• Nutrition Research and Practice
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• 제3권4호
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• pp.272-278
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• 2009

Postprandial hypoglycemic effect of mulberry leaf (Morus alba L.) was compared in two animal models: Goto-Kakizaki (GK) rats, a spontaneous non-obese animal model for type II diabetes, and their counterpart control Wistar rats. First, the effect of a single oral administration of mulberry leaf aqueous extract (MLE) on postprandial glucose responses was determined using maltose or glucose as substrate. With maltose-loading, MLE reduced peak responses of blood glucose significantly in both GK and Wistar rats (P < 0.05), supporting the inhibition of $\alpha$-glucosidase by MLE in the small intestine. With glucose-loading, MLE also significantly reduced blood glucose concentrations, measured at 30 min, in both animal models (P < 0.01), proposing the inhibition of glucose transport by MLE. Next, dried mulberry leaf powder (MLP) was administered for 8 weeks by inclusion in the diet. By MLP administration, fasting blood glucose was significantly reduced at weeks 4 and 5 (P < 0.05), but then returned to values that were similar to those of the control at the end of experimental period in GK rats. Insulin, HOMA-IR, C-reactive protein, and triglycerides tended to be decreased by MLP treatment in GK rats. All other biochemical parameters were not changed by MLP administration in GK rats. Collectively, these findings support that MLE has significant postprandial hypoglycemic effect in both non-obese diabetic and healthy animals, which may be beneficial as food supplement to manage postprandial blood glucose. Inhibitions of glucose transport as well as $\alpha$-glucosidase in the small intestine were suggested as possible mechanisms related with the postprandial hypoglycemic effect of MLE.

• 대한의용생체공학회:의공학회지
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• 제44권1호
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• pp.33-40
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• 2023

Transcutaneous auricular vagus nerve stimulation (taVNS) is known to be effective in improving symptoms of numerous diseases such as depression and epilepsy by increasing vagus nerve activity through electrical stimulation. The purpose of this study is to investigate the effect of vagus nerve stimulation on the activity of autonomic nervous system and the changes in postprandial blood glucose levels. Seven healthy adults participated in a non-invasive transcutaneous auricular vagus nerve stimulation experiment. taVNS (25 Hz, 200 ㎲, biphasic pulse) was applied to the cymba concha (taVNS group) or the earlobe (Sham-taVNS group) of the left ear. As autonomic nervous system signals, skin conductance level, skin temperature, and heart rate were recorded during the application of taVNS. Postprandial blood glucose changes due to food intake were recorded at 5 min intervals for 25 minutes after taVNS or sham-taVNS. The taVNS showed a significantly lower skin conductance level than the shamtaVNS (p < 0.05). The increase rate of postprandial blood glucose was significantly lower in the taVNS than in the sham-taVNS (p < 0.05). These results showed that taVNS reduced the activity of the sympathetic nerve system and alleviated early rise in postprandial blood glucose. Although further studies in diabetic patients are needed, this study suggest that taVNS has a potential for clinical use to improve postprandial blood glucose.

• Preventive Nutrition and Food Science
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• 제21권3호
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• pp.181-186
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• 2016

This study was designed to investigate the inhibitory effect of Gynura procumbens extract against carbohydrate digesting enzymes and its ability to ameliorate postprandial hyperglycemia in streptozotocin (STZ)-induced diabetic mice. G. procumbens extract showed prominent ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibitory effects. The half-maximal inhibitory concentration ($IC_{50}$) of G. procumbens extract against ${\alpha}$-glucosidase and ${\alpha}$-amylase was $0.092{\pm}0.018$ and $0.084{\pm}0.027mg/mL$, respectively, suggesting that the ${\alpha}$-amylase inhibition activity of the G. procumbens extract was more effective than that of the positive control, acarbose ($IC_{50}=0.164mg/mL$). The increase in postprandial blood glucose levels was more significantly alleviated in the G. procumbens extract group than in the control group of STZ-induced diabetic mice. Moreover, the area under the curve significantly decreased with G. procumbens extract administration in STZ-induced diabetic mice. These results suggest that G. procumbens extract may help alleviate postprandial hyperglycemia by inhibiting carbohydrate digesting enzymes.

