Safety and efficacy of acarbose in the treatment of Type 2 diabetes: data from a 5-year surveillance study

Design, synthesis of new phenyl acetylene and isoxazole analogues of arjunolic acid as potent tyrosinase and alpha glucosidase inhibitors

A series of new phenyl acetylene and isoxazole analogues of arjunolic acid were designed, synthesized and evaluated (3-8) for their tyrosinase and alpha glucosidase inhibitory potential. All the tested analogues exhibited stronger inhibitory activity than the standard drug or parent compound. Of these, compound (7) displayed the most potent tyrosinase inhibitory action with IC₅₀ (14.3 ± 7.6) of about three folds more than the standard drug, kojic acid (41.5 ± 1.0). Further, compound (8) (14.5 ± 0.15) possessed the potent alpha glucosidase inhibitory action with IC₅₀ value comparable to that of standard, acarbose (10.4 ± 0.06). Henceforth, compounds (7) and (8) are promising candidates for further studies.

Inhibition Mechanism of Components Isolated from Morus alba Branches on Diabetes and Diabetic Complications via Experimental and Molecular Docking Analyses

Previously, we reported the anti-diabetic effect of Morus alba root bark and the compounds therein. In our continuous study of other parts of this plant, the ability of the branch of Morus alba to inhibit α-glucosidase, protein tyrosine phosphatase 1B (PTP1B), and advanced glycation end products (AGEs) formation was evaluated. Moreover, there are no previous studies that have performed enzyme kinetics and molecular docking analyses, along with assessments of peroxynitrite (ONOO⁻) inhibitory activities. Since the Morus alba branch exhibited favorable inhibitory effects, repeated column chromatography was performed to obtain eight compounds, including four flavonoids (1, 3, 6, 8), one arylbenzofuran (2), one stilbene (5), one Diels–Alder-type adduct (7), and one sterol (4). Among them, compounds 1–3 and 5–7 were mixed-type inhibitors of α-glucosidase, sharing the same catalytic residues with acarbose and the same allosteric sites with (Z)-3-bytylidenephthalide. On the other hand, kuwanon C (1) and oxyresveratrol (5) interacted with residues of the allosteric site (α3 and α6 helices) of PTP1B, indicating their use as non-competitive inhibitors. Interestingly, kuwanon G (7) directly bound the catalytic site, or interrupted the binding between the substrate and the active site, as a mixed-type inhibitor. Moreover, most of the compounds exhibited greater activity against AGE formation and ONOO⁻ than positive controls. The IC₅₀ values required to inhibit ONOO⁻ using compounds 1, 3, 5, 6, and 7 were reported for the first time, and range from 1.08 to 12.92 μM. Based on the structure–activity relationship, the presence of hydroxyl, resorcinol, and prenyl moieties was important in the prevention of diabetes’ pathological mechanisms, and these findings have been further supported by molecular docking analysis. These computational and experimental results will be useful in the development of therapeutic candidates to prevent/treat diabetes and its complications.

Extraction and Study of Hypoglycemic Constituents from Myrica rubra Pomace

Myrica rubra pomace accounts for 20% of the fruit’s weight that is not utilized when it is juiced. The pomace contains bioactive phenolic substances such as anthocyanins and flavonoids. To improve the utilization value of Myrica rubra pomace, an optimized extraction method for the residual polyphenols was developed using response surface methodology (RSM). The resulting extract was analyzed by high performance liquid chromatography (HPLC), and the in vitro hypoglycemic activity and antioxidant activity of the polyphenolic compounds obtained were also investigated. The optimum extraction conditions (yielding 24.37 mg·g⁻¹ total polyphenols content) were: extraction temperature 60 °C, ultrasonic power 270 W, ethanol concentration 53%, extraction time 57 min, and solid to liquid ratio 1:34. Four polyphenolic compounds were identified in the pomace extract by HPLC: myricitrin, cyanidin-O-glucoside, hyperoside, and quercitrin. DPPH and hydroxyl radical scavenging tests showed that the Myrica rubra polyphenols extract had strong antioxidant abilities. It is evident that the residual polyphenols present in Myrica rubra pomace have strong hypoglycemic activity and the juiced fruits can be further exploited for medicinal purposes.

Purification and Functional Characterization of the Chloroform/Methanol-Soluble Protein 3 (CM3) From Triticum aestivum in Drosophila melanogaster

Non-celiac wheat sensitivity (NCWS) has been proposed to be an independent disease entity that is characterized by intestinal (e.g., abdominal pain, flatulence) and extra-intestinal symptoms (e.g., headache, fatigue), which are propagated following the ingestion of wheat products. Increased activity of amylase trypsin inhibitors (ATIs) in modern wheat is suggested to be major trigger of NCWS, while underlying mechanisms still remain elusive. Here, we aimed to generate and functionally characterize the most abundant ATI in modern wheat, chloroform/methanol-soluble protein 3 (CM3), in vitro and in Drosophila melanogaster. We demonstrate that CM3 displays α-glucosidase but not α-amylase or trypsin inhibitory activity in vitro. Moreover, fruit flies fed a sucrose-containing diet together with CM3 displayed significant overgrowth of intestinal bacteria in a sucrose-dependent manner while the consumption of α-amylase and α-glucosidase inhibitors was sufficient to limit bacterial quantities in the intestine. Notably, both CM3 and acarbose-treated flies showed a reduced lifespan. However, this effect was absent in amylase inhibitor (AI) treated flies. Together, given α-glucosidase is a crucial requirement for disaccharide digestion, we suggest that inhibition of α-glucosidase by CM3 enhances disaccharide load in the distal gastrointestinal tract, thereby promoting intestinal bacteria overgrowth. However, it remains speculative if this here described former unknown function of CM3 might contribute to the development of gastrointestinal symptoms observed in NCWS patients which are very similar to symptoms of patients with small intestinal bacterial overgrowth.

