Maltase-glucoamylase Research Articles

Molecular structure similarity analysis using Tanimoto coefficient and its correlation analysis with Maltase-glucoamylase inhibitory activity of Nigella sativa’s compounds

Nigella sativa is one of the medicinal plants that are efficacious for treating diabetes mellitus. Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycemia due to damage of insulin action, insulin production, and/or both. In this study, the molecular structure similarity analysis of the compounds in Nigella sativa to acarbose and the correlation analysis of the similarity with its activity as antidiabetic with the mechanism of maltase glucoamylase (MGAM) inhibition was carried out. Similarity analysis has been done used Tanimoto coefficient. The prediction of MGAM inhibitory activity has been done using molecular docking with molegro virtual docker. The Kaempferol 3-glucosyl-(1-2)-galactosyl-(1-2)-glucoside; (S)-2,3-Epoxysqualene; Quercetin 3-glucosyl-(1-2)-galactosyl-(1-2)-glucoside; Oleic Acid has activity as an inhibitor of MGAM with rerank score -107.8770, -102.1760, -95.7338, -92.4246 respectively and these has Tanimoto score 0.426, 0.319, 0.413, 0.357 respectively. The correlation analysis obtained that there is a significant relationship between the Tanimoto Coefficient and Rerank Score with the opposite relationship because the correlation value is negative. Greater the degree of molecular structure similarity of Nigella sativa’s compounds to acarbose more likely has the similar biological activity as MGAM inhibitory

Mammalian maltase-glucoamylase and sucrase-isomaltase inhibitory effects of Artocarpus heterophyllus: An in vitro and in silico approach

Alpha-glucosidase (maltase, sucrase, isomaltase and glucoamylase) activities which are involved in carbohydrate metabolism are present in human intestinal maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI). Hence, these proteins are important targets to identify drugs against postprandial hyperglycemia thereby for diabetes. To find natural-based drugs against MGAM and SI, Artocarpus heterophyllus leaf was explored for MGAM and SI inhibition in in vitro and in silico. A. heterophyllus leaf aqueous active fraction (AHL-AAF) was prepared using Soxhlet extraction followed by silica column chromatography. The phytoconstituents of AHL-AAF were determined using LC-ESI-MS/MS. AHL-AAF showed dose-dependent and mixed inhibition against maltase (IC50 = 460 µg/ml; Ki = 300 µg/ml), glucoamylase (IC50 = 780 µg/ml; Ki = 480 µg/ml), sucrase (IC50 = 900 µg/ml, Ki = 504 µg/ml) and isomaltase (IC50 = 860 µg/ml, Ki = 400 µg/ml). AHL-AAF phytoconstituents interaction with N-terminal (Nt) and C-terminal (Ct) subunits of human MGAM and SI was analyzed using induced-fit docking, molecular dynamics (MD), and binding free energy calculation. In docking studies, rhamnosyl hexosyl methyl quercetin (RHMQ), P-coumaryl-O-16-hydroxy palmitic acid (PCHP), and spirostanol interacted with active site amino acids of human MGAM and SI. Among these RHMQ stably interacted with all the subunits (Nt-MGAM, Ct-MGAM, Nt-SI and Ct-SI) whereas PCHP with Ct-MGAM and Nt-SI during MD analysis. In molecular docking, the docking score of RHMQ with NtMGAM, CtMGAM, NtSI and CtSI was −8.48, −12.88, −11.98 and −11.37 kcal/mol. The docking score of PCHP for CtMGAM and NtSI was −8.59 and −8.4 kcal/mol, respectively. After MD simulation, the root mean square deviation (RMSD) and root mean square fluctuation (RMSF) values further confirmed the stable protein-ligand interaction. The RMSD value of all the complexes were around 2.5 Å and the corresponding RMSF values were also quite low. In MM/GBSA analysis, the involvement of Van der Waals and lipophilic energy in the protein/ligand interactions are understood. Further binding free energy for Nt-MGAM-PCHP, Nt-MGAM-RHMQ, Nt-SI-PCHP, Nt-SI-RHMQ, Ct-MGAM-PCHP, Ct-MGAM-RHMQ and Ct-SI-RHMQ complexes was found to be −24.94, −46.60, −46.56, −44.48, −40.3, −41.86 and −19.39 kcal/mol, respectively. Altogether, AHL-AAF showed inhibition of α-glucosidase activities of MGAM and SI. AHL-AAF could be further studied for its effect on diabetes in in vivo.

