Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.20 (alpha-glucosidase)
4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hypolactasia associated with severe iron-deficiency anemia has been reported in several studies. The objective of the present study was to determine whether hypolactasia is associated with the degree and duration of iron-deficiency anemia. Newly weaned male Wistar rats were divided into a control group receiving a diet supplemented with iron (C) and an experimental group (E) receiving a diet not supplemented with iron (iron-deficiency diet). The animals were studied on the 3rd, 5th, 7th, 14th, 21st, 28th and 35th days of the experiment, when overall and iron nutritional status and disaccharidase activity in the small intestine were determined by the Dahlqvist method. A reduction in weight occurred in the anemic animals starting on the 5th day of the study. Anemia was present in the experimental animals, with a progressive worsening up to the 14th day (hemoglobin: C = 13.27 and E = 5.37) and stabilizing thereafter. Saccharase and maltase activities did not differ significantly between groups, whereas lactase showed a significant reduction in total (TA) and specific activity (SA) in the anemic animals starting on the 21st day of the study. Median lactase TA for the C and E groups was 2.27 and 1.25 U on the 21st day, 2.87 and 1. 88 U on the 28th day, and 4.20 and 1.59 U on the 35th day, respectively. Median lactase SA was 0.31 and 0.20 U/g wet weight on the 21st day, 0.39 and 0.24 U/g wet weight on the 28th day, and 0.42 and 0.23 U/g wet weight on the 35th day, respectively. These findings suggest a relationship between the enzymatic alterations observed and both the degree and duration of the anemic process. Analysis of other studies on intestinal disaccharidases in anemia suggests that the mechanism of these changes may be functional, i.e., that the enterocytes may suffer a reduction in their ability to synthesize these enzymes.
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PMID:Relation of the disaccharidases in the small intestine of the rat to the degree of experimentally induced iron-deficiency anemia. 1077 85

We sought to determine whether a single reduction of hyperglycemia and those derivatives from nonenzymatic protein glycosylation may be effective in reducing the development of diabetic endothelial dysfunction. Therefore, we investigated how acarbose, an inhibitor of intestinal alpha-glucosidase that reduce hyperglycemia by lowering glucose absorption, may prevent the impairment of acetylcholine (ACh)-induced endothelium-dependent relaxations observed in isolated vascular segments from untreated streptozotocin-induced diabetic rats. When administered after diabetes induction, 10 mg/kg acarbose decreased modestly the enhancement of blood glucose and glycosylated hemoglobin (HbA1c) levels, but not those of advanced glycosylation end products (AGEs). This effect was linked to a partial improvement of ACh-induced responses both in conductance vessels, such as aortic segments, and resistance vasculature, like mesenteric microvessels. When acarbose was introduced after 6 weeks of untreated diabetes, blood glucose, HbA1c, and AGE levels were not affected and endothelial dysfunction remained unchanged in mesenteric microvessels, whereas a small improvement was observed in aortic segments. The addition of 100 U/ml superoxide dismutase enhanced the impaired relaxations to values similar to vessels from nondiabetic rats, indicating a main role for superoxide anions in diabetes-induced endothelial dysfunction. We conclude that hyperglycemia itself or elevated HbA1c, but not plasma AGEs, are related to enhanced oxidative stress and to the impairment of endothelium function associated to diabetes. This process can be partially prevented by reducing glucose absorption with acarbose.
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PMID:Treatment with acarbose may improve endothelial dysfunction in streptozotocin-induced diabetic rats. 1094 69

The effect of hyperglycemia and insulin deficiency on the plasma level of lysosomal glycohydrolases, namely N-acetyl-beta-D-glucosaminidase, beta-D-glucuronidase, alpha-D-galactosidase, and alpha-D-glucosidase, was investigated. Two patient groups were assessed: (1) 28 children with type 1 diabetes at onset (fasting blood glucose, 444+/-154 mg/100 mL; hemoglobin A1c, 11.9%+/-2.4%; symptom duration, 15.9+/-8 days; and absence of complications), (2) 14 adult subjects undergoing an intravenous glucose tolerance test (IVGTT), consisting of 8 non-obese subjects (body mass index, 26+/-0.04 kg/m2; fasting blood glucose, 82+/-13 mg/100 mL; blood insulin, 6+/-0.04 mU/L) and 6 obese subjects (fasting blood glucose, 97+/-3.5 mg/100 mL; blood insulin, 27+/-6 mU/L, with normal oral glucose tolerance test). Enzyme activity was determined with the fluorimetric method. The mean level of all evaluated enzymes was significantly increased in patients with type 1 diabetes at diagnosis compared with normal controls. Increased enzyme levels were also detected in the group of adults undergoing an IVGTT in whom hyperglycemia was accompanied by insulin resistance (ie, obese subjects). Glycohydrolase abnormalities appear to be related to insulin deficiency rather than hyperglycemia. Lysosomal apparatus abnormalities seem to be an inherent feature of diabetes that is present at disease onset. The possible role of insulin in the regulation of plasma glycohydrolase levels is discussed.
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PMID:Plasma glycohydrolase levels in patients with type 1 diabetes at onset and in subjects undergoing an intravenous glucose tolerance test. 1107 28

