The effect of luseogliflozin and alpha-glucosidase inhibitor on heart failure with preserved ejection fraction in diabetic patients: rationale and design of the MUSCAT-HF randomised controlled trial

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is a strong risk factor for coronary artery disease and heart failure, particularly heart failure with preserved ejection fraction (HFpEF). The aim of the ongoing MUSCAT-HF (It stands for Prospective Comparison of Luseogliflozin and Alpha-glucosidase on the Management of Diabetic Patients with Chronic Heart Failure and Preserved Ejection Fraction) trial is to evaluate the efficacy of luseogliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, versus voglibose, an alpha-glucosidase inhibitor, using brain natriuretic peptide (BNP) as the index of therapeutic effect in T2DM patients with HFpEF.

METHODS AND ANALYSIS

A total of 190 patients with T2DM and HFpEF (ejection fraction >45%) who are drug-naïve or taking any anti-diabetic agents will be randomised (1:1) to receive luseogliflozin 2.5 mg one time per day or voglibose 0.2 mg three times per day. The patients will be stratified by age (<65 years, ≥65 years), baseline haemoglobin A1c (<8.0%, ≥8.0%), baseline BNP (<100 pg/mL, ≥100 pg/mL), baseline renal function (estimated glomerular filtration rate ≥60 mL/min/1.73 m², <60 mL/min/1.73 m²), use of thiazolidine or not and presence or absence of atrial fibrillation and flutter at screening. After randomisation, participants will receive the study drug for 12 weeks in addition to their background therapy. The primary endpoint is the proportional change in baseline BNP after 12 weeks of treatment. The key secondary endpoints are the change from baseline in the ratio of early mitral inflow velocity to mitral annular early diastolic velocity, body weight and glycaemic control after 12 weeks of treatment.

ETHICS AND DISSEMINATION

The study has been approved by the ethics committee and the patients will be included after informed consent. The results will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

UMIN000018395.

Eruptive xanthomas in a patient with soft-drink diabetic ketosis and apolipoprotein E4/2

Soft-drink diabetic ketosis, characterized by acute onset ketosis induced by excessive ingestion of sugar-containing drinks, is often seen in obese, young patients, even with undiagnosed type 2 diabetes. We herein report a 15-year-old obese patient with the apolipoprotein E4/2 phenotype, in whom eruptive xanthomas lead to a diagnosis of soft-drink diabetic ketosis. He developed multiple asymptomatic yellowish papules on the auricles, back, buttocks and the extensor surfaces of the elbows and knees. He initially visited a dermatology clinic and his blood triglyceride and HbA1c levels were found to be 6,490 mg/dL and 16.5%, respectively. He was referred to our hospital for treatment of hyperglycemia and hypertyriglyceridemia. On admission, he had ketonuria and increased blood levels of 3-hydroxybutylate and acetoacetate. He habitually drank 1-3 litters of sweet beverages daily to quench his thirst. Therefore, "soft-drink diabetic ketosis" was diagnosed. Severe hypertriglyceridemia was considered to have been a consequence of impaired insulin action and his apolipoprotein E4/2 phenotype. We treated the diabetic ketosis and hypertriglyceridemia with intensive insulin therapy and a fat-restricted diet. At discharge, he no longer required insulin therapy and his blood glucose levels were controlled with metformin and voglibose. Along with amelioration of the hyperglycemia, triglyceride levels decreased to 247 mg/dL without administration of anti-hyperlipidemia agents. The eruptive xanthoma lesions gradually diminished in size and number and eventually disappeared by 12 months. This case provides an instructive example of eruptive xanthomas serving as a sign of severe dysregulation, not only of lipid, but also glucose, metabolism.

Enhancement of postprandial endogenous insulin secretion rather than exogenous insulin injection ameliorated insulin antibody-induced unstable diabetes: a case report

BACKGROUND

Insulin injection, especially with insulin analogs, occasionally induces the production of insulin antibodies with high binding capacity and low affinity, similar to the insulin autoantibodies characteristic of insulin autoimmune syndrome (IAS). Production of these "IAS-like" insulin antibodies causes marked glycemic fluctuations with postprandial hyperglycemia and fasting hypoglycemia.

CASE PRESENTATION

A 66-year-old man with a 27-year history of diabetes was admitted because of marked glycemic fluctuations. Human insulin treatment had been initiated at age 56, followed by multiple daily injections of insulin analogs 5 years later. After the initial year of insulin analog treatment, the patient began to experience frequent morning hypoglycemic attacks and day-time hyperglycemia. Marked hyperinsulinemia (4500 μU/mL) and high titers of insulin antibodies (80.4%) with high binding capacity and low affinity indicated that IAS-like insulin antibodies were causing severe glucose fluctuations. Altering insulin formulations (insulin aspart → regular human insulin→ insulin lispro) proved to be ineffective. After several therapeutic trials, cessation of exogenous insulin and addition of mitiglinide to liraglutide with voglibose finally attenuated glycemic fluctuations with increased postprandial insulin secretion. Continuous glucose monitoring revealed improvement of morning hypoglycemia and postprandial hyperglycemia with smaller mean amplitude of glycemic excursion. Therefore, compared to exogenously injected insulin, endogenously secreted insulin directly and rapidly acts on hepatocytes and suppresses postprandial glucose output.

CONCLUSIONS

Proper enhancement of postprandial endogenous insulin aimed at suppressing postprandial glucose output without stimulating excessive glucose uptake in the periphery is potentially useful for treating diabetes with insulin antibody-induced glycemic instability.

Efficacy and safety of sitagliptin added to metformin and insulin compared with voglibose in patients with newly diagnosed type 2 diabetes

OBJECTIVE

To assess the efficacy and safety of sitagliptin compared with voglibose added to combined metformin and insulin in patients with newly diagnosed type 2 diabetes (T2DM).

METHODS

In this 12-week prospective, randomized, parallel trial, 70 newly diagnosed T2DM patients with glycosylated hemoglobin (HbA1c) ≥9% and/or fasting plasma glucose (FPG) ≥11.1 mmol/L were randomized (1:1) to receive sitagliptin 100 mg per day + metformin + insulin glargine or voglibose 0.2 mg three times daily + metformin + insulin glargine. Change in HbA1c at week 12 was the primary endpoint.

RESULTS

The mean baseline HbA1c was 11.0% in the patients. The changes in HbA1c from baseline were -6.00% in the sitagliptin group and -3.58% in the voglibose group, and the between-group difference was -2.42% (95% CI -1.91 to -2.93, p=0.02). The differences in FPG and homeostatic model assessment of β-cell function (HOMA-β) and the change in body weight between groups from baseline were -2.95 mmol/L (p=0.04), 43.91 (p=0.01) and -2.23 kg (p=0.01), respectively. One patient (2.9%) in the sitagliptin group and three patients (8.6%) in the voglibose group exhibited hypoglycemia.

CONCLUSIONS

Sitagliptin added to combined metformin and insulin therapy showed greater efficacy and good safety regarding hypoglycemia in patients with newly diagnosed T2DM compared with voglibose.

Effects of validamycin in controlling Fusarium head blight caused by Fusarium graminearum: Inhibition of DON biosynthesis and induction of host resistance

Validamycin, known to interfere with fungal energy metabolism by inhibiting trehalase, has been extensively used to control plant diseases caused by Rhizoctonia spp. However, the effect of validamycin on controlling Fusarium graminearum has not been previously reported. In this study, when applied to F. graminearum in vitro, validamycin inhibited the synthesis of deoxynivalenol (DON), which is a mycotoxin and virulence factor, by decreasing trehalase activity and the production of glucose and pyruvate, which are precursors of DON biosynthesis. Because FgNTH encodes the main trehalase in F. graminearum, these effects were nullified in the FgNTH deletion mutant ΔFgNTH but restored in the complemented strain ΔFgNTHC. In addition, validamycin also increased the expression of pathogenesis-related genes (PRs) PR1, PR2, and PR5 in wheat, inducing resistance responses of wheat against F. graminearum. Therefore, validamycin exhibits dual efficacies on controlling Fusarium head blight (FHB) caused by F. graminearum: inhibition of DON biosynthesis and induction of host resistance. In addition, field trials further confirmed that validamycin increased FHB control and reduced DON contamination in grain. Control of FHB and DON contamination by validamycin increased when the antibiotic was applied with the triazole fungicide metconazole. Overall, this study is a successful case from foundational research to applied research, providing useful information for wheat protection programs against toxigenic fungi responsible for FHB and the consequent mycotoxin accumulation in grains.

