• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.1-3
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• 2015

This study investigated the inhibitory activities of 2-hydroxyquinoline and its analogs against ${\alpha}$-glucosidase and ${\alpha}$-amylase. Based on the $IC_{50}$ values of 2-hydroxyquinoline analogs tested against ${\alpha}$-glucosidase and ${\alpha}$-amylase, 2-hydroxyquinoline had potent inhibitory activity (64.4 and $130.5{\mu}g/mL$, respectively), while 2-methyl-8-hydroxyquinoline showed weakly inhibitory activity (90.7 and $215.4{\mu}g/mL$, respectively). 2-Methylquinoline demonstrated no activity against ${\alpha}$-glucosidase and ${\alpha}$-amylase. In conclusion, 2-hydroxyquinoline analogs, with the existence of a methyl group and hydroxyl on quinoline, can be useful as a new diabetes treatment.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.601-608
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• 1997

In order to search for the way to utilize rice hull as a renewable resource, the inhibition on ${\alpha}-glucosidase$ and the fractionation of rice hull extract was investigated. An ethanol extract of rice hull from Japonica-type rice seeds exhibited 30% inhibitory activity on rat intestinal brush border ${\alpha}-glucosidase$ (1.4 mU/mL) in vitro at the concentration of 0.8 mg/mL using 6 mM p-nitrophenyl ${\alpha}-D-glucopyranoside$ as a substrate $(IC_{50}\;162\;mg/mL)$. Among the fractions obtained by partitioning the ethanol extract successively with solvents, the ethyl acetate fraction at the concentration of 0.8 mg/mL was found to exhibit the most potent inhibitory activity i.e. 65% inhibition of ${\alpha}-glucosidase\;(IC_{50}\;0.14\;mg/mL)$. Silica gel column chromatography of the ethyl acetate fraction exhibited slightly higher (90%) inhibitory activity, and its subsequent fractionation by Sephadex LH-20 column chromatography did not improve inhibitory activity. Considering the inhibitory activity and yield, the ethyl acetate fraction obtained by the solvent-partitioning process would be a candidate for the hypoglycemic food if it has in vivo effectiveness.

• Journal of Pharmacopuncture
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• v.22 no.2
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• pp.115-121
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• 2019

Objectives: The objective of this study was to evaluate antidiabetic activity of Chaturmukha rasa based on streptozotocin induced diabetes model, alpha amylase inhibitory activity, alpha Glucosidase inhibitory activity and inhibition of sucrase. Methods: Chaturmukha rasa was prepared as per Ayurvedic formulary. Antidiabetic activity was measured in experimentally streptozotocin induced rats. The dose was taken as 45 mg/kg, i.p. The antidiabetic activity of Chaturmukha rasa was compared Triphala Kwatha, a marketed formulation. Further In vitro $\acute{\alpha}$- Amylase Inhibitory Assay, In vitro salivary amylase Inhibitory Assay, In vitro ${\alpha}-Glucosidase$ Inhibitory Assay and In vitro Sucrase Inhibitory Assay was performed with respect to Chaturmukha rasa. The IC50 value was calculated for all the above activity. Results: Streptozotocin with Acarbose showed significant decrease in blood glucose level whereas streptozotocin with Triphala kwatha showed more decrease in blood glucose level than Streptozotocin with Acarbose. The combination of Streptozotocin + Triphala kwatha + Chaturmukha rasa showed a significant decrease in blood glucose level on 21st day. In vitro $\acute{\alpha}$- Amylase Inhibitory Assay the Chaturmukha rasa showed IC50 value $495.94{\mu}l$ when compared with Acarbose $427.33{\mu}l$, respectively. In the ${\alpha}-Glucosidase$ Inhibitory Assay Chaturmukha rasa showed IC50 value $70.93{\mu}l$ when compared with Acarbose $102.28{\mu}l$, respectively. In vitro Sucrase Inhibitory Assay Chaturmukha rasa showed IC50 value $415.4{\mu}l$ when compared with Acarbose $371.43{\mu}l$, respectively. Conclusion: This study supports that Chaturmukha rasa may inhibit diabetes by inhibition of salivary amylase or alpha Glucosidase or sucrase. This may be the mechanism by which Chaturmukha rasa inhibits diabetes. Further this study supports the usage of Chaturmukha rasa for the management of diabetes.

• The Korean Journal of Mycology
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• v.43 no.3
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• pp.174-179
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• 2015

For development a new anti-diabetic compound from edible mushroom, antihyperglycemic ${\alpha}$-glucosidase inhibitory activities of Pleurotus ostreatus, Pleurotus cornucopiae, Pleurotus salmoneostramineus, Pleurotus eryngii and Neolentinus lepideus were investigated on its water and ethanol extracts. ${\alpha}$-Glucosidase inhibitory activity of Neolentinus lepideus fruiting body showed the highest at 86.3% in the 95% ethanol extracts and water extract from Pleurotus cornucopiae was also higher at 48.5% among water extracts. Therefore, Neolentinus lepideus which showed very high ${\alpha}$-glucosidase inhibitory activity was selected as a new anti-diabetic agent-containing mushroom and the ${\alpha}$-glucosidase inhibitor was maximally extracted when treated with 95% ethanol at $30^{\circ}C$ for 48 hr. The ethanol extracts from Neolentinus lepideus fruiting body showed dosage-dependent hypoglycemic action after administration to 120 min in the SD-rat and streptozotocin-induced diabetic SD-rat.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.9
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• pp.1243-1248
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• 2010