Polyphenolic and Methylxanthine Bioaccessibility of Cocoa Bean Shell Functional Biscuits: Metabolomics Approach and Intestinal Permeability through Caco-2 Cell Models

Cocoa bean shell (CBS), a by-product with considerable concentrations of bioactive compounds and proven biofunctional potential, has been demonstrated to be a suitable ingredient for high-fiber functional biscuits adapted to diabetic consumers. In this work, the in vitro bioaccessibility and intestinal absorption of polyphenols and methylxanthines contained in these biscuits were evaluated, and the effect of the food matrix was studied. Biscuits containing CBS and the CBS alone underwent in vitro digestion followed by an intestinal permeability study. The results confirmed that compounds were less bioavailable in the presence of a food matrix, although the digestion contributed to their release from this matrix, increasing the concentrations available at the intestinal level and making them capable of promoting antioxidant and antidiabetic activities. After digestion, CBS biscuits were shown to possess α-glucosidase inhibition capacity comparable to that of acarbose. Moreover, the presence of the food matrix improved the stability of polyphenols throughout the digestion process. Intestinal absorption of flavan-3-ols seemed to be limited to a maximum threshold and was therefore independent of the sample, while procyanidin was not absorbed. Methylxanthine absorption was high and was boosted by the presence of the food matrix. The results confirmed the biofunctional potential of CBS-based biscuits.

Effects of a novel combination of orlistat and acarbose on tolerability, appetite, and glucose metabolism in persons with obesity

OBJECTIVE

There is an unmet medical need for a safe and effective weight loss product with minimal systemic side-effects. In this study, the effect of a novel modified-release fixed-dose combination of orlistat and acarbose (MR-OA) was compared with conventional orlistat (CO) regarding tolerability, appetite and glucose metabolism.

METHODS

Sixty-seven men with obesity, aged 24 to 60 years with body mass indexes (BMIs) 33 to 40 kg m-2 or BMIs 30 to 32 kg m-2 and waist circumference above 102 cm were included. They were randomized to either three different doses of the test formulation MR-OA (60 mg orlistat/20 mg acarbose, 90/30 and 120/40) or CO (Xenical, 120 mg orlistat) for a 2-week study of daily treatment. The participants spent days 1 and 14 at the clinical research centre where they received standardized meals, had blood sampling and filled in questionnaires regarding tolerability and appetite after meals. In days 2 to 13, the participants were at home and continued to fill in the questionnaires daily.

RESULTS

In the MR-OA groups, reports of liquid and oily stools as well as faecal incontinence were fewer, whereas reports of gastric distension and flatulence were higher, compared with the CO group. More participants reported decreased hunger in the 90/30 and 120/40 MR-OA, and postprandial plasma glucose concentration was reduced in all MR-OA groups compared with CO.

CONCLUSIONS

This study shows that by using a modified-release dosage form, orlistat and acarbose can be combined without compromising tolerability. Furthermore, MR-OA shows promising effects regarding reduction of appetite and reduces postprandial glucose. Tolerability is coupled to compliance and thereby efficacy of a treatment; therefore, this novel combination MR-OA could be an effective approach for weight loss treatment. A follow-up study in a more diverse population and for a longer duration with weight loss as primary outcome variable is planned.

Acarbose With Comparable Glucose-Lowering but Superior Weight-Loss Efficacy to Dipeptidyl Peptidase-4 Inhibitors: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

Background: Acarbose and dipeptidyl peptidase-4 inhibitors (DPP-4is) have several similarities regarding their efficacy. Assessing the hypoglycemic and weight-loss effects, as well as the tolerability between them at their optimal dosages, could provide a better management of adult type 2 diabetics. Methods: We performed a systematic review and network meta-analysis (NMA) on randomized controlled trials that were identified from the databases of EMBASE, MEDLINE, Cochrane Central Register of Controlled Trials, Web of Science, Conference Proceedings Citation Index, ClinicalTrials.gov, China National Knowledge Infrastructure, Wan Fang, and SinoMed. The trials with 300 mg/day of acarbose or the recommended doses of DPP-4is were the most optimal for our NMA. The mean differences (MD) and relative risk (RR) derived from eligible studies were used. Results: Among the 15,411 obtained potential studies, 13 pair-wise trials and 48 monotherapy studies were included in the meta-analysis and NMA, respectively. DPP-4is had a greater glucose-lowering effect, but a weaker weight-loss effect than acarbose in pair-wise meta-analysis (p < 0.05). However, NMA with 11,877 participants showed that, at their optimal doses, acarbose and DPP-4is had similar glucose-lowering effects on the 2-h postprandial glucose (MD 0.96 mmol/L, 95% credible interval -0.56 to 2.54), HbA1c (0.05%, -0.25 to 0.33), fasting plasma glucose reductions (-0.27 mmol/L, -0.76 to 0.24), and HbA1c < 7.0% target goal achievement (RR 1.33, 0.51 to 3.64). Acarbose was superior to DPP-4is regarding weight loss (MD -1.23 kg, -2.08 to -0.33). Acarbose had more withdrawal, gastrointestinal, and overall adverse events than DPP-4is (p < 0.05), but the differences disappeared after longer treatment (p > 0.05). Conclusions: Acarbose and DPP-4is have similar glucose-lowering effects, but the weight-loss effects of acarbose are superior. Therefore, in the use of the most optimal dosages, overweight/obese type 2 diabetics might benefit more from a treatment with acarbose than DPP-4is.

Considerations when using alpha-glucosidase inhibitors in the treatment of type 2 diabetes

Introduction: Alpha-glucosidase inhibitors (AGIs) - oral antihyperglycemic drugs, inhibit upper gastrointestinal enzymes that break down complex carbohydrates into glucose. As a result, the absorption of glucose is delayed, postprandial glucose reduced, and glycemic control improved.Areas covered: In this review, the authors describe the current recommendations on the use of the three major approved AGIs (acarbose, miglitol, voglibose). Efficacy and safety parameters together with ethnic considerations have been highlighted throughout the manuscript. The article also discusses potential diabetes prevention and cardiovascular effects of these medications.Expert opinion: The overall safety and efficacy of this class of drug appears to be high: AGIs do not increase the risk of hypoglycemia, do not cause weight gain; they also significantly improve postprandial hyperglycemia, have been associated with the reduction in risk factors for cardiovascular disease and may also delay the progression of prediabetes to T2DM. In general, we continue to believe that acarbose, miglitol, and voglibose should be used as third-line add on treatment options to other anti-hyperglycemic agents. However, this class can have earlier consideration in elderly and/or when metformin is contraindicated.