• Preventive Nutrition and Food Science
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• 제19권1호
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• pp.5-9
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• 2014

This study was designed to investigate the inhibitory effects of Polyopes lancifolia extract (PLE) on ${\alpha}$-glucosidase activity, ${\alpha}$-amylase activitiy, and postprandial hyperglycemia in streptozotocin (STZ)-induced diabetic mice. The results of this study revealed a marked inhibitory effect of PLE on ${\alpha}$-glucosidase and ${\alpha}$-amylase activities. The $IC_{50}s$ of PLE against ${\alpha}$-glucosidase and ${\alpha}$-amylase were 0.20 mg/mL and 0.35 mg/mL, respectively. PLE was a more effective inhibitor of ${\alpha}$-glucosidase and ${\alpha}$-amylase activities than acarbose, the positive control. The postprandial blood glucose levels of STZ-induced diabetic mice were significantly lower in the PLE treated group than in the control group. Moreover, PLE administration was associated with a decreased area under the curve for the glucose response in diabetic mice. These results indicate that PLE may be a potent inhibitor of ${\alpha}$-glucosidase and ${\alpha}$-amylase activities and may suppress postprandial hyperglycemia.

• Nutritional Sciences
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• 제8권2호
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• pp.83-88
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• 2005

This study was to investigate the effect of psyllium seed husk (PSYL) on postprandial glucose control and insulin secretion dynamics in Sprague-Dawley rats. In experiment 1, the rise in postprandial serum glucose was monitored during a 240-min period using a maltose loading test In normal rats given 16.6 mg/l00 g B.W./ml of PSYL orally, all the blood glucose levels during the 240-min period did not show statistically significant differences from the corresponding levels in normal rats given water. However, in streptozotocin-induced diabetic rats given the same amount of PSYL, the blood glucose level at 30 min was significantly lower than that in diabetic rats given water, and the peak time of the rise in the postprandial glucose was delayed In experiment 2, the normal (N) and diabetic (Db) rats were given PSYL (25 mg/l00 g B.W./ml/day) orally for 5 days. Blood samples were collected in order to measure the s-glucose and s-insulin levels. The final s-glucose level at day 5 in Db-PSYL was significantly lower than that in the corresponding control rats (Db-CONT) and the final s-insulin level in Db-PSYL was significantly greater than that in Db-CONT. In vitro 40-min pancreas perfusion was performed at day 5 in order to examine the insulin secretion dynamics. Results showed that the amounts of insulin secreted during the first phase (11-20 min) and the second phase (21-40 min) in the Db-PSYL were significantly greater than those in Db-CONT. Therefore, it is concluded that psyllium seed husk could be beneficial for controlling postprandial glucose levels in the stretozotocin-induced diabetic rats, and it may be partially mediated by insulin secretion dynamics.

• Preventive Nutrition and Food Science
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• 제7권2호
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• pp.174-178
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• 2002

The influence of physical forms of gelatinized rice products on enzymatic hydrolysis in vitro and glycemic and insulinemic responses in normal subjects were studied. Densities of garaedu, bagsulgi, and cooked rice were 1.20, 1.18 and 1.11 g/mL, respectively, while moisture contents of garaeduk, bagsulgi, and cooked rice were 47.5, 43.1 and 66.0% (wt.), respectively. The highest initial rate of in vitro hydrolysis by porcine pancreatic $\alpha$-amylase was observed in bagsulgi followed by cooked rice and garaeduk. However, time for complete hydrolysis seemed to reach a plateau value. Postprandial glucose and insulin responses and satiety of rice products were studied in 12 normal subjects (mean age 23.2 $\pm$ 2.4 years, 6 men and 6 women). Postprandial serum glucose and insulin levels, after consumption of the rice products, reached a peak at 30 min. Garaeduk showed significantly less incremental responses for glucose (1627.5$\pm$134.9 mg.min/dL) and insulin (2041$\pm$287.0 uU.min/mL) than did bagsulgi for glucose (2407.4$\pm$208.3 mg.min/dL) and insulin (3582$\pm$264.4 uU.min/mL). Satiety responses to the rice products were not significantly different. Therefore, it can be concluded that garaeduk may be more beneficial in controlling postprandial hyperglycemia and hyperinsulinemia than bagsulgi. These results also suggest that physical properties of starch products, acquired by the specific processing methods, affect postprandial metabolism of carbohydrate foods.

• Nutrition Research and Practice
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• 제5권6호
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• pp.533-539
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• 2011

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.

• Nutrition Research and Practice
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• 제12권5호
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• pp.371-377
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• 2018