Alpha-glucosidase inhibitors for prevention or delay of type 2 diabetes mellitus and its associated complications in people at increased risk of developing type 2 diabetes mellitus

BACKGROUND

Alpha-glucosidase inhibitors (AGI) reduce blood glucose levels and may thus prevent or delay type 2 diabetes mellitus (T2DM) and its associated complications in people at risk of developing of T2DM.

OBJECTIVES

To assess the effects of AGI in people with impaired glucose tolerance (IGT), impaired fasting blood glucose (IFG), moderately elevated glycosylated haemoglobin A1c (HbA1c) or any combination of these.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, and the reference lists of systematic reviews, articles and health technology assessment reports. The date of the last search of all databases was December 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), with a duration of one year or more, comparing AGI with any pharmacological glucose-lowering intervention, behaviour-changing intervention, placebo or no intervention in people with IFG, IGT, moderately elevated HbA1c or combinations of these.

DATA COLLECTION AND ANALYSIS

Two review authors read all abstracts and full-text articles or records, assessed quality and extracted outcome data independently. One review author extracted data, which were checked by a second review author. We resolved discrepancies by consensus or involvement of a third review author. For meta-analyses we used a random-effects model with assessment of risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the overall quality of the evidence by using the GRADE instrument.

MAIN RESULTS

For this update of the Cochrane Review (first published 2006, Issue 4) we included 10 RCTs (11,814 participants), eight investigating acarbose and two investigating voglibose, that included people with IGT or people "at increased risk for diabetes". The trial duration ranged from one to six years. Most trials compared AGI with placebo (N = 4) or no intervention (N = 4).Acarbose reduced the incidence of T2DM compared to placebo: 670 out of 4014 people (16.7%) in the acarbose groups developed T2DM, compared to 812 out of 3994 people (20.3%) in the placebo groups (RR 0.82, 95% CI 0.75 to 0.89; P < 0.0001; 3 trials; 8008 participants; moderate-certainty evidence). One trial including participants with coronary heart disease and IGT contributed 64% of cases for this outcome. Acarbose reduced the risk of T2DM compared to no intervention: 7 out 75 people (9.3%) in the acarbose groups developed T2DM, compared to 18 out of 65 people (27.7%) in the no-intervention groups (RR 0.31, 95% CI 0.14 to 0.69; P = 0.004; 2 trials; 140 participants; very low-certainty evidence).Acarbose compared to placebo did not reduce or increase the risk of all-cause mortality (RR 0.98, 95% CI 0.82 to 1.18; P = 0.86; 3 trials; 8069 participants; very low-certainty evidence), cardiovascular mortality (RR 0.88; 95% CI 0.71 to 1.10; P = 0.26; 3 trials; 8069 participants; very low-certainty evidence), serious adverse events (RR 1.12, 95% CI 0.97 to 1.29; P = 0.13; 2 trials; 6625 participants; low-certainty evidence), non-fatal stroke (RR 0.50, 95% CI 0.09 to 2.74; P = 0.43; 1 trial; 1368 participants; very low-certainty evidence) or congestive heart failure (RR of 0.87; 95% CI 0.63 to 1.12; P = 0.40; 2 trials; 7890 participants; low-certainty evidence). Acarbose compared to placebo reduced non-fatal myocardial infarction: one out of 742 participants (0.1%) in the acarbose groups had a non-fatal myocardial infarction compared to 15 out of 744 participants (2%) in the placebo groups (RR 0.10, 95% CI 0.02 to 0.53; P = 0.007; 2 trials; 1486 participants; very low-certainty evidence). Acarbose treatment showed an increased risk of non-serious adverse events (mainly gastro-intestinal events), compared to placebo: 751 of 775 people (96.9%) in the acarbose groups experienced an event, compared to 723 of 775 people (93.3%) in the placebo groups (RR 1.04; 95% CI 1.01 to 1.06; P = 0.0008; 2 trials; 1550 participants). Acarbose compared to no intervention showed no advantage or disadvantage for any of these outcome measures (very low-certainty evidence).One trial each compared voglibose with placebo (1780 participants) or diet and exercise (870 participants). Voglibose compared to placebo reduced the incidence of T2DM: 50 out of 897 participants (5.6%) developed T2DM, compared to 106 out of 881 participants (12%) in the placebo group (RR 0.46, 95% CI 0.34 to 0.64; P < 0.0001; 1 trial; 1778 participants; low-certainty evidence). For all other reported outcome measures there were no clear differences between voglibose and comparator groups. One trial with 90 participants compared acarbose with diet and exercise and another trial with 98 participants reported data on acarbose versus metformin. There were no clear differences for any outcome measure between these two acarbose interventions and the associated comparator groups.None of the trials reported amputation of lower extremity, blindness or severe vision loss, end-stage renal disease, health-related quality of life, time to progression to T2DM, or socioeconomic effects.

AUTHORS' CONCLUSIONS

AGI may prevent or delay the development of T2DM in people with IGT. There is no firm evidence that AGI have a beneficial effect on cardiovascular mortality or cardiovascular events.

Evolution from Natural β-Carboline Alkaloids to Obtain 1,2,4,9-tetrahydro-3-thia-9-aza-fluorene Derivatives as Potent Fungicidal Agents against Rhizoctonia solani

Rice sheath blight, caused by Rhizoctonia solani, is a globally important rice disease and the increasing resistance of this pathogen highlights the need for new active compounds against rice sheath blight. In this study, natural β-carboline alkaloids were optimized to obtain a series of 1,2,4,9-tetrahydro-3-thia-9-aza-fluorene derivatives and evaluated for their fungicidal activity and mode of action against R. solani. Of these compounds, 18 exhibited significant in vitro fungicidal activity against R. solani, with an EC50 value of 2.35 μg/mL, and was more active than validamycin A. In vivo bioassay also demonstrated that 18 displayed superior protective and curative activities as compared to validamycin A. Mechanistically, 18 not only induced the loss of mitochondrial membrane potential and accumulation of reactive oxygen species, but also interfered with DNA synthesis. Therefore, compound 18 displayed pronounced in vitro and in vivo fungicidal activity against R. solani and could be used as a potential candidate for the control of rice sheath blight.

Increased salt and drought tolerance by D-pinitol production in transgenic Arabidopsis thaliana

D-ononitol epimerase (OEP) catalyzes the conversion of D-ononitol to D-pinitol, which is the last step in the biosynthetic pathway, where myo-inositol is converted to pinitol in higher plants. In this study, OEP cDNA was isolated from Glycine max (GmOEP) and was functionally characterized, which confirmed that GmOEP expression was induced by high salinity and drought stress treatments. To understand the biological function of GmOEP, transgenic Arabidopsis plants overexpressing this protein were constructed. The transgenic Arabidopsis plants displayed enhanced tolerance to high salinity and drought stress treatments.

Interaction of antidiabetic α-glucosidase inhibitors and gut bacteria α-glucosidase

Carbohydrate hydrolyzing α-glucosidases are commonly found in microorganisms present in the human intestine microbiome. We have previously reported crystal structures of an α-glucosidase from the human gut bacterium Blaubia (Ruminococcus) obeum (Ro-αG1) and its substrate preference/specificity switch. This novel member of the GH31 family is a structural homolog of human intestinal maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI) with a highly conserved active site that is predicted to be common in Ro-αG1 homologs among other species that colonize the human gut. In this report, we present structures of Ro-αG1 in complex with the antidiabetic α-glucosidase inhibitors voglibose, miglitol, and acarbose and supporting binding data. The in vitro binding of these antidiabetic drugs to Ro-αG1 suggests the potential for unintended in vivo crossreaction of the α-glucosidase inhibitors to bacterial α-glucosidases that are present in gut microorganism communities. Moreover, analysis of these drug-bound enzyme structures could benefit further antidiabetic drug development.

Glucose excursions and hypoglycemia in patients with type 2 diabetes treated with mitiglinide/voglibose versus glimepiride: A randomized cross-over trial

BACKGROUND

Glucose excursions and hypoglycemia are associated with cardiovascular complications. However, no studies have evaluated glucose excursions and the frequency of hypoglycemia in patients treated with mitiglinide/voglibose versus glimepiride as add-on to dipeptidyl peptidase-4 inhibitor therapy.