Diabetes pharmacotherapy and effects on the musculoskeletal system

Persons with type 1 or type 2 diabetes have a significantly higher fracture risk than age-matched persons without diabetes, attributed to disease-specific deficits in the microarchitecture and material properties of bone tissue. Therefore, independent effects of diabetes drugs on skeletal integrity are vitally important. Studies of incretin-based therapies have shown divergent effects of different agents on fracture risk, including detrimental, beneficial, and neutral effects. The sulfonylurea class of drugs, owing to its hypoglycemic potential, is thought to amplify the risk of fall-related fractures, particularly in the elderly. Other agents such as the biguanides may, in fact, be osteo-anabolic. In contrast, despite similarly expected anabolic properties of insulin, data suggests that insulin pharmacotherapy itself, particularly in type 2 diabetes, may be a risk factor for fracture, negatively associated with determinants of bone quality and bone strength. Finally, sodium-dependent glucose co-transporter 2 inhibitors have been associated with an increased risk of atypical fractures in select populations, and possibly with an increase in lower extremity amputation with specific SGLT2I drugs. The role of skeletal muscle, as a potential mediator and determinant of bone quality, is also a relevant area of exploration. Currently, data regarding the impact of glucose lowering medications on diabetes-related muscle atrophy is more limited, although preclinical studies suggest that various hypoglycemic agents may have either aggravating (sulfonylureas, glinides) or repairing (thiazolidinediones, biguanides, incretins) effects on skeletal muscle atrophy, thereby influencing bone quality. Hence, the therapeutic efficacy of each hypoglycemic agent must also be evaluated in light of its impact, alone or in combination, on musculoskeletal health, when determining an individualized treatment approach. Moreover, the effect of newer medications (potentially seeking expanded clinical indication into the pediatric age range) on the growing skeleton is largely unknown. Herein, we review the available literature regarding effects of diabetes pharmacotherapy, by drug class and/or by clinical indication, on the musculoskeletal health of persons with diabetes.

Hypoglycemic effect of standardized Chrysanthemum zawadskii ethanol extract in high-fat diet/streptozotocin-induced diabetic mice and rats

Chrysanthemum zawadskii (CZ) is a perennial herb belonging to the Asteraceae family. CZ is used medicinally to treat inflammatory and uterine diseases in Asia. CZ was extracted with 50% ethanol and CZ extract (CZE; at 125, 250, and 500 mg/kg body weight) was administered orally every day for 5 or 6 weeks to investigate the anti-diabetic effects in streptozotocin (STZ)-induced rats and STZ + high-fat diet (HFD)-fed mice. CZE significantly decreased fasting blood glucose levels in STZ- and STZ + HFD-induced diabetic models. In addition, glucose tolerance and insulin tolerance were improved in the STZ + HFD + CZE group by increasing insulin levels and decreasing hemoglobin A1c (HbA1c) levels in serum. Furthermore, CZE supplements decreased components of the serum lipid profile such as triglyceride, total cholesterol, and low-density lipoprotein cholesterol levels. These results suggest that CZE may be a potential candidate for controlling hyperglycemia.

Associations between changes in glucagon-like peptide-1 and bodyweight reduction in patients receiving acarbose or metformin treatment

BACKGROUND

The present post hoc analysis investigated whether changes in endogenous glucagon-like peptide-1 (∆GLP-1) levels are associated with weight loss in newly diagnosed diabetes patients.

METHODS

In all, 784 subjects from the Metformin and AcaRbose in Chinese as initial Hypoglycemic treatment (MARCH) study were stratified according to ∆GLP-1. Changes in clinical and physiological parameters were evaluated across ∆GLP-1 subgroups (low, medium, and high) to assess correlations between ∆GLP-1 and weight loss in acarbose- versus metformin-treated groups.

RESULTS

After 24 weeks treatment, greater ∆GLP-1 was associated with significantly greater weight loss (-2 vs -1 kg in the medium/high vs low ∆GLP-1 groups, respectively) and reduction in body mass index (BMI; -0.88, -0.83, and -0.69 kg/m² in the high, medium, and low ∆GLP-1 groups, respectively). In the acarbose-treated group, there was a significant association between ∆GLP-1 and BMI reductions, and greater ∆GLP-1 across the high, medium, and low ∆GLP-1 groups was correlated with greater weight loss (-2.8, -2.1, and -1.9 kg, respectively) and reductions in fasting plasma glucose (-1.57, -1.28, and -1.02 mmol/L, respectively) at Week 24. No significant differences were found across ∆GLP-1 subgroups in metformin-treated patients (P > 0.05). Multivariate linear regression analysis revealed that gender, baseline BMI, and ∆GLP-1 at Week 24 were associated with weight loss. Baseline BMI and ∆GLP-1 in the acarbose-treated group and baseline BMI in the metformin-treated group predicted weight loss at Week 24.

CONCLUSION

Changes in GLP-1 levels are associated with weight loss in newly diagnosed Chinese diabetes patients receiving acarbose.

Toxicity of Oral Agents Used to Treat Diabetes

Oral agents used for the management of type 2 diabetes mellitus include sulfonylureas, biguanides, thiazolidinediones, metglitinides, and/or α -glucosidase inhibitors. These medication classes can be further classified as hypoglycemic and antihyperglycemic agents. Hypoglycemia is a major symptom of toxicity of these agents, particularly with the sulfonylureas, including combination medications that include sulfonylureas. In overdose situations, metformin, a biguanide, can lead to considerable gastrointestinal adverse effects and potentially lactic acidosis in severe cases. Data on the management of toxicities of the other classes are limited. This article will review the treatment modalities that have been used for treating symptomatic hypoglycemia and metformin-induced lactic acidosis.

Action of Celgosivir (6 O-Butanoyl Castanospermine) against the Pestivirus BVDV: Implications for the Treatment of Hepatitis C

α-Glucosidase I inhibitors have been shown to inhibit the replication of a broad range of enveloped viruses by preventing the correct folding of their envelope glycoproteins. This study assesses the potential of 6 O-butanoyl castanospermine (cel-gosivir) as a treatment for hepatitis C virus (HCV). In the absence of an adequate culture system for HCV, the closely related virus, bovine viral diarrhoea virus (BVDV), was used as a surrogate model. Using both a plaque assay and a cytopathic effect assay, celgosivir (IC50 16 and 47 μM respectively) was shown to be more potent than N-nonyl DNJ (105 and 74 μM), castanospermine (110 and 367 μM) and N-butyl DNJ (>250 and 550 μM). Of the α-glucosi-dase inhibitors tested, only N-nonyl DNJ showed evidence of toxicity (CC50 ≥120 μM). Two-way combinations of interferon-α, ribavirin and either celgosivir or castanospermine demonstrated that each could enhance the antiviral efficacy of the others, either additively or synergistically. The observation that the number of viral genomes released from BVDV-infected cells was inhibited by either castanospermine or celgosivir in parallel with the number of infectious units was taken as confirmation that these α-glucosidase I inhibitors block the production or release of flavivirus particles.

