• Nutrition Research and Practice
• /
• v.1 no.3
• /
• pp.184-188
• /
• 2007

The major goal in the treatment of diabetes mellitus is to achieve near-normal glycemic control. To optimize both fasting blood glucose and postprandial glucose levels is important in keeping blood glucose levels as close to normal as possible. ${\alpha}-Glucosidase$ is the enzyme that digests dietary carbohydrate, and inhibition of this enzyme could suppress postprandial hyperglycemia. The purpose of this study was to test the inhibitory activity of methanol extract of Euonymus alatus on ${\alpha}-glucosidase$ in vitro and in vivo to evaluate its possible use as an anti-diabetic agent. Yeast ${\alpha}-glucosidase$ inhibitory activities of methanol extract of E. alatus were measured at concentrations of 0.50, 0.25, 0.10, and 0.05 mg/ml. The ability of E. alatus to lower postprandial glucose was studied in streptozotocin-induced diabetic rats. A starch solution (1 g/kg) with and without E. alatus extract (500 mg/kg) was administered to diabetic rats by gastric intubation after an overnight fast. Plasma glucose levels were measured at 30, 60, 90, 120, 180, and 240 min. Plasma glucose levels were expressed in increments from baseline, and incremental areas under the response curve were calculated. Extract of E. alatus, which had an $IC_{50}$ value of 0.272 mg/ml, inhibited yeast ${\alpha}-glucosidase$ activity in a concentration-dependent manner. A single oral dose of E. alatus extract significantly inhibited increases in blood glucose levels at 60 and 90 min (p<0.05) and significantly decreased incremental response areas under the glycemic response curve (p<0.05). These results suggest that E. alatus has an antihyperglycemic effect by inhibiting ${\alpha}-glucosidase$ activity in this animal model of diabetes mellitus.

• Preventive Nutrition and Food Science
• /
• v.17 no.1
• /
• pp.8-13
• /
• 2012

This study was designed to investigate whether Sargassum ringgoldianum extract may inhibit ${\alpha}$-glucosidase and ${\alpha}$-amylase activities, and alleviate postprandial hyperglycemia in streptozotocin-induced diabetic mice. The $IC_{50}$ values of Sargassum ringgoldianum extract against ${\alpha}$-glucosidase and ${\alpha}$-amylase were 0.12 mg/mL and 0.18 mg/mL, respectively, which evidenced higher activities than those of acarbose. The blood glucose levels of the Sargassum ringgoldianum extract administered group were significantly lower compared to the control group in the streptozotocin-induced diabetic mice. Moreover, the area under the two-hour blood glucose response curve was significantly reduced and the absorption of dietary carbohydrates was delayed after administration of Sargassum ringgoldianum extract in the diabetic mice. Therefore, these results indicated that Sargassum ringgoldianum extract may help decrease the postprandial blood glucose level via inhibiting ${\alpha}$-glucosidase.

• Journal of Life Science
• /
• v.27 no.9
• /
• pp.1052-1058
• /
• 2017

Gelidium amansii shows antioxidant and anti-obesity effects; however, the effect on postprandial blood glucose levels is not known. The objective of the present study was to investigate the inhibitory effect of Gelidium amansii extract (GAE) on carbohydrate-digesting enzymes and its ability to alleviate postprandial hyperglycemia in streptozotocin (STZ)-induced diabetic mice. Gelidium amansii was extracted with 80% ethanol and concentrated for use in this study. The ${\alpha}-glucosidase$ and ${\alpha}-amylase$ inhibition assays were performed using the colorimetric method. ICR normal and STZ-induced diabetic mice were orally administered GAE (300 mg/kg body weight) or acarbose (100 mg/kg body weight) alone or soluble starch (2 g/kg body weight). Blood samples were taken from the tail vein at 0, 30, 60 and 120 min. Our results indicated that GAE markedly inhibited ${\alpha}-glucosidase$ and ${\alpha}-amylase$ activities with $IC_{50}$ values of $0.099{\pm}0.009mg/ml$ and $0.178{\pm}0.038mg/ml$, respectively, and was a more effective inhibitor than acarbose, the positive control. Further, the postprandial blood glucose levels of STZ-induced diabetic mice in the GAE-administered group were significantly lower than those of control group mice (p<0.05). Moreover, the area under the curves (AUC) significantly decreased with GAE administration in STZ-induced diabetic mice (p<0.05). These results indicate that GAE may be effective in decreasing postprandial blood glucose levels by inhibiting carbohydrate-digesting enzymes such as ${\alpha}-amylase$ and ${\alpha}-glucosidase$. Therefore, GAE could be used as a potential functional food for alleviating postprandial hyperglycemia.

