Postprandial Rise In Blood Glucose Research Articles

Effect of dietary fiber-enriched brown rice crackers on suppressing elevation of blood glucose level

Background: Rice crackers are composed of carbohydrates refined from rice and enjoyed as a snack in Japan. Most rice crackers are crafted from white rice, and the potential postprandial blood glucose rise following their consumption may pose a clinical concern. Brown rice contains more dietary fiber than white rice and has been reported to suppress elevations of blood glucose. Dietary fiber-enhanced brown rice crackers have a significantly higher dietary fiber content than regular brown rice crackers and can be expected to suppress blood glucose elevations more reliably.Methods: We conducted a crossover trial in humans using white rice crackers and dietary fiber-enhanced brown rice crackers to investigate the effect of dietary fiber-enhanced brown rice crackers on postprandial blood glucose elevations. Participants ingested the 100 g rice crackers with 200 mL water for 10 min, and blood was collected from the fingertip at 7 time points: baseline, and at 15, 30, 45, 60, 90, and 120 min after ingestion of the rice cracker. The primary outcome measure was the blood glucose levels, and the secondary outcome measure was the incremental area under curve of blood glucose.Results: Glucose levels and incremental areas under curve at 60 min and 120 min after intake were significantly lower with dietary fiber-enhanced brown rice crackers than with white rice crackers. Incremental area under curves at 60 min and 120 min after intake of rice crackers were also significantly lower in dietary fiber-enhanced brown rice crackers than white rice crackers.Conclusions: Ingesting dietary fiber-enhanced brown rice crackers instead of white rice crackers could be useful for achieving better glycemic control.Keywords: Brown rice crackers, Dietary fiber, Postprandial blood glucose

Incorporation of okra (Abelmoschus esculentus (L.) Moench) seed powder into fresh rice noodles with tapioca starch improves postprandial glycemia, insulinemia and satiety in healthy human volunteers

This study investigates freeze-dried okra seed flour (OSF) as a functional ingredient to attenuate postprandial blood glucose rise by creating lower glycemic index (GI) rice noodles. Secondary objectives are postprandial gut hormone responses, noodle satiety, and sensory evaluation. Twenty healthy individuals consumed control rice noodle (CON), 10 % okra seed fortified noodle (OKN), 20 % OKN and glucose reference drinks on separate visits. 20 % OKN significantly lowered the postprandial glucose and insulin peaks compared to CON. Compared to CON, there was a 20-point reduction of GI value for 20 % OKN to 64. All noodles produced similar responses in postprandial ghrelin and glucagon-like peptide-1 (GLP-1). OKN were found to be more satiating than control noodles given the same amount of available carbohydrates. Sensory evaluation revealed that OSF can be added to noodle to create sensorially acceptable products, though ratings for sensory characteristics decreased with increased fortification.

Inhibition mechanism of alpha-amylase, a diabetes target, by a steroidal pregnane and pregnane glycosides derived from Gongronema latifolium Benth.

Alpha-amylase is widely exploited as a drug target for preventing postprandial hyperglycemia in diabetes and other metabolic diseases. Inhibition of this enzyme by plant-derived pregnanes is not fully understood. Herein, we used in vitro, in silico, and in vivo studies to provide further insights into the alpha-amylase inhibitory potential of selected pregnane-rich chromatographic fractions and four steroidal pregnane phytochemicals (SPPs), viz: marsectohexol (P1), 3-O-[6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→14)-β-D-oleandropyranosyl]-11,12-di-O-tigloyl-17β-marsdenin (P2), 3-O-[6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl]-17β-marsdenin (P3), and 3-O-[6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-canaropyranosyl]-17β-marsdenin (P4) derived from Gongronema latifolium Benth. The results revealed that the SPPs source pregnane-rich chromatographic fractions and the SPPs (P1–P4) exhibited inhibitory potential against porcine pancreatic alpha-amylase in vitro. Compounds P1 and P2 with IC50 values 10.01 and 12.10 µM, respectively, showed greater inhibitory potential than the reference acarbose (IC50 = 13.47 µM). Molecular docking analysis suggests that the SPPs had a strong binding affinity to porcine pancreatic alpha-amylase (PPA), human pancreatic alpha-amylase (HPA), and human salivary alpha-amylase (HSA), interacting with the key active site residues through an array of hydrophobic interactions and hydrogen bonds. The strong interactions of the SPPs with Glu233 and Asp300 residues may disrupt their roles in the acid-base catalytic mechanism and proper orientation of the polymeric substrates, respectively. The interactions with human pancreatic amylase were maintained in a dynamic environment as indicated by the root mean square deviation, radius of gyration, surface accessible surface area, and number of hydrogen bonds computed from the trajectories obtained from a 100-ns molecular dynamics simulation. Key loop regions of HPA that contribute to substrate binding exhibited flexibility and interaction potential toward the compounds as indicated by the root mean square fluctuation. Furthermore, P1 significantly reduced blood glucose levels and area under the curve in albino rats which were orally challenged with starch. Therefore, Gongronema latifolium and its constituent SPPs may be exploited as inhibitors of pancreatic alpha-amylase as an oral policy for impeding postprandial blood glucose rise.