Acarbose reduces body weight irrespective of glycemic control in patients with diabetes: results of a worldwide, non-interventional, observational study data pool

OBJECTIVE

The objective of this study is to examine the effect of acarbose, an alpha-glucosidase inhibitor, on body weight in a real-life setting by pooling data from post-marketing surveillance.

METHODS

Data from 10 studies were pooled (n=67,682) and the effect of acarbose on body weight was analysed taking into account baseline body weight, glycemic parameters and other baseline characteristics.

RESULTS

The mean relative reduction in body weight was 1.45 ± 3.24% at the 3-month visit (n=43,510; mean baseline 73.4 kg) and 1.40 ± 3.28% at the last visit (n=54,760; mean baseline 73.6 kg) (both p<0.0001). These reductions were dependent on baseline body weight (overweight: -1.33 ± 2.98% [n=13,498; mean baseline 71.6 kg]; obese: -1.98 ± 3.40% [n=20,216; mean baseline 81.3 kg]). When analysed by baseline glycemic parameter quartiles, the reduction was independent of fasting plasma glucose (FPG), postprandial plasma glucose (PPG), glycated hemoglobin (HbA1c) and postprandial glucose excursion (PPGE). A bivariate analysis of covariance identified female sex, South East Asian and East Asian ethnicity, younger age, higher body mass index, short duration of diabetes, and no previous treatment as factors likely to impact positively on body weight reduction with acarbose.

CONCLUSIONS

This post-hoc analysis showed that acarbose treatment reduces body weight independent of glycemic control status but dependent on baseline body weight.

Chemical Composition andα-Glucosidase Inhibitory Activity of VietnameseCitrusPeels Essential Oils

Background. Inhibition ofα-glucosidase is an important factor to control postprandial hyperglycemia in type 2 diabetes mellitus.Citrusessential oils (CEO) are among the most widely used essential oils, and some of them exhibited promising antidiabetic effect. However, theα-glucosidase inhibition of CEO has not been investigated so far. The present work aims to evaluate theα-glucosidase inhibition of essential oils from six VietnameseCitruspeels.Methods. The chemical composition of essential oils obtained by hydrodistillation from sixCitruspeels was analyzed by GC-MS. All essential oils were tested for their inhibitory activity onα-glucosidase usingp-nitrophenyl-α-D-glucopyranoside as substrate.Results. In Buddha’s hand and lime peels, the major components were limonene (59.0–61.31%) andγ-terpinene (13.98–23.84%) while limonene (90.95–95.74%) was most abundant in pomelo, orange, tangerine, and calamondin peels. Among the essential oils, the Buddha’s hand oil showed the most significantα-glucosidase inhibitory effect with the IC50value of 412.2 μg/mL. The combination of the Buddha’s hand essential oil and the antidiabetic drug acarbose increased the inhibitory effect.Conclusions. The results suggested the potential use of Buddha’s hand essential oil as an alternative in treatment of type 2 diabetes mellitus.

Therapeutic potential of α-glucosidase inhibitors in type 2 diabetes mellitus: an evidence-based review

INTRODUCTION

Postprandial hyperglycemia (PPHG) contributes to micro- and macro-vascular complications more than fasting hyperglycemia in patients with type 2 diabetes mellitus. Due to the traditional carbohydrate-rich diet, Asians, particularly Indians and Chinese need agents to control the higher risk of uncontrolled PPHG. Targeting PPHG with α-glucosidase inhibitors (AGIs), either alone or in combination with other oral hypoglycemic agents and insulin, provide overall glycemic control with transient mild gastrointestinal disorders. Treatment with AGIs, especially acarbose, has also shown to provide beneficial effects on lipid levels, blood pressure, coagulation factors, carotid intima-media thickness and endothelial dysfunction. New insights of acarbose therapy obtained like increased activity of gut hormones and improved gut microbiota may explain the benefits on weight, whereas increased production of H2 may explains its cardiovascular benefits to some extent.

AREAS COVERED

A systematic search strategy was developed to identify randomized controlled trials in MEDLINE, PubMed, EMBASE and ongoing trials databases.

EXPERT OPINION

AGIs as a class and acarbose in particular, are most useful in combatting PPHG and glucose variability across the spectrum of diabetes therapy, particularly in Asian patients. Together with their effects on incretin hormones and gut-microbiota AGIs can be considered beyond glycemic control as 'cardio-protective agents.'

Acarbose: safe and effective for lowering postprandial hyperglycaemia and improving cardiovascular outcomes

α-Glucosidase inhibitors (AGIs) are a class of oral glucose-lowering drugs used exclusively for treatment or prevention of type 2 diabetes mellitus. AGIs act by altering the intestinal absorption of carbohydrates through inhibition of their conversion into simple sugars (monosaccharides) and thus decrease the bioavailability of carbohydrates in the body, significantly lowering blood glucose levels. The three AGIs used in clinical practice are acarbose, voglibose and miglitol. This review will focus on the cardiovascular properties of acarbose. The current available data suggest that AGIs (particularly acarbose) may be safe and effective for the treatment of prediabetes and diabetes.

How do high glycemic load diets influence coronary heart disease?

Background

Diet has a significant relationship with the risk of coronary heart disease (CHD). Traditionally the effect of diet on CHD was measured with the biomarker for low-density lipoprotein (LDL) cholesterol. However, LDL is not the only or even the most important biomarker for CHD risk. A suitably integrated view of the mechanism by which diet influences the detailed CHD pathogenetic pathways is therefore needed in order to better understand CHD risk factors and help with better holistic CHD prevention and treatment decisions.

