• Korean Journal of Medicinal Crop Science
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• v.15 no.2
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• pp.128-131
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• 2007

This study was carried out to investigate inhibitory effect of extracts from Artemisia capillaris Thumb. on maltase, sucrase, ${\alpha}-amylase$, nonspecific ${\alpha}-glucosidase$, and postprandial hyperglycemia. Methanol extract and organic solvent (n-hexane, ethyl acetate, butanol, aqueous) fractions from the medicinal herb were determined for the inhibitory activities against maltase, sucrase and ${\alpha}-amylase$. The methanol extract from A. capillaris strongly inhibited maltase (57%) and ${\alpha}-glucosidase$ (72%) at the concentration of 100 ${\mu}g/m{\ell}$. Among the four fractions (n-hexane, ethyl acetate, butanol, aqueous) examined, the butanol fraction from A. capillaris showed potent inhibitory effects on maltase (73%), sucrase (33%), and ${\alpha}-amylase$ (75%) at the concentration of 100 ${\mu}g/m{\ell}$. The butanol fraction from Artemisia capillaris also exhibited significant reductions (20%) of blood glucose elevation in mice loaded with maltose. These results suggest that the extract from Artemisia capillaris can be used as a new nutraceutical for inhibition on postprandial hyperglycemia

• Journal of Life Science
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• v.32 no.8
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• pp.589-594
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• 2022

The objective of this study was to investigate whether betulinic acid can inhibit the activities of carbohydrate-digesting enzymes and reduce postprandial hyperglycemia in mice with streptozotocin-induced diabetes. Our results revealed that betulinic acid has potent inhibitory effects on α-glucosidase and α-amylase activities. The half-maximal inhibitory concentrations (IC₅₀) of betulinic acid were 12.83±6.81 and 18.32±3.24 μM for α-glucosidase and α-amylase, respectively. This result indicates lower IC₅₀ values and higher inhibitory activities than those of acarbose, an oral hypoglycemic drug. The increase in postprandial blood glucose levels was significantly suppressed in the betulinic acid group than in the control group of diabetic and normal mice. Postprandial blood glucose levels were 23.22±1.1, 24.38±1.31, and 21.05±1.36 μM in the betulinic acid group compared to 24.64±1.7, 27.22±1.58, and 26.36±1.40 μM in the control group of diabetic mice at 30, 60 and 120 min, respectively. The area under the curve also significantly decreased with the administration of betulinic acid in diabetic mice, however, it did not decrease more than that after acarbose administration. Our results showed that betulinic acid may be a potent inhibitor of carbohydrate-digesting enzymes and ameliorate postprandial hyperglycemia in diabetic mice.

• Nutrition Research and Practice
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• v.9 no.3
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• pp.262-267
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• 2015

BACKGROUND/OBJECTIVES: The primary objective of the treatment of diabetes mellitus is the attainment of glycemic control. Hyperglycemia increases oxidative stress which contributes to the progression of diabetic complications. Thus, the purpose of this study was to investigate the hypoglycemic and antioxidant effects of Daraesoon (Actinidia arguta shoot) in animal models of diabetes mellitus. MATERIALS/METHODS: Rats with streptozotocin-induced diabetes received an oral administration of a starch solution (1 g/kg) either with or without a 70% ethanol extract of Daraesoon (400 mg/kg) or acarbose (40 mg/kg) after an overnight fast and their postprandial blood glucose levels were measured. Five-week-old C57BL/6J mice were fed either a basal or high-fat/high-sucrose (HFHS) diet with or without Daraesoon extract (0.4%) or acarbose (0.04%) for 12 weeks after 1 week of adaptation to determine the effects of the chronic consumption of Daraesoon on fasting hyperglycemia and antioxidant status. RESULTS: Compared to the control group, rats that received Daraesoon extract (400 mg/kg) or acarbose (40 mg/kg) exhibited a significant reduction in the area under the postprandial glucose response curve after the oral ingestion of starch. Additionally, the long-term consumption of Daraesoon extract or acarbose significantly decreased serum glucose and insulin levels as well as small intestinal maltase activity in HFHS-fed mice. Furthermore, the consumption of Daraesoon extract significantly reduced thiobarbituric acid reactive substances and increased glutathione levels in the livers of HFHS-fed mice compared to HFHS-fed mice that did not ingest Daraesoon. CONCLUSIONS: Daraesoon effectively suppressed postprandial hyperglycemia via the inhibition of ${\alpha}$-glucosidase in STZ-induced diabetic rats. Chronic consumption of Daraesoon alleviated fasting hyperglycemia and oxidative stress in mice fed a HFHS diet.

