Metabolic alterations including postprandial hyperglycemia have been implicated in the development of obesity-related diseases. Xylose is a sucrase inhibitor suggested to suppress the postprandial glucose surge. The objectives of this study were to assess the inhibitory effects of two different concentrations of xylose on postprandial glucose and insulin responses and to evaluate its efficacy in the presence of other macronutrients. Randomized double-blind cross-over studies were conducted to examine the effect of D-xylose on postprandial glucose and insulin response following the oral glucose tolerance test (OGTT). In study 1, the overnight-fasted study subjects (n = 49) consumed a test sucrose solution (50 g sucrose in 130 ml water) containing 0, 5, or 7.5 g D-xylose powder. In study 2, the overnight-fasted study subjects (n = 50) consumed a test meal (50 g sucrose in a 60 g muffin and 200 ml sucrose-containing solution). The control meal provided 64.5 g of carbohydrates, 4.5 g of fat, and 10 g of protein. The xylose meal was identical to the control meal except 5 g of xylose was added to the muffin mix. In study 1, the 5 g xylose-containing solutions exhibited significantly lower area under the glucose curve (AUCg) and area under the insulin curve (AUCi) values for 0-15 min (P < 0.0001, P < 0.0001), 0-30 min (P < 0.0001, P < 0.0001), 0-45 min (P < 0.0001, P < 0.0001), 0-60 min (P < 0.0001, P < 0.0001), 0-90 min (P < 0.0001, P < 0.0001) and 0-120 min (P = 0.0071, P = 0.0016). In study 2, the test meal exhibited significantly lower AUCg and AUCi values for 0-15 min (P < 0.0001, P < 0.0001), 0-30 min (P < 0.0001, P < 0.0001), 0-45 min (P < 0.0001, P = 0.0005), 0-60 min (P = 0.0002, P = 0.0025), and 0-90 min (P = 0.0396, P = 0.0246). In conclusion, xylose showed an acute suppressive effect on the postprandial glucose and insulin surges.
Carbohydrates ; Cross-Over Studies ; Glucose ; Glucose Tolerance Test ; Hyperglycemia ; Insulin ; Meals ; Sucrase ; Sucrose ; Xylose

OBJECTIVETo investigate the effect of lemon peel extracts (LPE) on the activity of lactate dehydrogenase and sucrase of Streptococcus mutans (Sm).

METHODSAfter serial dilution with trypticase soy broth (TSB) medium containing 2% glucose, LPE was used as the experimental group, and TSB without LPE as the control group. Sm was added to each group, which was then cultured for 6, 18, 24 and 48 hours in the anaerobic tank. The activity of lactate dehydrogenase(LDH) was measured with the method of oxidation of reduction coenzymeIand the pH value of the culture solution was also detected. The activity of the sucrose was determined with the method of coloration of 3,5-dinitrosalicylic acid.

RESULTSThe activity of LDH, sucrase and the changes of solution pH were decreased with the increase of the concentration of LPE (P < 0.01). The activity of LDH were declined from (0.8025 ± 0.0913) × 10(3) U/L to (0.2099 ± 0.0283) × 10(3) U/L; the activity of sucrase were declined from (-0.0107 ± 0.0003) × 10(3) U/L to (-0.0078 ± 0.0002) × 10(3) U/L; the ΔpH were declined from (2.8067 ± 0.0404) to (2.5033 ± 0.0416) (24 h results). The differences were significant between experimental groups and the control group (P < 0.01), and there were also significant differences among experimental groups with different LPE concentration (P < 0.01). The inhibitory effect of acid generation and lactate dehydrogenas' activity of Sm were positively correlated (P < 0.01).

CONCLUSIONSLPE can inhibit the activity of lactate dehydrogenase, sucrase and the acid production capacity of the Sm in a dose dependent manner. The inhibitory effects in logarithmic phase is stronger than that in other phases of growth cycle.