Protective Role of Mitochondrial Uncoupling Proteins against Age-Related Oxidative Stress in Type 2 Diabetes Mellitus.

The accumulation of oxidative damage to DNA and other biomolecules plays an important role in the etiology of aging and age-related diseases such as type 2 diabetes mellitus (T2D), atherosclerosis, and neurodegenerative disorders. Mitochondrial DNA (mtDNA) is especially sensitive to oxidative stress. Mitochondrial dysfunction resulting from the accumulation of mtDNA damage impairs normal cellular function and leads to a bioenergetic crisis that accelerates aging and associated diseases. Age-related mitochondrial dysfunction decreases ATP production, which directly affects insulin secretion by pancreatic beta cells and triggers the gradual development of the chronic metabolic dysfunction that characterizes T2D. At the same time, decreased glucose oxidation in skeletal muscle due to mitochondrial damage leads to prolonged postprandial blood glucose rise, which further worsens glucose homeostasis. ROS are not only highly reactive by-products of mitochondrial respiration capable of oxidizing DNA, proteins, and lipids but can also function as signaling and effector molecules in cell membranes mediating signal transduction and inflammation. Mitochondrial uncoupling proteins (UCPs) located in the inner mitochondrial membrane of various tissues can be activated by ROS to protect cells from mitochondrial damage. Mitochondrial UCPs facilitate the reflux of protons from the mitochondrial intermembrane space into the matrix, thereby dissipating the proton gradient required for oxidative phosphorylation. There are five known isoforms (UCP1-UCP5) of mitochondrial UCPs. UCP1 can indirectly reduce ROS formation by increasing glutathione levels, thermogenesis, and energy expenditure. In contrast, UCP2 and UCP3 regulate fatty acid metabolism and insulin secretion by beta cells and modulate insulin sensitivity. Understanding the functions of UCPs may play a critical role in developing pharmacological strategies to combat T2D. This review summarizes the current knowledge on the protective role of various UCP homologs against age-related oxidative stress in T2D.

The Regulatory Effect of D-Alloxan on Glucose Metabolism and Lipid Metabolism in Diabetic Mice

To investigate the regulatory effect of d-alloxan on glucose metabolism and lipid metabolism in diabetic mice. Twenty five mice were divided into control group, glucose group, fructose group, d-alloxan group and cellulose group. The results showed that the blood glucose of mice in each group reached the peak at 90 min and the blood glucose concentration of d-alloxan group was significantly lower than that of other groups (p<0.05). The blood glucose concentration of fructose group was significantly higher than that of other groups (p<0.05). The blood glucose concentration before and after meal in d-alloxan group was significantly lower than that in other groups (p<0.05), the liver glycogen concentration before and after meal was significantly higher than that in other groups (p<0.05), the insulin level was higher than that in other groups, but the difference was not significant (p>0.05), the muscle glycogen concentration before and after meal was not significant (p>0.05). The results showed that the triglyceride concentration of d-alloxan group was significantly lower than that of other groups (p<0.05). While it was not significantly lower than that of control group (p>0.05) and there was no significant difference in total cholesterol level between groups (p>0.05). The free fatty acid concentration in glucose group, fructose group and d-alloxan group was lower than that in control group and cellulose group (p<0.05). Compared with the control group, the low density lipoprotein concentration of the other four groups was significantly lower (p<0.05) and the low density lipoprotein concentration of the d-alloxan group was significantly lower than that of the other groups (p<0.05) and there was no significant difference between them (p>0.05). The results showed that the content of succinate dehydrogenase in the blood and tissues of d-alloxan group was significantly higher than that of other groups (p<0.05) and the level of hepatic lipase in d-alloxan group was higher than that of other groups, but there was no significant difference (p>0.05). Alloxan can effectively regulate blood glucose concentration, inhibit postprandial blood glucose rise, improve insulin level and liver glycogen level, but has no significant effect on muscle glycogen. It can be used as an ideal substitute of sucrose once the disorder of lipid metabolism is improved, the ability of fat metabolism is increased and antioxidation function is improved.

