strong binding affinities of 7f and 7e derivatives with intestinal alkaline phosphatase (IAP), further supported by Molecular Dynamics (MD) simulations. This comprehensive integration of experimental and computational approaches sheds the light on the potential therapeutic applications of the synthesized compounds. By providing a detailed investigation of these aspects, this research opens the avenues for the development of novel pharmacologically active compounds with diverse applications.

Abstract 1909 Linking Organic Chemistry II, Physical Chemistry, and Biochemistry Laboratories in the Study of the Inhibition of Alkaline Phosphatase by Phenylalanine Derivatives

Abstract 1909 Linking Organic Chemistry II, Physical Chemistry, and Biochemistry Laboratories in the Study of the Inhibition of Alkaline Phosphatase by Phenylalanine Derivatives

Exploring Ocimum basilicum's Secondary Metabolites: Inhibition and Molecular Docking against Rhynchophorus ferrugineus for Optimal Action.

The objective of our work is to create a practical procedure to produce in vitro cell suspensions of O. basilicum and to ascertain the factors that encourage enhanced secondary metabolite production. We investigated the impact of these metabolites on Rhynchophorus ferrugineus's adult and larval target enzymes. The explants were cultivated on Murashige and Skoog (MS) media with 0.1 to 1 mg/L plant growth regulators (PGRs) to create calluses. 2,4-Dichlorophenoxyacetic acid (2,4-D), kinetin, 1-naphthylacetic acid (NAA), and indole-3-butryic acid (IBA) at 0.5, 0.5, 0.1, and 1 mg/L, respectively, with 3% sucrose led to the highest biomass accumulation. In cell suspensions, the total phenolic content (TPC) and total flavonoid content (TFC) were 39.68 and 5.49 mg/g DW, respectively, with abiotic Verticillium dahliae as an activator. Rosmarinic acid, ursolic acid, nepetoidin A and B, salvigenin, and quercetin-3-O-rutinoside as flavonoids and phenolics were analyzed using UPLC-I TQD MS, with the highest concentrations reached after 40 days. The extract demonstrates insecticidal activity against the fourth-instar larvae of R. ferrugineus, with adults at 1197 µg/mL and 12.5 µg/larvae as LC50 and LD50 values. The extract inhibited acetylcholine esterase (AChE), acid phosphatases (ACPs), alkaline phosphatases (ALPs), and gamma-aminobutyric acid-transaminase (GABA-T) in larval tissue in vitro, with IC50 values of 124.2, 149.3, 157.8, and 204.8 µg/mL, and in vivo, with IC50 values of 157.2, 179.4, 185.3, and 241.6 µg/mL, after 24 h. Pure compounds identified the activity of the extract, showing the inhibition of AChE, ACPs, ALPs, and GABA-T with IC50 values ˂ 200 µg/mL (in vitro). The ABMET examination revealed good oral permeability, and docking tests showed that the compounds bind AChE, ACPs, ALPs, and GABA-T. These findings show that a green bioprocessing method such as an O. basilicum cell suspension is a quick and straightforward technique for producing phenolic compounds, and it may be used to develop sustainable bio-insecticides and new green procedures.

Exploring biological activity and In-vitro anticancer effects of a new biomaterial derived from Schiff base isolated from Homarus americanus (Lobster) shell waste

In this study, chitin, a valuable biopolymer material, was extracted from lobster (Homarus americanus) shell waste using a chemical method. Afterward, the biopolymer was added to a mixture of the precursor (β-diketone and acidhydrazide) and monochloroacetic acid to prepare the biomaterial/hydrazone-based O-carboxymethyl chitosan Schiff base compounds. The prepared biomaterials were studied for potential biological applications, such as antimicrobial, antioxidant, wound healing, cytotoxicity, phosphate inhibition, and anticancer studies. The inhibition of alkaline phosphatase (ALP) enzyme was recorded using UV–Vis spectrophotometry. Wound healing studies of biopolymer materials and their derivatives were studied to RAW 264.7 (murine monocyte / macrophage) cells by scratch wound healing analysis. Additionally, using MTT analysis the in-vitro, anticancer efficacies (cell viability/cell proliferation/cytotoxicity) were conducted for SK-MEL-28 (human melanoma cells), MDA-MB-231 (human breast cancer cells), and the U87 (human glioma brain cells). The half maximal inhibitory concentration (IC50) values for SK-MEL-28 cells had 0.71 μg/mL at 24 h, and was a potent activity as compared to U-87 (35.98 μg/mL) and MDA-MB-231 (18.31 μg/mL) cells. The water-soluble / swelling nature of prepared biomaterials is utilized in the bio-ink formulation by the incorporation of the biopolymers such as cellulose, sodium alginate, gelatin, hyaluronic acid, and laponite RDS for potential biomedical applications.