METHODS

This cross-over trial included 20 patients with type 2 diabetes. After initiating vildagliptin 100 mg, patients were randomly assigned to receive mitiglinide 10 mg/voglibose 0.2 mg three times daily for 3 days followed by glimepiride 1 mg once daily for the subsequent 3 days as add-on therapy, or vice versa. Glucose excursions and hypoglycemia frequency were measured using 24-h continuous glucose monitoring. Metabolic profile changes were evaluated using a meal tolerance test.

RESULTS

The mean glucose levels in the mitiglinide/voglibose and glimepiride phases were identical (8.01 vs 8.24 mmol/L, respectively). However, during the mitiglinide/voglibose phase compared with the glimepiride phase, the standard deviation of glucose (1.30 vs 2.10 mmol/L; P < 0.001), mean amplitude of glycemic excursions (3.47 vs 5.28 mmol/L; P < 0.001), M-value (24.6 vs 70.0; P < 0.001), continuous overlapping net glycemic action for a 1-h time interval (22.6 vs 31.0; P < 0.001), and area under the curve >10 mmol/L (0.18 vs 0.52 mmol/L per h; P < 0.001) were significantly lower. Hypoglycemia (glucose <3.8 mmol/L) was not observed during the mitiglinide/voglibose phase, but occurred 0.35 times/day in those taking glimepiride. Moreover, the mitiglinide/voglibose phase had higher premeal and lower post-meal glucose levels than the glimepiride phase.

CONCLUSIONS

Adding mitiglinide/voglibose to vildagliptin therapy results in more efficient postprandial glucose control and less hypoglycemia than adding glimepiride.

The use of inositol(s) isomers in the management of polycystic ovary syndrome: a comprehensive review

The aim of this review is to present the current data about the role of inositols in the management of polycystic ovary syndrome (PCOS) women and in the prevention and treatment of gestational diabetes mellitus (GDM). We analyzed the available literature with key words PCOS, Myo-inositol, D-chiro-inositol, assisted reproductive technologies and GDM. The most recent literature would suggest that Myo-inositol, D-chiro-inositol and their combination in physiological ratio 40:1 could represent an important therapeutic strategy for the improvement of metabolic, hormonal and reproductive aspects of PCOS. In assisted reproductive technologies, however, myo-inositol and the combined treatment, despite D-chiro-inositol monotherapy, are able to improve clinical outcomes. Myo-inositol monotherapy results more effective in preventing and treating GDM even if a larger cohort of studies is needed to better clarify these results.

Effects of linagliptin versus voglibose on treatment-related quality of life in patients with type 2 diabetes: sub-analysis of the L-STEP study

Treatment-related quality of life (QOL) is an important aspect of diabetes management. However, no studies have compared the influence of dipeptidyl peptidase-4 inhibitors versus alpha-glucosidase inhibitors on treatment-related QOL. This prespecified sub-analysis of the Linagliptin Study of Effects on Postprandial blood glucose (L-STEP) compared the effects of linagliptin (5 mg once daily) and voglibose (0.2 mg/meal thrice daily) on treatment-related QOL in Japanese patients with type 2 diabetes (T2DM) inadequately controlled with diet and exercise therapy. Among 366 subjects in the original study, 182 in the linagliptin group and 173 in the voglibose group were included in this analysis. The outcome of this study was change in QOL as assessed by the Diabetes Therapy-Related Quality of Life 17 (DTR-QOL17) questionnaire from baseline to week 12. Compared with baseline data, total DTR-QOL17 scores were significantly higher after 12 weeks of linagliptin and voglibose treatment. The change in the total DTR-QOL17 score and the score of one domain, burden on social activities and daily activities, was significantly greater in the linagliptin group than in the voglibose group. In addition, only linagliptin treatment was identified as a factor associated with an increased total DTR-QOL17 score. Linagliptin is superior to voglibose in terms of improving treatment-related QOL in Japanese patients with T2DM.

Quercitol: From a Taxonomic Marker of the Genus Quercus to a Versatile Chiral Building Block of Antidiabetic Agents

Quercitol is a cyclohexanepentol that has been recognized as a biomarker of plants in genus Quercus, which includes oak. As a result of its glucose-like structure, it has been introduced as an alternative chiral building block in the synthesis of several bioactive compounds. Our continuing investigations on the synthesis of antidiabetic agents from quercitol have demonstrated that this chiral synthon can generate diverse structural features with improved hypoglycemic activity.

Dipeptidyl peptidase-4 inhibitor-associated bullous pemphigoid in a patient with acquired reactive perforating collagenosis

Bullous pemphigoid (BP) is a common autoimmune blistering disorder with unknown etiology. Recently, increasing numbers of BP cases which developed under the medication with dipeptidyl peptidase-4 inhibitors (DPP4i), widely used antihyperglycemic drugs, have been reported in published works. Here, we report a case of DPP4i (teneligliptin)-associated BP that developed in a 70-year-old Japanese man. Interestingly, the patient had acquired reactive perforating collagenosis (ARPC), which is also known to be associated with the onset of BP. In the present case, clinical, histopathological and immunological findings suggested that DPP4i rather than ARPC was associated with the onset of BP.

Effects of linagliptin monotherapy compared with voglibose on postprandial lipid profiles in Japanese patients with type 2 diabetes: linagliptin study of effects on postprandial blood glucose (L-STEP) sub-study 1

Recently, we reported that linagliptin had equivalent efficacy to voglibose in reducing postprandial blood glucose levels in drug-naïve patients with type 2 diabetes (L-STEP Study). As a sub-study of the L-STEP Study we examined the effect of linagliptin on postprandial lipids profile. Between October 2012 and April 2014, the study enrolled patients with type 2 diabetes mellitus who had inadequate glycemic control. Patients were randomly assigned to either the linagliptin group (5 mg once daily, n = 85) or the voglibose group (0.2 mg/meal thrice daily, n = 71). Meal tolerance tests were performed at baseline (week 0) and endpoint (week 12). The increments in 4-h postprandial triglyceride, remnant lipoprotein cholesterol (RLP-C), and apolipoprotein B48 (ApoB48) from baseline to endpoint in the linagliptin group were lower (p < 0.001, p = 0.025 and p < 0.001). 4-h postprandial ApoB48 at endpoint was lower in the linagliptin group (p = 0.007), and positive correlation was detected between change of ApoB48 and changes in both triglyceride (r = 0.67, p < 0.001) and RLP-C (r = 0.73, p < 0.001) at 4 h. This study revealed that in drug-naïve Japanese patients with relatively mild type 2 diabetes mellitus, linagliptin improves not only postprandial blood glucose level but also levels of lipids such as TG and RLP-C by reducing the ApoB48 level compared with voglibose.

Biosynthesis of quebrachitol, a transportable photosynthate, in Litchi chinensis

Although methylated cyclitols constitute a major proportion of the carbohydrates in many plant species, their physiological roles and biosynthetic pathway are largely unknown. Quebrachitol (2-O-methyl-chiro-inositol) is one of the major methylated cyclitols in some plant species. In litchi, quebrachitol represents approximately 50% of soluble sugars in mature leaves and 40% of the total sugars in phloem exudate. In the present study, we identified bornesitol as a transient methylated intermediate of quebrachitol and measured the concentrations of methyl-inositols in different tissues and in tissues subjected to different treatments. 14CO2 feeding and phloem exudate experiments demonstrated that quebrachitol is one of the transportable photosynthates. In contrast to other plant species, the biosynthesis of quebrachitol in litchi is not associated with osmotic stress. High quebrachitol concentrations in tissues of the woody plant litchi might represent a unique carbon metabolic strategy that maintains osmolality under reduced-sucrose conditions. The presence of bornesitol but not ononitol in the leaves indicates a different biosynthetic pathway with pinitol. The biosynthesis of quebrachitol involves the methylation of myo-inositol and the subsequent epimerization of bornesitol. An inositol methyltransferase gene (LcIMT1) responsible for bornesitol biosynthesis was isolated and characterized for the first time, and the biosynthesis pathways of methyl-inositols are discussed.

Effects of a Carob-Pod-Derived Sweetener on Glucose Metabolism

BACKGROUND

Patients with type 2 diabetes mellitus (T2DM) have a higher incidence of cardiovascular (CV) events. The ingestion of high-glycemic index (GI) diets, specially sweetened beverage consumption, has been associated with the development of T2DM and CV disease.

OBJECTIVE

We investigated the effects of the intake of a sweetened beverage, obtained from natural carbohydrates containing pinitol (PEB) compared to a sucrose-enriched beverage (SEB) in the context of impaired glucose tolerance (IGT) and diabetes.