Autumn olive (Elaeagnus umbellata Thunb.) berry reduces fasting and postprandial glucose levels in mice.

BACKGROUND/OBJECTIVESFasting and postprandial hyperglycemia should be controlled to avoid complications of diabetes mellitus. This study investigated the effects of autumn olive (Elaeagnus umbellata Thunb.) berry (AOB) on fasting and postprandial hyperglycemia in mice.MATERIALS/METHODSIn vitro α-glucosidase inhibitory effect of AOB was determined. Maltose solution (2 g/kg) with and without AOB extract at 500 mg/kg or acarbose at 50 mg/kg was orally administered to normal mice after overnight fasting and glucose levels were measured. To study the effects of chronic consumption of AOB, db/db mice received the basal diet or a diet containing AOB extract at 0.4% or 0.8%, or acarbose at 0.04% for 7 weeks. Blood glycated hemoglobin and serum glucose and insulin levels were measured. Expression of adiponectin protein in epididymal white adipose tissue was determined by Western blotting.RESULTSIn vitro inhibitory effect of AOB extract on α-glucosidase was 92% as strong as that of acarbose. The AOB extract (500 mg/kg) or acarbose (50 mg/kg) significantly suppressed the postprandial rise of blood glucose after maltose challenge and the area under the glycemic response curve in normal mice. The AOB extract at 0.4% or 0.8% of diet or acarbose at 0.04% of diet significantly lowered levels of serum glucose and blood glycated hemoglobin and homeostasis model assessment for insulin resistance values in db/db mice. The expression of adiponectin protein in adipose tissue was significantly elevated by the consumption of AOB at 0.8% of diet.CONCLUSIONSAutumn olive (E. umbellata Thunb.) berry may reduce postprandial hyperglycemia by inhibiting α-glucosidase in normal mice. Chronic consumption of AOB may alleviate fasting hyperglycemia in db/db mice partly by inhibiting α-glucosidase and upregulating adiponectin expression.

Wholegrains in the Management of Diabetes

Dietary fibre is responsible for the decrease in the rate of glucose absorption along with aiding decrease in postprandial rise in blood glucose. Substantial research establishes the connection between consumption of wholegrains and type 2 diabetes management. Wholegrains are widely recognized for contributing significantly to our health and well-being as they contain essential nutrients and bioactive compounds, along with being rich in dietary fibre. This review article attempts to discuss the effect of the fibre in wholegrains on blood glucose, type 2 diabetes and HbA1c.

Erythritol reduces small intestinal glucose absorption, increases muscle glucose uptake, improves glucose metabolic enzymes activities and increases expression of Glut-4 and IRS-1 in type 2 diabetic rats.

Studies have reported that erythritol, a lowor non-glycemic sugar alcohol possesses anti-hyperglycemic and anti-diabetic potentials but the underlying mode of actions is not clear. This study investigated the underlying mode of actions behind the anti-hyperglycemic and anti-diabetic potentials of erythritol using different experimental models (experiment 1, 2 and 3). Experiment 1 examined the effects of increasing concentrations (2.5-20%) of erythritol on glucose absorption and uptake in isolated rat jejunum and psoas muscle, respectively. Experiments 2 and 3 examined the effects of a single oral dose of erythritol (1g/kg bw) on intestinal glucose absorption, gastric emptying and postprandial blood glucose increase, glucose tolerance, serum insulin level, muscle/liver hexokinase and liver glucose-6 phosphatase activities, liver and muscle glycogen contents and mRNA and protein expression of muscle Glut-4 and IRS-1 in normal and type 2 diabetic animals. Experiment 1 revealed that erythritol dose dependently enhanced muscle glucose ex vivo. Experiment 2 demonstrated that erythritol feeding delayed gastric emptying and reduced small intestinal glucose absorption as well as postprandial blood glucose rise, especially in diabetic animals. Experiment 3 showed that erythritol feeding improved glucose tolerance, muscle/liver hexokinase and liver glucose-6 phosphatase activities, glycogen storage and also modulated expression of muscle Glut-4 and IRS-1 in diabetic animals. Data suggest that erythritol may exert anti-hyperglycemic effects not only via reducing small intestinal glucose absorption, but also by increasing muscle glucose uptake, improving glucose metabolic enzymes activity and modulating muscle Glut-4 and IRS-1 mRNA and protein expression. Hence, erythritol may be a useful dietary supplement for managing hyperglycemia, particularly for T2D.