Stereo- and Regio-selective benzo- and Benzohalo-conduritols: Anti-diabetes &anti-tumor activity investigation, kinetic and molecular docking studies

In this study, benzoconduritols, benzohalogenoconduritol, and benzodihalogenoconduritols with conduritol-A and –C structures from oxo-norbornene derivative endo-10 b, exo-11 b cleavaged by Lewis acids (BBr3, BCl3, BF3· OEt2) and Ac2O/H2SO4 were defined. These compounds (10a, 24, 25, 26, 27, 28, 29, 34, and 35) have been evaluated for their potential to inhibit the α-glucosidase enzyme against acarbose-positive control. Among the compounds, halogen-substituted compounds 24, 25, 27, and 34 showed potent inhibition of the α-glucosidase enzyme compared with acarbose, while other compounds showed moderate inhibition. The kinetic studies of the most active compounds 24, 25, 27, and 34 were evaluated, then determined that they were mixed, non-competitive, and competitive type inhibitors. In addition, the in vitro cytotoxicity activities of these compounds were tested against human breast (BT-20), melanoma (SK-MEL128), prostate (DU-145), liver (SNU-398), lung (A549) cancer, and normal human fibroblast (HFC) cell lines. Among these compounds, the dichloro-substituted compound 25 showed the highest cytotoxic effect in the range of CC50 = 11.5–31.6 μg/mL against SNU-398, DU-145, SK-MEL128, A549, and HFC cell lines. The experimentally determined α-glucosidase and anticancer activity were studied by docking studies to demonstrate the binding orientation and interaction of the synthesized compound with amino acid residues present in the active site of human Maltase–Glucoamylase, topoisomerase II alpha, and Anaplastic Lymphoma Kinase enzymes.

IN SILICO AND IN VIVO STUDY OF THE ANTIDIABETIC PROPERTIES OF SOME NATURAL BIOLOGICALLY ACTIVE SUBSTANCES

Relevance. According to the Federal Register of Diabetes Mellitus, the number of patients diagnosed with diabetes is 4.9 million people, which is 3.31% of the population of the Russian Federation. The search for new antidiabetic drugs today is still an urgent task of pharmacy. Currently, doctors have a fairly wide range of synthetic drugs in their arsenal, but the issue of rational pharmacotherapy is still open. And in this regard, medicinal prod-ucts of natural origin look promising. The aim of the study was to evaluate the theoretical possibility of intermolecular interaction of a number of biologically active substances of plant origin with the active site of non-receptor type 1 tyrosine-protein phosphatase (PTP1B) and the active site of the intestinal maltase-glucoamylase (MGA) enzyme by molecular docking, as well as pharmacological confirmation of specific activity in the experiment. Material and methods. Male Wistar rats weighing 200–220 grams were used in the study. Modeling of diabetes mellitus was performed by a single intraperitoneal injection of alloxan (150 mg/kg) with a preliminary injection of nicotinamide (250 mg/kg). Animals with a model of diabetes mellitus (n=21) were introduced daily with the original combined substance of plant extracts of Galega officinalis L., Glycyrrhiza glabra L. and Mentha piperita L. at a dose of 500 mg/kg, reference drug - substance gliclazide – 60 mg/kg. The determination of the hypoglycemic effect was carried out after a single introductions and on the 14th day. Results. The hypoglycemic effect of the phytosubstance was established and the possibility of the influence of biologically active substances on PTP1B and MGA was evaluated. The results of molecular docking indicate a possible interaction of the studied objects with PTP1B and MGA; the highest values of docking are typical for kaempferol, caffeic and ellagic acids. In an in vivo study, a statistically significant decrease in the concentration of glucose in the blood of animals by 49.3% was found. Conclusions. The possibility of interaction of biologically active substances that are part of plant extracts with specific targets PTP1B and MGA was established by molecular docking, and the hypoglycemic effect of the proposed combined substance of plant extracts of goat's rue, licorice and pep-permint was confirmed in the experiment.

Synergistic Activity of Cinnamomum burmannii (Nees & T. Nees) Blume and Aquilaria malaccensis Lamk. Extracts for Antidiabetic Study

