Since the discovery of α-glucosidase inhibitors and their inhibitory effects on the digestion of carbohydrates, promising results have been obtained as to the antidiabetic effects of this family of compounds. Antiangiogenic compounds have been identified that suppress tumor growth via a unique mechanism, confirming that such compounds can act as clinically applicable anticancer agents. Lipid peroxidation and lipid glycation have been suggested to play roles in food deterioration and in the pathophysiology of human diseases such as atherogenesis and diabetes, and antioxidative and antiglycative compounds can potentially be used in the prevention of food deterioration as well as to treat disease. On this basis, this review describes studies of α-glucosidase inhibition by mulberry 1-deoxynojirimycin, antiangiogenic effects of rice bran tocotrienol, and membrane lipid peroxidation/glycation and its inhibitors. These studies are ongoing in our work, with an emphasis on analytical techniques.

Objective Although the major cause of morbidity and mortality in patients with diabetes mellitus (DM) is cardiovascular disease, DM is also associated with certain site-specific cancers. However, whether DM is associated with an increased risk of cancer of the digestive tract remains undetermined. A nationwide, population-based database in Taiwan was analyzed to explore the relationship between DM and cancer of the digestive organs. Methods From 2000 to 2007, a study cohort consisting of 39,515 patients with newly diagnosed diabetes without a previous diagnosis of gastrointestinal (GI) cancer was identified from the National Health Insurance Research Database in Taiwan. A control cohort of 79,030 age- and sex-matched non-diabetic subjects was selected to compare the occurrence of GI malignancies between the two groups. The association between the incidence of GI cancers and the use of glucose-lowering therapies was also investigated. Results During the 7-year follow-up period, GI cancers developed in 929 diabetic patients (2.35%) and 1,126 subjects (1.42%) in the comparison cohort. DM was associated with a 2.75-fold (95% confidence interval (CI), 2.51-3.02) higher risk of developing GI malignancy. Among GI cancers, the incidences of stomach (adjusted hazard ratio (HR), 1.49; 95% CI, 1.16-1.92), liver (adjusted HR, 2.65; 95% CI, 2.29-3.07), colon (adjusted HR, 1.58; 95% CI, 1.28-1.94) and pancreatic cancers (adjusted HR, 4.35; 95% CI, 2.93-6.47) were significantly increased in the patients with DM. An analysis of the effects of various glucose-lowering therapies in the diabetic patients revealed the use of α-glucosidase inhibitors to be associated with a lower risk of hepatic cancer (adjusted HR, 0.62; 95% CI, 0.4-0.94). Thiazolidinedione (TZD) treatment was associated with lower stomach (adjusted HR, 0.11; 95% CI, 0.02-0.82) and hepatic cancer risks (adjusted HR, 0.46; 95% CI, 0.29-0.73), while sulfonylurea use was associated with a lower colon cancer risk (adjusted HR, 0.74; 95% CI, 0.51-1.09) and a higher pancreatic cancer risk (adjusted HR, 2.36; 95% CI, 1.21-4.61). Conclusion Patients with DM have an increased risk of GI malignancy that may be affected by the use of different categories of glucose-lowering therapies.