In vitro digestion of beta-glucan rich cereal products results in extracts with physicochemical and rheological behavior like pure beta-glucan solutions – A basis for increased understanding of in vivo effects.

Cereal beta-glucans may reduce fasting LDL-cholesterol and post-prandial blood glucose rise in humans. Several studies have shown that physicochemical properties of beta-glucan such as molecular weight (M) and solubility/extractability as well as the viscosity of food products after in vitro digestion are important for this physiological effect. In this study, we directly compare beta-glucan physicochemical properties and flow behavior of different cereal products after analytical (thermostable alpha-amylase) and physiological (in vitro digestion) extractions. The beta-glucan weight average molecular weights (Mw) were similar for both types of extractions, while differences in beta-glucan solubility between the food products were only evident after in vitro digestion. The extracts after in vitro digestion behaved essentially as pure beta-glucan solutions. Viscosity dropped to 0.8–1.2 mPa after incubation with a beta-glucanase for all extracts, but was not influenced by xylanase addition. The relationship of beta-glucan Mw (or intrinsic viscosity calculated from Mw), concentration and zero shear viscosity measured in the extracts closely resembled the general relationship reported for “random coil” polysaccharides with two distinct regions, below and above the occurrence of coil overlap. A standardized presentation of previously published in vivo data on blood glucose response showed a distinct grouping of samples with significant effect in the range of coil overlap. This points towards an important role of coil overlap for the reduction of post-prandial glycemic response by beta-glucan rich foods and demonstrates the potential of such a general comparison of different studies to increase the understanding of beta-glucan rich food products in vivo effects.

Antidiabetic effect of chitosan oligosaccharide (GO2KA1) is mediated via inhibition of intestinal alpha-glucosidase and glucose transporters and PPARγ expression.

We have previously reported that administration of low molecular weight chitosan oligosaccharide (GO2KA1) significantly suppressed postprandial blood glucose rise with increased plasma adiponectin and HbA1c levels in animals and humans. However, the cellular mechanisms whereby GO2KA1 exerts antihyperglycemic effects still remain to be determined. Using intestinal Caco-2 cells and 3T3-L1 cells, here we show that GO2KA1 has dual modes of antidiabetic action by (1) inhibiting intestinal α-glucosidase as well as glucose transporters SGLT1 and GLUT2 that were distinct from the acarbose effect; (2) enhancing adipocyte differentiation, PPARγ expression and its target genes, such as FABP4, adiponectin, and GLUT4, whereas the effects were abolished by co-treatment with BADGE, a PPARγ antagonist. Moreover, GO2KA1 significantly increased glucose uptake, which was reduced in the presence of BADGE. Our data show that GO2KA1 may prevent hyperglycemia by inhibiting intestinal glucose digestion and transport and also enhance glucose uptake, at least in part, by upregulating adiponectin expression through PPARγ in adipocytes. These findings may provide potential molecular modes of action for the antidiabetic effects of chitosan oligosaccharide observed in clinical and animal studies. © 2016 BioFactors, 43(1):90-99, 2017.

English

The antidiabetic properties of extracts of three Nigerian medicinal plants - Ocimum basilicum L. (Lamiaceae, formerly Labiatae), Phyllanthus niruri L. (Euphorbiaceae) and Viscum album L. (Viscaceae or Loranthaceae) parasitic on Psidium guajava L. (Myrtaceae) on normoglycemic and alloxan-induced diabetic rats were studied. The extracts (258.3 g, 6.89% w/w of P. niruri, 189.17 g, 6.76% w/w of V. album and 131.50 g, 6.41% w/w of O. basilicum), obtained by 48 h cold maceration in methanol: methylene chloride (1:1), were evaluated for hypoglycemic and oral glucose tolerance effects in normoglycemic rats and antihyperglycemic effect in alloxan (100 mg/kg i.p) diabetic (blood glucose level ≥ 200 mg/dl) rats. The results showed that acute oral administration of the extracts to normoglycemic rats caused a mild to moderate non-dose-related reduction in blood glucose levels. The extracts significantly (P < 0.05) suppressed the acute postprandial rise in blood glucose to varying extents. Extract of O. basilicum lowered the elevated glucose level to 13.67% at 180 min while P. niruri and V. album reduced the glucose level to 16.87 and 17.33%, respectively. In alloxan diabetic rats, the extracts caused a significant (P < 0.05) non-dose-related reduction in blood glucose with 52.31 (O. basilicum), 44.29 (P. niruri) and 16.71% (V. album) maximum reduction at 6 h. Key words: Alloxan, diabetes mellitus, Nigerian medicinal plants.