Abstract 18522: Pyridoxamine (vitamin B6) Mitigation Of Structural Valve Degeneration Of Bioprosthetic Heart Valves

Introduction: Bioprosthetic heart valves (BHV) fabricated from glutaraldehyde treated bovine pericardium (BP) have limited durability due to structural valve degeneration (SVD) resulting from both calcification and advanced glycation end product (AGE) deposition. Hypothesis: We investigated the hypothesis that PYR modification of BHV leaflets mitigates AGE-serum protein uptake, oxidation, and calcification mechanisms in model studies, both in vitro and in vivo. Methods: To model AGE accumulation in BHV, we used well-established in vitro and in vivo models. AGE and serum albumin (SA) uptake in BP were quantitated per immunohistochemistry (IHC) staining intensity. PYR uptake was quantified using a novel fluorescent assay. BP collagen was examined by second-harmonic generation (SHG) microscopy. Calcification studies investigated the activity of BP alkaline phosphatase (ALP), and BP calcium levels were quantitated using a colorimetric assay. In vivo studies used a juvenile rat subdermal BP implantation model with PYR oral administration or BP-PYR modification. Endpoints were calcification, SA, and AGE accumulation per IHC and ALP activity per enzyme histochemistry. Results: PYR modification of BP resulted in high-affinity binding of PYR with 2.0±0.2 μg/mg of PYR binding to BP that was stable for 28 days in physiological conditions. Modification had an inhibitory effect on SA uptake in vitro with 60±5% (p<0.001) reduction in IHC staining intensity; PYR modification of BP resulted in increased protection from oxidative damage in vitro with collagen structure preservation (by SHG) after ten days, while control tissues were degraded. After 28-day of in vivo subdermal BP implantation in rats, a significant 70±5% (p<0.001) decrease and 80±5% (p<0.001) decrease in SA IHC staining and AGE staining, respectively, as well as ALP activity was documented in BP-PYR. Quantitative analysis of calcium content demonstrated a reduction from 108±5 μg/mg in control to 77±5 μg/mg in BP-PYR explants (p<0.001). Conclusions: Our study demonstrated that PYR mitigates SVD mechanisms in vitro and in vivo, limiting both AGE-serum protein accumulation and calcification with associated inhibition of ALP.

1, 8]-Naphthyridine derivatives as dual inhibitor of alkaline phosphatase and carbonic anhydrase

[1,8]-Naphthyridine derivatives have been reported to possess important biological activities and may serve as attractive pharmacophores in the drug discovery process. [1,8]-Naphthyridine derivatives (1a-1l) were evaluated for inhibitory potential for isozymes of carbonic anhydrase (CA) and alkaline phosphatase (ALP). CAs have been reported to carry out reversible hydration of CO2 into HCO3−, secretion of electrolytes, acid–base regulation, bone resorption, calcification, and biosynthetic reactions. Whereas ALPs hydrolyze monophosphate esters with the release of inorganic phosphate and play an important role in bone mineralization. Both enzymes have been found to be over-expressed and raised functional activities in patients suffering from rheumatoid arthritis. The discovery of dual inhibitors of these enzymes may provide a synergistic effect to cure bone disorders such as rheumatoid arthritis and ankylosing spondylitis. Among the test compounds, the most potent inhibitors for CA-II, CA-IX, and CA-XII were 1e, 1g, and 1a with IC50 values of 0.44 ± 0.19, 0.11 ± 0.03 and 0.32 ± 0.07 µM, respectively. [1,8]-Naphthyridine derivatives (1a–1l) were approximately 4 folds more potent than standard CA inhibitor acetazolamide. While in the case of ALPs, the most potent compounds for b-TNAP and c-IAP were 1b and 1e with IC50 values of 0.122 ± 0.06 and 0.107 ± 0.02 µM, respectively. Thus, synthesized derivatives proved to be 100 to 800 times more potent as compared to standard inhibitors of b-TNAP and c-IAP (Levamisole and L-phenyl alanine, respectively). In addition, selectivity and dual inhibition of [1,8]-Naphthyridine derivatives confer precedence over known inhibitors. Molecular docking and molecular simulation studies were also conducted in the present studies to define the type of interactions between potential inhibitors and enzyme active sites.