METHODS

The study was divided in three different phases: (1) a discovery phase where the plasma proteomic profile was investigated by 2-DE (two-dimensional electrophoresis) followed by mass spectrometry (matrix-assisted laser desorption/ionization time-of-flight-MALDI-TOF/TOF) in healthy and IGT volunteers; (2) a verification phase where the potential mechanisms behind the observed protein changes were investigated in the discovery cohort and in an additional group of T2DM volunteers; and (3) the results were validated in a proof-of-concept interventional study in an animal model of diabetic rats with complementary methodologies.

RESULTS

Six weeks of pinitol-enriched beverage (PEB) intake induced a significant increase in two proteins involved in the insulin secretion pathway, insulin-like growth factor acid labile subunit (IGF1BP-ALS; 1.3-fold increase; P = 0.200) and complement C4A (1.83-fold increase; P = 0.007) in IGT subjects but not in healthy volunteers. Changes in C4A were also found in the serum samples of Zucker diabetic fatty (ZDF) rats after four weeks of PEB intake compared to basal levels (P = 0.042). In addition, an increased expression of the glucose transporter-2 (GLUT2) gene was observed in the jejunum (P = 0.003) of inositol-supplemented rats when compared to sucrose supplementation. This change was correlated with the observed change in C4A (P = 0.002).

CONCLUSIONS

Our results suggest that the substitution of a common sugar source, such as sucrose, by a naturally-based, pinitol-enriched beverage induces changes in the insulin secretion pathway that could help to reduce blood glucose levels by protecting β-cells and by stimulating the insulin secretion pathway. This mechanism of action could have a relevant role in the prevention of insulin resistance and diabetes progression.

Alkaline pH shock enhanced production of validamycin A in fermentation of Streptomyces hygroscopicus

Validamycin A (Val-A) is produced by Streptomyces as a secondary metabolite with wide agricultural applications of controlling rice sheath blight, false smut and damping-off diseases. The effect of alkaline pH shock on enhancing Val-A production and its mechanism were investigated. A higher yield of Val-A was achieved by NaOH shock once or several times together with faster protein synthesis and sugar consumption and alkaline pH shock can increase Val-A production by 27.43%. Transcription of genes related to amino acid metabolism, carbon metabolism and electron respiratory chain was significantly up-regulated, accompanied by the substantial increase of respiratory activity and glutamate concentration. Val-A production was promoted by a series of complex mechanisms and made a response to pH stress signal, which led to the enhancement of glutamate metabolism and respiration activity. The obtained information will facilitate future studies for antibiotic yield improvement and the deep revealment of molecular mechanism.

Bacterial volatile ammonia regulates the consumption sequence of d-pinitol and d-glucose in a fungus associated with an invasive bark beetle

Interactions among microbial symbionts have multiple roles in the maintenance of insect-microbe symbiosis. However, signals mediating microbial interactions have been scarcely studied. In the classical model system of bark beetles and fungal associates, fungi increase the fitness of insects. However, not all interactions are mutualistic, some of these fungal symbionts compete for sugars with beetle larvae. How this antagonistic effect is alleviated is unknown, and recent research suggests potential roles of bacterial symbionts. Red turpentine beetle (RTB), Dendroctonus valens LeConte, is an invasive pest in China, and it leads to wide spread, catastrophic mortality to Chinese pines. In the symbiotic system formed by RTB, fungi and bacteria, volatiles from predominant bacteria regulate the consumption sequence of carbon sources d-pinitol and d-glucose in the fungal symbiont Leptographium procerum, and appear to alleviate the antagonistic effect from the fungus against RTB larvae. However, active components of these volatiles are unknown. We detected 67 volatiles by Gas Chromatography-Mass Spectrometer (GC-MS). Seven of them were identified as candidate chemicals mediating bacteria-fungus interactions, among which ammonia made L. procerum consume its secondary carbon source D-pinitol instead of its preferred carbohydrate D-glucose. In conclusion, ammonia regulated the consumption sequence of these two carbon sources in the fungal symbiont.

Plicosepalin A, a new antioxidant catechin-gallic acid derivative of inositol from the mistletoe Plicosepalus curviflorus

Phytochemical investigation of the semi-parasitic plant, Plicosepalus curviflorus (Loranthaceae) growing in Saudi Arabia resulted in the isolation of a new catechin-gallic acid derivative of inositol, plicosepalin A (1) [(+) catechin-4'-O-(1″-O-galloyl-5″-O-methyl)-myo-inositol], along with seven known compounds: methyl gallate (2), catechin (3), quercetin (4), gallic acid (5), lupeol (6), β-sitosterol (7), and ursolic acid (8). Their structures were elucidated on the basis of spectroscopic analyses, including HRESIMS, ESIMS, 1H and 13C NMR, HSQC, and HMBC, as well as comparison with reported data. The antioxidant and antimicrobial activities of 1 were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the disc diffusion assay, respectively. Compound 1 exhibited potent free radical scavenging activity with an IC50 value of 9.0 ± 0.27 μM. Moreover, significant activities against Staphylococcus aureus and Bacillus subtilis were recorded.

Carboxylesterase Precursor (EST-1) Mediated the Fungicide Jinggangmycin-Suppressed Reproduction of Sogatella furcifera (Hemiptera: Delphacidae)

The jinggangmycin (JGM) is a widely used fungicide for controlling the rice sheath blight, Rhizoctonia solani, in China. Previous experiments under lab conditions showed that JGM foliar spray suppressed Sogatella furcifera (Horvath) reproduction. However, the molecular mechanisms of JGM-driven changes in S. furcifera reproduction are unclear. Therefore, we selected carboxylesterase precursor (EST-1) as a target gene for silencing by RNAi based on gene expression profiles. The present results demonstrated that JGM and control + dsSfEST-1 treatments significantly reduced the number of eggs laid (down by 58% and 54%, respectively), oviposition period (down by 57% and 38%, respectively), and longevity (down by 32% and 38%, respectively) in adult females compared with untreated controls, while no pronounced differences in the preoviposition period were observed. Meanwhile, the dietary control + dsSfEST-1 treatment also severely impeded protein synthesis, specifically soluble ovarian protein content (down by 20% and 24%, respectively) and soluble sugar content (down by 42% and 35%, respectively), which led to stunted growth and reduced body weight in adult females. We thereby speculate that downregulated SfEST-1 expression may be one molecular mechanism underlying JGM-driven reproduction in S. furcifera.

Jinggangmycin-suppressed reproduction in the small brown planthopper (SBPH), Laodelphax striatellus (Fallen), is mediated by glucose dehydrogenase (GDH)

The small brown planthopper (SBPH), Laodelphax striatellus (Fallen), is a serious pest insect of rice, wheat, and maize in China. SBPH not only sucks plant sap but also transmits plant disease viruses, causing serious damage. These viruses include rice striped virus disease (RSV disease), black streaked dwarf, and maize rough disease virus. SBPH outbreaks are related to the overuse of pesticides in China. Some pesticides, such as triazophos, stimulate the reproduction of SBPH, but an antibiotic fungicide jinggangmycin (JGM) suppresses its reproduction. However, mechanisms of decreased reproduction of SBPH induced by JGM remain unclear. The present findings show that JGM suppressed reproduction of SBPH (↓approximately 35.7%) and resulted in the down-regulated expression of glucose dehydrogenase (GDH). GDH-silenced control females (control+dsGDH) show that the number of eggs laid was reduced by 48.6% compared to control females. Biochemical tests show that the total lipid and fatty acid contents in JGM-treated and control+dsGDH females decreased significantly. Thus, we propose that the suppression of reproduction in SBPH induced by JGM is mediated by GDH via metabolic pathways.