Methods

A systematic review of the existing literature was conducted. From this an integrated CHD pathogenetic pathway system was constructed. CHD biomarkers, which are found on these pathways, are the only measurable data to link diet with these CHD pathways. They were thus used to simplify the link between diet and the CHD mechanism. Data were systematically analysed from 294 cohort studies of CHD biomarkers constituting 1 187 350 patients.

Results and discussion

The resulting integrated analysis provides insight into the higher-order interactions underlying CHD and high-glycemic load (HGL) diets. A novel “connection graph” illustrates the measurable relationship between HGL diets and the relative risks attributed to the important CHD serological biomarkers.

The “connection graph” vividly shows that HGL diets not only influence the lipid and metabolic biomarkers, but also the inflammation, coagulation and vascular function biomarkers in an important way.

Conclusion

A focus primarily on the low density lipoprotein cholesterol biomarker for CHD risk has led to the traditional guidelines of CHD dietary recommendations. This has however inadvertently led to HGL diets. The influence of HGL diets on the other CHD biomarkers is not always fully appreciated. Thus, new diets or other interventions which address the full integrated CHD impact, as shown in this paper, are required.

Pharmacologic treatment of type 2 diabetes: oral medications

OBJECTIVE

To review the oral and injectable pharmacologic treatment options for type 2 diabetes.

DATA SOURCES

A literature search was conducted using PubMed electronic database for studies published in English between 1993 and September 2014. Search terms included diabetes mellitus, type 2 diabetes, and the individual name for each antidiabetic medication reviewed. In addition, manual searches were performed for cross-references from publications. Package inserts, United States Food and Drug Administration (FDA) Web site, Institute for Safe Medication Practices Web site, American Diabetes Association Web site and scientific session poster presentations, and individual drug company Web pages were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

This review focused on information elucidated over the past 10 years to assist prescribers in choosing optimal therapy based on individual patient characteristics. Studies leading to the approval of or raising safety concerns for the antidiabetic medications reviewed in this article were included.

DATA SYNTHESIS

In the past 10 years, there have been 4 novel oral antidiabetic medication classes and 9 new injectable agents and insulin products approved by the FDA for the treatment of type 2 diabetes as well as new information regarding the safety and use of several older antidiabetic medication classes. The distinctions were reviewed for each individual agent, and a comparison was completed if there was more than one agent in a particular therapeutic class. Using current information available, select investigational agents in phase III trials or those with a pending new drug application were highlighted.

CONCLUSION

There are now 9 distinct oral pharmacologic classes and a variety of insulin and noninsulin injectable medications available for the treatment of type 2 diabetes. Metformin remains the first-line treatment option for most patients. When considering options for alternative or additional treatment, prescribers must weigh the benefits and risks using individual patient characteristics.

Natural Flavonoids as Potential Herbal Medication for the Treatment of Diabetes Mellitus and its Complications

Diabetes mellitus, together with its various complications, is becoming a serious threat to human health. Natural products are secondary metabolites widely distributed in plants, having a broad range of biological activities. The development of antidiabetic medication from natural products, especially those originating from plants with a traceable folk-usage history in treating diabetes, is receiving more attention. Many studies highlighted not only the benefits of natural flavonoids with hypoglycemic effects, but also their importance in the management of diabetic complications. This review describes selected natural flavonoids that have been validated for their hypoglycemic properties, together with their mechanisms of action. Also discussed are their activities in the treatment of diabetic complications demonstrated via laboratory diabetic animal models, in vitro and clinical trials using human subjects. Published papers from 2000 to date on flavonoids and diabetes were covered through accessing Web of Science and multiple databases for biomedical sciences. The major potential benefits of natural flavonoids discussed in this review clearly suggest that these substances are lead compounds with sufficient structural diversity of great importance in the antidiabetic drug developing process.

Achieving glycemic control in elderly patients with type 2 diabetes: a critical comparison of current options

The prevalence of type 2 diabetes mellitus (T2DM) is increasing in the elderly. Because of the unique characteristics of elderly people with T2DM, therapeutic strategy and focus should be tailored to suit this population. This article reviews the guidelines and studies related to older people with T2DM worldwide. A few important themes are generalized: 1) the functional and cognitive status is critical for older people with T2DM considering their life expectancy compared to younger counterparts; 2) both severe hypoglycemia and persistent hyperglycemia are deleterious to older adults with T2DM, and both conditions should be avoided when determining therapeutic goals; 3) recently developed guidelines emphasize the avoidance of hypoglycemic episodes in older people, even in the absence of symptoms. In addition, we raise the concern of glycemic variability, and discuss the rationale for the selection of current options in managing this patient population.

Mulberry leaf extract improves postprandial glucose response in prediabetic subjects: a randomized, double-blind placebo-controlled trial

This study was a randomized, double-blind placebo-controlled trial to assess the efficacy of 4 weeks of mulberry leaf aqueous extract (MLAE) supplementation (5 g/day) for postprandial glycemic control in 36 subjects with impaired fasting glucose (IFG) tolerance. Postprandial responses in the glucose, insulin, and C-peptide levels were measured after a carbohydrate load both at baseline and after 4 weeks of MLAE supplementation. The postprandial glycemic response was attenuated in the MLAE group after the treatment period, particularly 30 and 60 min after loading (P=.003 and 0.0325 for glucose, P=.0005 and .0350 for insulin, and P=.0151 and .0864 for C-peptide). Additionally, the incremental area under the curve for insulin was significantly lower in the MLAE group than in the placebo group (P=.0207). Four weeks of MLAE supplementation improved postprandial glycemic control in individuals with IFG tolerance.

