Effects of two new alpha-glucosidase inhibitors on glycemic control in patients with insulin-dependent diabetes mellitus

Novel carbohydrate-triazole derivatives as potential α-glucosidase inhibitors

A series of novel pyrano[2, 3-d]trizaole compounds were synthesized and their α-glucosidase inhibitory activities were evaluated by in vitro enzyme assay. The experimental data demonstrated that compound 10f showed up to 10-fold higher inhibition (IC₅₀74.0 ± 1.3 μmol·L^-1) than acarbose. The molecular docking revealed that compound 10f could bind to α-glucosidase via the hydrophobic, π-π stacking, and hydrogen bonding interactions. The results may benefit further structural modifications to find new and potent α-glucosidase inhibitors.

Improved glycaemic control with miglitol in inadequately-controlled type 2 diabetics

OBJECTIVE

The study compared the long-term efficacy and safety of miglitol to placebo in Type 2 diabetic outpatients inadequately controlled on combination therapy of diet, glibenclamide and metformin.

METHODS

Type 2 diabetic patients (n = 154) receiving glibenclamide 7-20 mg/day and at least one 500-850 mg tablet metformin per day were randomized to receive additional miglitol or placebo for 24 weeks, titrated up stepwise from 25 to 100 mg trice daily.

RESULTS

Addition of miglitol to sulphonylureas and metformin (per protocol analysis) produced a statistically, significantly greater reduction in HbA1c (-0.55%, P = 0.04) and postprandial glucose (-2.6 mmol/l, P = 0.0009) from baseline to endpoint than placebo (-0.2% and -0.6 mol/l, respectively). Reduction in fasting blood glucose was greater with miglitol than placebo, and there was a possible difference in favor of miglitol for fasting and postprandial triglyceride levels, but these did not reach statistical significance. Flatulence and diarrhea were reported by statistically, significantly more patients receiving miglitol than placebo, but adverse events overall were reported by only 10% more patients in the miglitol group. No cases of hypoglycaemia were reported.

CONCLUSIONS

Miglitol can safely and effectively be added to long-term combination therapy in people with Type 2 diabetes inadequately controlled with glibenclamide plus metformin.

The effects of the intestinal glucosidase inhibitory BAY M 1099 (miglitol) on glycemic status of obese-diabetic rats

1. Groups of lean and obese-diabetic (NIDDM) congenic male SHR/Nutl parallel-cp rats were fed a nutritionally adequate, high carbohydrate diet ad libitum with or without the alpha-glucosidase inhibitor miglitol (150 mg/kg diet) from 8 until 15 weeks of age, and key glycemic parameters were monitored throughout the study. 2. Miglitol treatment resulted in clinical improvement toward normal in percent glycosylated hemoglobin, glycemic and insulinogenic responses to an oral glucose tolerance, and in liver glucokinase activity, in concert with modest decreases in weight gain in obese rats. 3. These observations are consistent with improved insulin sensitivity in peripheral tissues following miglitol treatment, and indicate that this drug may be a useful adjunct to diet in the treatment of obesity, NIDDM, and possibly other disorders of carbohydrate metabolism.

Effects of alpha-glucosidase inhibitors on mouth to caecum transit time in humans

The alpha-glucosidase inhibitors acarbose and miglitol have been successfully used to control postprandial hyperglycaemia in diabetics. They probably work by slowing carbohydrate digestion and absorption, but their effect on mouth to caecum transit time has not been studied. The effect acarbose (100 mg), miglitol (100 mg), and placebo on mouth to caecum transit time (380 kcal breakfast with 20 g of lactulose) was investigated in 18 normal volunteers using breath hydrogen analysis. Both miglitol and acarbose significantly increased breath hydrogen excretion (F2,34 = 6.31, p = 0.005) and shortened the mouth to caecum transit time (F2,34 = 3.49, p = 0.04) after breakfast compared with placebo. There was a significant negative correlation between breath hydrogen excretion and mouth to caecum transit time suggesting that with shorter transit times significantly more carbohydrates were spilled into the colon. These results indicate that alpha-glucosidase inhibitors accelerate mouth to caecum transit time by inducing carbohydrate malabsorption.

