Background: One of the therapeutic strategies for type 2 diabetes mellitus involves suppressing postprandial hyperglycemia by inhibiting key enzymes in carbohydrate digestion, α-glucosidase and α-amylase. While such inhibitors are commercially available, some researchers have turned to plants for potentially cheaper and safer alternatives. Objectives: The study aimed to investigate the in vitro α-glucosidase and α-amylase inhibitory activities of the leaf methanolic extracts of two native Philippine plants Ficus nota Blanco Merr. and Ficus septica Burm F, as well as their effects on postprandial blood glucose levels in a mouse model. Methodology: The in vitro activities of the leaf methanolic extracts were evaluated against porcine pancreatic α-amylase and yeast αglucosidase. The most active extract was partially purified into fractions by sequential solvent partitioning and subjected to in vitro testing. Postprandial antihyperglycemic activity was then assessed in normoglycemic ICR mice. Phytochemical analysis was also performed Results: The most active extract and fraction in vitro were FS-crude and FS-HexF, respectively, having significantly more potent αglucosidase inhibitory activity than the commercial drug acarbose. FS-crude and FS-HexF exhibited strong inhibition of αglucosidase and weak inhibition of α-amylase, which is considered favorable for novel inhibitors as it is hypothesized to reduce gastrointestinal adverse effects. However, FS-crude and FS-HexF did not significantly attenuate postprandial blood glucose levels in the oral starch tolerance test. Phytochemical analysis of FS-HexF putatively identified 6-gingerol as one of the possible bioactive components. Conclusion F. septica could be a potential source of glycoside inhibitors as it showed promising in vitro inhibition of α-amylase and α-glucosidase. While it did not exhibit significant postprandial antihyperglycemic activity in this study, more robust testing is recommended to make a definitive conclusion.
Amylases ; Glucosidases ; Hypoglycemic Agents

BACKGROUND: Voglibose is an alpha-glucosidase inhibitor. The purpose of this study was to evaluate the pharmacodynamic characteristics of voglibose for determining the appropriate study design and parameters for a pharmacodynamic equivalence study of voglibose. METHODS: This study consisted of two studies. The single dose study had an open and single sequence design. Nineteen subjects received placebo and then one tablet of voglibose on two consecutive days with sucrose. The multiple dose study was performed with the similar design, except that it was a multiple dose of the single dose study. Nine subjects who showed an effective response in the single dose study received placebo three times and then voglibose 4 times on two consecutive days. Serial blood samples for pharmacodynamic parameters were taken until 180 mins after each administration. The baseline adjusted maximum serum glucose level (G(max)) and area under the serum glucose level-time profiles were determined and compared. RESULTS: In the single dose study, the difference in G(max) was -10.6 +/- 28.7 mg/dL. The area under the serum glucose concentration-time curve (AUGC(0-1h)) of placebo and voglibose were 7825.0 +/- 1145.3 mg.min/dL, 7907.5 +/- 917.2 mg.min/dL, respectively. In the multiple dose study, the difference in G(max) was 46.6 +/- 16.1 mg/dL. The AUGC(0-1h) of placebo and voglibose were 8138.6 +/- 721.9 mg.min/dL and 6499.7 +/- 447.2 mg.min/dL, respectively. The G(max) and AUGC(0-1h) of the multiple dose study was significantly different between placebo and voglibose in paired t-test. CONCLUSION: The differences in G(max) and AUGC(0-1h) are suitable for pharmacodynamic parameters to evaluate bioequivalence of voglibose.
alpha-Glucosidases ; Glucose ; Inositol ; Sucrose ; Therapeutic Equivalency

Aims: The study aimed to investigate the effect of glucose on alpha-amylase and glucoamylase production in some Indonesian indigenous fungi. Methodology and results: Fungi were screened for their ability to produce alpha-amylase and glucoamylase in the presence of glucose. The strains were grown in a medium containing starch and glucose as carbon sources with glucose concentrations varying from 0 to 5% for four days, and the alpha-amylase and glucoamylase were analyzed at the end of the growth period. Most strains showed repression on the amylases production when glucose was added to the medium. However, some strains showed no repression on amylases production when glucose was supplemented to the medium. The addition of glucose repressed glucoamylase production, but no repression on alpha-amylase was noted for strain KKB4, vice versa, there was repression on alpha-amylase production but no repression on glucoamylase production for strain FIG1. Strains FNCC 6151 and MLT1J1 showed no repression on both alpha-amylase and glucoamylase production when glucose was added to the medium up to 5%. The occurrence of repression in the production of alpha-amylase and glucoamylase was strain-specific. Conclusion, significance and impact of study Out of the nine indigenous fungi strains examined, strains FNCC 6151 and MLT1J1 showed no repression on both alpha-amylase and glucoamylase production when glucose was added to the medium up to 5%. Those two strains have the potential to be improved further to produce both alpha-amylase and glucoamylase.
Glucosidases ; alpha-Amylases ; Glucan 1,4-alpha-Glucosidase