• Nutritional Sciences
• /
• v.7 no.4
• /
• pp.208-213
• /
• 2004

In this study, we examined the effects of dietary 1,3-diacylglycerol (DG) compared to conventional triacylglycerol (TG) oil on the postprandial response of total and chylomicron TG, glucose, insulin, and free fatty acid (FFA). This study was conducted using a cross-over design. Ninety subjects participated in the high-fat meal tolerance test where they were randomly assigned to consume two experimental sandwiches containing mayonnaise with TG or DG oil with a seven-day interval. Blood samples were collected before ingestion and at 2, 3, 4 and 6 hr time point after ingestion and analyzed for total and chylomicron TG, glucose, insulin, FFA and phospholipid fatty acid composition. Both TG and DG ingestion had similar effects on postprandial TG response, but a different response from chylomicron TG. Compared with the TG group, TG levels were significantly lower only at 6 hr time point in the DG group. On the other hand, chylomicron TG rose steeply at 2 hr time point and decreased faster in this group. Also, the adjusted value to fasting levels was the same as the unadjusted level. Fasting levels and net differences in insulin were significantly lower at 3 hr time point where chylomicron TG levels were significantly lower in the DG group. But those of glucose and FFA in the TG and DG groups did not differ significantly. Fasting and postprandial levels of fatty acid composition in serum phospholipids in the two groups did not differ significantly. In conclusion, this study indicated that one could reduce the magnitude of postprandial lipemia without influencing glucose metabolism by consumning DG oil as a substitute for TG oil. Based on the correlation of coronary artery disease and postprandial lipemia, dietary DG ingestion might have a beneficial effect in treating such a disease. Further studies are required to clarify the long-tenn effects of dietary DG on blood lipid levels in humans.

• Nutrition Research and Practice
• /
• v.7 no.3
• /
• pp.166-171
• /
• 2013

The purpose of this study was to investigate the effects of lotus leaf on hyperglycemia and dyslipidemia in animal model of diabetes. Inhibitory activity of ethanol extract of lotus leaf against yeast ${\alpha}$-glucosidase was measured in vitro. The effect of lotus leaf on the postprandial increase in blood glucose levels was assessed in streptozotocin-induced diabetic rats. A starch solution (1 g/kg) with and without lotus leaf extract (500 mg/kg) was administered to the rats after an overnight fast, and postprandial plasma glucose levels were monitored. Four-week-old db/db mice were fed a basal diet or a diet containing 1% lotus leaf extract for 7 weeks after 1 week of acclimation to study the chronic effect of lotus leaf. After sacrifice, plasma glucose, insulin, triglycerides (TG), total cholesterol (CHOL), high-density lipoprotein (HDL)-CHOL, and blood glycated hemoglobin levels were measured. Lotus leaf extract inhibited ${\alpha}$-glucosidase activity by 37.9%, which was 1.3 times stronger than inhibition by acarbose at a concentration of 0.5 mg/mL in vitro. Oral administration of lotus leaf extract significantly decreased the area under the glucose response curve by 35.1% compared with that in the control group (P < 0.01). Chronic feeding of lotus leaf extract significantly lowered plasma glucose and blood glycated hemoglobin compared with those in the control group. Lotus leaf extract significantly reduced plasma TG and total CHOL and elevated HDL-CHOL levels compared with those in the control group. Therefore, we conclude that lotus leaf is effective for controlling hyperglycemia and dyslipidemia in an animal model of diabetes mellitus.

