• 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.

• Nutrition Research and Practice
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• v.4 no.6
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• pp.486-491
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• 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 Mushroom
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• v.18 no.3
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• pp.260-267
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• 2020

Phellinus baumii, a white-rot fungus, has been used for centuries as folk medicine in China, Japan, and Korea. This study aimed to evaluate the in vitro anti-diabetic, and anti-cholinesterase, and in vivo anti-inflammatory effects of the fruiting bodies of P. baumii. The methanol (ME) and hot water (HE) extracts (2.0 mg/mL) of P. baumii fruiting bodies suppressed α-amylase activity, exactly 61.33%, and 65.00%, respectively; of note, acarbose, the positive control, inhibited 93.33% of the α-amylase activity. Moreover, the ME and HE (2.0 mg/mL) inhibited 89.67% and 91.00%, respectively, of the activity of α-glucosidase activity, whereas the same concentration of acarbose suppressed 84.67% of the α-glucosidase activity. The ME and HE (1.0 mg/mL) also inhibited 96.05% and 94.58%, respectively, of the acetylcholinesterase (AChE) activity; galanthamine, the positive control, led to an inhibition of 81.12%. The butyrylcholinesterase (BChE) activity was also inhibited by ME and HE (1.0 mg/mL; 91.05% and 82.27%, respectively); of note, the same concentration of galanthamine suppressed 81.12% of the BChE activity. The production of NO in LPS-induced RAW 264.7 macrophages was significantly suppressed by both ME and HE treatments. Importantly, the carrageenan-activated rat hind-paw edema was significantly reduced 2-6 h after ME administration (50 mg/mL). Taken together, the results suggest that the fruiting bodies of P. baumii have α-amylase, α-glucosidase, α-cholinesterase, and anti-inflammatory activities, and, therefore, may be good natural sources for the promotion of human health.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.8
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• pp.1079-1085
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• 2011

We investigated the biological activities of extracts from the flowers of Angelica gigas Nakai. The $IC_{50}$ of the DPPH radical scavenging activity was 3,535 and 105.0 ${\mu}g/mL$ in the water and ethanol extracts, respectively, whereas it was 12.7 ${\mu}g/mL$ for ascorbic acid. The results showed that the total polyphenol content of the ethanol extracts (48.43${\pm}$0.18 mg/g) was higher than that of the water extracts (39.03${\pm}$0.69 mg/g). The flavonoid content of the ethanol extracts (67.02${\pm}$4.38 mg/g) was higher than that of the water extracts (50.32${\pm}$1.24 mg/g). The ethanol extract showed a 34.45% lower ${\alpha}$-glucosidase inhibition activity than that for acarbose. The ethanol extract showed a 23.62% lower ${\alpha}$-amylase inhibition activity compared with that for acarbose. The water extract showed 16.76% lower pancreatic lipase inhibition activity. Anti-cancer and anti-inflammatory activity was also lower. These results suggest that the flower of Angelica gigas Nakai may be useful as an anti-oxidative agent.

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

• 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.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.267-269
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• 2001

• Preventive Nutrition and Food Science
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• v.17 no.4
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• pp.239-244
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• 2012

This study investigated the hypoglycemic effect of the Padina arborescens extract in STZ-induced diabetic mice. Freeze-dried Padina arborescens were extracted with 80% methanol and concentrated for use in this study. The hypoglycemic effect was determined by inhibitory activities against ${\alpha}$-glucosidase and ${\alpha}$-amylase as well as the alleviation of postprandial blood glucose level. Padina arborescens extracts showed higher inhibitory activities than acarbose, a positive control against ${\alpha}$-glucosidase and ${\alpha}$-amylase. The $IC_{50}$ values of Padina arborescens extracts against ${\alpha}$-glucosidase and ${\alpha}$-amylase were 0.26 and 0.23 mg/mL, respectively, which evidenced as more effective than observed with acarbose. The increase of postprandial blood glucose levels were significantly suppressed in the Padina arborescens extract administered group than the control group in the streptozotocin induced diabetic mice. Furthermore, the area under the curve (AUC) was significantly lowered via Padina arborescens extract administration in diabetic mice (p 0.05). These results indicated that the Padina arborescens extract might be used as an inhibitor of ${\alpha}$-glucosidase and ${\alpha}$-amylase and delay absorption of dietary carbohydrates.

• Korean Journal of Pharmacognosy
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• v.35 no.4 s.139
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• pp.271-275
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• 2004

Distylium racemosum Sieb. Et Zucc contains some compounds inhibit -amylase activity in experimental conditions. The inhibitory test showed that 50% acetone extracts from the bark and leaves of the plant strongly inhibited salivary -amylase activity. Proanthocyanidin(PA) which has strong inhibitory activity was extracted from the leaves by chromatography on Sephadex LH-20. The inhibitory activities and the inhibition kinetics of the PA were studied against three kinds of enzymes: human salivary ${\alpha}-Amylase$ (SAA), pork pancreatin ${\alpha}-Amylase$ (PAA) and yeast ${\alpha}-Glucosidase$ (AG). Then the activities of PA against SAA, PAA and AG were compared with those of acarbose, a commercial agent. The inhibitory activities of PA were stronger than those of acarbose. Inhibition kinetics of the PA showed competitive inhibition for SAA and PAA, and non competitive inhibition for GA.

• Nutrition Research and Practice
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• v.8 no.5
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• pp.602-606
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• 2014

BACKGROUND/OBJECTIVES: We investigated total 26 ingredients of Saengshik which will be commercially produced as an anti-diabetic dietary supplement. SUBJECTS/METHODS: Thirteen vegetables, nine cereals, three legumes and one seed were extracted with aqueous ethanol for 2 h at $60^{\circ}C$, and evaluated for their inhibitory effects against ${\alpha}$-amylase and ${\alpha}$-glucosidase and for total phenolic and flavonoid contents. RESULTS: All ingredients inhibited ${\alpha}$-amylase activity except cabbage. Strong inhibitory activity of ${\alpha}$-amylase was observed in leek, black rice, angelica and barley compared with acarbose as a positive control. Stronger inhibition of ${\alpha}$-glucosidase activity was found in small water dropwort, radish leaves, sorghum and cabbage than acarbose. All Saengshik ingredients suppressed ${\alpha}$-glucosidase activity in the range of 0.3-60.5%. Most ingredients contained total phenols which were in the range of 1.2-229.4 mg gallic acid equivalent/g dried extract. But, total phenolic contents were not observed in carrot, pumpkin and radish. All ingredients contained flavonoid in the range of 11.6-380.7 mg catechin equivalent/g dried extract. CONCLUSIONS: Our results demonstrate that Saengshik containing these ingredients would be an effective dietary supplement for diabetes.