This study investigated the antioxidant activity of methanol (MeOH) and water extracts from roots of Cirsium japonicum in vitro. MeOH extract showed a stronger free radical scavenging activity than water extract. However, both of extracts showed a concentration dependent hydroxyl radical scavenging activity, reducing power and metal chelating ability. MeOH extract had greater phenolic and flavonoid contents than water extract. The antidiabetic activity of these two extracts was evaluated by the alpha-glucosidase inhibition assay. The water extract showed a considerable alpha-glucosidase inhibitory activity. To our knowledge, this may be the first time to report the antioxidant and antidiabetic activities in Cirsium japonicum roots.
alpha-Glucosidases ; Cirsium ; Hydroxyl Radical ; Methanol ; Phenol ; Water

The chemical constituents of the seeds of Moringa oleifera were isolated and purified by using Sephadex LH-20, Toyo-pearl HW-40F, silica gel, ODS, and MCI column chromatography. The structures of compounds were identified by high-resolution mass spectrometry, ~1H-NMR, ~(13)C-NMR, HMQC, HMBC, and ~1H-~1H COSY, as well as physicochemical properties of compounds and literature data. Twelve compounds were isolated from 30% ethanol fraction of the seeds of M. oleifera and identified as ethyl-4-O-α-L-rhamnosyl-α-L-rhamnoside(1), ethyl-3-O-α-L-rhamnosyl-α-L-rhamnoside(2),(4-hydroxybenzyl)ethyl carbamate(3),(4-aminophenyl)acetic acid(4), ethyl-α-L-rhamnoside(5), methyl-α-L-rhamnoside(6), moringapyranosyl(7), 2-[4-(α-L-rhamnosyl)phenyl]methyl acetate(8), niaziridin(9), 5-hydroxymethyl furfural(10), 4-hydroxybenzeneacetamide(11), and 4-hydroxybenzoic acid(12). Among them, compounds 1 and 2 are two new compounds, compound 3 is a new natural product, and compounds 4-5 were yielded from Moringa plant for the first time. All compounds were evaluated for α-glucosidase inhibitory activity in vitro. Compound 10 showed excellent inhibitory activity with IC_(50) of 210 μg·mL~(-1).
Moringa oleifera/chemistry* ; alpha-Glucosidases ; Moringa ; Seeds ; Plant Extracts/pharmacology*

Aims: This study aimed to evaluate antidiabetic potential of indigenous Lactobacillus isolates by measuring the ability of α-glucosidase inhibitory (AGI) and antioxidant activity. The mechanism of probiotics as antidiabetic can occur through the AGI and antioxidant activity of LAB, which is able to suppress oxidative stress that causes chronic inflammation and pancreatic β cell apoptosis, and then through the ability to produce exopolysaccharide (EPS) and short chain fatty acids (SCFA). Methodology and results: MRS broth enriched with 10% glucose was selected as the growth medium for Lactobacillus. The growth medium was then centrifuged to obtain CFS and CFE was produced by extracting the medium with 96% ethanol as a solvent. The results showed that Lactobacillus pentosus MK42 had the highest AGI activity of 80.32 ± 2.20%. Antioxidant activity was not significantly different (P>0.05) among the tested Lactobacillus isolates. Lactobacillus paracasei RK41 produced the highest EPS (360.13 ± 50.01 mg/L), which was not significantly different (P>0.05) from Lactobacillus plantarum1 RB210. All Lactobacillus isolates were able to produce acetic acid, but not all were able to produce propionic and butyric acid. The highest propionic acid was produced by L. plantarum1 RB210 at 0.40 ± 0.31 mmol/L and the highest butyric acid was produced by L. plantarum1 MK2 at 0.22 ± 0.08 mmol/L. Conclusion, significance and impact of study The results show definitively that indigenous Lactobacillus isolates have considerable α-glucosidase inhibitor, antioxidant activity and the ability to produce of EPS and SCFA. This preliminary study suggests the use of indigenous Lactobacillus isolates which have the potential as antidiabetic agent, although the responsible compounds are unknown.
alpha-Glucosidases ; Antioxidants ; Lactobacillus--isolation & ; purification ; Hypoglycemic Agents