Citrus ; chemistry ; Glucose ; L-Lactate Dehydrogenase ; metabolism ; Lactic Acid ; Plant Extracts ; pharmacology ; Streptococcus mutans ; enzymology ; Sucrase ; metabolism

The objectives of this study were to investigate the antihyperglycemic and hypolipidmic effects of sea oak (Eisenia bicyclis, EB) in the diabetic state and to examine the appropriateness of formulated EB pill for the effects. The various test materials obtained from EB were included in the experimental diets with 15% fat/0.5% cholesterol and fed to streptozotocin-induced diabetic mice weighing 35.0 +/- 0.7 g for three weeks but not in the control diet having the same composition. The test materials were EB dry powder, water and ethanol extracts, viscozyme-treated EB water extract (EB enzyme-TR) and formulated pill containing dry powders of the EB, two kinds of seaweed, black soybean, sesame, onion and garlic. BG was measured during feeding period and serum insulin, lipids and thiobarbituric acid reactive substances (TBARS) and intestinal disaccharidase activities were measured at the end of the three weeks of the feeding. BG increase was lower in the EB enzyme-TR group after 10 days of the experimental diet but lower in EB pill group after 15 days compared with the control group. Serum insulin levels were higher in the EB enzyme-TR and EB pill groups. Intestinal maltase but not sucrase activity was higher in EB enzyme-TR fed group than the control group. Serum levels of total cholesterol and triglyceride were reduced by the EB enzyme-TR and EB pill compared with the control diet. HDL-/total cholesterol was increased by all EB test materials. Serum TBARS levels were lower in the EB ethanol extract and EB pill groups than in the control group and tended to be lower in the other EB groups. It is concluded that the EB enzyme-TR is the best among the EB preparations to be utilized as a functional component for improving blood glucose and lipid profile in diabetic subjects in the future. However, the pill containing low level of the EB powder is also regarded as effective and readily usable when formulated with the several other ingredients of the proper composition. (Supported by the RIC Program of MOCIE, Korea).
Animals ; Blood Glucose ; Cholesterol ; Diet ; Ethanol ; Garlic ; Insulin ; Mice ; Onions ; Powders ; Seaweed ; Sesamum ; Soybeans ; Sucrase ; Thiobarbiturates ; Thiobarbituric Acid Reactive Substances ; Water

BACKGROUND/OBJECTIVES: Mulberry leaf (ML) has been shown to have an inhibitory effect on α-glucosidase, and suppresses postprandial hyperglycemia, which may be related to its deoxynojirimycin (DNJ) content. This study was conducted to investigate the hypoglycemic and dyslipidemic effects of rice coated with ML rich in DNJ in a type 2 diabetes mouse model. MATERIALS/METHODS: The mice were divided into four groups (n = 8 each): non-diabetic normal control (NC); diabetic control (DM-C), fed with 10% polished rice powder (DM-R); and fed with 10% polished rice powder coated with DNJ-rich ML (DM-DNJR). RESULTS: Supplementation with DNJR for six weeks decreased levels of fasting blood glucose, plasma insulin, triglyceride, total cholesterol, and blood glycosylated hemoglobin; conversely, levels of glucagon-like peptide-1 and high-density lipoprotein-cholesterol showed an increase in the same treatment. In addition, weights of mesenteric, epididymal, and total adipose tissues decreased with DNJR supplementation, when compared with diabetic control db/db mice, while maltase, lactase, and sucrase activity in the small intestine were inhibited. The anti-diabetic effects were marginally greater in the DM-DNJR group than in the DM-R group. CONCLUSIONS: These results suggest that rice coated with ML rich in DNJ can reduce hyperglycemia and hyperlipidemia in db/db mice, and may prove useful for individuals with diabetes.
Animals ; Blood Glucose ; Cholesterol ; Diabetes Mellitus ; Dyslipidemias* ; Fasting ; Glucagon-Like Peptide 1 ; Hemoglobin A, Glycosylated ; Hyperglycemia* ; Hyperlipidemias ; Hypoglycemia ; Insulin ; Intestine, Small ; Lactase ; Mice* ; Morus* ; Plasma ; Sucrase ; Triglycerides ; Weights and Measures