Type 2 diabetes mellitus (T2DM) is a growing health problem worldwide. Whether sulphonylureas show better, equal or worse therapeutic effects in comparison with other antidiabetic interventions for patients with T2DM remains controversial.To assess the effects of sulphonylurea monotherapy versus placebo, no intervention or other antidiabetic interventions for patients with T2DM.We searched publications in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, LILACS and CINAHL (all until August 2011) to obtain trials fulfilling the inclusion criteria for our review.We included clinical trials that randomised patients 18 years old or more with T2DM to sulphonylurea monotherapy with a duration of 24 weeks or more.Two authors independently assessed the risk of bias. The primary outcomes were all-cause and cardiovascular mortality. Secondary outcomes were other patient-important outcomes and metabolic variables. Where possible, we used risk ratios (RR) with 95% confidence intervals (95% CI) to analyse the treatment effect of dichotomous outcomes. We used mean differences with 95% CI to analyse the treatment effect of continuous outcomes. We evaluated the risk of bias. We conducted trial sequential analyses to assess whether firm evidence could be established for a 10% relative risk reduction (RRR) between intervention groups.We included 72 randomised controlled trials (RCTs) with 22,589 participants; 9707 participants randomised to sulphonylureas versus 12,805 participants randomised to control interventions. The duration of the interventions varied from 24 weeks to 10.7 years. We judged none of the included trials as low risk of bias for all bias domains. Patient-important outcomes were seldom reported.First-generation sulphonylureas (FGS) versus placebo or insulin did not show statistical significance for all-cause mortality (versus placebo: RR 1.46, 95% CI 0.87 to 2.45; P = 0.15; 2 trials; 553 participants; high risk of bias (HRB); versus insulin: RR 1.18, 95% CI 0.88 to 1.59; P = 0.26; 2 trials; 1944 participants; HRB). FGS versus placebo showed statistical significance for cardiovascular mortality in favour of placebo (RR 2.63, 95% CI 1.32 to 5.22; P = 0.006; 2 trials; 553 participants; HRB). FGS versus insulin did not show statistical significance for cardiovascular mortality (RR 1.36, 95% CI 0.68 to 2.71; P = 0.39; 2 trials; 1944 participants; HRB). FGS versus alpha-glucosidase inhibitors showed statistical significance in favour of FGS for adverse events (RR 0.63, 95% CI 0.52 to 0.76; P = 0.01; 2 trials; 246 participants; HRB) and for drop-outs due to adverse events (RR 0.28, 95% CI 0.12 to 0.67; P = 0.004; 2 trials; 246 participants; HRB).Second-generation sulphonylureas (SGS) versus metformin (RR 0.98, 95% CI 0.61 to 1.58; P = 0.68; 6 trials; 3528 participants; HRB), thiazolidinediones (RR 0.92, 95% CI 0.60 to 1.41; P = 0.70; 7 trials; 4955 participants; HRB), insulin (RR 0.96, 95% CI 0.79 to 1.18; P = 0.72; 4 trials; 1642 participants; HRB), meglitinides (RR 1.44, 95% CI 0.47 to 4.42; P = 0.52; 7 trials; 2038 participants; HRB), or incretin-based interventions (RR 1.39, 95% CI 0.52 to 3.68; P = 0.51; 2 trials; 1503 participants; HRB) showed no statistically significant effects regarding all-cause mortality in a random-effects model. SGS versus metformin (RR 1.47; 95% CI 0.54 to 4.01; P = 0.45; 6 trials; 3528 participants; HRB), thiazolidinediones (RR 1.30, 95% CI 0.55 to 3.07; P = 0.55; 7 trials; 4955 participants; HRB), insulin (RR 0.96, 95% CI 0.73 to 1.28; P = 0.80; 4 trials; 1642 participants; HRB) or meglitinide (RR 0.97, 95% CI 0.27 to 3.53; P = 0.97; 7 trials, 2038 participants, HRB) showed no statistically significant effects regarding cardiovascular mortality. Mortality data for the SGS versus placebo were sparse. SGS versus thiazolidinediones and meglitinides did not show statistically significant differences for a composite of non-fatal macrovascular outcomes. SGS versus metformin showed statistical significance in favour of SGS for a composite of non-fatal macrovascular outcomes (RR 0.67, 95% CI 0.48 to 0.93; P = 0.02; 3018 participants; 3 trials; HRB). The definition of non-fatal macrovascular outcomes varied among the trials. SGS versus metformin, thiazolidinediones and meglitinides showed no statistical significance for non-fatal myocardial infarction. No meta-analyses could be performed for microvascular outcomes. SGS versus placebo, metformin, thiazolidinediones, alpha-glucosidase inhibitors or meglitinides showed no statistical significance for adverse events. SGS versus alpha-glucosidase inhibitors showed statistical significance in favour of SGS for drop-outs due to adverse events (RR 0.48, 95% CI 0.24 to 0.96; P = 0.04; 9 trials; 870 participants; HRB). SGS versus meglitinides showed no statistical significance for the risk of severe hypoglycaemia. SGS versus metformin and thiazolidinediones showed statistical significance in favour of metformin (RR 5.64, 95% CI 1.22 to 26.00; P = 0.03; 4 trials; 3637 participants; HRB) and thiazolidinediones (RR 6.11, 95% CI 1.57 to 23.79; P = 0.009; 6 trials; 5660 participants; HRB) for severe hypoglycaemia.Third-generation sulphonylureas (TGS) could not be included in any meta-analysis of all-cause mortality, cardiovascular mortality or non-fatal macro- or microvascular outcomes. TGS versus thiazolidinediones showed statistical significance regarding adverse events in favour of TGS (RR 0.88, 95% CI 0.78 to 0.99; P = 0.03; 3 trials; 510 participants; HRB). TGS versus thiazolidinediones did not show any statistical significance for drop-outs due to adverse events. TGS versus other comparators could not be performed due to lack of data.For the comparison of SGS versus FGS no meta-analyses of all-cause mortality, cardiovascular mortality, non-fatal macro- or microvascular outcomes, or adverse events could be performed.Health-related quality of life and costs of intervention could not be meta-analysed due to lack of data.In trial sequential analysis, none of the analyses of mortality outcomes, vascular outcomes or severe hypoglycaemia met the criteria for firm evidence of a RRR of 10% between interventions.There is insufficient evidence from RCTs to support the decision as to whether to initiate sulphonylurea monotherapy. Data on patient-important outcomes are lacking. Therefore, large-scale and long-term randomised clinical trials with low risk of bias, focusing on patient-important outcomes are required.