Acarbose improves glycemic control and reduces body weight: Subanalysis data of South Asia region

Alpha-glucosidase inhibitors (AGIs) are widely used especially in Asian countries as a treatment option for type 2 diabetes patients with high postprandial glycaemia. However, data from South Asia region is very limited. In order to examine the effect of AGI in real-life setting, 10 PMS/NIS from all over the world from the launch of acarbose to date were pooled in one database and exploratory analysis was performed for glycemic parameters and weight. In total 62,905 patients were pooled from 21 countries and regions. Mean follow up (± SD) was 12.2 ± 4.8 weeks (range 0.1-108.9). From South Asia region (India and Pakistan), 8,738 Asian patients were enrolled. Mean PPG decreased from 240.0 and 261.1 mg/dl at baseline by 70.26 ± 65.10 and 82.96 ± 56.59 mg/dl at the last visit in total and South Asian populations, respectively (n = 53,883; n = 7,991, P < 0.0001 for both). Mean FPG decreased from 171.6 and 176.5 mg/dl at baseline by 38.48 ± 47.83 and 49.59 ± 41.41 mg/dl at the last visit in total and South Asian populations, respectively (n = 56,672; n = 7,837, P < 0.0001 for both). Mean HbA1c decreased from 8.4 and 8.4% at baseline by 1.11 ± 1.31% and 0.91 ± 0.93% at the last visit in total and South Asian populations, respectively (n = 38,843; n = 2,343, P < 0.0001 for both). Mean relative reduction of body weight (BW) was 1.40 ± 3.28% and 1.10 ± 3.39% at the last visit for mean baseline BW 73.6 and 74.2 kg in total and South Asian populations, respectively (n = 54,760; n = 7,718, P < 0.0001 for both). Consistent with RCT meta-analyses, post-hoc analysis of real-life data showed acarbose treatment improved glycaemic control and reduced the BW. Acarbose treatment in real life setting showed significant reductions in all glycemic parameters and BW in Asian patients from South Asia region.

An observational study of acarbose treatment in patients with type 2 diabetes from the Middle East and Morocco

BACKGROUND

The prevalence of type 2 diabetes is increasing dramatically in the Middle East and North Africa region. However, there are few trials that have determined the effect of antidiabetic treatment in an observational setting in these countries.

METHODS

This was a noninterventional study performed in Morocco in 2006-2007 and in the Middle East in 2005-2006 to observe the efficacy and safety of acarbose in patients with pretreated or untreated type 2 diabetes. Glycemic parameters (fasting blood glucose, one-hour postprandial blood glucose, and HbA1c) were recorded within a 3-month period. The observation period included an initial visit at the start of acarbose therapy and up to three follow-ups.

RESULTS

Acarbose was effective in reducing glycemic parameters in patients from Morocco (n = 1082) and the Middle East (n = 1737). The mean one-hour postprandial blood glucose decreased by 35.5% to 165.4 ± 47.9 mg/dL in the Middle East and by 35.5% to 179.0 ± 49.9 mg/dL in Morocco. Mean fasting blood glucose decreased by 30.8% to 126.6 ± 34.2 mg/dL (Middle East) and by 34.5% to 150.6 ± 47.1 mg/dL (Morocco). The absolute reduction in HbA1c was 1.3% in the Middle East (final value 7.4%) and 1.0% in Morocco (final value 7.5%). Overall, 107 patients (Middle East) and 26 patients (Morocco) experienced minor drug-related adverse events, which were mainly gastrointestinal. The tolerability of acarbose was rated as very good/good by 80.8% in the Middle East and by 68.6% in Morocco.

CONCLUSION

This study illustrates the efficacy and safety of acarbose in the treatment of type 2 diabetic patients in an observational setting.

Evaluation of the efficacy and tolerability of acarbose in patients with diabetes mellitus : a postmarketing surveillance study

OBJECTIVE

The efficacy and tolerability of acarbose were examined in a postmarketing surveillance study of 27 803 patients with diabetes mellitus (26 044 were diagnosed as having type 2 diabetes) over a 12-week treatment period. PATIENTS AND M ethods: Overall efficacy data were reported for type 1 and type 2 diabetes, and a detailed data analysis was conducted for patients with type 2 diabetes. Tolerability was described for the total group. Of the type 2 diabetes patients, 37.6% were treated with diet only; 44.2% were additionally treated with sulphonylureas; 6.3% with metformin or metformin plus sulphonylurea; and 11.6% with insulin alone or in combination with oral treatment. The frequency of two or more concomitant diseases was 45.8% for all type 2 diabetes patients, and 62.4% in elderly patients (age >/=70 years).

RESULTS

In patients with type 2 diabetes, acarbose administration in addition to the existing treatment resulted in reductions in mean blood glucose levels (fasting 50 mg/dL, 1h post-prandial [pp] 60 mg/dL, 2h pp 56 mg/dL), glycosylated haemoglobin (HbA(1c) 1.3%; HbA(1) 1.6%) and bodyweight (1.5 kg). Results for type 1 diabetes patients were similar. No clinically relevant influence of age, body mass index or number of concomitant diseases on the results could be observed. Tolerability was good: 83% of patients had no adverse events, 13.7% reported flatulence, and 2.2% had at least one occurrence of diarrhoea. Hypoglycaemia was found in 0.07% of patients, mainly in combination with metformin or insulin. Tolerability was independent of patients' age. Laboratory investigations gave no indication of other adverse events.

CONCLUSION

This postmarketing surveillance study documents the therapeutic benefit and good tolerability and compliance of acarbose as mono- and combination therapy, even in elderly and multimorbid patients.

Acarbose revisited for efficacy, safety and cardiovascular benefits: a key role for controlling glycemic variability

There is a growing body of evidence to illustrate the effect of postprandial hyperglycemia (PPHG) in cardiovascular disease development and as a key component of diurnal hyperglycemia. Agents such as acarbose, which has been shown to reduce 24-h glycemia and glycated hemoglobin (mainly via its effects on PPHG), may have the potential to reduce the risk of adverse cardiovascular outcomes as indicated in secondary analyses of the STOP-NIDDM trial. Although the results of the NAVIGATOR trial showed no effect of PPHG reduction on cardiovascular outcomes, acarbose has a different mode of action to nateglinide. This could lead to marked cardiovascular differences, and it is important to fully investigate this. The ongoing ACE trial will determine the effect of acarbose on a composite primary end point of cardiovascular outcomes.

Critical evaluation of the role of acarbose in the treatment of diabetes: patient considerations

The alpha-glucosidase inhibitor acarbose has been used for more than 20 years in the management of hyperglycemia. Owing to its unique mode of action in the gastrointestinal tract, its properties are very different from other antidiabetic medications. Patients on long-term treatment to control a chronic disease are not only interested in good treatment efficacy, but are also even more interested in the safety and side effects of their medications. Significant aspects of acarbose predominantly regarding safety and tolerability in the management of type 2 diabetes and prediabetes are reviewed. It is concluded that acarbose is a convenient long-term treatment option, with benefits for both type 2 diabetics and patients in a prediabetic state.