Anti-hyperglycemic activity of polyphenols isolated from barnyard millet (Echinochloa utilis L.) and their role inhibiting α-glucosidase

The extracts and chemical compounds isolated from barnyard millet (Echinochloa utilis) grains were investigated as part of a search for naturally derived anti-hyperglycemic medicinal plants. Among the five different solvent extracts, the ethyl acetate extract showed the lowest IC50 value against Saccharomyces cerevisiae α-glucosidase (70.2 μg/mL). Chromatography yielded eight phenolic compounds that may have been responsible for this effect. Among them, N-p-coumaroyl serotonin (1, CS), feruloyl serotonin (2, FS), and luteolin (5) potently inhibited α-glucosidase with IC50 values of 1.3–17.8 μM compared with those of deoxynojirimycin (DNJ, IC50 = 2.5 ± 0.1 μM) and acarbose (IC50 = 255.1 ± 15.6 μM). Additionally, for the first time, we found that CS and FS were significantly inhibited mammalian rat intestinal sucrase (IC50 of 3.0 and 8.2 μM) and reduced glucose content (73 and 52 % at 0.1 mg/wells) in Caco-2 (human intestinal epithelial) cells. Furthermore, oral glucose tolerance test revealed improved glucose tolerance following treatment with the barnyard millet grains extract by retarding the postprandial rise in blood glucose in vivo. These results suggest that barnyard millet grain can be used as a natural functional medicine to prevent and alleviate type-2 diabetes.

Gastric Emptying Is More Rapid in Adolescents With Type 1 Diabetes and Impacts on Postprandial Glycemia.

Gastric emptying is a critical determinant of postprandial glycemic control in health and type 1 diabetes. There are few studies that assess the relationship between gastric emptying and postprandial glycaemia in adolescents with type 1 diabetes. The objectives of the study were to quantify gastric emptying in adolescents with type 1 diabetes and examine its relationship to postprandial glycaemia and autonomic function. This was a case-control study. Gastric half-emptying time of a solid meal was measured by a (13)C-octanoate breath test. Cardio-autonomic function was measured by heart rate variability. Chronic and postprandial gastrointestinal symptoms were evaluated by questionnaire and visual analog scales. Blood glucose concentrations were monitored frequently during the study. The study was conducted at a tertiary pediatric hospital in South Australia. Thirty adolescents (aged 15 ± 2.5 y) with type 1 diabetes and age- and sex-matched controls (gastric emptying, n = 20; heart rate variability, n = 135) participated in the study. Gastric half-emptying time was the main outcome in the study. Gastric emptying was more rapid in subjects with type 1 diabetes than controls [median half emptying time 78 (interquartile range 61-99) vs 109 (interquartile range 71-124) min, P = .02]. The postprandial rise in blood glucose at 60 minutes was strongly related to gastric half-emptying time (R = -0.65, P = .0001). Gastric emptying was slower in subjects with fasting hyperglycemia but was not related to heart rate variability. Nausea, bloating, and anxiety were related to fasting glycemia (P = .03). Rapid gastric emptying is a major determinant of postprandial glycemia in adolescents with type 1 diabetes. This observation has significant implications for therapy.

The Reduction Effect of Low Molecular Weight Chitosan Oligosaccharide (GO2KA1) on Postprandial Blood Glucose Levels in Healthy Individuals

We investigated the effects of chitosan oligosaccharide (GO2KA1, a‐glucosidase inhibitor) on the level of postprandial blood glucose in adult subjects with normal blood glucose level. Postprandial blood glucose levels were tested for 2 hr after sucrose administration with or without 500 mg of GO2KA1. GO2KA1 significantly lowered the mean, maximum, and minimum level of postprandial blood glucose at 30 and 90 min after meal. GO2KA1 treatment reduced the blood glucose‐time curve (AUC) and the blood glucose peak (Cmax) value while the time of peak plasma concentration of glucose (Tmax) value was significantly increased (p&lt;0.05). Our findings suggest that GO2KA1 reduces postprandial blood glucose rise due to slow absorption of glucose in the small intestine, via carbohydrate hydrolyzing enzymes inhibition.