BACKGROUND: Type 2 diabetes mellitus affects glucose metabolism resulting in hyperglycemia. The bark of Cinnamomum burmannii (CB) and the leaves of Aquilaria malaccensis (AM) are believed to be effective for diabetes treatment. This study evaluated the synergistic effect of CB and AM, the extracts' phytochemical profiles, and the interaction between CB and AM metabolites with a-glucosidase through molecular docking.METHODS: The dried material was macerated with ethanol and then tested for a-amylase and a-glucosidase inhibitory activities and glucose diffusion inhibition in varied combination proportions. The extract fingerprinting was performed using a UV-Vis spectrophotometer followed by thin layer chromatography to determine the class of secondary metabolite in the extracts. Human maltase-glucoamylase (MGAM) receptor, ligands from acarbose and selected metabolites of CB and AM were studied in silico using UCSF Chimera, AutoDockTools, Autodock Vina Wizard (PyRx), and Biovia Discovery Studio software.RESULTS: The best ratio of CB:AM for a-amylase and a-glucosidase inhibition was 0.75:0.25 mg/mL, with inhibitory activities of 86.36 and 96.38 %, respectively. The best glucose diffusion inhibition was achieved at a ratio of 0.5:0.5 mg/mL CB and AM. The b-caryophyllene of CB and palustrol of AM had a significantly higher binding affinity of -10.7 kcal/mol and -10.2 kcal/mol, respectively than acarbose, which had a binding affinity of -8.1 kcal/mol.CONCLUSION: A ratio of CB to AM suppresses the activity of diabetes-related enzymes more efficiently. The in silico study suggested that the presence of b-caryophyllene in CB and palustrol in AM supported the synergistic activity.KEYWORDS: Aquilaria malaccensis, Cinnamomum burmannii, diabetes mellitus, a-amylase inhibition, a-glucose inhibition, glucose inhibition

Interaction between the α-glucosidases, sucrase-isomaltase and maltase-glucoamylase, in human intestinal brush border membranes and its potential impact on disaccharide digestion.

The two major intestinal α-glycosidases, sucrase-isomaltase (SI) and maltase-glucoamylase (MGAM), are active towards α-1,4 glycosidic linkages that prevail in starch. These enzymes share striking structural similarities and follow similar biosynthetic pathways. It has been hypothesized that starch digestion can be modulated via "toggling" of activities of these mucosal α-glycosidases, suggesting a possible interaction between these two enzyme complexes in the intestinal brush border membrane (BBM). Here, the potential interaction between SI and MGAM was investigated in solubilized BBMs utilizing reciprocal pull down assays, i.e., immunoprecipitation with anti-SI antibody followed by Western blotting with anti-MGAM antibody and vice versa. Our results demonstrate that SI interacts avidly with MGAM concomitant with a hetero-complex assembly in the BBMs. This interaction is resistant to detergents, such as Triton X-100 or Triton X-100 in combination with sodium deoxycholate. By contrast, inclusion of sodium deoxycholate into the solubilization buffer reduces the enzymatic activities towards sucrose and maltose substantially, most likely due to alterations in the quaternary structure of either enzyme. In view of their interaction, SI and MGAM regulate the final steps in starch digestion in the intestine, whereby SI assumes the major role by virtue of its predominant expression in the intestinal BBMs, while MGAM acts in auxiliary supportive fashion. These findings will help understand the pathophysiology of carbohydrate malabsorption in functional gastrointestinal disorders, particularly in irritable bowel syndrome, in which gene variants of SI are implicated.

Estimating the prevalence of congenital disaccharidase deficiencies using allele frequencies from gnomAD

Background: There are currently three known congenital disaccharidase deficiencies: congenital lactase deficiency (CLD), congenital sucrase-isomaltase deficiency (CSD), and congenital trehalase deficiency (CTD). No congenital deficiency has been described for maltase-glucoamylase (MGAM).Methods: A literature search was performed in PubMed for the pathogenic variants CLD, CSD, and CTD and the articles retrieved were analyzed to estimate the prevalence of congenital disaccharidase deficiencies.Results: Based on reported variants, the estimated prevalence was 1.3 per 106 births (95% CI: 1.1–1.7) for CLD, and 31.4 per 106 births (95% CI: 28.3–34.8) for CSD. Using data on previously reported variants and variants predicted to be loss-of-function in gnomAD, the overall estimated prevalence was 2.3 per 106 births (95% CI: 1.9–2.9) for CLD, 57.6 per 106 births (95% CI:52.5–63.2) for CSD, and 9.2 per 106 births (95% CI: 2.5–3.7) for CTD.Conclusion: The prevalence of CSD was found to be relatively high, while for other congenital disaccharidase deficiencies, the estimated prevalence was very low.

Exploration of the Interactions between Maltase–Glucoamylase and Its Potential Peptide Inhibitors by Molecular Dynamics Simulation

Diabetes mellitus, a chronic metabolic disorder, represents a serious threat to human health. The gut enzyme maltase–glucoamylase (MGAM) has attracted considerable attention as a potential therapeutic target for the treatment of type 2 diabetes. Thus, developing novel inhibitors of MGAM holds the promise of improving clinical management. The dipeptides, Thr-Trp (TW) and Trp-Ala (WA), are known inhibitors of MGAM; however, studies on how they interact with MGAM are lacking. The work presented here explored these interactions by utilizing molecular docking and molecular dynamics simulations. Results indicate that the active center of the MGAM could easily accommodate the flexible peptides. Interactions involving hydrogen bonds, cation-π, and hydrophobic interactions are predicted between TW/WA and residues including Tyr1251, Trp1355, Asp1420, Met1421, Glu1423, and Arg1510 within MGAM. The electrostatic energy was recognized as playing a dominant role in both TW-MGAM and WA-MGAM systems. The binding locations of TW/WA are close to the possible acid-base catalytic residue Asp1526 and might be the reason for MGAM inhibition. These findings provide a theoretical structural model for the development of future inhibitors.