Development of a novel apigenin prodrug programmed for alkaline-phosphatase instructed self-inhibition to combat cancer

Elevated levels of alkaline phosphatase (ALP) in the tumor microenvironment (TME) are a hallmark of cancer progression and thus inhibition of ALP could serve as an effective approach against cancer. Herein, we developed a novel prodrug approach to tackle cancer that bears self-inhibiting alkaline phosphatase-responsiveness properties that can enhance at the same time the solubility of the parent compound. To probe this novel concept, we selected apigenin as the cytotoxic agent since we first unveiled, that it directly interacts and inhibits ALP activity. Consequently, we rationally designed and synthesized, using a self-immolative linker, an ALP responsive apigenin-based phosphate prodrug, phospho-apigenin. Phospho-apigenin markedly increased the stability of the parent compound apigenin. Furthermore, the prodrug exhibited enhanced antiproliferative effect in malignant cells with elevated ALP levels, compared to apigenin. This recorded potency of the developed prodrug was further confirmed in vivo where phospho-apigenin significantly suppressed by 52.8% the growth of PC-3 xenograft tumors. Communicated by Ramaswamy H. Sarma

Fluorimetric microplate assay for the determination of extracellular alkaline phosphatase kinetics and inhibition kinetics in activated sludge

The microbial enzyme alkaline phosphatase contributes to the removal of organic phosphorus compounds from wastewaters. To cope with regulatory threshold values for permitted maximum phosphor concentrations in treated wastewaters, a high activity of this enzyme in the biological treatment stage, e.g., the activated sludge process, is required. To investigate the reaction dynamics of this enzyme, to analyze substrate selectivities, and to identify potential inhibitors, the determination of enzyme kinetics is necessary. A method based on the application of the synthetic fluorogenic substrate 4-methylumbelliferyl phosphate is proven for soils, but not for activated sludges. Here, we adapt this procedure to the latter. The adapted method offers the additional benefit to determine inhibition kinetics. In contrast to conventional photometric assays, no particle removal, e.g., of sludge pellets, is required enabling the analysis of the whole sludge suspension as well as of specific sludge fractions. The high sensitivity of fluorescence detection allows the selection of a wide substrate concentration range for sound modeling of kinetic functions.•Fluorescence array technique for fast and sensitive analysis of high sample numbers•No need for particle separation – analysis of the whole (diluted) sludge suspension•Simultaneous determination of standard and inhibition kinetics

The Usability of Sorbents in Restoring Enzymatic Activity in Soils Polluted with Petroleum-Derived Products.

Due to their ability to adsorb or absorb chemical pollutants, including organic compounds, sorbents are increasingly used in the reclamation of soils subjected to their pressure, which results from their high potential in eliminating xenobiotics. The precise optimization of the reclamation process is required, focused primarily on restoring the condition of the soil. This research are essential for seeking materials sufficiently potent to accelerate the remediation process and for expanding knowledge related to biochemical transformations that lead to the neutralization of these pollutants. The goal of this study was to determine and compare the sensitivity of soil enzymes to petroleum-derived products in soil sown with Zea mays, remediated using four sorbents. The study was conducted in a pot experiment, with loamy sand (LS) and sandy loam (SL) polluted with VERVA diesel oil (DO) and VERVA 98 petrol (P). Soil samples were collected from arable lands, and the effects of the tested pollutants were compared with those used as control uncontaminated soil samples in terms of Zea mays biomass and the activity of seven enzymes in the soil. The following sorbents were applied to mitigate DO and P effects on the test plants and enzymatic activity: molecular sieve (M), expanded clay (E), sepiolite (S), and Ikasorb (I). Both DO and P exerted a toxic effect on Zea mays, with DO more strongly disturbing its growth and development and the activities of soil enzymes than P. In sandy clay (SL), P was found to be a significant inhibitor of dehydrogenases (Deh), catalase (Cat), urease (Ure), alkaline phosphatase (Pal), and arylsulfatase (Aryl) activities, while DO stimulated the activity of all enzymes in this soil. The study results suggest that the sorbents tested, mainlya molecular sieve, may be useful in remediating DO-polluted soils, especially when alleviating the effects of these pollutants in soils of lower agronomic value.