Suppressing the activity of trehalase with validamycin disrupts the trehalose and chitin biosynthesis pathways in the rice brown planthopper, Nilaparvata lugens

Trehalase (TRE) is a key enzyme in trehalose degradation and has important functions in insect growth and chitin synthesis. Though validamycin has the potential for pest control by suppressing TRE activities, it is not known whether validamycin acts on both trehalose and chitin metabolism. TRE1 and TRE2 activities and glucose and glycogen contents decreased significantly after the injection of different doses of validamycin solution compared with the control group, while the trehalose content increased significantly. Overall, it showed that about 13 to 38% insects was appeared abnormal phenotypes, and 10 to 57% of insects died 48h after injection of solutions with different concentrations of validamycin; the chitin content also decreased significantly. Validamycin altered the relative expression levels of trehalose, glycogen and chitin metabolism-related genes by suppressing the activities of two TREs. We showed that the expression levels of three TRE and two trehalose-6-phosphate synthase (TPS) genes increased, while the expression levels of GP; CHS1 and its two transcripts, CHS1a, CHS1b; six chitinases, including Cht3, Cht4, Cht5, Cht6, Cht7, Cht9; and the HK, G6PI2, GFAT, GNPNA, PAGM1, UAP, VVL, CI and AP genes decreased significantly 48h after the injection of any validamycin concentration compared with the control group. These results demonstrate that by inhibiting the activities of two TREs, validamycin alters N. lugens chitin synthesis and degradation and affects trehalose and chitin metabolism-related gene expression. The development of TRE inhibitors may provide effective pest control in the future.

Glycogen Phosphorylase and Glycogen Synthase: Gene Cloning and Expression Analysis Reveal Their Role in Trehalose Metabolism in the Brown Planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae)

RNA interference has been used to study insects' gene function and regulation. Glycogen synthase (GS) and glycogen phosphorylase (GP) are two key enzymes in carbohydrates' conversion in insects. Glycogen content and GP and GS gene expression in several tissues and developmental stages of the Brown planthopper Nilaparvata lugens Stål (Hemiptera: Delphacidae) were analyzed in the present study, using quantitative reverse-transcription polymerase chain reaction to determine their response to double-stranded trehalases (dsTREs), trehalose-6-phosphate synthases (dsTPSs), and validamycin injection. The highest expression of both genes was detected in the wing bud, followed by leg and head tissues, and different expression patterns were shown across the developmental stages analyzed. Glycogen content significantly decreased 48 and 72 h after dsTPSs injection and 48 h after dsTREs injection. GP expression increased 48 h after dsTREs and dsTPSs injection and significantly decreased 72 h after dsTPSs, dsTRE1-1, and dsTRE1-2 injection. GS expression significantly decreased 48 h after dsTPS2 and dsTRE2 injection and 72 h after dsTRE1-1 and dsTRE1-2 injection. GP and GS expression and glycogen content significantly decreased 48 h after validamycin injection. The GP activity significantly decreased 48 h after validamycin injection, while GS activities of dsTPS1 and dsTRE2 injection groups were significantly higher than that of double-stranded GFP (dsGFP) 48 h after injection, respectively. Thus, glycogen is synthesized, released, and degraded across several insect tissues according to the need to maintain stable trehalose levels.

[Effects of pigment gene deletions on validamycin A production in Streptomyces hygroscopicus var. jinggangensis]

OBJECTIVE

We studied the contributions of four pigment biosynthetic genes to validamycin A yield, biomass accumulation, and the color of fermentation broth via individual gene deletions.

METHODS

The deletion mutants were obtained via homologous recombination. The titer of validamycin A was detected by HPLC. The transcription of validamycin biosynthetic genes was quantified by qRT-PCR, and the growth was measured with dry cell weight.

RESULTS

Compared with the parent strain, the deletion of DOPA melanin genes increased the validamycin A titer from 20.6 to 23.1 g/L (by 12%), whereas the deletion of type Ⅲ polyketide synthase melanin genes showed no effect. The inactivation of type Ⅱ polyketide synthase spore pigment genes and ochronotic pigment genes decreased validamycin A production by 11.7% and 17.2%, respectively. All these mutant strains had no significant change in transcriptional level and the color of supernatant.

CONCLUSION

Pigment biosynthetic gene deletions showed different effects on validamycin yield and biomass accumulation, and the deletion of DOPA melanin biosynthetic genes redirected the precursor flux and successfully increased the yield of validamycin A.

Effects of linagliptin monotherapy compared with voglibose on postprandial blood glucose responses in Japanese patients with type 2 diabetes: Linagliptin Study of Effects on Postprandial blood glucose (L-STEP)

AIMS

To compare the efficacy on glycemic parameters between a 12-week administration of once-daily linagliptin and thrice-daily voglibose in Japanese patients with type 2 diabetes.

METHODS

In a multi-center, randomized, parallel-group study, 382 patients with diabetes were randomized to the linagliptin group (n=192) or the voglibose group (n=190). A meal tolerance test was performed at weeks 0 and 12. Primary outcomes were the change from baseline to week 12 in serum glucose levels at 2h during the meal tolerance test, HbA1c levels, and serum fasting glucose levels, which were compared between the 2 groups.

RESULTS

Whereas changes in serum glucose levels at 2h during the meal tolerance test did not differ between the groups, the mean change in HbA1c levels from baseline to week 12 in the linagliptin group (-0.5±0.5% [-5.1±5.4mmol/mol]) was significantly larger than in the voglibose group (-0.2±0.5% [-2.7±5.4mmol/mol]). In addition, there was significant difference in changes in serum fasting glucose levels (-0.51±0.95mmol/L in the linagliptin group vs. -0.18±0.92mmol/L in the voglibose group, P<0.001). The incidences of hypoglycemia, serious adverse events (AEs), and discontinuations due to AEs were low and similar in both groups. However, gastrointestinal AEs were significantly lower in the linagliptin group (1.05% vs. 5.85%; P=0.01).

CONCLUSIONS

These data suggested that linagliptin monotherapy had a stronger glucose-lowering effect than voglibose monotherapy with respect to HbA1c and serum fasting glucose levels, but not serum glucose levels 2h after the start of the meal tolerance test.

Beneficial effects of voglibose administration on body weight and lipid metabolism via gastrointestinal bile acid modification

This study was designed with the goal of examining the effects of voglibose administration on body weight and lipid metabolism and underlying mechanism high fat diet-induced obese mice. Male C57BL/6 mice were randomly assigned to one of four groups: a control diet (CTL), high-fat diet (HF), high-fat diet supplemented with voglibose (VO), and high fat diet pair-fed group (PF). After 12 weeks, the following characteristics were investigated: serum lipid and glucose levels, serum polar metabolite profiles, and expression levels of genes involved in lipid and bile acid metabolism. In addition, pyrosequencing was used to analyze the composition of gut microbiota found in feces. Total body weight gain was significantly lower in the VO group than in the CTL, HF, and PF groups. The VO group exhibited improved metabolic profiles including those of blood glucose, triglyceride, and total cholesterol levels. The 12-week voglibose administration decreased the ratio of Firmicutes to Bacteroidetes found in feces. Circulating levels of taurocholic and cholic acid were significantly higher in the VO group than in the HF and CTL groups. Deoxycholic acid levels tended to be higher in the VO group than in the HF group. Voglibose administration downregulated expression levels of CYP8B1 and HNF4α genes and upregulated those of PGC1α, whereas FXRα was not affected. Voglibose administration elicits changes in the composition of the intestinal microbiota and circulating metabolites, which ultimately has systemic effects on body weight and lipid metabolism in mice.

Transmission Electron Microscopy (TEM) Observations of Female Oocytes From Nilaparvata lugens (Hemiptera: Delphacidae): Antibiotic Jinggangmycin (JGM)-Induced Stimulation of Reproduction and Associated Changes in Hormone Levels

Previous studies have demonstrated that the agricultural antibiotic jinggangmycin (JGM) stimulates reproduction in the brown planthopper Nilaparvata lugens Stål and that the stimulation of brown planthopper reproduction induced by JGM is regulated by the fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) genes. However, a key issue in the stimulation of reproduction induced by pesticides involves the growth and development of oocytes. Therefore, the present study investigated oocyte changes via transmission electron microscopy (TEM) and changes in hormone levels (juvenile hormones (JH) and 20-hydroxyecdysone (20 E)) in JGM-treated females. TEM observations showed that the size of the lipid droplets in the oocytes of JGM-treated females, compared with those in the oocytes of the control females, significantly reduced by 32.6 and 29.8% at 1 and 2 d after emergence (1 and 2 DAE), respectively. In addition, the JH levels of JGM-treated females at 1 and 2 DAE were increased by 49.7 and 45.7%, respectively, whereas 20 E levels decreased by 36.0 and 30.0%, respectively. We conclude that JGM treatments lead to substantial changes in lipid metabolism, which are directly and indirectly related to stimulation of reproduction of brown planthopper together with our previous findings.