Introduction: The purpose of this study was to explore whether diabetes mellitus (DM) correlates with the risk of kidney cancer in Taiwan. Materials and

Methods:

We designed a population-based case-control study from the Taiwan National Health Insurance Database, which consisted of 116 patients with newly diagnosed kidney cancer as cases and 464 subjects without kidney cancer as controls in 2000 to 2009. Both cases and controls were aged ≥20 years. Baseline comorbidities were compared between kidney cancer cases and controls.

Results:

Multivariable analysis showed no association was detected between DM and kidney cancer (OR 1.06, 95% CI, 0.58 to 1.94). Hypertension (OR 2.05, 95% CI, 1.23 to 3.42), chronic kidney diseases (OR 2.57, 95% CI, 1.23 to 5.37), cystic kidney diseases (OR 18.6, 95% CI, 1.84 to 187.6) and kidney stones (OR 4.02, 95% CI, 2.43 to 6.66) were significant comorbidities associated with increased risk of kidney cancer. Use of alpha-glucosidase inhibitor was associated with increased risk of kidney cancer (OR 4.31, 95% CI, 1.07 to 17.3).

Conclusion:

DM does not correlate with the risk of kidney cancer. Hypertension, chronic kidney diseases, cystic kidney diseases, kidney stones and use of alpha-glucosidase inhibitors are associated with kidney cancer.

Objective:

We investigated the effect of addition of alogliptin, while continuing the α-glucosidase inhibitor (αGI) administration at the same or reduced dose, or discontinuing the drug, on the glycemic control in type 2 diabetic patients showing inadequate response to αGI treatment. Research design and methods: A prospective, randomized, controlled, multicenter interventional study trial. Subjects were randomly assigned to treatment with alogliptin alone (Intake 0 group), or alogliptin in addition to an αGI administered once-/twice-/thrice-daily (Intake 1, 2 and 3 groups).

Main outcome measures:

Changes in glycemic control were measured.

Results:

The HbA1c and glycoalbumin levels at 1 and 3 months were significantly lower than the values at the baseline in the Intake 1, 2 and 3 groups, but not the Intake 0 group. The body weight at 3 months was significantly lower than that at the baseline in the Intake 3 group. There were no significant differences in the degree of satisfaction or participating volition recorded, before and after the start of the study treatments.

Conclusions:

Addition of alogliptin to once-/twice-daily administration of an αGI may be effective for obtaining improved glycemic control, without lowering the treatment satisfaction level, in type 2 diabetic patients.

Deoxynojirimycin (DNJ) based imino sugars display antiviral activity in the tissue culture surrogate model of Hepatitis C (HCV), bovine viral diarrhoea virus (BVDV), mediated by inhibition of ER α-glucosidases. Here, the antiviral activities of neoglycoconjugates derived from deoxynojirimycin, and a novel compound derived from deoxygalactonojirimycin, by click chemistry with functionalised adamantanes are presented. Their antiviral potency, in terms of both viral infectivity and virion secretion, with respect to their effect on α-glucosidase inhibition, are reported. The distinct correlation between the ability of long alkyl chain derivatives to inhibit ER α-glucosidases and their anti-viral effect is demonstrated. Increasing alkyl linker length between DNJ and triazole groups increases α-glucosidase inhibition and reduces the production of viral progeny RNA and the maturation of the envelope polypeptide. Disruption to viral glycoprotein processing, with increased glucosylation on BVDV E2 species, is representative of α-glucosidase inhibition, whilst derivatives with longer alkyl linkers also show a further decrease in infectivity of secreted virions, an effect proposed to be distinct from α-glucosidase inhibition.

Host cellular endoplasmic reticulum α-glucosidases I and II are essential for the maturation of viral glycosylated envelope proteins that use the calnexin mediated folding pathway. Inhibition of these glycan processing enzymes leads to the misfolding and degradation of these viral glycoproteins and subsequent reduction in virion secretion. We previously reported that, CM-10-18, an imino sugar α-glucosidase inhibitor, efficiently protected the lethality of dengue virus infection of mice. In the current study, through an extensive structure-activity relationship study, we have identified three CM-10-18 derivatives that demonstrated superior in vitro antiviral activity against representative viruses from four viral families causing hemorrhagic fever. Moreover, the three novel imino sugars significantly reduced the mortality of two of the most pathogenic hemorrhagic fever viruses, Marburg virus and Ebola virus, in mice. Our study thus proves the concept that imino sugars are promising drug candidates for the management of viral hemorrhagic fever caused by variety of viruses.