A randomised crossover placebo-controlled trial investigating the effect of brown seaweed (Ascophyllum nodosum and Fucus vesiculosus) on postchallenge plasma glucose and insulin levels in men and women

This study examined the impact of brown seaweed on post-load plasma glucose and insulin concentrations in men and women. Twenty-three participants (11 men, 12 women) aged 19-59 years were recruited in this double-blind, randomized, placebo-controlled crossover study. The test product consisted of a commercially available blend of brown seaweed (Ascophyllum nodosum and Fucus vesiculosus) with known inhibitory action on α-amylase and α-glucosidase activities (InSea²). Two 250 mg seaweed capsules and 2 placebo capsules were consumed on each occasion 30 min prior to the consumption of 50 g of carbohydrates from bread. Plasma glucose and insulin concentrations were measured over a period of 3 h postcarbohydrate ingestion at predetermined time points. Both treatments were separated by a 1-week washout period. Data were analysed using mixed models for repeated measures. Compared with placebo, consumption of seaweed was associated with a 12.1% reduction in the insulin incremental area under the curve (p = 0.04, adjusted for baseline) and a 7.9% increase in the Cederholm index of insulin sensitivity (p < 0.05). The single ingestion of 500 mg of brown seaweed had no significant effect on the glucose response (p = 0.24, adjusted for baseline). Glucose and insulin responses were similar between men and women. Consumption of the seaweed capsules was not associated with any adverse event. These data suggest that brown seaweed may alter the insulin homeostasis in response to carbohydrate ingestion.

A review of methods used in assessing non-serious adverse drug events in observational studies among type 2 diabetes mellitus patients

Clinical drug trials are often conducted in selective patient populations, with relatively small numbers of patients, and a short duration of follow-up. Observational studies are therefore important for collecting additional information on adverse drug events (ADEs). Currently, there is no guidance regarding the methodology for measuring ADEs in such studies. Our aim was to evaluate whether the methodology used to assess non-serious ADEs in observational studies is adequate for detecting these ADEs, and for addressing limitations from clinical trials in patients with type 2 diabetes mellitus. We systematically searched MEDLINE and EMBASE for observational studies reporting non-serious ADEs (1999-2008). Methods to assess ADEs were classified as: 1) medical record review; 2) surveillance by health care professionals (HCP); 3) patient survey; 4) administrative data; 5) laboratory/clinical values; 6) not specified. We compared the range of ADEs identified, number and selection of patients included, and duration of follow-up. Out of 10,125 publications, 68 studies met our inclusion criteria. The most common methods were based on laboratory/clinical values (n = 25) and medical record review (n = 18). Solicited surveillance by HCP (n = 17) revealed the largest diversity of ADEs. Patient surveys (n = 15) focused mostly on hypoglycaemia and gastrointestinal ADEs, laboratory values based studies on hepatic and metabolic ADEs, and administrative database studies (n = 5) on cardiovascular ADEs. Four studies presented ADEs that were identified with the use of more than one method. The patient population was restricted to a lower risk population in 19% of the studies. Less than one third of the studies exceeded pre-approval regulatory requirements for sample size and duration of follow-up. We conclude that the current assessment of ADEs is hampered by the choice of methods. Many observational studies rely on methods that are inadequate for identifying all possible ADEs. Patient-reported outcomes and combinations of methods are underutilized. Furthermore, while observational studies often include unselective patient populations, many do not adequately address other limitations of pre-approval trials. This implies that these studies will not provide sufficient information about ADEs to clinicians and patients. Better protocols are needed on how to assess adverse drug events not only in clinical trials but also in observational studies.

Evaluation of efficacy of acarbose on glucose fluctuation and postprandial glucose using continuous glucose monitoring in type 2 diabetes mellitus

BACKGROUND

The objective of this study was to evaluate the effects of the α-glucosidase inhibitor acarbose on glucose fluctuations in patients with type 2 diabetes using continuous glucose monitoring (CGM).

METHODS

CGM was performed for 4 days (72 h), and acarbose at 300 mg/day was administered on two of these days but not on the other two days. The effects on blood glucose fluctuations were evaluated.

RESULTS

We recruited a total of 10 patients (five men and five women) with a mean ± SD age of 63.1 ± 12.1 years, body mass index of 22.6 ± 5.4 kg/m(2), and glycohemoglobin of 9.9 ± 1.9%. During treatment with acarbose, significant decreases in median (range) SD of 24-h mean blood glucose (22.48 [6.39-47.22] mg/dL vs. 32.78 [18.83-58.93] mg/dL, P = 0.004), 24-h blood glucose fluctuations (453.27 [128.51-903.94] mg·h/dL vs. 677.05 [358.03-1,234.57] mg·h/dL, P = 0.002), and mean amplitude of glycemic excursions (65.00 [18.17-117.50] vs. 97.09 [53.00-166.67], P = 0.010) occurred compared with no treatment.

CONCLUSIONS

Acarbose reduced excessive blood glucose fluctuations.

International noninterventional study of acarbose treatment in patients with type 2 diabetes mellitus

AIM

To obtain data on efficacy, safety and tolerability of acarbose monotherapy or combination therapy during daily-life treatment.

METHODS

This prospective, non-controlled, observational study enrolled patients with type 2 diabetes, whose physician decided that acarbose treatment was appropriate, from China, Middle East, Indonesia, Morocco, Pakistan, Philippines, Poland and Taiwan. The observation period included an initial visit and up to three follow-up visits; an extension of 2 years was realized in Pakistan and Poland.

RESULTS

Of 14,574 patients enrolled, 14,418 comprised the intent-to-treat population. At the initial visit, 74.1% of patients had been treated with a glucose-lowering agent. Fasting blood glucose was reduced from 175.2mg/dL at the initial visit to 133.7 mg/dL at the last visit (mean of 11.3 weeks after initial visit; P<0.0001). Mean 2-h postprandial blood glucose decreased from 244.7 mg/dL to 172.4 mg/dL (P<0.0001). HbA1c reduced from 8.4% to 7.4% (P<0.0001). Glycemic efficacy was maintained over the 2-year extension period. There were 432 adverse events in 293 patients (2.03%), mainly gastrointestinal. Physicians assessed efficacy as "very good"/"good" in 85.1% of patients, and were "very satisfied"/"satisfied" with acarbose therapy in 94.3% of cases.