• Journal of Life Science
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• v.27 no.1
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• pp.32-37
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• 2017

Cyanidin-3-O-glucoside (C3G) shows anti-inflammatory and antioxidant effects; however, its effect on postprandial blood glucose levels remains unknown. Alpha-glucosidase inhibitors regulate post-prandial hyperglycemia by impeding carbohydrate digestion in the small intestine. Here, the effect of C3G on ${\alpha}-glucosidase$ and ${\alpha}-amylase$ inhibition and its ability to ameliorate postprandial hyperglycemia in streptozotocin (STZ)-induced diabetic mice were evaluated. ICR normal and STZ-induced diabetic mice were orally administered soluble starch alone or with C3G or acarbose. The half-maximal inhibitory concentrations of C3G for ${\alpha}-glucosidase$ and ${\alpha}-amylase$ were 13.72 and $7.5{\mu}M$, respectively, suggesting that C3G was more effective than acarbose. The increase in postprandial blood glucose levels was more significantly reduced in the C3G groups than in the control group for both diabetic and normal mice. The area under the curve for the diabetic mice was significantly reduced following C3G administration. C3G may be a potent ${\alpha}-glucosidase$ inhibitor and may delay dietary carbohydrate absorption.

• Journal of Life Science
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• v.30 no.12
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• pp.1054-1062
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• 2020

This study was designed to investigate whether extracts from Oxya chinensis sinuosa Mistshenk (an edible insect considered a grasshopper) could inhibit the activity of carbohydrate digestive enzymes and alleviate postprandial hyperglycemia in diabetic mice. Oxya chinensis sinuosa Mistshenk was extracted with 80% ethanol (OEE) or water (OWE) and then concentrated. The carbohydrate digestive enzyme-inhibiting activity of the resulting extracts was evaluated by examining α-glucosidase and α-amylase. The IC50 values of OEE against α-glucosidase and α-amylase were 0.229 mg/ml and 0.106 mg/ml, respectively. This result indicated that OEE has stronger inhibitory effects than OWE and positive control. The blood glucose levels of the diabetic control mice increased after one meal. However, when OEE (300 mg/kg) was added to starch, this increase in postprandial blood glucose levels was significantly suppressed. The area under the curve also significantly decreased following the administration of OEE, which exhibited no cytotoxicity. These results indicate that OEE is more efficacious than OWE and may be used as a carbohydrate digestive enzyme inhibitor, delay carbohydrate digestion and glucose absorption, and thus alleviate postprandial hyperglycemia caused by dietary carbohydrates.

• Natural Product Sciences
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• v.11 no.3
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• pp.127-130
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• 2005

This study was carried out to investigate inhibitory effect of extracts from root cortex of Paeonia suffruticosa on ${\alpha}-glucosidase$ (EC 3. 2. 1. 20) and postprandial hyperglycemia. Methanol extract and organic solvent (n-hexane, ethyl acetate, butanol, aqueous) fractions from the crude drug were determined for the inhibitory activities against maltase, sucrase and ${\alpha}-amylase$. The methanol extract from the crude drug strongly inhibited maltase (72%) and sucrase (76%) at the concentration of $100\;{\mu}g/ml$. Among the fractions examined, the ethyl acetate fraction from the natural plant drug showed potent inhibitory effects on maltase (85%) and sucrase (81%) at the concentration of $100\;{\mu}g/ml$. The ethyl acetate fraction from root cortex of Paeonia suffruticosa also exhibited significant reductions (21%) of blood glucose elevation in mice loaded with maltose.

• Biomolecules & Therapeutics
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• v.6 no.3
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• pp.242-246
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• 1998

The inhibitory activities of Amberlite active fraction, which was obtained from methanol soluble fraction of freeze dried slikworm urine, on the rat intestinal glycosidase-catalyzed enzymatic reaction were examined in in viro and in vivo experiments. Amberlite active fraction showed significant inhibitory effects on the hydrolysis of o-glycosidic bond, especially $\alpha$-1,4 bond. On the other hand, the inhibition on the hydrolysis of $\beta$-glycosidic bond was very weak. Oral administration of Amberlite active fraction resulted in a dose-dependent decrease in the blood glucose after an oral maltose load, and postprandial hyperglycemia in carbohydrate-loaded mice was suppressed by Amberlite active fraction at 60 mgHg in decreasing order of maltose, starch, sucrose and lactose. 60 mg/kg of Amberlite active fraction lowered the blood glucose level markedly after 18, 35, and 60 min after an oral maltose load and the antihyperglycemic activity was maintained upto 90 min. In alloxan-induced hyperglycemic mice, Amberlite active fraction at a dose of 100 mg/kg also significantly lowered blood glucose after an oral maltose load, and its efficacy was almost equivalent to that of acarbowe.