AIMS:

To evaluate the long-term safety and efficacy of linagliptin as add-on therapy to one approved oral antidiabetic drug (OAD) in Japanese patients with type 2 diabetes mellitus and insufficient glycaemic control.

METHODS:

This 52-week, multicentre, open-label, parallel-group study evaluated once-daily linagliptin 5 mg as add-on therapy to one OAD [biguanide, glinide, glitazone, sulphonylurea (SU) or α-glucosidase inhibitors (A-GI)] in 618 patients. After a 2-week run-in, patients on SU or A-GI were randomized to either linagliptin (once daily, 5 mg) or metformin (twice or thrice daily, up to 2250 mg/day) as add-on therapy. Patients receiving the other OADs received linagliptin add-on therapy (non-randomized).

RESULTS:

Adverse events were mostly mild or moderate, and rates were similar across all groups. Hypoglycaemic events were rare, except in the SU group. Overall, 26 (5.8%) hypoglycaemic events were reported in patients receiving linagliptin (non-randomized). Hypoglycaemic events were similar for linagliptin and metformin added to A-GI (1/61 vs. 2/61, respectively) or SU (17/124 vs. 10/63, respectively). Significant reductions in glycated haemoglobin (HbA1c) levels (between -0.7 and -0.9%) occurred throughout the study period for the background therapy groups that received linagliptin (baseline HbA1c 7.9-8.1%). The decline in HbA1c levels was indistinguishable between linagliptin and metformin groups when administered as add-on therapy to A-GI or SU.

CONCLUSIONS:

Once-daily linagliptin showed safety and tolerability over 1 year and provided effective add-on therapy leading to significant HbA1c reductions, similar to metformin, over 52 weeks in Japanese patients.

Processing α-glucosidase I (GluI) is a key member of the eukaryotic N-glycosylation processing pathway, selectively catalyzing the first glycoprotein trimming step in the endoplasmic reticulum. Inhibition of GluI activity impacts the infectivity of enveloped viruses; however, despite interest in this protein from a structural, enzymatic, and therapeutic standpoint, little is known about its structure and enzymatic mechanism in catalysis of the unique glycan substrate Glc3Man9GlcNAc2. The first structural model of eukaryotic GluI is here presented at 2-Å resolution. Two catalytic residues are proposed, mutations of which result in catalytically inactive, properly folded protein. Using Autodocking methods with the known substrate and inhibitors as ligands, including a novel inhibitor characterized in this work, the active site of GluI was mapped. From these results, a model of substrate binding has been formulated, which is most likely conserved in mammalian GluI.

SCOPE:

Berries are an excellent source of dietary flavonoids which have several health benefits.

METHODS AND RESULTS:

We evaluated well-characterized anthocyanins (ANCs) and proanthocyanidins (PACs) from fermented blueberry-blackberry beverages. Wines were produced from highbush blueberries and blackberries grown in Illinois and blended to create ratios ranging from 100% blueberry to 100% blackberry. Total ANCs of the wine were strongly correlated to total phenolics (r = 0.99, p < 0.05) and to antioxidant capacity (r = 0.77, p < 0.05). ANC- and PAC-enriched fractions were purified from each wine blend and a phenolic profile was generated. ANCs increased with more blackberries from 1114 to 1550 mg cyanidin-3-O-glucoside (C3G) equivalents/L. Hydrolysable tannins were identified in the PAC-enriched fraction. Both ANC- and PAC-enriched fractions inhibited starch-degrading enzyme α-glucosidase and dipeptidyl peptidase-IV activity. Computational docking demonstrated that delphinidin-3-arabinoside effectively inactivated dipeptidyl peptidase-IV by binding with the lowest interaction energy (-3228 kcal/mol). ANC and PAC (100 μM C3G and epicatechin equivalents, respectively) from blueberry-blackberry blends reduced LPS-induced inflammatory response in mouse macrophages via the nuclear factor kappa B-mediated pathway.

CONCLUSION:

ANC- and PAC- (including hydrolysable tannins in blackberry) enriched fractions from blueberry and blackberry fermented beverages are beneficial sources of antioxidants, inhibitors of carbohydrate-utilizing enzymes, and potential inhibitors of inflammation.