CONCLUSION

Acarbose therapy was efficacious and well tolerated in daily life in patients with type 2 diabetes.

Potent α-amylase inhibitory activity of Indian Ayurvedic medicinal plants

BACKGROUND

Indian medicinal plants used in the Ayurvedic traditional system to treat diabetes are a valuable source of novel anti-diabetic agents. Pancreatic α-amylase inhibitors offer an effective strategy to lower the levels of post-prandial hyperglycemia via control of starch breakdown. In this study, seventeen Indian medicinal plants with known hypoglycemic properties were subjected to sequential solvent extraction and tested for α-amylase inhibition, in order to assess and evaluate their inhibitory potential on PPA (porcine pancreatic α-amylase). Preliminary phytochemical analysis of the lead extracts was performed in order to determine the probable constituents.

METHODS

Analysis of the 126 extracts, obtained from 17 plants (Aloe vera (L.) Burm.f., Adansonia digitata L., Allium sativum L., Casia fistula L., Catharanthus roseus (L.) G. Don., Cinnamomum verum Persl., Coccinia grandis (L.) Voigt., Linum usitatisumum L., Mangifera indica L., Morus alba L., Nerium oleander L., Ocimum tenuiflorum L., Piper nigrum L., Terminalia chebula Retz., Tinospora cordifolia (Willd.) Miers., Trigonella foenum-graceum L., Zingiber officinale Rosc.) for PPA inhibition was initially performed qualitatively by starch-iodine colour assay. The lead extracts were further quantified with respect to PPA inhibition using the chromogenic DNSA (3, 5-dinitrosalicylic acid) method. Phytochemical constituents of the extracts exhibiting≥ 50% inhibition were analysed qualitatively as well as by GC-MS (Gas chromatography-Mass spectrometry).

RESULTS

Of the 126 extracts obtained from 17 plants, 17 extracts exhibited PPA inhibitory potential to varying degrees (10%-60.5%) while 4 extracts showed low inhibition (< 10%). However, strong porcine pancreatic amylase inhibitory activity (> 50%) was obtained with 3 isopropanol extracts. All these 3 extracts exhibited concentration dependent inhibition with IC50 values, viz., seeds of Linum usitatisumum (540 μgml-1), leaves of Morus alba (1440 μgml-1) and Ocimum tenuiflorum (8.9 μgml-1). Acarbose as the standard inhibitor exhibited an IC50 (half maximal inhibitory concentration)value of 10.2 μgml-1. Phytochemical analysis revealed the presence of alkaloids, tannins, cardiac glycosides, flavonoids, saponins and steroids with the major phytoconstituents being identified by GC-MS.

CONCLUSIONS

This study endorses the use of these plants for further studies to determine their potential for type 2 diabetes management. Results suggests that extracts of Linum usitatisumum, Morus alba and Ocimum tenuiflorum act effectively as PPA inhibitors leading to a reduction in starch hydrolysis and hence eventually to lowered glucose levels.

The investigation of the efficacy of insulin glargine on glycemic control when combined with either repaglinide or acarbose in obese Type 2 diabetic patients

Combinations of insulin and oral antidiabetic drugs (OAD) are often prescribed instead of insulin alone. In this study, the effects of insulin glargine (IG) in combination with repaglinide or acarbose on glycemic parameters were investigated. Obese Type 2 diabetic patients with fasting blood glucose (FBG) levels >or= 7.7 mmol/l [corrected] and hemoglobin glycated (A1C) >or=9% under maximal OAD combination therapy were enrolled. Previous therapies were discontinued, and patients were randomized into 2 groups. The combinations of IG and repaglinide were administered to group 1, and of IG and acarbose to group 2 for 13 weeks. Twenty patients in group 1 and 18 patients in group 2 completed the study. A1C levels were significantly decreased from 10.9+/-1.4% to 7.7+/-1.1% in group 1 and 11.0+/-1.4% to 8.1+/-1.4% in group 2. FBG levels were significantly decreased from 11.9+/-2.7 to 7.1+/-2.3 mmol/l in group 1 and 11.1+/-2.5 to 6.8+/-1.4 mmol/l in group 2. Post-prandial glucose levels were significantly decreased from 15.3+/-3.8 to 10.3+/-3.0 mmol/l in group 1 and 14.0+/-3.1 to 8.9+/-2.2 mmol/l in group 2. Intergroup comparisons indicated no significant differences. More weight gain was detected in group 1, compared to the baseline. Symptomatic hypoglycemia incidence was similar in both groups. Severe hypoglycemic attacks were seen in two patients in group 1. Flatulence incidence was higher in acarbose group. Conclusively, repaglinide and acarbose were equally effective when combined with IG for obese Type 2 diabetic patients controlled inadequately with OAD alone. Furthermore, acarbose seems to have advantages over repaglinide concerning weight gain and severe hypoglycemic attacks.

Acarbose: oral anti-diabetes drug with additional cardiovascular benefits

Acarbose is an alpha-glucosidase inhibitor acting specifically at the level of postprandial glucose excursion. This compound lowers HbA(1c) by 0.5-1% in patients with Type 2 diabetes, either drug naive or in combination with other antidiabetic drugs. In those with impaired glucose tolerance (IGT), it reduces the incidence of newly diagnosed diabetes by 36.4%. Furthermore, it has beneficial effects on overweight, reduces blood pressure and triglycerides, and downregulates biomarkers of low-grade inflammation. In the Study To Prevent Non-Insulin-Dependent-Diabetes-Mellitus (STOP-NIDDM) trial, acarbose significantly reduced the progression of intima media thickness, incidence of cardiovascular events and of newly diagnosed hypertension. In a meta-analysis of patients with Type 2 diabetes (MERIA), acarbose intake was associated with a reduction of cardiovascular events by 35%. Acarbose is a very safe drug but in approximately 30% of patients, it can cause gastrointestinal complaints due to its mode of action, which in the majority disappear after 1-2 months. Acarbose is approved for treatment of IGT in 25 countries. It can be given alone or in combination with other oral antidiabetics and insulin. Acarbose is particularly effective in those with IGT and early diabetes and patients with comorbidities of the metabolic syndrome.