Water soluble extract of Rhizoma Polygonati Odorati (RPO) was studied for its hypoglycemic effect in diabetic mice and rats. Results showed that RPO significantly lowered hyperglycemia caused by starch loading in both normal and diabetic mice. Four week's administration with RPO reduced fasting blood glucose, decreased glycosylated hemoglobin (GHb), and improved the glucose tolerance in diabetic mice. In diabetic rats complicated with hyperlipemia, RPO prevented and reduced both hyperglycemia and hypertriglyceridemia. The results support the view that RPO may influence glucose or carbohydrate metabolism of diabetic animals in many ways including inhibiting the activity of alpha-glucosidase in digestive canal, and improving the metabolism of glucose and triglyceride.
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PMID:Hypoglycemic effects of aqueous extract of Rhizoma Polygonati Odorati in mice and rats. 1127 22

Water-extracted Touchi, a traditional Chinese food, exerts a strong inhibitory activity against rat intestinal alpha-glucosidase in foodstuffs, and Touchi-extract (TE) has been shown to have an antihyperglycemic effect in rats and humans after a single oral administration. In the present complementary study, the effects of powdered Houji-tea with or without (placebo) TE, a formula designed to enhance good compliance, were monitored in a 3-mo double-blind randomized group comparison study with placebo controls in humans with borderline and mild type-2 diabetes (n = 36). All subjects ingested Houji-tea with or without 0.3 g of TE before each of three meals per day for 3 mo. In the TE group, initial fasting blood glucose (6.9 +/- 0.1 mmol/L) and glycated hemoglobin (HbA(1c); 6.1 +/- 0.1%) levels gradually decreased; fasting blood glucose decreased significantly after 3 mo (6.4 +/- 0.3 mmol/L; P < 0.05) as did HbA(1c) (5.6 +/- 0.2%; P < 0.01) levels at 2 mo postingestion of TE and thereafter. In contrast, fasting blood glucose and HbA(1c) levels did not change in the placebo group. In this study, other biochemical variables were not affected in any of the subjects, and no one complained of any side effects or abdominal distension. Moreover, there was no deterioration as assessed by fasting blood glucose and HbA(1c) levels after withdrawal of TE ingestion. Thus, the alpha-glucosidase inhibitory TE demonstrated an antihyperglycemic effect and may prove useful for improving glycemic control in subjects suffering from borderline and type-2 diabetes mellitus.
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PMID:Long-term ingestion of a fermented soybean-derived Touchi-extract with alpha-glucosidase inhibitory activity is safe and effective in humans with borderline and mild type-2 diabetes. 1148 2

The role of postprandial hyperglycemia in the etiology of diabetes-related complications and outcomes, although still being elucidated, is greater than previously thought. Acute glucose elevations after meal ingestion are associated with a variety of glucose-mediated tissue defects-oxidative stress, glycation, and advanced glycation end product formation-which have far-reaching structural and functional consequences for virtually every human organ system. Lowering glycosylated hemoglobin to levels that prevent or delay these complications can be achieved only by reducing both postprandial and fasting plasma glucose levels. The alpha-glucosidase inhibitors (acarbose, voglibose, miglitol) have been effective in delaying the digestion and absorption of carbohydrates, thus diminishing the postprandial surge in blood glucose levels without loss of calories. However, greater emphasis needs to be placed on the measurement of postprandial glycemia, so that readings can be used to guide treatment.
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PMID:Pathophysiologic mechanisms of postprandial hyperglycemia. 1157 19