Investigation of effective natural inhibitors for starch hydrolysing enzymes from Simaroubaceae plants by molecular docking analysis and comparison with in-vitro studies

The present study aims to find the effective natural enzyme inhibitors against alpha-amylase and alpha-glucosidase from the array of compounds identified in plants of the Simaroubaceae family using molecular docking and ADME/Toxicity studies. Among the 218 compounds docked against seven enzymes, buddlenol-A and citrusin-B showed the best binding energies (kcal/mol) of -7.830 and -7.383 against human salivary alpha-amylase and pancreatic alpha-amylase respectively. The other two compounds 9-hydroxycanthin-6-one and bruceolline-B had the best binding energy of -6.461 and -7.576 against N-terminal and C-terminal maltase glucoamylase respectively. Whereas the binding energy of prosopine (-6.499) and fisetinidol (-7.575) was considered as the best against N-terminal and C-terminal sucrase-isomaltase respectively. Picrasidine-X showed the best binding energy (-7.592) against yeast alpha-glucosidase. The study revealed that the seven compounds which showed the best binding energy against respective enzymes are considered as the ‘lead hit compounds’. Even though the ‘lead hit compounds’ are not obeying all the laws of ADMET, the drug-likeness properties of 9-hydroxycanthin-6-one, fisetinidol, picrasidine-X, and prosopine were considerable. Also, kaempferol-3-O-pentoside was the recent compound identified from the Simarouba glauca plant extract found to be one among the top five lead hit compounds against four enzymes. This study provides valuable insight into the direction of developing natural compounds as potential starch hydrolysing enzyme inhibitors for managing type 2 diabetes.

Inhibition of α-amylase and α-glucosidase by Morus australis fruit extract and its components iminosugar, anthocyanin, and glucose.

The inhibition of α-amylase and α-glucosidase are important for the maintenance of blood glucose level. Mammalian α-glucosidase includes maltase-glucoamylase and sucrase-isomaltase complexes. In this study, we examined the inhibitory effects of Morus australis fruit extract and its components, that is, three iminosugars (1-deoxynojirimycin [1-DNJ], fagomine, and 2-O-α-D-galactopyranosyl deoxynojirimycin), two anthocyanins (cyanidin-3-glucoside and cyanidin-3-rutinoside), and glucose, against α-amylase and α-glucosidase. We also quantified the concentration of each component in M. australis fruit extract. The IC50 values of the fruit extracts of four M. australis subspecies were >10 mg/ml for α-amylase, 1.1-1.7 mg/ml for maltase, 6.9-8.6 mg/ml for glucoamylase, 0.13-1.0 mg/ml for sucrase, and 0.46-1.4 mg/ml for isomaltase. When the IC50 value of each component and the concentration of each component in the fruit extract were taken into consideration, our results indicated that glucose are involved in the inhibition of α-amylase, and 1-DNJ and glucose are involved in the inhibition of α-glucosidase. This is in contrast to that in M. australis leaf, neither anthocyanin nor glucose are contained, and 1-DNJ is a main inhibitor. PRACTICAL APPLICATION: It is widely accepted that inhibition of α-amylase and α-glucosidase is one of the strategies to treat type-2 diabetes. Today, acarbose, miglitol, and voglibose are clinically used for this purpose. Our results that 1-DNJ and anthocyanin are present in Morus australis fruit and are involved in the inhibition of α-amylase and α-glucosidase suggest that M. australis fruit is a healthy sweetener.