Isolation and Quantification of Pinitol, a Bioactive Cyclitol, in Retama spp

The genus Retama (Fabaceae) is widely distributed in the Mediterranean region. In the present study, pinitol (3-O-methyl-chiro-inositol), an anti-inflammatory and antidiabetic molecule, was isolated from aerial parts of R. monosperma, and its structure established on the basis of spectroscopic techniques (1D/2D NMR) and MS. Identification and quantification of pinitol in R. raetam and R. sphaerocarpa were also performed. R. monosperma had the highest concentration of pinitol (2.3%). The presence of pinitol in aqueous extracts of Retama spp. may explain the adaptation of these plants to drought and salinity. Furthermore, pinitol could be considered as a mediator in the anti-inflammatory and hypoglycemic activities of Retama spp., which are traditionally used to treat diabetes.

Retrospective comparison of voglibose or acarbose as an add-on therapy to sulfonylureas in Western Indian patients with uncontrolled overweight/obese type 2 diabetes

AIM

The study was aimed to investigate the effect of voglibose or acarbose as an add-on treatment in overweight/obese type 2 diabetes (T2DM) patients who are uncontrolled with metformin and sulfonylureas (SUs) in Western part of India.

PARTICIPANTS AND METHODS

A retrospective study included 77 participants (BMI≥25kg/m(2); HbA1c level>8% and<9.5%) with overweight/obese T2DM. These participants were treated with either voglibose or acarbose. Glycemic parameters (fasting blood glucose and glycated hemoglobin [HbA1c]), bodyweight, BMI and lipid parameters were evaluated at baseline, 3-month, 6-month and 9-month of treatment. Adverse events were also captured at respective time points.

RESULTS

Voglibose showed significant reduction in HbA1c and bodyweight with short duration of treatment (6 months; P<0.05 and 9 months; P<0.01) whereas acarbose showed significant reduction with longer duration of treatment (9 months; P<0.05) when compared with baseline. Moreover, both treatment groups were reported with reduction in BMI. Further, significant improvement in lipid parameters except LDL and HDL were observed in both treatment groups when compared with baseline. None of participant was discontinued due to side effects of the treatment. In addition, the frequency of hypoglycemia was decreased in both treatment groups.

CONCLUSION

Voglibose or acarbose as an add-on treatment with metformin and sulfonylureas in uncontrolled obese/overweight T2DM provides desired glycemic control, reduces bodyweight and improves lipid parameters with good tolerability profile.

Application of comprehensive NMR-based analysis strategy in annotation, isolation and structure elucidation of low molecular weight metabolites of Ricinus communis seeds

INTRODUCTION

Powder-like extract of Ricinus communis seeds contain a toxic protein, ricin, which has a history of military, criminal and terroristic use. As the detection of ricin in this "terrorist powder" is difficult and time-consuming, related low mass metabolites have been suggested to be useful for screening as biomarkers of ricin.

OBJECTIVE

To apply a comprehensive NMR-based analysis strategy for annotation, isolation and structure elucidation of low molecular weight plant metabolites of Ricinus communis seeds.

METHODOLOGY

The seed extract was prepared with a well-known acetone extraction approach. The common metabolites were annotated from seed extract dissolved in acidic solution using (1)H NMR spectroscopy with spectrum library comparison and standard addition, whereas unconfirmed metabolites were identified using multi-step off-line HPLC-DAD-NMR approach.

RESULTS

In addition to the common plant metabolites, two previously unreported compounds, 1,3-digalactoinositol and ricinyl-alanine, were identified with support of MS analyses.

CONCLUSION

The applied comprehensive NMR-based analysis strategy provided identification of the prominent low molecular weight metabolites with high confidence.

Postprandial Reactive Hypoglycemia Treated with a Low-dose Alpha-glucosidase Inhibitor: Voglibose May Suppress Oxidative Stress and Prevent Endothelial Dysfunction

We encountered a 62-year-old woman who experienced frequent episodes of hypoglycemia. She was diagnosed with postprandial reactive hypoglycemia according to the results of oral glucose and sucrose tolerance tests, having undergone an endocrinological examination and image inspection. The administration of low-dose voglibose, an alpha-glucosidase inhibitor (α-GI), improved the glucose fluctuations and inhibited hypoglycemic symptoms. Voglibose is also known to diminish oxidative stress and maintain endothelial function after hyperglycemia. An α-GI might effectively prevent hypoglycemic symptoms and endothelial dysfunction by suppressing oxidative stress in such cases.

Enhanced Germicidal Efficacy by Co-Delivery of Validamycin and Hexaconazole with Methoxy Poly(ethylene glycol)-Poly(lactide-co-glycolide) Nanoparticles

Co-delivery system has been proposed in pharmaceutical field aim to synergistic treatments. The combination formulation is also important in traditional pesticides formulations based on the low pest resistance risk and wide fungicidal spectrum. However, co-delivery nanoparticles (NPs) tend to be more environmentally friendly for the sustained-release behaviour and none of toxic organic solvents or dusts. Hence, we constructed co-delivery NPs which could delivery two kinds of pesticides, which function was similar with pesticides combination formulation. The co-delivery NPs of validamycin and hexaconazole were prepared with the amphiphilic copolymer methoxy poly(ethylene glycol)- poly(lactide-co-glycolide) (mPEG-PLGA) used an improved double emulsion method. The chemical structure of mPEG-PLGA copolymer was confirmed using fourier transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance spectroscopy (NMR). The co-delivery NPs all exhibited good size distribution and held sustained-release property. Germicidal efficacy of the co-delivery NPs against Rhizoctonia cerealis was also studied. The germicidal efficacy of co-delivery NPs against Rhizoctonia cerealis was better than that of traditional pesticides formulation. In addition, co-delivery NPs showed a lasting impact against Rhizoctonia cerealis.

Synergistic effect of (+)-pinitol from Saraca asoca with β-lactam antibiotics and studies on the in silico possible mechanism

Saraca asoca bark has been used in the Ayurvedic system of medicine for female urino-genital disorders. We have recently reported the isolation and characterization of several compounds as markers to develop HPLC profiling of its methanol and aqueous methanol extracts. Now, a HPLC-PDA inactive compound, (+)-pinitol has been isolated and characterized from the bark of this medicinally important tree. Pinitol is a well known bioactive compound for a variety of biological activities, including hypoglycemic and anti-inflammatory activities. A process for the isolation of relatively good concentration of (+)-pinitol from S. asoca bark has been developed and its in vitro anti TNF-α and anti-inflammatory activities against carragenan-induced edema confirmed. While conducting experiments on the possible agonistic activity, it was found that (+)-pinitol showed up to eight fold reduction in the doses of β-lactam antibiotics. The mechanism of its agonistic activity was studied by docking experiments which showed that different conformations of (+)-pinitol and antibiotics were actually in the same binding site with no significant change in the binding energy. These docking simulations, thus predict the possible binding mode of studied compounds and probable reason behind the synergistic effect of (+)-pinitol along with β-lactam antibiotics.

The effects of nonyl phenoxypolyethoxyl ethanol on cell damage pathway gene expression in SK-NSH cells

BACKGROUND/AIMS

Most pesticide formulations contain both chief and additive ingredients. But, the additives may not have been tested as thoroughly as the chief ingredients. The surfactant, nonyl phenoxypolyethoxylethanol (NP40), is an additive frequently present in pesticide formulations. We investigated the effects of NP40 and other constituents of a validamycin pesticide formulation on cell viability and on the expression of genes involved in cell damage pathways.

METHODS

The effects of validamycin pesticide ingredients on cell viability and of NP40 on the mRNA expression of 80 genes involved in nine key cellular pathways were examined in the human neuroblastoma SK-N-SH cell line.

RESULTS

The chemicals present in the validamycin pesticide formulation were cytotoxic to SK-N-SH cells and NP40 showed the greatest cytotoxicity. A range of gene expression changes were identified, with both up- and down-regulation of genes within the same pathway. However, all genes tested in the necrosis signaling pathway were down-regulated and all genes tested in the cell cycle checkpoint/arrest pathway were up-regulated. The median fold-change in gene expression was significantly higher in the cell cycle checkpoint/arrest pathway than in the hypoxia pathway category (p = 0.0064). The 70 kDa heat shock protein 4 gene, within the heat shock protein/unfolded protein response category, showed the highest individual increase in expression (26.1-fold).

CONCLUSIONS

NP40 appeared to be particularly harmful, inducing gene expression changes that indicated genotoxicity, activation of the cell death (necrosis signaling) pathway, and induction of the 70 kDa heat shock protein 4 gene.

