Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The sea urchin embryo is a model for studying cellular interactions that occur in higher organisms because of its availability, transparency, and accessibility to molecular probes. In previous studies, we found that the mannose/glucose-binding lectin Lens culinaris agglutinin entered living sea urchin embryos, bound to specific cell types and caused exogastrulation, when the developing gut (archenteron) falls out of the embryo proper. We have proposed that the lectin bound to sugar-containing ligands, thus preventing attachment of the archenteron to the blastocoel roof, resulting in exogastrulation. Here, we have continued our study of cellular interactions in this model using Lytechinus pictus sea urchin embryos, and have found that inhibitors of glycoprotein/proteoglycan synthesis, tunicamycin and sodium selenate, and the specific glycosidases, beta-amylase, alpha-glucosidase, and alpha-mannosidase, all inhibit archenteron organization, elongation, and attachment to the blastocoel roof in viable swimming embryos. We also show that single cells obtained by disaggregation of 32-h-old sea urchin embryos bind to L. culinaris agglutinin- and concanavalin A-derivatized beads; the binding is blocked by alpha-methyl mannose, but not l-fucose. These cells also bind to beads derivatized with mannan. These results provide evidence for a role of carbohydrate-containing molecules in cellular interactions in sea urchin gastrulation. In a second set of experiments, we found that the supernatant obtained by disaggregation of 24-32-h-old L. pictus embryos in calcium- and magnesium-free sea water contains molecules that cause exogastrulation, archenteron disorganization, inhibition of archenteron elongation and inhibition of archenteron attachment to the blastocoel roof in viable swimming embryos. We propose that the supernatant contains ligands and/or receptors that mediate archenteron development and attachment to the blastocoel roof and are released when embryos are disaggregated into single cells. These studies may lead to a better understanding of the molecular basis of mechanisms that control cellular interactions during development.
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PMID:Carbohydrate involvement in cellular interactions in sea urchin gastrulation. 1514 30

Diabetes has a markedly greater incidence of cardiovascular disease than the non-diabetic population. The heart shows a slowly developing increase in fibrosis in diabetes. Extended cardiac fibrosis results in increased myocardial stiffness, causing ventricular dysfunction and, ultimately, heart failure. Reversal of fibrosis may improve organ function survival. Postprandial hyperglycemia plays an important role in the development of type 2 diabetes and cardiovascular complications, and has been proposed as an independent risk factor for cardiovascular diseases. Salacia oblonga (S.O.) is traditionally used in the prevention and treatment of diabetes. We investigated the effects of its water extract on cardiac fibrosis and hyperglycemia in a genetic model of type 2 diabetes, the obese Zucker rat (OZR). Chronic administration of the extract markedly improved interstitial and perivascular fibrosis in the hearts of the OZR. It also reduced plasma glucose levels in non-fasted OZR, whereas it had little effect in the fasted animals, suggesting inhibition of postprandial hyperglycemia in type 2 diabetic animals, which might play a role in improvement of the cardiac complications of OZR. Furthermore, S.O. markedly suppressed the overexpression of mRNAs encoding transforming growth factor betas 1 and 3 in the OZR heart, which may be an important part of the overall molecular mechanisms. S.O. dose-dependently inhibited the increase of plasma glucose in sucrose-, but not in glucose-loaded mice. S.O. demonstrated a strong inhibition of alpha-glucosidase activity in vitro, which is suggested to contribute to the improvement of postprandial hyperglycemia.
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PMID:Salacia oblonga improves cardiac fibrosis and inhibits postprandial hyperglycemia in obese Zucker rats. 1526 73

The present study investigated the effects of Ginkgo biloba extract and its flavonoid fractions on alpha-amylase and alpha-glucosidase activity in vitro. Ginkgo biloba extracts and their flavonoid fraction significantly inhibited alpha-amylase and alpha-glucosidase activity in vitro. Furthermore, Ginkgo biloba extracts and their flavonoid fraction reduced the elevation of rat plasma glucose level after oral administration of various saccharinity agents. In addition, we examined the effects of the flavonoid fraction isolated from Ginkgo biloba extracts on the plasma glucose level in streptozotocin-induced diabetic rats. When flavonoid fractions were orally administered to the rats three times daily for 9 days, plasma glucose concentrations were decreased compared with those in the water treatment group. Furthermore, flavonoid fractions reduced the elevation of rat plasma glucose levels after oral administration of sucrose and glucose in streptozotocin-induced diabetic rats.
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PMID:[Effects of the flavonoid fraction from Ginkgo biloba extract on the postprandial blood glucose elevation in rats]. 1534 Jan 82