Anti-Hyperglycemic Activities, Molecular Docking and Structure-Activity Relationships (SARs) Studies of Endiandric Acids and Kingianins from Endiandra kingiana

Diabetes has become a severe chronic disease worldwide with patients significantly increasing daily. Due to the side effects of insulin and oral hypoglycaemic agents employed in diabetes treatment, scientists are working hard to develop alternative approaches from natural plants that inhibit α-amylase and α-glucosidase. Consequently, by performing a phytochemical analysis on the bark of Endiandra kingiana, the present study isolated 11 cyclic polyketides. Analyses with one-dimensional and two-dimensional nuclear magnetic resonance (1D- and 2D-NMR), highresolution electron ionization mass spectrometry (HRESIMS), and comparison with previous literature confirmed the compounds characteristics. Subsequently, the compounds were screened for in vitro α-amylase and α-glucosidase inhibiting activities. Compounds 9 and 2 exhibited potent inhibition towards α-amylase at 0.0008903 ± 0.5 and 0.02 ± 0.3 mg mL−1 of half-maximal inhibitory concentration (IC50) values, respectively. In the α-glucosidase inhibition assay, compounds 10 and 5 demonstrated good inhibition with IC50 values of 0.11 ± 0.08 and 0.14 ± 0.05 mg mL−1, respectively. The molecular docking examination demonstrated that the compounds adhered to the active sites on the C-terminal of the human pancreatic α-amylase (Protein Data Bank Identification (PDB ID): 2QV4, resolution: 1.97 Å) and maltase-glucoamylase (MGAM) (PDB ID: 3TOP, resolution: 2.88 Å), agreeing with α-amylase and α-glucosidase enzymes inhibitory reactions.

Detoxification, Hydrogen Sulphide Metabolism and Wound Healing Are the Main Functions That Differentiate Caecum Protein Expression from Ileum of Week-Old Chicken

Sections of chicken gut differ in many aspects, e.g., the passage of digesta (continuous vs. discontinuous), the concentration of oxygen, and the density of colonising microbiota. Using an unbiased LC-MS/MS protocol, we compared protein expression in 18 ileal and 57 caecal tissue samples that originated from 7-day old ISA brown chickens. We found that proteins specific to the ileum were either structural (e.g., 3 actin isoforms, villin, or myosin 1A), or those required for nutrient digestion (e.g., sucrose isomaltase, maltase–glucoamylase, peptidase D) and absorption (e.g., fatty acid-binding protein 2 and 6 or bile acid–CoA:amino acid N-acyltransferase). On the other hand, proteins characteristic of the caecum were involved in sensing and limiting the consequences of oxidative stress (e.g., thioredoxin, peroxiredoxin 6), cell adhesion, and motility associated with wound healing (e.g., fibronectin 1, desmoyokin). These mechanisms are coupled with the activation of mechanisms suppressing the inflammatory response (galectin 1). Rather prominent were also expressions of proteins linked to hydrogen sulphide metabolism in caecum represented by cystathionin beta synthase, selenium-binding protein 1, mercaptopyruvate sulphurtransferase, and thiosulphate sulphurtransferase. Higher mRNA expression of nuclear factor, erythroid 2-like 2, the main oxidative stress transcriptional factor in caecum, further supported our observations.

Neither low salivary amylase activity, cooling cooked white rice, nor single nucleotide polymorphisms in starch-digesting enzymes reduce glycemic index or starch digestibility: a randomized, crossover trial in healthy adults

It was suggested that low salivary-amylase activity (SAA) and cooling or stir-frying cooked starch decreases its digestibility and glycemic index. We determined the effects of SAA, cooling, and single-nucleotide polymorphisms (SNPs) in the salivary amylase (AMY1), pancreatic amylase (AMY2A, AMY2B), maltase-glucoamylase (MGAM), and sucrase-isomaltase (SI) genes on starch digestibility and glycemic index of cooked polished rice. Healthy subjects [pilot, n=12; main, n=20 with low-SAA (<50 U/mL), and n=20 with high-SAA (>105 U/mL)] consumed test meals containing 25g (pilot) or 50g (main) available carbohydrate at a contract research organization using open-label (pilot) or assessor-blinded (main), randomized, crossover, Latin-square designs (trial registration: NCT03667963). Pilot-trial test meals were dextrose, freshly cooked polished rice, cooked rice cooled overnight, stir-fried hot rice, or stir-fried cold rice. Main-trial test meals were dextrose, dextrose plus 10g lactulose, plain hot rice, or plain cold rice. In both trials, blood glucose was measured fasting and at intervals over 2h. In the main trial, breath hydrogen was measured fasting and hourly for 6h to estimate in vivo starch digestibility. Data were analyzed by repeated-measures ANOVA for the main effects of temperature and stir-frying (pilot trial) or the main effects of SAA and temperature (main trial) and their interactions. Effects of 24 single nucleotide polymorphisms (SNPs) were assessed separately. Means were considered to be equivalent if the 95% CI of the differences were within ±20% of the comparator mean for glucose response/glycemic index or ±7% for digestibility. Pilot: neither temperature nor stir-frying significantly affected glucose incremental AUC (primary endpoint, n=12). Main: mean±SEM glycemic index (primary endpoint, n=40) was equivalent for low-SAA compared with high-SAA (73±3 vs. 75±4) and cold rice compared with hot rice (75±3 vs. 70±3). Estimated starch digestibility (n=39) was equivalent for low-SAA compared with high-SAA (95%±1% vs. 92%±1%) and hot rice compared with cold rice (94%±1% vs. 93%±1%). No meaningful associations were observed between genotypes and starch digestibility or glycemic index for any of the SNPs. The results do not support the hypotheses that low-SAA, cooling, and common genetic variations in starch-digesting enzymes affect the glycemic index or in vivo carbohydrate digestibility of cooked polished rice. This trial was registered at clinicaltrials.gov as NCT03667963.