The aim of this study was to investigate whether combination therapy of alpha-glucosidase inhibitor and a sulfonylurea (SU) drug can prolong the duration of good glycemic control compared with SU alone in patients with type 2 diabetes. The open prospective study included 124 Japanese patients with type 2 diabetes and inadequate glycemic control (hemoglobin A(1c) [HbA(1c)] gt; 7.0%). Patients were given either voglibose plus a SU compound (glibenclamide or gliclazide, n = 61) or SU drug alone (n = 63). The first 6-month run-in period (targeted to HbA(1c) </= 7.0%) was followed by treatment for 3 years. The endpoint was deterioration of glycemic control (HbA(1c) >/= 8.0%). Fifty patients on combination therapy and 48 patients on SU alone completed the trial. During the follow-up, 21 patients on combination therapy and 30 patients on SU alone showed deterioration of glycemic control and reached the endpoint (P =.04). The combination therapy significantly prolonged the duration of good glycemic control (HbA(1c) < 8.0%) compared with SU alone by Kaplan-Meier estimated survival analysis using a log-rank test (P =.02). Thus, combination therapy with voglibose and a SU agent prolongs the duration of good glycemic control compared with SU alone in patients with type 2 diabetes.
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PMID:Combination therapy of alpha-glucosidase inhibitor and a sulfonylurea compound prolongs the duration of good glycemic control. 1248 66

Chloroform extracts of the bark of Quassia amara in different dilutions was used to assess its impact on the male reproductive system of albino rats. Single daily intramuscular injections of the extract for 15 days resulted in a significant reduction in the weight of testis and epididymis but not that of the seminal vesicles and prostate (all lobes). A marked decrease in the sperm count, motility, viability was also observed in sperm collected from the cauda epididymis of treated animals. A number of abnormalities like double heads, double tails, detached heads and fragile tails were frequently seen. Epididymal alpha-glucosidase activity was drastically reduced. However, prostatic acid phosphatase activity and citric acid levels and seminal vesicle fructose concentrations remained unchanged following treatment. Thus, it appears that the prime site of action is at the level of both the testis and the epididymis. Examination of the blood showed that cell counts and hemoglobin levels were in the normal range. Bilirubin, SGPT, SGOT, protein and urea were also not altered by the herbal extract. From the selective action on the male reproductive tract we suggest that the chloroform extract of the bark of Quassia amara has potential for use as an antifertility agent.
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PMID:A comprehensive evaluation of the reproductive toxicity of Quassia amara in male rats. 1250 57

There was an ionic interaction between acidic polysaccharides (APS) and proteins at the pH range in which APS were negatively charged and proteins were positively charged, and in enzymes the interaction was detected as a change in the enzyme activity. At pH 4.7, acid phosphatase (pI, 5.4), alpha-glucosidase (pI, 5.7), and beta-glucosidase (pI, 7.3) were inhibited by APS to various extents. On the other hand, alpha-glucosidase and alkaline phosphatase (pI, 4.5) were not inhibited by APS at pH 6.8 and 9.8, respectively, most of these two enzymes being negatively charged at the respective pHs. Sulfated polysaccharides combined with hemoglobin (pI, 6.8 to approximately 7.0) by an ionic bond at pH 2 to make hemoglobin unsusceptible to proteolysis by pepsin, but polyuronides which were not charged at this pH did not affect hydrolysis of hemoglobin.
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PMID:Interaction between acidic polysaccharides and proteins. 1295 27

Measurement of glycosylated hemoglobin (HbA1c) remains the gold standard for the assessment of glycemic control in patients with type 2 diabetes. Recent investigations have studied the correlations between HbA1c levels and other aspects of glucose metabolism, specifically, postprandial glucose (PPG) and fasting plasma glucose (FPG). The results suggest that PPG is also important to overall glycemic control and may be a better index of glucose regulation than FPG. Further, elevated PPG values have been associated with cardiovascular complications and cardiovascular mortality. Such evidence has led to recommendations that PPG levels be monitored as part of type 2 diabetes management, in addition to HbA1c and FPG. These glycemic parameters are differentially affected by the various classes of oral antidiabetic agents used in the treatment of type 2 diabetes--sulfonylureas, meglitinides, insulin sensitizers and alpha-glucosidase inhibitors. The sulfonylureas, for example, lower HbA1c, PPG and FPG, while the meglitinides have virtually no effect on FPG. The insulin sensitizer metformin, on the other hand, does not affect PPG levels, whereas the alpha-glucosidase inhibitors, in the presence of a high-carbohydrate diet, can effectively lower PPG. Many patients receive combination therapy, thereby benefiting from multiple mechanisms of glucose control, although in most cases insulin must later be added to the regimen in order to effectively suppress FPG. Thus, all aspects of glucose metabolism appear to be clinically relevant and should be monitored for effective diabetes management. Further study will more precisely define the clinical significance of PPG.
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PMID:Clinical significance of targeting postprandial and fasting hyperglycemia in managing type 2 diabetes mellitus. 1460 87


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