BACKGROUND/OBJECTIVES: Elevation of postprandial lipemia characterized by a rise in triglyceride (TG)-rich lipoproteins can increase the risk of atherogenesis. The objective of this study was to investigate postprandial lipemia response to a single dietary fat/sugar load test and monitor beneficial changes induced by the consumption of Platycodi radix (AP) beverage in healthy subjects. SUBJECTS/METHODS: A total of 52 subjects were randomly assigned to either placebo or AP beverage group with a high-fat shake in a randomized controlled crossover trial. Postprandial blood was collected at 0, 1, 2, 4, and 6 h and analyzed for TG and lipoprotein lipase mass. Inhibition of pancreatic lipase was determined in vitro. RESULTS: AP inhibited pancreatic lipase activity in vitro ($IC_{50}=5mg/mL$). Compared to placebo beverage, AP beverage consumption with a high-fat shake induced significant increase of plasma lipoprotein lipase mass (P = 0.0111, ${\beta}$ estimate = 4.2948) with significant reduction in very low-density lipoprotein (VLDL) TG concentration (P = 0.038, ${\beta}$ estimate = -52.69) at 6 h. Based on significant correlation between high-fat dietary scores MEDFICTS and postprandial TG responses in VLDL (P = 0.0395, r = 0.2127), subgroup analysis revealed that 6 h-postprandial VLDL TG response was significantly decreased by AP consumption in subjects with MEDFICTS ${\geq}40$ (P = 0.0291, ${\beta}$ estimate = -7214). CONCLUSIONS: AP beverage might have potential to alleviate postprandial lipemia through inhibiting pancreatic lipase activity and elevating lipoprotein lipase mass. Subgroup analysis revealed that subjects with high-fat dietary pattern could be classified as responders to AP beverage among all subjects.

• 생명과학회지
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• 제28권4호
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• pp.421-428
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• 2018

식후고혈당은 제 2형 당뇨병의 발병에 부정적인 영향을 미치고 미세혈관 및 대혈관 질환 등의 당뇨병 합병증 유발과 밀접한 관계가 있다. 따라서 식후고혈당을 조절하는 것이 당뇨병 합병증의 위험을 줄이는 가장 중요한 요소이다. 식후고혈당은 소장에서 ${\alpha}$-글루코시다아제와 같은 탄수화물 소화 효소를 저해함으로써 조절될 수 있다. 이에 본 연구는 쇠비름 에탄올 추출물(PEE)과 물 추출물(PWE)이 탄수화물 소화 효소를 저해하고, 당뇨병 마우스에서 식후 고혈당을 강하시키는 효과에 대해 조사하였다. ${\alpha}$-글루코시다아제와 ${\alpha}$-아밀라아제에 대한 저해효과는 두 추출물 모두 양성대조군인 acarbose보다 더 효과적이었으며, PEE에 의한 ${\alpha}$-글루코시다아제 저해 효과가 PWE 보다 더 효과적이었다. Diabetic mice에 전분(2 g/kg)을 투여한 후의 혈당 증가는 30, 60, 120분에 각각 383.7, 429.3, 360.2 mg/dL로 나타났고, 전분(2 g/kg)과 PEE 또는 PWE 추출물(300 mg/Kg)을 투여한 후의 혈당 증가는 30, 60, 120분에 각각 337.0, 368.5, 290.1 mg/dL과 365.8, 379.2, 324.3 mg/dL로 나타나, PEE 추출물 투여군이 대조군에 비해 식후 혈당 강하가 효과적으로 나타남을 알 수 있었다. 이러한 결과는 쇠비름 추출물이 탄수화물 소화효소를 저해함으로써 식후 고혈당을 완화시키고, 특히 쇠비름 에탄올 추출물(PEE)이 쇠비름 물 추출물(PWE) 보다 식후 고혈당을 완화시키는데 더욱 효과가 있는 것으로 나타났다.

• 생명과학회지
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• 제26권8호
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• pp.921-927
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• 2016

식후 고혈당은 제2형 당뇨병 초기 진단과 항당뇨병의 중요한 바이오마커 중 하나이다. α-글루코시다아제 억제제는 소장에서 탄수화물 소화의 속도를 방해함으로써 식후 고혈당을 조절한다. 본 연구에서는 오디열매추출물이 α-글루코시다아제와 α-아밀라아제에 미치는 억제효과 및 스트렙토조토신(STZ)이 유발하는 당뇨병 생쥐의 식후고혈당에 미치는 완화 효과를 조사하였다. α-글루코시다아제와 α-아밀라아제에 대한 오디열매추출물(MFE)의 IC₅₀ 값은 각각 0.16과 0.14 mg/ml의 결과값을 나타내어, 양성대조군인 acarbose보다 더 효과적이었다. STZ으로 유발된 당뇨병 흰쥐의 식후 혈당 수치는 정상 대조군에 비해 오디열매추출물에서 유의적으로 더 낮았다. 더욱이, 오디열매추출물 투여는 당뇨병 흰쥐에서 포도당 반응에 대한 곡선하면적 감소와 관련이 있었다. 결론적으로, 오디열매추출물은 α-글루코시다아제와 α-아밀라아제 활성의 강력한 억제제이며 식후 고혈당을 완화할 수 있다는 내용이다. 따라서 오디열매추출물은 당뇨병 치료제 및 기능성식품의 소재로 가치가 높다고 사료된다.