OBJECTIVE: The specific activity of lactase-phlorizin hydrolase (LPH) is very high at birth and sharply declines after weaning, producing lactose intolerance. The prevalence of lactose intolerance is up to 85% in Korean adults. Molecular basis of the regulatory mechanisms responsible for the decline of LPH specific activity is still unknown. In order to elucidate the molecular mechanisms regulating the LPH expression during development, LPH specific activity and mI4NA level of Korean fetal and adult intestines were compared. METHODS: 20 fetal small intestines (16-27 weeks) were obtained during therapeutic abortion and were divided into 3 equal length. 20 adult jejunal tissues were obtained from patients without small intestinal disease during laparotomy. Mucosal homogenates were prepared for dissacharidases specific activities measurement and total RNA was extracted for northern and slot hvbridization. LPH mRNA level was measured by laser densitometer. RESULTS: LPH specific activities of proximal, middle and distal portion of fetal intestines (n=20) were 36.2 +/- 22.5, 38.6 +/- 23.2 and 23.2 +/- 19.9 mu/mg protein, respectively. LPH specific activity of adult jejunum (n=8) was 5.9 +/- 1.8 mu/mg protein and significantly (p<0.05) lower than those of fetal intestines. However, there was no significant difference in sucrase and trehalase specific activities between fetal intestines and adult jejunum. Although LPH specific activity of adult jejunum was lower than those of fetal intestines, LPH mBNA level of adult jejunum was as high as those of fetal intestines. CONCLUSION: These results show that LPH specific activity and mRNA level do not parallel, indicating the posttranscriptional control of fetal development of LPH expression.
Abortion, Therapeutic ; Adult* ; Female ; Fetal Development ; Fetus* ; Humans ; Intestinal Diseases ; Intestine, Small* ; Intestines ; Jejunum ; Lactase* ; Lactase-Phlorizin Hydrolase ; Lactose Intolerance ; Laparotomy ; Parturition ; Pregnancy ; Prevalence ; RNA ; RNA, Messenger* ; Sucrase ; Trehalase ; Weaning

BACKGROUND/OBJECTIVES: Type 2 diabetes (T2D) is more frequently diagnosed and is characterized by hyperglycemia and insulin resistance. D-Xylose, a sucrase inhibitor, may be useful as a functional sugar complement to inhibit increases in blood glucose levels. The objective of this study was to investigate the anti-diabetic effects of D-xylose both in vitro and stretpozotocin (STZ)-nicotinamide (NA)-induced models in vivo. MATERIALS/METHODS: Wistar rats were divided into the following groups: (i) normal control; (ii) diabetic control; (iii) diabetic rats supplemented with a diet where 5% of the total sucrose content in the diet was replaced with D-xylose; and (iv) diabetic rats supplemented with a diet where 10% of the total sucrose content in the diet was replaced with D-xylose. These groups were maintained for two weeks. The effects of D-xylose on blood glucose levels were examined using oral glucose tolerance test, insulin secretion assays, histology of liver and pancreas tissues, and analysis of phosphoenolpyruvate carboxylase (PEPCK) expression in liver tissues of a STZ-NA-induced experimental rat model. Levels of glucose uptake and insulin secretion by differentiated C2C12 muscle cells and INS-1 pancreatic beta-cells were analyzed. RESULTS: In vivo, D-xylose supplementation significantly reduced fasting serum glucose levels (P < 0.05), it slightly reduced the area under the glucose curve, and increased insulin levels compared to the diabetic controls. D-Xylose supplementation enhanced the regeneration of pancreas tissue and improved the arrangement of hepatocytes compared to the diabetic controls. Lower levels of PEPCK were detected in the liver tissues of D-xylose-supplemented rats (P < 0.05). In vitro, both 2-NBDG uptake by C2C12 cells and insulin secretion by INS-1 cells were increased with D-xylose supplementation in a dose-dependent manner compared to treatment with glucose alone. CONCLUSIONS: In this study, D-xylose exerted anti-diabetic effects in vivo by regulating blood glucose levels via regeneration of damaged pancreas and liver tissues and regulation of PEPCK, a key rate-limiting enzyme in the process of gluconeogenesis. In vitro, D-xylose induced the uptake of glucose by muscle cells and the secretion of insulin cells by beta-cells. These mechanistic insights will facilitate the development of highly effective strategy for T2D.
Animals ; Blood Glucose* ; Complement System Proteins* ; Diet ; Fasting ; Gluconeogenesis ; Glucose Tolerance Test ; Glucose* ; Hepatocytes ; Hyperglycemia ; Insulin ; Insulin Resistance ; Liver ; Models, Animal ; Muscle Cells ; Pancreas ; Phosphoenolpyruvate Carboxylase* ; Phosphoenolpyruvate* ; Rats* ; Rats, Wistar ; Regeneration ; Sucrase ; Sucrose ; Xylose*

AIMTo study the absorption characteristics of berberine and its influence on glucose absorption.