Estriol blunts postprandial blood glucose rise in male rats through regulating intestinal glucose transporters.

Despite increased total food intake in healthy, late-stage pregnant women, their peak postprandial blood sugar levels are normally much lower than the levels seen in healthy nonpregnant women. In this study, we sought to determine whether estriol (E3), an endogenous estrogen predominantly produced during human pregnancy, contributes to the regulation of the postprandial blood glucose level in healthy normal rats. In vivo studies using rats showed that E3 blunted the speed and magnitude of the blood glucose rise following oral glucose administration, but it did not appear to affect the total amount of glucose absorbed. E3 also did not affect insulin secretion, but it significantly reduced the rate of intestinal glucose transport compared with vehicle-treated animals. Consistent with this finding, expression of the sodium-dependent glucose transporter 1 and 2 was significantly downregulated by E3 treatment in the brush-border membrane and basolateral membrane, respectively, of enterocytes. Most of the observed in vivo effects were noticeably stronger with E3 than with 17β-estradiol. Using differentiated human Caco-2 enterocyte monolayer culture as an in vitro model, we confirmed that E3 at physiologically relevant concentrations could directly inhibit glucose uptake via suppression of glucose transporter 2 expression, whereas 17β-estradiol did not have a similar effect. Collectively, these data showed that E3 can blunt the postprandial glycemic surge in rats through modulating the level of intestinal glucose transporters.

Postprandial blood glucose level reducing effect of low molecular weight chitosan oligosaccharide, GO2KA1, in healthy individuals (1139.12)

We investigated the effects of chitosan oligosaccharide (GO2KA1) on the level of postprandial blood glucose in adult subjects with normal blood glucose level. Postprandial blood glucose levels were tested for 2 hours after sucrose administration with or without 500 mg of GO2KA1. GO2KA1 significantly lowered the mean, maximum and minimum level of postprandial blood glucose at 30 and 90 min after meal. Additionally, GO2KA1 treatment reduced the AUC and Cmax while Tmax was significantly increased. Our findings suggest that GO2KA1 reduces postprandial blood glucose rise due to slow absorption of glucose in the small intestine, via carbohydrate hydrolyzing enzymes inhibition.

Dried Plums and Their Products: Composition and Health Effects–An Updated Review

This paper describes composition of dried plums and their products (prune juice and dried plum powder) with special attention to possibly bioactive compounds. Dried plums contain significant amounts of sorbitol, quinic acid, chlorogenic acids, vitamin K1, boron, copper, and potassium. Synergistic action of these and other compounds, which are also present in dried plums in less conspicuous amounts, may have beneficial health effects when dried plums are regularly consumed. Snacking on dried plums may increase satiety and reduce the subsequent intake of food, helping to control obesity, diabetes, and related cardiovascular diseases. Despite their sweet taste, dried plums do not cause large postprandial rise in blood glucose and insulin. Direct effects in the gastrointestinal tract include prevention of constipation and possibly colon cancer. The characteristic phenolic compounds and their metabolites may also act as antibacterial agents in both gastrointestinal and urinary tracts. The indirect salutary effects on bone turnover are supported by numerous laboratory studies with animals and cell cultures. Further investigation of phenolic compounds in dried plums, particularly of high molecular weight polymers, their metabolism and biological actions, alone and in synergy with other dried plum constituents, is necessary to elucidate the observed health effects and to indicate other benefits.