Since ages, botanical substances are in use for the remedy of diabetes with considerable degree of success. One of the such; an extract of Commelina communis L. (CE-L) after decoction in water has been traditionally used for the treatment of diabetes in Korea. However, its action mechanism has not yet been established. To explore the inside of its action-mechanism, in this study, the effect of the aqueous extract of C. communis L. (CE-L) on the activity of alpha-glucosidase was evaluated in vitro and in vivo. Aqueous extract of CE-L showed inhibitory activity of the alpha-glucosidase in a dose-dependent manner, in vitro. CE-L also seems to be by and large free from exerting any cytotoxic effect at least in CHO-K1 fibroblast and 3T3-L1 adipocyte. CE-L alleviated hyperglycemia caused by maltose or starch loading in normal and Streptozotocin (STZ)-induced diabetic mice with better efficacy than that of acarbose. In addition, prolonged administration of CE-L tends to normalize hyperglycemia in STZ-induced diabetic mice. Such results suggest that inhibitory activity of CE-L on alpha-glucosidase may contribute to delay in carbohydrate digestion and glucose absorption. Thus, CE-L has potential for use in the management of non-insulin-dependent diabetes.
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PMID:Anti-hyperglycemic activity of Commelina communis L.: inhibition of alpha-glucosidase. 1556 67

A hot water extract obtained by boiling adzuki beans (Vigna angularis) to produce bean paste for Japanese cake showed inhibitory activity against alpha-glucosidase, alpha-amylase, maltase, sucrase, and isomaltase after HP-20 column chromatography. The IC(50) values for each hydrolylase were 0.78 mg/ml (alpha-amylase), 2.45 mg/ml (maltase), 5.37 mg/ml (sucrase), and 1.75 mg/ml (isomaltase). The active fraction showed potential hypoglycemic activity in both normal mice and streptozotocin (STZ)-induced diabetic rats after an oral administration of sucrose, but did not show any effect on the blood glucose concentration after glucose administration, suggesting that the active fraction suppressed the postprandial blood glucose level by inhibiting alpha-glucosidase and alpha-amylase, irrespective of the endogenous blood insulin level.
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PMID:Suppressive effect of a hot water extract of adzuki beans (Vigna angularis) on hyperglycemia after sucrose loading in mice and diabetic rats. 1561 10

A method was developed to detect and identify Enterobacter sakazakii in environmental samples. The method is based on selective enrichment at 45+/-0.5 degrees C in lauryl sulfate tryptose broth supplemented with 0.5 M NaCl and 10 mg/liter vancomycin (mLST) for 22 to 24 h followed by streaking on tryptone soy agar with bile salts. When exposed to light during incubation at 37 degrees C, E. sakazakii produces yellow colonies within 24 h; identification was confirmed by testing for alpha-glucosidase activity and by using API 20E strips. All of the E. sakazakii strains tested (n = 99) were able to grow in mLST at 45+/-0.5 degrees C, whereas 35 of 39 strains of potential competitors, all belonging to the Enterobacteriaceae, were suppressed. A survey was carried out with 192 environmental samples from four different milk powder factories. Using this new protocol, E. sakazakii was isolated from almost 40% of the samples, whereas the reference procedure (enrichment in buffered peptone water, isolation on violet red bile glucose agar, and biochemical identification of randomly chosen colonies) only yielded 26% positive results. This selective method can be very useful for the rapid and reliable detection of E. sakazakii in environmental samples.
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PMID:A simple and rapid cultural method for detection of Enterobacter sakazakii in environmental samples. 1569 Aug 5

The 40% ethanol eluent of the fraction of hot-water extract from adzuki beans (EtEx.40) adsorbed onto DIAION HP-20 resin has many biological activities, for example, antioxidant, antitumorigenesis, and intestinal alpha-glucosidase suppressing activities. This study examined the inhibitory effect of EtEx.40 on experimental lung metastasis and the invasion of B16-BL6 melanoma cells. EtEx.40 was found significantly to reduce the number of tumor colonies. It also inhibited the adhesion and migration of B16-BL6 melanoma cells into extracellular matrix components and their invasion into reconstituted basement membrane (matrigel) without affecting cell proliferation in vitro. These in vivo data suggest that EtEx.40 possesses a strong antimetastatic ability, which might be a lead compound in functional food development.
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PMID:Potential ability of hot water adzuki (Vigna angularis) extracts to inhibit the adhesion, invasion, and metastasis of murine B16 melanoma cells. 1578 70