Proteomic analysis of aqueous humor in canine primary angle-closure glaucoma in American Cocker Spaniel dogs.

To analyze proteomic profiles of the aqueous humor (AH) of canines with primary angle-closure glaucoma (PACG) and identify associated protein alterations. Six American Cocker Spaniels with PACG and six American Cocker Spaniels without ocular diseases. Aqueous humor samples were collected from six American Cocker Spaniels with PACG at Seoul National University, VMTH, and six healthy Cocker Spaniels without ocular disease at Irion Animal Hospital. For the PACG group, AH samples were obtained by anterior chamber paracentesis prior to glaucoma treatment. For the AH control group, AH samples were collected from patients anesthetized for other reasons. Total AH protein concentration was determined by the bicinchoninic acid (BCA) assay. AH protein samples were quantified by liquid chromatography-mass spectrometry (LC-MS/MS). Raw MS spectra were processed using MaxQuant software 30, and the Gene Ontology (GO) enrichment analysis was performed using ClueGO. The AH protein concentration in the PACG group (10.49±17.98µg/µl) was significantly higher than that of the control group (0.45±0.11µg/µl; p<.05). A total of 758 proteins were identified in the AH. Several proteins both significantly increased (n=69) and decreased (n=252) in the PACG group compared to those in the control group. GO enrichment analysis showed that the "response to wounding," "negative regulation of endopeptidase activity," and "cell growth" pathways were the most enriched terms in the PACG group compared to the control group. The top 5 proteins that were significantly increased in the AH of the PACG group were secreted phosphoprotein 1 (SPP1), peptidoglycan recognition proteins 2 (PGLYRP2), tyrosine 3-monooxygenase (YWHAE), maltase-glucoamylase (MGAM), and vimentin (VIM). Gene Ontology enrichment analysis using the proteomic data showed that proteins and pathways related to inflammation were significantly upregulated in the various stage of PACG. Proteomic analysis of the AH from the PACG may provide valuable insights into PACG pathogenesis.

Targeting N-Terminal Human Maltase-Glucoamylase to Unravel Possible Inhibitors Using Molecular Docking, Molecular Dynamics Simulations, and Adaptive Steered Molecular Dynamics Simulations.

There are multiple drugs for the treatment of type 2 diabetes, including traditional sulfonylureas biguanides, glinides, thiazolidinediones, α-glucosidase inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase IV (DPP-4) inhibitors, and sodium-glucose cotransporter 2 (SGLT2) inhibitors. α-Glucosidase inhibitors have been used to control postprandial glucose levels caused by type 2 diabetes since 1990. α-Glucosidases are rather crucial in the human metabolic system and are principally found in families 13 and 31. Maltase-glucoamylase (MGAM) belongs to glycoside hydrolase family 31. The main function of MGAM is to digest terminal starch products left after the enzymatic action of α-amylase; hence, MGAM becomes an efficient drug target for insulin resistance. In order to explore the conformational changes in the active pocket and unbinding pathway for NtMGAM, molecular dynamics (MD) simulations and adaptive steered molecular dynamics (ASMD) simulations were performed for two NtMGAM-inhibitor [de-O-sulfonated kotalanol (DSK) and acarbose] complexes. MD simulations indicated that DSK bound to NtMGAM may influence two domains (inserted loop 1 and inserted loop 2) by interfering with the spiralization of residue 497–499. The flexibility of inserted loop 1 and inserted loop 2 can influence the volume of the active pocket of NtMGAM, which can affect the binding progress for DSK to NtMGAM. ASMD simulations showed that compared to acarbose, DSK escaped from NtMGAM easily with lower energy. Asp542 is an important residue on the bottleneck of the active pocket of NtMGAM and could generate hydrogen bonds with DSK continuously. Our theoretical results may provide some useful clues for designing new α-glucosidase inhibitors to treat type 2 diabetes.