In-vivo inhibition by polycations of small intestinal absorption of methyl alpha-D-glucoside and leucine in the rat

Polycations are able to inhibit active transport processes in rat small intestine in vitro. Whether this effect can also be confirmed in vivo is the concern of this study. Therefore, the effect of various polycations, e.g., protamine and polylysine, on the absorption of methyl alpha-D-glucoside and leucine was investigated in vivo by single-pass perfusion of rat jejunum. The inhibition of absorption of methyl alpha-D-glucoside and leucine by the polycations was strongly dose dependent. At a substrate concentration of 1 mmol/l a 50% inhibition was achieved with a protamine concentration of 3.2 mg/ml. The inhibition increased as the chain length of the polycation increased. In the presence of protamine the concentration-dependent leucine absorption was reduced at leucine concentrations below 60 mmol/l, but was increased at 100 mmol/l. Absorption of mannitol and 2-deoxy-D-glucose was significantly enhanced by the polycations. These results demonstrate that polycations inhibit active transport and increase passive diffusion processes in the rat small intestine in vivo. In addition, pretreatment of rats with a polycation added to the drinking water impaired the small intestinal absorption of methyl alpha-D-glucoside as subsequently measured by the tissue accumulation technique in vitro. Since polycations are hardly absorbed in the intestine, but do attach to negatively charged groups at the mucosal surface, polycations may be useful to study the influence of these negative groups on the absorption of nutrients and drugs.

[Results of clinical trials with the gluconeogenesis inhibitor 2-(3-methylcinnamylhydrazono)-propionate (MCHP)]

Many compounds which directly or indirectly inhibit gluconeogenesis have been described. Some of them showed hypoglycemic action in animal experiments. 2-(3-Methylcinnamylhydrazono)-Propionat (MCHP) a derivative of hydrazine demonstrated marked hypoglycemic action in animal experiments. Nontheless the administration of MCHP to type II diabetic patients showed no hypoglycemic action. Clinical or biochemical sideeffects could not be observed.

Effects of prolonged administration of two new alpha-glucosidase inhibitors on blood glucose control, insulin requirements and breath hydrogen excretion in patients with insulin-dependent diabetes mellitus

Alpha-glucosidase inhibitors delay carbohydrate absorption. In order to study the effects of two new alpha-glucosidase inhibitors with long (BAYo1248) and short (BAYm1099) duration of action on glycaemic control, seventeen insulin-dependent diabetics were connected to the Biostator for 24 h and postprandial hyperglycaemia, insulin requirements and breath H2 concentrations were assessed under three conditions: (a) before administration of any alpha-glucosidase inhibitor (control experiments), (b) after administration of BAYo1248 (40 mg before breakfast, nine patients) or BAYm1099 (100 mg before breakfast and dinner, eight patients) for 1 month, (c) after 1-month administration of placebo (double-blind crossover study). All patients were on standard diets (30 kcal kg-1, 45% carbohydrate, 35% fat, 20% protein). BAYo1248 reduced postprandial hyperglycaemia and insulin requirements (vs. values in control and placebo experiments) after breakfast (124 +/- 8 vs. 159 +/- 8 and 158 +/- 8 mg dl-1, 16 +/- 2 vs. 24 +/- 4 and 23 +/- 3 units, P less than 0.01) and lunch (138 +/- 7 vs. 155 +/- 11 and 162 +/- 13 mg dl-1, 19 +/- 3 vs. 24 +/- 3 and 23 +/- 3 units, P less than 0.01) whereas BAYm1099 reduced postprandial hyperglycaemia and insulin requirements after breakfast (127 +/- 4 vs. 167 +/- 12 and 159 +/- 6 mg dl-1, 15 +/- 3 vs. 24 +/- 4 and 21 +/- 3 units, P less than 0.02) and dinner (128 +/- 4 vs. 169 +/- 7 and 157 +/- 10 mg dl-1, 19 +/- 2 vs. 28 +/- 3 and 25 +/- 2 units, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of two new glucosidase inhibitors on blood glucose in healthy volunteers and in type II diabetics

Two new glucosidase inhibitors (BAY m 1099 and BAY o 1248) were studied in volunteers and type II diabetics under various conditions. In 6 non-diabetic controls BAY m 1099 when given 3 X 50 mg/day caused a marked depression of the post-meal glucose rise. The effect was found to be more marked after breakfast than after lunch or after dinner. In type II diabetics BAY m 1099, when given in a dose of 2 X 25 mg/day over one week, had no significant effect on post-meal glucose or serum insulin levels. BAY o 1248, when given as a single dose of 15 mg in the morning to type II diabetics, induced a significant decrease of post-meal glucose rise (35 mg/dl after breakfast, 25 mg/dl after lunch) when compared to placebo. Although in parallel serum insulin levels were slightly lower, this change was statistically not significant. The drug reduced glycosuria by 50%. Both compounds induced side effects, such as flatulence or diarrhea when given in therapeutically effective amounts, but were tolerable in most cases. On a weight basis BAY o 1248 was found to have greater therapeutic effects than BAY m 1099. Both drugs can be recommended for use in unsatisfactorily controlled type II diabetics. Further studies should concentrate on the critical dosage which may strike a satisfactory balance between effects and side effects.