METHODSRat recirculating perfusion model was used to study berberine absorption characteristics and Caco-2 cell model was used to explore the influence of berberine on disaccharidase, using HPLC to assay the appearance of glucose to indicate enzyme activities.

RESULTSBerberine was found to be hardly absorbed in the intestine (less than 5% in 2.5 h). However, sucrase and maltase activities were found to be inhibited by berberine, its ID50 to sucrase is 1.830 mg.L-1, and showed no dose dependent influence on maltase activity. Berberine also showed influence on glucose absorption. However, this effect is not significant.

CONCLUSIONBerberine may act as an alpha-glucosidase inhibitor, which is its main mechanism in diabetes treatment.

Animals ; Berberine ; pharmacokinetics ; pharmacology ; Caco-2 Cells ; Glucose ; pharmacokinetics ; Glycoside Hydrolase Inhibitors ; Humans ; Hypoglycemic Agents ; pharmacology ; Intestinal Absorption ; drug effects ; Male ; Maltose ; metabolism ; Rats ; Rats, Sprague-Dawley ; Sucrase ; metabolism

The aim of this study was to investigate the effects of mulberry juice and cake powder on blood glucose and lipid status along with intestinal disaccharidase and erythrocyte antioxidative enzyme system in streptozotocin (STZ )-induced diabetic rats. Sprague-Dawley male rats weighing 100 +/- 10 g were randomly assigned to one normal group, and eight STZ-induced diabetic groups: control diet group without mulberry juice and cake powders (DM-C ), three mulberry juice powder groups (0.5%:DM-0.5J, 1%:DM-1J, 2%:DM-2J )and four mulberry cake powder groups (0.25%:DM-0.25C, 0.5%:DM-0.5C, 1%:DM-1C, 2%:DM-2C ). After three-week feeding of each experimental diet, diabetes was induced by intravenous injection of 50 mg/kg body weight of STZ in sodium citrate buffer (pH 4.3 )via tail vein of eight DM groups. Rats were sacrificed at the 9th day of diabetic states. Level of blood glucose was 505 mg/dl in DM-C group but it was 28% and 39% lower in mulberry juice and cake powder fed groups, respectively, than the DM-C group. Activities of maltase, sucrase and lactase in proximal part of small intestine were significantly lower in the mulberry juice and cake powder groups by 42~47% than those of DM-C group. Erythrocytic superoxide dismutase, glutathione peroxidase and catalase activities were significantly reduced by STZ but increased close to normal levels along with less accumulation of thiobarbituric acid reactive substances (TBARS ). Serum levels of triglyceride and total cholesterol and HDL-cholesterol by STZ-DM were reduced and increased respectively, to the normal levels by the mulberry juice and cake powder. Except the levels of TBARS, the effects on the other measure-ments by the various dietary levels of mulberry juice and cake powder were almost same and the effect of the cake powder was most significant at the lowest level. These results indicate that mulberry juice and cake powders have considerable hypoglycemic effect and strengthening antioxidant defense systems at the low levels in diabetic state and may be able to reduce diabetic complications.
Animals ; Blood Glucose* ; Body Weight ; Catalase ; Cholesterol ; Citric Acid ; Diabetes Complications ; Diet ; Erythrocytes ; Glutathione Peroxidase ; Humans ; Hypoglycemic Agents ; Injections, Intravenous ; Intestine, Small ; Lactase ; Male ; Morus* ; Powders* ; Rats* ; Rats, Sprague-Dawley ; Sodium ; Streptozocin* ; Sucrase ; Superoxide Dismutase ; Thiobarbituric Acid Reactive Substances ; Triglycerides ; Veins