Metformin attenuates diabetes-induced osteopenia in rats is associated with down-regulation of the RAGE-JAK2-STAT1 signal axis.

Osteopenia and fragile fractures are diabetes-associated complications. Many hypoglycemic drugs have effects on bone metabolism. Metformin, as is a prescribed medication for type 2 diabetes mellitus (T2DM), had been reported to have osteoprotective effects beyond its hypoglycemic effect, however the potential mechanism behind these effects remains unclear. In this study, we aimed to investigate the comprehensive effects of metformin on bone metabolism in T2DM rat model and elucidate the potential mechanism. Goto-Kakizaki spontaneous T2DM rats with significant hyperglycemia were treated with/without metformin for 20 weeks. Glucose tolerance was tested and all rats were weighed every two weeks. The osteoprotective effects of metformin in diabetic rats were determined by quantifying serum bone biomarkers, μ-CT imaging, histological staining, bone histomorphometry, and biomechanical properties analyses. Potential targets of metformin in the treatment of T2DM and osteoporosis were predicted using network pharmacology. The effects of metformin on mesenchymal stem cells (C3H10) cultured in high glucose medium were evaluated by CCK-8 assay, alkaline phosphatase (ALP) staining, qPCR and western blotting. This study demonstrated that metformin significantly attenuated osteopenia, decreased serum glucose and glycated serum protein (GSP) levels, improved bone microarchitecture, and biomechanical properties in GK rats with T2DM. Metformin significantly increased biomarkers of bone formation, and significantly decreased muscle ubiquitin C (Ubc) expression. Network pharmacology analysis found that signal transducer and activator of transcription1 (STAT1) would be a potential target of metformin for regulating bone metabolism. Metformin increased C3H10​cell viability in vitro, alleviated ALP inhibition caused by hyperglycemia, increased the osteogenic gene expression of runt-related transcription factor 2 (RUNX2), collagen type I alpha 1 (Col1a1), osteocalcin (OCN), and ALP, while suppressing RAGE and STAT1 expression. Metformin also increased the protein expression of Osterix and decreased that of RAGE, p-JAK2, and p-STAT1. Our results demonstrate that metformin attenuated osteopenia and improved bone microarchitecture in GK rats with T2DM and significantly promoted stem cell osteogenic differentiation under high glucose condition. The effects of metformin on bone metabolism are closely associated with the suppression of RAGE-JAK2-STAT1 signaling axis. Our research provides experiment evidence and potential mechanistic rationale for the use of metformin as an effective candidate for diabetes-induced osteopenia treatment.

Kinetic evaluation and study of gold-based nanoparticles and multi-walled carbon nanotubes as an alkaline phosphatase inhibitor in serum and pure form

Kinetic evaluation and study of gold-based nanoparticles and multi-walled carbon nanotubes as an alkaline phosphatase inhibitor in serum and pure form

Design, synthesis, biochemical and in silico characterization of novel naphthalene-thiourea conjugates as potential and selective inhibitors of alkaline phosphatase.