The physiological activities of Strychnos nux-vomica extracts were investigated through the total phenolic contents (TPC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (RSA), comet assay, and $\alpha$-glucosidase inhibitory activity. S. nux-vomica extracts were prepared with methanol, ethanol, and acetone. The methanol extract showed the highest phenolic content (71 mg/100 g gallic acid equivalents). Pretreatment with S. nux-vomica extracts resulted in significant reductions in oxidative DNA damage at all of the concentrations tested ($1{\sim}50\;{\mu}g/mL$). The $\alpha$-glucosidase inhibitory activity of a methanol extract was 12.8% at the concentration of 1 mg/mL. Therefore, these results indicate that S. nux-vomica might be a noble potential candidate exhibiting antioxidant and $\alpha$-glucosidase inhibitory activity.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.239-244
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• 2009

In the current study, inhibitory activity of 8 selected Korean edible plants of Lamiaceae family against $\alpha$-glucosidases, prepared from rat small intestine acetone powder was evaluated. Total flavonoids and oxygen radical absorbance capacity (ORAC) were also investigated. Methyl alcohol extracts of Scutellaria indica (SI) had the highest $\alpha$-glucosidase inhibitory activity relevant for potentially managing hyperglycemia, followed by Clinopodium gracile (CG) and Thymus quinquecostatus (TQ). These 3 species also showed significant antioxidant activity in ORAC system. The $\alpha$-glucosidase inhibitory activity of the extracts was compared to selected phenolics. Among the standard phenolics tested quercetin which was major flavonoid in the extracts had the highest $\alpha$-glucosidase inhibitory activity. CG, TQ, and SI which had high quercetin content and ORAC values also exhibited significant sucrase inhibitory activity. Results suggested that selected 3 Korean Lamiaceae species have the potential development of effective dietary strategy for postprandial hyperglycemia and oxidative stress-linked diabetes complications.

• Microbiology and Biotechnology Letters
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• v.18 no.1
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• pp.39-43
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• 1990

The inhibitor had the inhibitory activities against hydrolysis of PNPG, sucrose and ONPG by $\alpha$-Dglucosidase, $\alpha$ - and $\beta$ -galactosidase, but it did not inhibit amylases and other carbohydrases. Kinetic studies exhibited that the inhibitory substance non-competitively inhibited the enzyme reaction with a Ki value of 118 $\mu$g/m$\ell$, and enzyme-inhibitor complex was formed slowly.

• 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.10 no.3
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• pp.282-287
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• 2016

BACKGROUND/OBJECTIVES: Jerusalem artichoke has inhibitory activity against ${\alpha}$-glucosidase and decreases fasting serum glucose levels, which may be related to its fructan content. The biological activity of fructan can be influenced by the degree of polymerization. Thus, in this study, the inhibitory effects of original and fermented purple Jerusalem artichoke (PJA) on ${\alpha}$-glucosidase were compared in vitro. Additionally, the anti-diabetes effect of Lactobacillus plantarum-fermented PJA (LJA) was studied in a non-insulin-dependent diabetes mellitus animal model (C57BIKsJ db/db). MATERIALS/METHODS: The water extract of PJA was fermented by L. plantarum, and two strains of Bacillus subtilis to compare their anti-${\alpha}$-glucosidase activities in vitro by ${\alpha}$-glucosidase assays. The anti-diabetes effect of LJA was studied in a non-insulin-dependent diabetes mellitus animal model (C57BIKsJ db/db) for seven weeks. During the experiment, food intake, body weight, and fasting blood glucose were measured every week. At the end of the treatment period, several diabetic parameters and the intestinal ${\alpha}$-glucosidase activity were measured. RESULTS: The LJA showed the highest ${\alpha}$-glucosidase inhibitory activity in vitro. In the in vivo study, it resulted in a significantly lower blood glucose concentration than the control. Serum insulin and HDL cholesterol levels were significantly higher and the concentrations of triglycerides, non-esterified fatty acids, and total cholesterol were significant lower in mice treated with LJA after seven weeks. In addition, the intestinal ${\alpha}$-glucosidase activity was partially inhibited. CONCLUSIONS: These results suggested that LJA regulates blood glucose and has potential use as a dietary supplement.

• Korean Journal of Plant Resources
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• v.26 no.3
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• pp.374-382
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• 2013

The objective of this study was determined to evaluate ${\alpha}$-amylase, ${\alpha}$-glucosidase, pancreatic lipase inhibition in vitro and DPPH radical scavenging activity of the several Korean resources plants. The ${\alpha}$-amylase inhibitory activity of Salicornia herbacea, Erythronium japonicum (flower) and Phragmites communis (root) in water extract showed relatively high 62.8%, 66.5% and 69.3%, respectively. The ${\alpha}$-amylase inhibitory activity of Citrus junos (pericarp) and Cornus officinalis in methanol extract was found to have an effect with 32.8% in Citrus junos (pericarp) and 60.9% in Cornus officinalis. Corylopsis coreana in both water and methanol extract had the highest ${\alpha}$-glucosidase inhibitory activity of 81.7% and 89.5%, while the extract of Portulaca oleracea, Ficus carica and Citrus junos was not measured ${\alpha}$-glucosidase inhibitory activity at given experiment concentration. Depending on the extraction solvent and the plant species, it was observed that there was a significant difference in ${\alpha}$-glucosidase inhibitory activity. The pancreatic lipase inhibitory activity showed relatively higher in the methanol extract than water extract except pericarp of Citrus junos. The DPPH radical scavenging activity of selected plants was much difference between measured plant species, and showed that the increase was proportional to the concentration. These results suggested that selected plants had the potent biological activity on carbohydrate, lipid Inhibitory activity and antioxidant activity, therefore these plant resources could be a good materials to develop medicinal preparations, nutraceuticals or health functional foods for diabetes or obesity.