Long-term type 2 diabetes can lead to numerous biological complications, such as hypertension and cardio-vascular disease. Key enzymes involved in the enzymatic breakdown of complex carbohydrates,pancreatic alpha-amylase and intestinal alpha-glucosidase, have been targeted as potential avenues for modulation of type 2 diabetes-associated post-prandial hyperglycemia through mild inhibition of their enzymatic activities so as to decrease meal-derived glucose absorption. Further, inhibition of hypertension-linked angiotensin I-converting enzyme (ACE) was targeted as a potential approach for modulation of diabetes-linked hypertension. Water-soluble extracts of soybean optimized for phenolic content via sprouting or bioprocessing by dietary fungus (Rhizopus oligosporus, Lentinus edodes) were investigated for inhibitory activity against porcine pancreatic alpha-amylase (PPA), yeast alpha-glucosidase, and rabbit lung ACE in vitro. PPA was allowed to react with each phenolic-optimized extract and the derivatized enzyme-phytochemical mixtures obtained were characterized for residual amylase activity. Alpha-glucosidase and ACE activities were determined in the presence of each phenolic-optimized extract. All of the soybean extracts possessed marked anti-amylase activity, with extracts of R. oligosporus-bioprocessed soybean having the strongest inhibitory activity, but only slight anti-glucosidase activity. The anti-amylase activity of each extract seemed associated with extract antioxidant activity. Anti-enzyme activity was slightly associated with total soluble phenolic content per se, but seemed more associated to the length of sprouting or bioprocessing of the soybean substrate. Short-term sprouting or bioprocessing seemed to improve anti-amylase activity, while long-term sprouting or bioprocessing seemed to aid anti-glucosidase activity. While ACE activity was strongly inhibited by all of the soybean extracts (44-97%), only sprouting was found to increase this inhibition and bioprocessing of soybean with L. edodes decreased inhibitory activity of soybean extract. The results suggest that sprouting and dietary fungal bioprocessing of soybean improve the anti-diabetic potential of soybean extracts, potentially through modulation of the phenolic profile of the extract, and further suggest that enzyme inhibitory activity may be linked to phenolic antioxidant mobilization during spouting and/ or bioprocessing. The significance of food-grade, plant-based enzyme inhibitors for modulation of carbohydrate breakdown and control of glycemic index of foods in the context of preventing hyperglycemia and diabetes mellitus complications such as hypertension in the long-term is hypothesized and discussed.
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PMID:Anti-diabetic and anti-hypertensive potential of sprouted and solid-state bioprocessed soybean. 1592 31

Hydroquinone-alpha-glucoside was synthesised from hydroquinone and maltose as glucosyl donor by transglucosylation in a water system with alpha-glucosidase from baker's yeast. Only one phenolic -OH group was alpha-anomer-selectively glucosylated. The optimum conditions for transglucosylation reaction were at 30 degrees C for 20 h with 50 mM: hydroquinone and 1.5 M: maltose in 100 mM: sodium citrate/phosphate buffer at pH 5.5. The glucoside was obtained at 0.6 mg/ml with a 4.6% molar yield with respect to hydroquinone.
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PMID:Synthesis of hydroquinone-alpha-glucoside by alpha-glucosidase from baker's yeast. 1597 88

We tested whether seasonal changes in the sources of organic substances for microbial metabolism were reflected changes in the activities of five extracellular enzymes in the eighth order lowland River Elbe, Germany. Leucine aminopeptidase showed the highest activities in the water column and the sediments, followed by phosphatase > beta-glucosidase > alpha-glucosidase > exo-1,4-beta-glucanase. Individual enzymes exhibited characteristic seasonal dynamics, as indicated by their relative contribution to cumulative enzyme activity. Leucine aminopeptidase was significantly more active in spring and summer. In contrast, the carbohydrate-degrading enzymes peaked in autumn, and beta-glucosidase activity peaked once again in winter. Thus, in sediments, the ratio of leucine aminopeptidase/beta-glucosidase reached significant higher medians in spring and summer (5-cm depth: ratio 7.7; 20-cm depth: ratio 10.1) than in autumn and winter (5-cm depth: ratio 3.7, 20-cm depth: ratio 6.3). The relative activity of phosphatase in the sediments was seasonally related to both the biomass of planktonic algae as well as to the high content of total particulate phosphorus in autumn and winter. Due to temporal shifts in organic matter supply and changes in the storage capacity of sediments, the seasonal peaks of enzyme activities in sediments exhibited a time lag of 2-3 months compared to that in the water column, along with a significant extension of peak width. Hence, our data show that the seasonal pattern of extracellular enzyme activities provides a sensitive approach to infer seasonal or temporary availability of organic matter in rivers from autochthonous and allochthonous sources. From the dynamics of individual enzyme activities, a consistent synoptic pattern of heterotrophic functioning in the studied river ecosystem could be derived. Our data support the revised riverine productivity model predicting that the metabolism of organic matter in high-order rivers is mainly fuelled by autochthonous production occurring in these reaches and riparian inputs.
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PMID:Regulation and seasonal dynamics of extracellular enzyme activities in the sediments of a large lowland river. 1620 47


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