Examining the response of needle carbohydrates from Siberian larch trees to climate using compound-specific δ(13) C and concentration analyses

Little is known about the dynamics of concentrations and carbon isotope ratios of individual carbohydrates in leaves in response to climatic and physiological factors. Improved knowledge of the isotopic ratio in sugars will enhance our understanding of the tree ring isotope ratio and will help to decipher environmental conditions in retrospect more reliably. Carbohydrate samples from larch (Larix gmelinii) needles of two sites in the continuous permafrost zone of Siberia with differing growth conditions were analysed with the Compound-Specific Isotope Analysis (CSIA). We compared concentrations and carbon isotope values (δ(13) C) of sucrose, fructose, glucose and pinitol combined with phenological data. The results for the variability of the needle carbohydrates show high dynamics with distinct seasonal characteristics between and within the studied years with a clear link to the climatic conditions, particularly vapour pressure deficit. Compound-specific differences in δ(13) C values as a response to climate were detected. The δ(13) C of pinitol, which contributes up to 50% of total soluble carbohydrates, was almost invariant during the whole growing season. Our study provides the first in-depth characterization of compound-specific needle carbohydrate isotope variability, identifies involved mechanisms and shows the potential of such results for linking tree physiological responses to different climatic conditions.

Anti-inflammatory Inositol Derivatives from the Whole Plant of Inula cappa

Twelve new inositol derivatives, classified into myoinositol (1-6) and l-inositol (10-15) types, along with five known analogues were isolated from the whole plant of Inula cappa. The structures of the new compounds were established by extensive analysis of mass spectrometric and 1D and 2D NMR spectroscopic data. All the tested compounds showed anti-inflammatory activities against the production of NO in RAW264.7 macrophages stimulated by lipopolysaccharide, with IC50 values ranging from 7 to 23 μM.

Labeling Cell Surface GPIs and GPI-Anchored Proteins through Metabolic Engineering with Artificial Inositol Derivatives

Glycosylphosphatidylinositol (GPI) anchoring of proteins to the cell surface is important for various biological processes, but GPI-anchored proteins are difficult to study. An effective strategy was developed for the metabolic engineering of cell-surface GPIs and GPI-anchored proteins by using inositol derivatives carrying an azido group. The azide-labeled GPIs and GPI-anchored proteins were then tagged with biotin on live cells through a click reaction, which allows further elaboration with streptavidin-conjugated dyes or other molecules. The strategy can be used to label GPI-anchored proteins with various tags for biological studies.

Effects of D-Pinitol on Insulin Resistance through the PI3K/Akt Signaling Pathway in Type 2 Diabetes Mellitus Rats

D-pinitol, a compound isolated from Pinaceae and Leguminosae plants, has been reported to possess insulin-like properties. Although the hypoglycemic activity of D-pinitol was recognized in recent years, the molecular mechanism of D-pinitol in the treatment of diabetes mellitus remains unclear. In this investigation, a model of type 2 diabetes mellitus (T2DM) with insulin resistance was established by feeding a high-fat diet (HFD) and injecting streptozocin (STZ) to Sprague-Dawley (SD) rats, targeting the exploration of more details of the mechanism in the therapy of T2DM. D-pinitol was administrated to the diabetic rats as two doses [30, 60 mg/(kg·body weight·day)]. The level of fasting blood glucose (FBG) was decreased 12.63% in the high-dosage group, and the ability of oral glucose tolerance was improved in D-pinitol-treated groups. The biochemical indices revealed that D-pinitol had a positive effect on hypoglycemic activity. Western boltting suggested that D-pinitol could promote the expression of the phosphatidylinositol-3-kinase (PI3K) p85, PI3Kp110, as well as the downstream target protein kinase B/Akt (at Ser473). Besides, D-pinitol inhibited the expression of glycogen synthesis kinase-3β (GSK-3β) protein and regulated the expression of glycogen synthesis (GS) protein and then accelerated the glycogen synthesis. Above all, D-pinitol played a positive role in regulating insulin-mediated glucose uptake in the liver through translocation and activation of the PI3K/Akt signaling pathway in T2DM rats.

N-Arylmethylaminoquercitols, a new series of effective antidiabetic agents having α-glucosidase inhibition and antioxidant activity

A new series of N-arylalkylaminoquercitols were synthesized by reductive amination of aminoquercitol bisacetonide 5 and a variety of aryl aldehydes. The targeted N-substituted aminoquercitols having phenolic moiety (7a-7c) displayed significantly enhanced α-glucosidase inhibition, which is 26-32 times more potent than that of the unmodified aminoquercitol 6. In addition, compounds 7a-7c also retained antioxidant activity with relatively more pronounced potency than their original phenolics. This recent finding suggests an approach to develop effective antidiabetic agents by incorporating antioxidative moiety into aminocyclitol core structure.

Comparison of thrice-daily premixed insulin (insulin lispro premix) with basal-bolus (insulin glargine once-daily plus thrice-daily prandial insulin lispro) therapy in east Asian patients with type 2 diabetes insufficiently controlled with twice-daily premixed insulin: an open-label, randomised, controlled trial

BACKGROUND

Unlike in western countries, premixed insulin is widely used as the starter insulin in Asian patients instead of basal insulin. The use of basal-bolus therapy as an intensification regimen is not common in Asia despite poor glycaemic control after starting insulin therapy. An alternative insulin intensification regimen with a similar efficacy and safety profile to basal-bolus therapy, but of higher convenience, is urgently needed. The efficacy and safety of insulin lispro mix thrice-daily was compared with basal-bolus therapy in Asian patients with type 2 diabetes who were insufficiently controlled on twice-daily premixed insulin.

METHODS

This open-label, randomised, active comparator-controlled, parallel-group trial was done at 24 centres in China, Taiwan, and South Korea. Patients with type 2 diabetes who were inadequately controlled on twice-daily premixed insulin were randomly assigned (1:1) to receive either insulin lispro mix (mix 50 before breakfast and lunch plus mix 25 before dinner) or basal-bolus therapy (insulin glargine at bedtime plus prandial insulin lispro thrice-daily) for 24 weeks. Randomisation was done by a computer-generated random sequence and was stratified by country or region and baseline HbA1c. Treatment assignments were masked from the study team assessing outcomes but not from investigators and patients. The primary outcome was change from baseline in HbA1c at week 24 in all randomly assigned patients who received at least one dose of study drug. Analysis was by modified intention to treat, with the per-protocol population used as a supportive analysis. This study is registered with ClinicalTrials.gov, number NCT01175811.

FINDINGS

Between Feb 7, 2011, and Nov 7, 2012, 402 patients were enrolled (199 in the premix group, 203 in the basal-bolus group) and 399 were included in the primary analysis (197 in the premix group, 202 in the basal-bolus group). HbA1c change at week 24 was -1.1% for both treatment groups. The least squares mean difference between groups in HbA1c change from baseline was 0% (95% CI -0.1 to 0.2). Insulin lispro mix was non-inferior to basal-bolus therapy based on the prespecified margin of 0.4%. The frequency of adverse events, and the incidences and 30-day rates of nocturnal and overall hypoglycaemia were comparable between groups. No severe hypoglycaemia was reported.

INTERPRETATION

A premixed insulin lispro regimen thrice-daily was non-inferior to basal-bolus therapy in terms of overall glycaemic control and thus could be an option for intensified insulin regimen in Asian patients with type 2 diabetes who are inadequately controlled with twice-daily premixed insulin.

Content of methylated inositols in familiar edible plants

Familiar plants contain large amounts of inositols; soybean, white clover, red clover, bush clover, locust tree, wisteria, and kudzu of the legume family contain pinitol (3-O-methyl-chiro-inositol) at approximately 200-600 mg/100 g fresh weight (FW). The contents of pinitol in other plants were 260 mg/100 g FW for sticky mouse-ear, 275 mg/100 g FW for chickweed, and 332 mg/100 g FW for ginkgo. chiro-Inositol of 191 and 156 mg/100 g FW was also found in dandelion and Japanese mallotus, respectively. Ononitol (4-O-methyl-myo-inositol) of 166 mg/100 g FW was found in sticky mouse-ear. Furthermore, young leaves of ginkgo contained sequoyitol (5-O-methyl-myo-inositol) of 287 mg/100 g FW. Hydroxyl radical scavenging activities of the methylated inositols were higher than those of the original inositols. Effective uses of these familiar edible plants are expected to promote good health.