Naphthalene ring is present in a number of FDA-approved, commercially available medications, including naphyrone, terbinafine, propranolol, naproxen, duloxetine, lasofoxetine, and bedaquiline. By reacting newly obtained 1-naphthoyl isothiocyanate with properly modified anilines, a library of ten novel naphthalene-thiourea conjugates (5a-5j) were produced with good to exceptional yields and high purity. The newly synthesized compounds were observed for their potential to inhibit alkaline phosphatase (ALP) and scavenge free radicals. All of the investigated compounds displayed a more powerful inhibitory profile than the reference agent, KH2PO4 particularly compound 5h and 5a exhibited strong inhibitory potential against ALP with IC50 value of 0.365 ± 0.011 and 0.436 ± 0.057 µM respectively. In addition, Lineweaver-Burk plots revealed the non-competitive inhibition mode of the most powerful derivative i.e., 5h (ki value 0.5 µM). To investigate the putative binding mode of selective inhibitor interactions, molecular docking was performed. It is recommended that future research will focus on developing selective alkaline phosphatase inhibitors by modifying the structure of the 5h derivative.

Antarctic Krill Oil Exhibited Synergistic Effects with Nobiletin and Theanine on Regulating Ligand-Specific Receptor-Mediated Transcytosis in Blood-Brain Barrier by Inhibiting Alkaline Phosphatase in SAMP8 Mice.

Blood-brain barrier (BBB) impairment is related to the development of Alzheimer's disease (AD), which is dependent not only on tight junction but also on transcytosis of brain endothelial cells (BECs) in the BBB. Aging induces the decrease of ligand-specific receptor-mediated transcytosis (RMT) and the increase of non-specific caveolar transcytosis in BECs, which lead to the entry into parenchyma of neurotoxic proteins and the smaller therapeutic index in central nervous system drug delivery, further provoking neurodegenerative disease. A previous study suggests that sea-derived Antarctic krill oil (AKO) exhibits synergistic effects with land-derived nobiletin (NOB) and theanine (THE) on ameliorating memory and cognitive deficiency in SAMP8 mice. However, it is still unclear whether BBB change is involved. Hence, the effects of AKO combined with NOB and THE on aging-induced BBB impairment, including tight junction between BECs, ligand-specific RMT, and non-specific caveolar transcytosis in BECs, are investigated. The results suggest that AKO exhibits synergistic effects with NOB and THE on regulating ligand-specific RMT in BBB by inhibiting alkaline phosphatase (ALPL). The study provides a potential strategy candidate or targeted dietary patterns to prevent and treat AD by improving the BBB function.

Exploring chromone sulfonamides and sulfonylhydrazones as highly selective ectonucleotidase inhibitors: Synthesis, biological evaluation and in silico study

Ectonucleotidases, a well-known superfamily of plasma membrane located metalloenzymes plays a central role in mediating the process of purinergic cell signaling. Major functions performed by these enzymes include the hydrolysis of extracellular nucleosides and nucleotides which are considered as important cell-signaling molecules. Any (patho)-physiologically induced disruption in this purinergic cell signaling leads to several disorders, hence these enzymes are important drug targets for therapeutic purposes. Among the major challenges faced in the design of inhibitors of ectonucleotidases, an important one is the lack of selective inhibitors. Access to highly selective inhibitors via a facile synthetic route will not only be beneficial therapeutically, but will also lead to an increase in our understanding of intricate interplay between members of ectonucleotidase enzymes in relation to their selective activation and/or inhibition in different cells and tissues. Herein we describe synthesis of highly selective inhibitors of human intestinal alkaline phosphatase (h-IAP) and human tissue non-specific alkaline phosphatase (h-TNAP), containing chromone sulfonamide and sulfonylhydrazone scaffolds. Compound 1c exhibited highest (and most selective) h-IAP inhibition activity (h-IAP IC50 = 0.51 ± 0.20 µM; h-TNAP = 36.5%) and compound 3k showed highest activity and selective inhibition against h-TNAP (h-TNAP IC50 = 1.41 ± 0.10 µM; h-IAP = 43.1%). These compounds were also evaluated against another member of ectonucleotidase family, that is rat and human ecto-5′-nucleotidase (r-e5′NT and h-e5′NT). Some of the compounds exhibited excellent inhibitory activity against ecto-5′-nucleotidase. Compound 2 g exhibited highest inhibition against h-e5′NT (IC50 = 0.18 ± 0.02 µM). To rationalize the interactions with the binding site, molecular docking studies were carried out.