The clinical data of 2 infants with infantile glycogen storage disease type II (GSD II) from one pedigree were collected. The method of dried blood spots (DBS) was applied to collect peripheral blood samples, and the activity of acid alpha-D-glucosidase (GAA) in leukocytes was measured. The coding region of GAA gene in this pedigree was amplified by polymerase chain reaction and then direct sequencing was used to analyze mutations in GAA gene. The two infants were twins, who were admitted to the hospital due to feeding difficulties, generalized muscle weakness and hypotonia, cardiomegaly, and cardiac insufficiency when they were 10 months old. The GAA activity in leukocytes in the two infants was significantly lower than in normal controls. Gene sequencing revealed 2 compound heterozygous mutations in the two infants, i.e., G1942A and G2214A, respectively. G1942A had been proved pathogenic, and the latter one, G2214A, was a nonsense mutation, resulting in the change of tryptophan, the 738th amino acid of GAA, into a stop codon. The two infants were diagnosed with GSD II by gene detection and no enzyme replacement therapy could be provided to them. Follow-up visits showed that the two infants died at home at the age of 15 months and 17 months, respectively. GSD II is caused by deficiency of GAA activity resulting from mutation of GAA gene. The detection of GAA activity in peripheral blood by DBS and GAA gene detection are effective and feasible methods for diagnosis of GSD II.
Female ; Glycogen Storage Disease Type II ; genetics ; Humans ; Infant ; Mutation ; Pedigree ; alpha-Glucosidases ; genetics

A recent report from International Diabetes Federation estimates that 366 million people have diabetes in 2011 and this will have risen to 552 million by 2030. That means one adult in 10 will have diabetes. The prevalence of diabetes among Korean adults aged 20 to 79 years in 2010 was estimated at 9.4% (3.3 million). Diabetes mellitus has thus become a social and economic burden in Korea. However, the percentage of patients to reach their target goal for glycemic control (hemoglobin A1c <7%) is only 40.3%. That indicates further effort for management of diabetic patients is needed. Current diabetic medication includes sulfonylurea, metformin, alpha-glucosidase inhibitor, thiazolidinedione and dipeptidyl peptidase-4 inhibitor as well as insulin. In this review article, we examine the clinical effects upcoming new diabetes medications and their differences from previous medications.
Adult ; Aged ; alpha-Glucosidases ; Diabetes Mellitus ; Humans ; Hyperglycemia ; Insulin ; Korea ; Metformin ; Prevalence ; Thiazolidinediones

To capture a state of the enzyme in complex with an intact substrate, we developed and adopted a novel freezing method in crystal preparation procedure. Neither the elimination of the catalytically indispensable ligands, nor mutation or modification of the active site is required. At -20 degrees C, we soaked the crystal of 6-phosphate-beta-glucosidase (Bg1A) in the liquor containing p-nitrophenyl-beta-D-glucopyranoside-6-phosphate (pNPbetaG6P). The diffraction data at 2 A resolution was collected and an intact and unambiguous electron density map of pNPbetaG6P was obtained. These results provide an effective method for the research of cryoenzymology and the intermediate state of enzyme-substrate complex in the future.
Cold Temperature ; Crystallization ; Glucosidases ; chemistry ; metabolism ; Substrate Specificity ; X-Ray Diffraction

OBJECTIVETo establish a method of determining alpha-glucosidase activity in seminal plasma by semi-automatic biochemistry analyzer.

METHODSAlpha-glucosidase activity in seminal plasma from 51 men with normal semen parameters in routine semen analysis were detected by semi-automatic biochemistry analyzer and manual glucose oxidase method, respectively. Then, the intra-assay and inter-assay coefficient variation (CV) and normal reference value were calculated. In the meanwhile, the correlation between the two methods was analyzed.

RESULTSThe intra-assay CVs of 2 seminal plasma samples with different alpha-glucosidase activity detected by semi-automatic biochemistry analyzer were 12.63% and 9.13%, and the inter-assay CVs were 10.67% and 13.49%, respectively. The normal reference value for seminal alpha-glucosidase activity detected with semi-automatic biochemistry analyzer ranged from 102.28 to 555.08 U/L. There was a significantly positive correlation between the semi-automatic biochemistry analyzer and the manual glucose oxidase method (r = 0.792, P < 0.01).

CONCLUSIONThe method of determining alpha-glucosidase activity in seminal plasma by semi-automatic biochemistry analyzer, with its simplicity, less cost of time and reagents, and more reliable result, could be applied to clinical laboratory medicine.

Adult ; Biochemistry ; instrumentation ; methods ; Humans ; Male ; Reference Values ; Reproducibility of Results ; Semen ; enzymology ; alpha-Glucosidases ; analysis ; metabolism