[Fixed-dose combination]

Many patients with type 2 diabetes mellitus(T2DM) do not achieve satisfactory glycemic control by monotherapy alone, and often require multiple oral hypoglycemic agents (OHAs). Combining OHAs with complementary mechanisms of action is fundamental to the management of T2DM. Fixed-dose combination therapy(FDC) offers a method of simplifying complex regimens. Efficacy and tolerability appear to be similar between FDC and treatment with individual agents. In addition, FDC can enhance adherence and improved adherence may result in improved glycemic control. Four FDC agents are available in Japan: pioglitazone-glimepiride, pioglitazone-metformin, pioglitazone-alogliptin, and voglibose-mitiglinide. In this review, the advantages and disadvantages of these four combinations are identified and discussed.

Production of validamycin A from hemicellulose hydrolysate by Streptomyces hygroscopicus 5008

Validamycin A (VAL-A) is an important agricultural antibiotic produced by Streptomyces hygroscopicus 5008, which uses starch as carbon source occupying about 20% of total production cost. To reduce the medium cost, corncob hydrolysate - a hemicellulose hydrolysate was applied as a low-cost substrate to VAL-A fermentation. It was found that three major sugars in corncob hydrolysate including d-glucose, d-xylose and l-arabinose could all be utilized by S. hygroscopicus 5008 to produce VAL-A while d-xylose was the main contributor. A higher VAL-A production titer from d-xylose was achieved by using a genetically engineered strain TC03 derived from S. hygroscopicus 5008, which resulted in 1.27-fold improvement of VAL-A production from the medium containing 13% (v/v) corncob hydrolysate compared to that by its original strain. A medium cost analysis was done and compared with previous reports. This work indicates a great potential of the hemicellulose hydrolysate as substrate for antibiotic fermentation.

D-Pinitol Protects Against Carbon Tetrachloride-Induced Hepatotoxicity in Rats

The aim of the study was to evaluate the protective activity of D-Pinitol against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. The animals were divided into six groups, with each group consisting of six animals. Group I animals served as normal controls and received olive oil vehicle (1.0 ml/kg body weight intraperitoneally). Group II rats served as CCl4 controls, which received 30% CCl4 suspended in olive oil (3.0 ml/kg body weight intraperitoneally) twice a week for 4 weeks. Group III rats were treated with 30% CCl4 suspended in olive oil (3.0 ml/kg body weight intraperitoneally) twice a week for 4 weeks, followed by D-Pinitol (100 mg/kg body weight) given for 28 days intragastrically. Group IV rats received D-Pinitol alone at a concentration of 100 mg/kg body weight for 28 days intragastrically. At the end of the experimental period, serum marker enzymes and lipid peroxidation (LPO) levels were significantly increased in group II animals. On the other hand, D-Pinitol treatment significantly decreased marker enzymes and LPO levels and increased the antioxidant level. CYP expression was also investigated. Therefore, the present study revealed that D-Pinitol acts as a protective agent by decreasing metabolic activation of xenobiotics through its antioxidant nature.

A prospective, randomized, multicenter trial comparing the efficacy and safety of the concurrent use of long-acting insulin with mitiglinide or voglibose in patients with type 2 diabetes

This trial was conducted to compare the efficacy and safety of combination therapy with basal insulin glargine plus mitiglinide to that of basal insulin glargine plus voglibosein patients with type 2 diabetes. This was a 20-week, randomized, multicenter non-inferiority trial. Patients with HbA1c levels over 7.0% were randomly assigned to receive either mitiglinide (10 mg tid) or voglibose (0.2 mg tid) concurrent with insulin glargine for 16 weeks after a 4-week of basal insulin glargine monotherapy. The intention-to-treat population included 156 patients; 79 were placed in the mitiglinide group, and 77 were placed in the voglibose group. At 20 weeks, there was no significant difference between the mitiglinide group and the voglibose group in terms of the mean HbA1c level or the mean decrease of the HbAlc level from baseline (-0.9% [-7.5 mmol/mol] and -0.7%, [-5.3 mmol/mol] respectively). The mean fasting plasma glucose level and data of self-monitoring blood glucosewere significantly decreased from baseline to week 20 in both groups, but there was no significant difference between the two groups. The changes in the basal insulin requirements of each group were not significant. The prevalence of adverse events and the risk of hypoglycemia were similar for both groups. Combination therapy with mitiglinide plus basal insulin glargine was non-inferior to voglibose plus basal insulin glargine in terms of the effect on overall glycemic control.

Analysis of validamycin as a potential antifungal compound against Candida albicans

Validamycin A has been successfully applied in the fight against phytopathogenic fungi. Here, the putative antifungal effect of this pseudooligosaccharide against the prevalent human pathogen Candida albicans was examined. Validamycin A acts as a potent competitive inhibitor of the cell-wall-linked acid trehalase (Atc1p). The estimated MIC50 for the C. albicans parental strain CEY.1 was 500 mg/l. The addition of doses below MIC50 to exponentially growing CEY.1 cells caused a slight reduction in cell growth. A concentration of 1 mg/ml was required to achieve a significant degree of cell killing. The compound was stable as evidenced by the increased reduction of cell growth with increasing incubation time. A homozygous atc1delta/atc1delta mutant lacking functional Atc1p activity showed greater resistance to the drug. The antifungal power of validamycin A was limited compared with the drastic lethal action caused by exposure to amphotericin B. The endogenous content of trehalose rose significantly upon validamycin and amphotericin B addition. Neither serum-induced hypha formation nor the level of myceliation recorded in macroscopic colonies were affected by exposure to validamycin A. Our results suggest that, although validamycin A cannot be considered a clinically useful antifungal against C. albicans, its mechanism of action and antifungal properties provide the basis for designing new, clinically interesting, antifungal-related compounds.

Synthesis of densely phosphorylated bis-1,5-diphospho-myo-inositol tetrakisphosphate and its enantiomer by bidirectional P-anhydride formation

The ubiquitous mammalian signaling molecule bis-diphosphoinositol tetrakisphosphate (1,5-(PP)2 -myo-InsP4 , or InsP8 ) displays the most congested three-dimensional array of phosphate groups found in nature. The high charge density, the accumulation of unstable P-anhydrides and P-esters, the lack of UV absorbance, and low levels of optical rotation constitute severe obstacles to its synthesis, characterization, and purification. Herein, we describe the first procedure for the synthesis of enantiopure 1,5-(PP)2 -myo-InsP4 and 3,5-(PP)2 -myo-InsP4 utilizing a C2 -symmetric P-amidite for desymmetrization and concomitant phosphitylation followed by a one-pot bidirectional P-anhydride-forming reaction that combines sixteen chemical transformations with high efficiency. The configuration of these materials is unambiguously shown by subsequent X-ray analyses of both enantiomers after being individually soaked into crystals of the kinase domain of human diphosphoinositol pentakisphosphate kinase 2.

Comparisons of topical and spray applications of two pesticides, triazophos and jinggangmycin, on the protein content in the ovaries and fat bodies of the brown planthopper Nilaparvata lugens Stål (Hemiptera:Delphacidae)

The pesticide-induced stimulation of reproduction in pests is one of the most important mechanisms of pest resurgence. There have been numerous reports on the insecticide-induced stimulation of reproduction. However, the relationship between pesticide application method and pest resurgence (stimulation of reproduction) has received little attention. Here, we studied the effect of two treatment methods, triazophos (TZP) and jinggangmycin (JGM), on the protein content in the ovaries and fat bodies of the brown planthopper (BPH) Nilaparvata lugens Stål. The results showed that pesticide treatment methods significantly affected the protein content in the ovaries and fat bodies of BPH. In addition, grand means (means of main effect) of the protein content at 2 and 3 days after emergence (2 and 3 DAE) for foliar sprays was significantly higher than that observed after topical treatments, which increased by 23.9% (from 1.42 to 1.76) and 8.82% (from 4.42 to 4.81), respectively. No significant differences on the protein content in the ovaries and fat bodies for the JGM topical treatment were observed compared with controls. However, the protein content for JGM foliar sprays was significantly higher than that for the controls. The protein contents in both topical and spray treatments of TZP were significantly higher than those of the controls. Ovarian protein is mainly yolk protein. There is a positive correlation between ovarian protein content and the number of eggs laid. These findings show that foliar spray of the pesticides promotes the resurgence of BPH. Therefore, the foliar spray of some pesticides, such as JGM, should be avoided for the control of pests, which is the sideeffects of the fungicide on non-target insect pests' occurrence.