Synthesis, Biological Evaluation of ortho-Carboxamidostilbenes as Potential Inhibitors of Hyperglycemic Enzymes, and Molecular Docking Study

A new series of ortho-carboxamidostilbenes derivatives were synthesized via Heck Coupling and screened for their α-amylase and α-glucosidase inhibitory potential. The results indicated that all the synthesized compounds showed a substantial α-glucosidase inhibitory potential (IC50 between 3-78 µg/mL) compared to acarbose (IC50 = 16.14 ± 1.05 µg/mL) as the standard. In addition, the IC50 values against α-amylase varying from 3-300 µg/mL when compared to a standard drug acarbose (IC50 = 21.12 ± 0.29 µg/mL). In silico studies were carried out to understand the binding interaction between active compounds and enzymes. The results indicated that the binding energy displayed by compound 5a-5e ranging from -7.9 to -9.0 and -7.2 to -8.5 kcal/mol for the C-terminal subunit of human maltase glucoamylase, ctMGAM (α-glucosidase) and α-amylase, respectively. The interaction modes of 5d (IC50 = 2.90 ± 0.58 µg/mL) in ctMGAM, showed that alkyl and methoxy group interacted with TRP1369 via hydrogen bond and hydrophobic interaction, respectively. Meanwhile, the interaction modes of 5e with (IC50 = 2.94 ± 0.69 µg/mL) in α-amylase showed that the methoxy group interacted with TYR151 via conventional hydrogen bond. These compounds may be considered promising candidates for the development of new anti-diabetic agents.

Effects of encapsulated cinnamaldehyde on growth performance, intestinal digestive and absorptive functions, meat quality and gut microbiota in broiler chickens.

Essential oils are potential antimicrobial alternatives and their applications in animal feeds are limited due to their fast absorption in the upper gastrointestinal tract. This study investigated the effects of encapsulated cinnamaldehyde (CIN) at 50 mg/kg or 100 mg/kg on the growth performance, organ weights, meat quality, intestinal morphology, jejunal gene expression, nutrient digestibility, and ileal and cecal microbiota. A total of 320 male day-old broiler Cobb-500 chicks were randomly allocated to four treatments with eight pens per treatment (10 birds per pen): 1) basal diet (negative control, NC); 2) basal diet supplemented with 30 mg/kg avilamycin premix (positive control, PC); 3) basal diet with 50 mg/kg encapsulated CIN (EOL); 4) basal diet with 100 mg/kg encapsulated CIN (EOH). Despite birds fed EOH tended to increase (P = 0.05) meat pH at 24 h, all pH values were normal. Similar to PC group, meats from birds fed EOL and EOH showed a reduced (P < 0.05) Warner–Bratzler force shear (WBFS) compared to the NC group. The highest villus to crypt ratios (VH/CD; P < 0.05) were observed in broilers fed either EOL or EOH, with an average of 14.67% and 15.13% in the duodenum and 15.13% and 13.58% in the jejunum, respectively. For jejunal gene expressions, only six out of the 11 studied genes showed statistically significant differences among the dietary treatments. Gene expressions of cationic amino acid transporter 1 (CAT-1) and neutral amino acid transporter 1 (B0AT-1) were upregulated in EOH-fed birds compared to PC and NC-fed birds (P < 0.05), respectively; while the expression of proliferating cell nuclear antigen (PCNA) was downregulated in EOL-fed birds when compared to NC birds (P < 0.05). Nonetheless, the expressions of cadherin 1 (CDH-1), zonula occludens 1 (ZO-1), and maltase-glucoamylase (MG) were all upregulated (P < 0.05) in EOH-fed birds compared to PC-fed birds. The apparent ileal digestibility (AID) of dry matter, crude protein, crude fat and of all 18 tested amino acids increased in EOL-fed birds (P < 0.01). Additionally, relative abundances (%) of ileal Proteobacteria decreased, while ileal and cecal Lactobacillus increased in EOH-fed birds (P < 0.05). In conclusion, dietary encapsulated CIN improved meat quality and gut health by reducing meat WBFS, increasing VH/CD in intestines, jejunal gene expressions, AID of nutrients and beneficial ileal and cecal microbiota composition.

P058 Proteomic analysis-based discovery of a novel biomarker that differentiates intestinal Behçet’s disease from Crohn’s disease

