Hydroxypropylated Tapioca Starch Retards the Development of Insulin Resistance in KKAy Mice, a Type 2 Diabetes Model, Fed a High-Fat Diet

In vivo study on the slow release of glucose in vacuum fried matrices

In vitro studies have shown that vacuum frying may be an effective process to reduce starch digestibility as it may limit gelatinization; this is significant as overconsumption of starchy foods contributes to obesity and type 2 diabetes. Although in vitro studies are an instrumental tool, in vivo studies allow observation of the overall effect on a living organism. The aim of this research was to assess how in vivo starch digestibility can be reduced when frying under vacuum (9.9 kPa), after feeding Sprague-Dawley rats, while also understanding its relationship to in vitro starch digestibility. Results showed that vacuum-fried dough has a lower degree of gelatinization (∼53.8%) and a maximal blood glucose level at 60 min (slower glycemic response) than atmospheric counterparts (∼98.3% degree of gelatinization and maximal blood glucose level at 30 min). Similarly, in vitro procedures exhibited less rapidly available glucose and higher unavailable glucose fractions in vacuum-fried dough.

Fucosylated chondroitin sulfate from sea cucumber improves insulin sensitivity via activation of PI3K/PKB pathway

This study was to investigate the effects of fucosylated chondroitin sulfate (CHS) from sea cucumber on insulin sensitivity in skeletal muscle of type 2 diabetic mice induced by a high-fat high-sucrose diet (HFSD). CHS supplementation for 19 wk significantly improved insulin sensitivity by 20%, and reduced blood glucose and insulin levels. Western blotting assay showed that CHS significantly increased insulin-stimulated glucose transporter 4 (GLUT4) translocation to 1.7-fold, phosphorylation of phosphoinositide 3-kinase (PI3K) at p85 to 5.0-fold, protein kinase B (PKB) at Ser473 to 1.5-fold, and Thr308 to 1.6-fold in skeletal muscle. However, PI3K, PKB, and GLUT4 total proteins expression were unchangeable. In addition, qRT-PCR analysis proved that the insulin signaling was activated by CHS treatment, showing the increased mRNA expressions of glucose uptake-related key genes. It indicated that CHS improved insulin sensitivity by activation of PI3K/PKB signaling in skeletal muscle of type 2 diabetic mice. Identification of potential mechanism by which CHS increased insulin sensitivity might provide a new functional food or pharmaceutical application of sea cucumber.

A novel 11β-HSD1 inhibitor improves diabesity and osteoblast differentiation

Selective inhibitors of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) have considerable potential as treatment for osteoporosis as well as metabolic syndrome including type 2 diabetes mellitus. Here, we investigated the anti-diabetic, anti-adipogenic, and anti-osteoporotic activity of KR-67500, as a novel selective 11β-HSD1 inhibitor. Cellular 11β-HSD1 activity was tested based on a homogeneous time-resolved fluorescence method. Oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) levels were measured in diet-induced obese (DIO)-C57BL/6 mice administered KR-67500 (50  mg/kg per day, p.o.) for 28 days and, additionally, its anti-diabetic effect was evaluated by OGTT and ITT. The in vitro anti-adipogenic effect of KR-67500 was determined by Oil Red O Staining. The in vitro anti-osteoporotic activity of KR-67500 was evaluated using bone morphogenetic protein 2 (BMP2)-induced osteoblast differentiation and receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation model systems. KR-67500 improved the in vivo glucose tolerance and insulin sensitivity in DIO-C57BL/6 mice. KR-67500 suppressed cortisone-induced differentiation of 3T3-L1 cells into adipocytes. KR-67500 enhanced BMP2-induced osteoblastogenesis in C2C12 cells and inhibited RANKL-induced osteoclastogenesis in mouse bone marrow-derived macrophages. KR-67500, a new selective 11β-HSD1 inhibitor, may provide a new therapeutic window in the prevention and/or treatment of type 2 diabetes, obesity, and/or osteoporosis.

Hydroxypropylation of high-amylose maize starch changes digestion and fermentation-dependent parameters in rats

It was examined whether the physiological effects of high-amylose maize starch (HAMS) are influenced by hydroxypropylation. Rats were fed one of the following three diets: an AIN-93-based diet with waxy maize starch (WMS) as a starch source, or this diet with 150 g of WMS replaced by either HAMS or hydroxypropylated HAMS (HP-HAMS). The activities of amylase in bile-pancreatic juice and sucrose, maltase and isomaltase of the jejunum and ileum were not affected by diet, but the digestibility of HAMS was decreased by hydroxypropylation. The amounts of SCFA in caecal content and H2 excreted in the breath and flatus for HAMS were decreased by hydroxypropylation. Plasma glucagon-like peptide-1 (GLP-1), glucose and insulin concentrations were not affected by diet. On the basis of PCR-denaturing gradient gel electrophoresis (DGGE) profiles, the similarity in caecal bacteria population of the HP-HAMS group and HAMS group was low, but that of the HP-HAMS and WMS groups was high. The amount of caecal IgA was not affected by hydroxypropylation, but those in the HAMS and HP-HAMS groups were greater than that in the WMS group. Plasma and liver concentrations of TAG and cholesterol for HAMS were not affected by hydroxypropylation. These results show that the small intestinal digestibility and fermentation-dependent parameters such as caecal SCFA and H2 productions and caecal bacterial profile of HAMS were affected by hydroxypropylation, but parameters of glucose metabolism such as GLP-1 and insulin, those of lipid metabolism such as plasma TAG and cholesterol and the amount of caecal IgA were not.

Anti-diabetic and anti-adipogenic effects of a novel selective 11β-hydroxysteroid dehydrogenase type 1 inhibitor in the diet-induced obese mice

Glucocorticoid excess (Cushing's syndrome) causes metabolic syndrome such as visceral obesity, insulin resistance, diabetes mellitus, dyslipidaemia and hypertension. The selective inhibitors of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) have considerable potential for treating type 2 diabetes mellitus and metabolic syndrome. In the present study, we investigated the anti-diabetic and anti-adipogenic effects of 4-(2-(1,1-dioxido-6-(2,4,6-trichlorophenyl)-1,2,6-thiadiazinan-2-yl)acetamido)adamantane-1-carboxamide (KR-67183), a novel selective 11β-HSD1 inhibitor; we also investigated the underlying molecular mechanisms in the cortisone-induced 3T3-L1 adipogenesis model system and diet-induced obese (DIO) mice. KR-67183 concentration-dependently inhibited 11β-HSD1 activity in human and mouse 11β-HSD1 over-expressed cells and in the ex vivo assay of C57BL/6 mice. In the study with DIO mice, the administration of KR-67183 (20 and 50mg/kg/day, orally for 28 days) improved the glucose tolerance and insulin sensitivity with suppressed 11β-HSD1 activity in the liver and fat. However, KR-67183 showed no change in the adrenal gland weight/body weight ratio and plasma corticosterone concentration in DIO mice. Further, KR-67183 suppressed adipocyte differentiation on cortisone-induced adipogenesis in 3T3-L1 cells is associated with the suppression of the cortisone-induced mRNA levels of FABP4, PPARγ2 and GLUT4, and 11β-HSD1 activity. Taken together, it is suggested that a selective 11β-HSD1 inhibitor, KR-67183, may provide a new therapeutic window in the prevention and treatment without toxicity in type 2 diabetes with obesity.