• Nutrition Research and Practice
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• v.5 no.2
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• pp.107-111
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• 2011

The objective of this study was to investigate the hypoglycemic effects of quercetin (QE) in animal models of diabetes mellitus (DM). A starch solution (1 g/kg) with and without QE (100 mg/kg) or acarbose (40 mg/kg) was orally administered to streptozotocin (STZ)-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 effects of chronic feeding of QE, five-week-old db/db mice were fed an AIN-93G diet, a diet containing QE at 0.08%, or a diet containing acarbose at 0.03% for 7 weeks after 1 week of adaptation. Plasma glucose and insulin, blood glycated hemoglobin, and maltase activity of the small intestine were measured. Oral administration of QE (100 mg/kg) or acarbose (40 mg/kg) to STZ-treated rats significantly decreased incremental plasma glucose levels 30-180 min after a single oral dose of starch and the area under the postprandial glucose response, compared with the control group. QE (0.08% of diet) or acarbose (0.03% of diet) offered to db/db mice significantly reduced both plasma glucose and blood glycated hemoglobin compared to controls without significant influence on plasma insulin. Small intestine maltase activities were significantly reduced by consumption of QE or acarbose. Thus, QE could be effective in controlling fasting and postprandial blood glucose levels in animal models of DM.

• Preventive Nutrition and Food Science
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• v.20 no.2
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• pp.88-93
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• 2015

The purpose of this research was to investigate the inhibitory effect of jicama extract on ${\alpha}$-glucosidase activity, ${\alpha}$-amylase activity, and postprandial hyperglycemia in streptozotocin (STZ)-induced diabetic mice. Jicama extract showed prominent inhibitory effects against ${\alpha}$-glucosidase and ${\alpha}$-amylase. The $IC_{50}$ values of jicama extract against ${\alpha}$-glucosidase and ${\alpha}$-amylase were $0.083{\pm}0.004$ and $0.091{\pm}0.017mg/mL$, respectively. The increase in postprandial blood glucose levels was more significantly suppressed in the jicama extract-administered group than in the control group of both STZ-induced diabetic and normal mice. Blood glucose levels of the control group increased to $383.75{\pm}11.54$ and $402.50{\pm}15.32mg/dL$ at 30 and 60 min after a meal and decreased to $349.67{\pm}11.62mg/dL$ at 120 min. However, postprandial blood glucose levels were significantly decreased, when diabetic mice were fed with jicama extract ($342.00{\pm}15.73$, $367.00{\pm}13.00$, and $329.67{\pm}12.43mg/dL$ at 30, 60, and 120 min, respectively). Furthermore, the area under the curve was significantly decreased with jicama extract administration in diabetic mice (P<0.05). Therefore, these results indicate that jicama extract may help decrease postprandial blood glucose level by inhibiting ${\alpha}$-glucosidase.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.808-812
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• 2009

The ${\alpha}-glucosidase$ inhibitory and antioxidant effects of water chestnut (Trapa japonica Flerov.) were assessed to explore its possible use as an anti-diabetic agent. Methanol extracts of the fruit shell and meat of water chestnut were assayed for inhibitory activity against yeast ${\alpha}-glucosidase$ and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Effect of fruit shell extract on postprandial glucose response was assessed. Compared with fruit meat, shell extract showed stronger inhibition against ${\alpha}-glucosidase$ with an $IC_{50}$ of 273 ${\mu}g/mL$. Oral administration of fruit shell extract (500 mg/kg) significantly lowered the postprandial area under the glucose response curve to starch (1 g/kg) in streptozotocin (STZ)-induced diabetic rats (p<0.01). Compared with fruit meat, shell extract showed stronger scavenging activity against DPPH, with an $IC_{50}$ of 27.1 ${\mu}g/mL$. The results indicate that the fruit shell of water chestnut was effective in controlling postprandial hyperglycemia and exerted an antioxidant effect. Therefore, water chestnut may be useful in treating diabetes.