Abstract Background Intestinal Behçet’s disease (BD) and Crohn’s disease (CD) present similar manifestations, but there are no specific pathognomonic clinical, laboratory, or histological diagnostic tests to differentiate intestinal BD from CD. We used a proteomic approach to discover a novel diagnostic biomarker specific to intestinal BD. Methods The colon mucosa tissue samples were obtained using colonoscopy-guided biopsy of the affected bowel from patients with intestinal BD or CD at the Inflammatory Bowel Disease Clinic of Severance Hospital, Seoul, Korea. Peptides from seven intestinal BD and seven CD patients were extracted and labeled using tandem mass tag (TMT) reagents. The labeled peptides were identified and quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The differentially expressed proteins were further validated using immunohistochemical (IHC) analysis with tissue samples and an ELISA test with serum samples from 20 intestinal BD and 20 CD patients. Results A total of 3,266 proteins were identified using TMT/LC-MS/MS-based proteomic quantification, including 39 candidate proteins differentially expressed between intestinal BD and CD. Beta-2 glycoprotein 1 (APOH) and maltase-glucoamylase (MGAM) showed significantly higher intensity in the IHC staining of the intestinal BD tissues than that of CD tissues. Furthermore, the serum MGAM level was significantly higher in patients with intestinal BD than in patients with CD. Conclusion Our proteomic analysis revealed that some proteins were differentially expressed in intestinal BD patients compared to CD patients. Differential MGAM expression in intestinal BD suggests its role as a potential novel diagnostic biomarker in the differentiation of intestinal BD from CD.

Proteomic analysis-based discovery of a novel biomarker that differentiates intestinal Beh\xe7et\u2019s disease from Crohn\u2019s disease

Intestinal Behçet’s disease (BD) and Crohn’s disease (CD) present similar manifestations, but there are no specific diagnostic tests to differentiate them. We used a proteomic approach to discover novel diagnostic biomarkers specific to intestinal BD. Colon mucosa tissue samples were obtained from patients with intestinal BD or CD using colonoscopy-guided biopsy of the affected bowel. Peptides from seven intestinal BD and seven CD patients were extracted and labeled using tandem mass tag (TMT) reagents. The labeled peptides were identified and quantified using liquid chromatography-tandem mass spectrometry (LC–MS/MS). The proteins were further validated using immunohistochemical (IHC) analysis with tissue samples and an ELISA test with serum samples from 20 intestinal BD and 20 CD patients. Using TMT/LC–MS/MS-based proteomic quantification, we identified 39 proteins differentially expressed between intestinal BD and CD. Beta-2 glycoprotein 1 (APOH) and maltase-glucoamylase (MGAM) showed higher intensity in the IHC staining of intestinal BD tissues than in CD tissues. The serum MGAM level was higher in intestinal BD patients. Proteomic analysis revealed that some proteins were differentially expressed in patients with intestinal BD compared with those with CD. Differential MGAM expression in intestinal BD suggests its role as a potential novel diagnostic biomarker.

Network pharmacology combined with metabolomics to study the mechanism of Shenyan Kangfu Tablets in the treatment of diabetic nephropathy

Ethnopharmacological relevanceShenyan Kangfu Tablets (SYKFT) is a traditional prescription evolved from Shenqi Pills. It has been included in the Synopsis of the Golden Chamber for more than 2000 years. SYKFT was listed as a national Chinese medicine protected class by the China Food and Drug Administration. Diabetic nephropathy (DN) is one of the serious microvascular diseases caused by diabetes and is also one of the important factors leading to the death of patients. The pathogenesis of DN is diverse and complex, and there is no particularly effective drug treatment. There is clinical evidence that SYKFT has a good therapeutic effect on DN with no obvious adverse effects, but the mechanism of treatment is not clear. Aim of the studyIn this study, network pharmacology was combined with metabolomics technology to explore the mechanism of SYKFT in the treatment of DN. Materials and methodsFirst, the research team conducted a qualitative study of the chemical components contained in SYKFT, and carried out network pharmacology to search for potential targets based on the characterized chemical components. Second, we analysed the metabolic profile of db/db mouse urine based on UHPLC-QTOF-MS technology, and biomarkers were identified by multivariate statistical analysis. Then, we performed further pathway enrichment analysis. Finally, the results of metabolomics and network pharmacology were conjointly analysed. ResultsSeventy-five chemical components of SYKFT were identified. According to the TCMSP database, the corresponding targets of the qualitatively identified components were searched, and a total of 36 potentially active components and 160 targets related to DN were obtained. A total of 38 biomarkers were found in metabolomics based on UHPLC-QTOF-MS technology. Biosynthesis of unsaturated fatty acids and starch and sucrose metabolism are the most related pathways, the former of which has been rarely reported concerning DN. Finally, the results of the joint analysis show that two targets, hexokinase 2 (HK2) and maltase glucoamylase (MGAM), are the overlapping targets. It means they are not only the related targets of pathways involved in potential biomarkers in metabolomics but also the intersection targets of diseases and drugs identified by network pharmacology. ConclusionsThe study reveals that the potential mechanism of SYKFT is most related to insulin resistance (IR) in the treatment of DN. It also proves that network pharmacology combined with metabolomics to find the mechanisms by which herbs treat complex diseases is a feasible tool.