• Nutrition Research and Practice
• /
• v.4 no.6
• /
• pp.486-491
• /
• 2010

Tight control of blood glucose is the most important strategy for the treatment of diabetes mellitus. Here, we investigated the beneficial effects of Welsh onion on fasting and postprandial hyperglycemia. Inhibitory activities of hot water extracts from the green stalk and white bulb, which are the edible portions of the Welsh onion, and the fibrous root extract against yeast ${\alpha}$-glucosidase were measured in vitro. To study the effects of Welsh onion on postprandial hyperglycemia, a starch solution (1 g/kg) with and without Welsh onion fibrous root extract (500 mg/kg) or acarbose (50 mg/kg) was administered to streptozotocin-induced diabetic rats after an overnight fast. Postprandial plasma glucose levels were measured and incremental areas under the response curve were calculated. To study the hypoglycemic effects of chronic feeding of Welsh onion, five-week-old db/db mice were fed an AIN-93G diet or a diet containing either Welsh onion fibrous root extract at 0.5% or acarbose at 0.05% for 7 weeks after 1 week of adaptation. Fasting plasma glucose and blood glycated hemoglobin were measured. Compared to the extract from the edible portions of Welsh onion, the fibrous root extract showed stronger inhibition against yeast ${\alpha}$-glucosidase, with an $IC_{50}$ of 239 ${\mu}g/mL$. Oral administration of Welsh onion fibrous root extract (500 mg/kg) and acarbose (50 mg/kg) significantly decreased incremental plasma glucose levels 30-120 min after oral ingestion of starch as well as the area under the postprandial glucose response curve, compared to the control group (P < 0.01). The plasma glucose and blood glycated hemoglobin levels of the Welsh onion group were significantly lower than those of the control group (P < 0.01), and were not significantly different from those fed acarbose. Thus, we conclude that the fibrous root of Welsh onion is effective in controlling hyperglycemia in animal models of diabetes mellitus.

• Journal of Nutrition and Health
• /
• v.31 no.7
• /
• pp.1139-1150
• /
• 1998

The purpose of this study is to investigate the effects of the silkworm powder on blood levels of glucose, Hb Alc, insulin, and lipids. Thirty-one NIDDM patients from Kyung Hee Medical Center were divided into two groups : patients with silkworm powder supplements and drug treatments(Drug diabetes) and patients with silkworm powder supplement only(Non-drug diabetes). For the control group, age-matched subjects were recruited. During the 4 weeks of the experimental period, silkworm powder(500mg/mea1) was given to the subjects right after each meal. Nutritional assessments and dietary education were carried out periodically, and body weight and blood pressure were measured when patients visited the hospital. Overnight fasting and 2-h postprandial blood glucose levels were measured at 2 week intervals. The blood levels of insulin, Hb Alc, and lipids were measured before and after the supplements. The mean ages of the three groups were 56.7-59.6 years old. The height, weight, and BMI did not differ among the groups. The fasting blood glucose levels were 138.1$\pm$22.0mg/dl for the Drug treated diabetes group, 175.0$\pm$32.0mg/dl for the Non-drug diabetes group, and 108. 3$\pm$16.gmg/dl for the control group at the begining of the supplement. After 4-wks of supplements, the blood levels of glucose tended to decrease in all three experimental groups. Before the supplements, the 2-h postprandial blood glucose levels of the Drug diabetes, Non drug diabetes, and control groups were 244.7$\pm$62.6mg/dl, 272.4$\pm$40.1mg/dl, and 147.7$\pm$28.0mg/dl, respectively. After the supplement, the levels were 197.2$\pm$30.gmg/dl, 208.6$\pm$ 56.6mg/dl, and 151.3$\pm$30.3mg/dl, respectively. This shows that silkworm powder tended to lower blood levels by 19.4% and 23.4% in NIDDM patient groups. However, the changes in the blood levels of insulin, Hb Alc, ind lipids were not observed after the supplement. In conclusion, the present study has demonstrated that silkworm powder has a tendency to decrease 2-h postprandial blood glucose levels, but it should be used with caution in controlling the diabetes. (Korean J Nutrition 31(7) 1139-1150, 1998)