Hydroxypropyl methylcellulose, a viscous soluble fiber, reduces insulin resistance and decreases fatty liver in Zucker Diabetic Fatty rats

BackgroundDiets producing a high glycemic response result in exaggerated insulin secretion which induces hepatic lipogenesis, contributing to development of insulin resistance and fatty liver. Viscous dietary fibers blunt the postprandial rise in blood glucose, however their effect on type 2 diabetes and obesity are not entirely known. This study examined the effect of chronic consumption of the viscous, non-fermentable dietary fiber, hydroxypropyl methylcellulose (HPMC), on glucose control, insulin resistance and liver lipids in an obese diabetic rat model.MethodsThree groups of Zucker Diabetic Fatty (ZDF) rats were fed diets containing either 5% non-viscous cellulose (control), low viscosity HPMC (LV-HPMC) or high viscosity HPMC (HV- HPMC) for six weeks. Zucker lean littermates consuming cellulose served as a negative control. Markers of glucose control, including oral glucose tolerance test, glycated hemoglobin and urinary glucose, were measured as well as adiposity and the accumulation of liver lipids.ResultsThe HPMC diets increased the viscosity of the small intestinal contents and reduced the postprandial rise in blood glucose. The food efficiency ratio was greater with HPMC feeding compared to the obese control and urinary excretion of glucose and ketone bodies was reduced. The two HPMC groups had lower glycated hemoglobin and kidney weights and a reduced area under the curve during a glucose tolerance test, indicating improved glucose control. Epididymal fat pad weight as percent of body weight was reduced in the HV-HPMC group compared to the obese control group. The HV-HPMC group also had lower concentrations of liver lipid and cholesterol and reduced liver weight. However, HV-HPMC feeding did not affect hepatic gene expression of SREBP-1c or FAS. Muscle concentration of acylcarnitines, a lipid intermediate in fatty acid β-oxidation, was not different between the HPMC groups and obese control, suggesting no change in muscle fatty acid oxidation by HPMC.ConclusionsConsumption of the viscous non-fermentable fiber HPMC decreased diabetic wasting, improved glucose control and reduced insulin resistance and fatty liver in a model of obesity with diabetes.

Viscous dietary fibers added to a high fat diet decrease adiposity, improve glucose control and alter fuel utilization in obese rats

Viscous dietary fibers reduce the postprandial rise in blood glucose and decrease adiposity in normal and diabetic rats. The purpose of this study was to examine the effects of viscous fibers on fat mass and fuel utilization in a model of diet‐induced obesity. Wistar rats were fed a high fat diet (60% energy from fat) containing 5% fiber as either cellulose (non‐viscous) or one of two highly viscous fibers ‐ hydroxypropyl methylcellulose (HPMC) or guar gum. After 10 weeks of feeding, the HPMC and guar groups had lower fat pad weights and total body fat mass compared to the cellulose group. The guar group had a decreased glucose tolerance test area under the curve (AUC) indicating improved glucose control. AUC during a meal tolerance test was not different with viscous fiber treatment. However, after 3 weeks of feeding, the respiratory quotient (RQ) AUC over 24 hours was increased with HPMC and guar compared to cellulose, implying greater carbohydrate oxidation. The RQ AUC during fasting did not differ between the HPMC and cellulose groups but after a meal it was greater in the HPMC and guar groups. This suggests a quicker transition from fatty acid to carbohydrate oxidation, possibly through decreased insulin resistance. These results indicate that consumption of viscous fibers with a high fat diet can improve glucose control, lower adiposity and increase fuel flexibility.Grant Funding Source: MN Agricultural Experiment Station, MN Obesity Consortium

Glycemic Response of some Local Nigerian Drinks in Healthy Subjects

Objective: This study was designed to determine the postprandial glycemic responses of healthy Nigerian subjects to five traditional drinks as a preliminary to the detailed study of the Nigerian mixed diet and identify drinks suitable for vulnerable groups such as diabetic patients. Subjects and methods: The drinks investigated were oil Palm-Wine, Bottled Raphia wine, ‘Kunu’, ‘Zobo’ drink, and Plantain-Wine. The proximate composition of the drinks were determined and the amounts that will deliver 50g carbohydrate were administered to the subjects after an overnight fast. Sixty healthy subjects were used for the study. Glucose (50g in 300ml) was fed to the control subjects. Glycemic response were calculated after 0, 30, 60, 120, and 180 minutes was calculated. Therefore, glucose response curves were constructed. Results: The results revealed that the Glycemic index GI was lowest for oil palm-wine (11±5). ‘Kunu’ had the highest GI value (63.0±8). Plantain, ‘Zobo’, and Raphia wine had 44.0±13, 33.0±3, and 36.0±4 respectively. Conclusion The local drinks elicit low to moderate postprandial rise of blood glucose in healthy subjects. Palm-wine should be the preferred choice for diabetic patients. These drinks are preferable to fizzy drinks in the Nigerian market.