• Korean journal of food and cookery science
• /
• v.11 no.3
• /
• pp.267-273
• /
• 1995

Twenty five cooking recipe with yam (Dioscorea japonica Thunb) have been developed and their hypoglycemic effects on diabetic patients were investigated. The results of the sensory evaluations revealed that the tested recipe were in good scores (overall acceptability scores 3.30-4.33) except Chojuli. The 10-panel members indicated that the yam cookings were more acceptable when they were cooked with other vegetables. Twenty seven diabetic patients were entered in a general hospital during the 2-month experimental period and they were allowed to consume the diet with yam cooking dish, 75 g of yam a day. The fasting blood glucose and 2-hour postprandial blood glucose levels were determined. The diabetic patients who consumed yam showed the lower blood glucose levels than those patients who were controlled with the hospital diet only. The hypoglycemic effects of the yam were more evident in the patients who were injected with insulin. The constant lowering effects of blood glucose levels were observed in the normal subjects who had taken the yam cookery, leading to that one subject who started with a low blood glucose level must stop the yam consumption after 10 days.

• Clinical and Experimental Reproductive Medicine
• /
• v.48 no.4
• /
• pp.374-379
• /
• 2021

Objective: We aimed to evaluate associations between the ratio of serum estrone (E1) to estradiol (E2) and parameters related to serum glucose metabolism and insulin resistance in women with polycystic ovary syndrome (PCOS). Methods: In total, 133 women between the ages of 18 and 35 diagnosed with PCOS were enrolled in this study. All participants with PCOS underwent blood tests to determine hormonal and biochemical metabolic parameters and a standard 2-hour 75-g oral glucose tolerance test. They were divided into two groups according to the serum E1-to-E2 ratio: group 1 (E1/E2 ratio <2.0) and group 2 (E1/E2 ratio ≥2.0). Results: In the comparative analysis, the waist-to-hip ratio (WHR) was the only clinical variable that was significantly different between the two groups. Patients with a higher E1/E2 ratio showed higher fasting insulin levels, homeostasis model for insulin resistance, and postprandial glucose level at 2 hours (PPG2). In a correlation analysis, only PPG2 was significantly related to the serum E1/E2 ratio. However, after controlling for the confounding effects of body mass index (BMI) and WHR, fasting glucose was also significantly correlated with the serum E1/E2 ratio. Conclusion: Women with PCOS with a higher serum E1/E2 ratio were found to be more likely to show higher fasting insulin and postprandial glucose levels. Significant correlations were found between the serum E1/E2 ratio and both fasting and postprandial serum glucose levels after adjusting for BMI and WHR in women with PCOS.

• Nutrition Research and Practice
• /
• v.2 no.2
• /
• pp.62-67
• /
• 2008

The present study was carried out to evaluate the physiological effects of seaweed supplementation on blood glucose levels, lipid profile, and antioxidant enzyme activities in subjects with type 2 diabetes mellitus. Subjects were randomized into either a control group or a seaweed supplementation group. Pills with equal parts of dry powdered sea tangle and sea mustard were provided to the seaweed supplementation group three times a day for 4 weeks. Total daily consumption of seaweed was 48 g. We found that total dietary fiber intake was 2.5 times higher in subjects receiving seaweed supplementation than in the control group. Accordingly, fasting blood glucose levels (p<0.01) and 2-hour postprandial blood glucose measurements (p<0.05) were decreased significantly in those ingesting seaweed. Furthermore, the serum concentrations of triglycerides were decreased and high-density lipoprotein cholesterol was increased significantly in seaweed supplement group (p<0.05). However, the concentrations of total cholesterol and low-density lipoprotein cholesterol were not affected by seaweed supplementation. The level of thiobarbituric acid reactive substances in erythrocytes was significantly lower with seaweed supplementation compared to controls (p<0.05). Catalase and glutathione peroxidase activities with seaweed supplementation were higher than the controls (p<0.05), but superoxide dismutase activity was not affected. We, therefore, conclude that ingestion of seaweed influences glycemic control, lowers blood lipids, and increases antioxidant enzyme activities.