• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.10
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• pp.1331-1335
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• 2009

We have studied the anti-diabetic effects of medicinal plant water extracts on hepatic glucose-regulating enzymes such as glucokinase (GK) and acetyl-CoA carboxylase (ACC). $\alpha$-Glucosidase inhibitor is usually used to prevent and treat type II diabetes; thus, anti-$\alpha$-glucosidase activity of medicinal plant water extracts was assayed. The hepatic cytosol faction of a type II diabetic animal (Goto-Kakizaki rat) was used in GK and ACC activity assays. The medicinal plants were Lycium chinense (JGP), Discorea japonica Thunb. (SY), Pyrus pyrifolia (YSB), Cornus officinalis (SSY), Paeonia suffruticosa ANDR. (MDP), Cordyceps militaris (DCH), and Acanthopanax senticosus (GSO). JGP, SY, YSB, and SSY water extracts increased the hepatic GK activity and all medicinal plant water extracts led to an increase in hepatic ACC activity. YSB, SSY, MDP, and GSO water extracts showed significantly higher anti-$\alpha$-glucosidase activity than control samples. The highest anti-$\alpha$-glucosidase activity was observed in GSO water extract and the anti-$\alpha$-glucoside activity was higher than that of Acarbose (reference $\alpha$-glucosidase inhibitor). We suggest that JGP, SY, YSB, and SSY water extracts may exert an anti-diabetic effect by enhancing the glucose metabolism and that YSB, MDP and GSO may be used as natural $\alpha$-glucosidase inhibitors in type II diabetic conditions. Increased ACC activity by plant water extracts may provide additional anti-diabetic effect.

• Journal of Mushroom
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• v.12 no.4
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• pp.330-340
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• 2014

Coprinellus micaceus, belongs to family Psathyrellaceae of Agaricales, Basidiomycota, has been used for edible purposes in the world. This study was initiated to evaluate the antioxidant, anti-diabetic, anti-cholinesterase, anti-tyrosinase, and nitric oxide inhibitory activities of fruiting bodies from C. micaceus extracted with methanol and hot water. The HPLC analysis of phenolic compounds from the mushroom extracts identified 4 phenolic compounds including procatechuic acid, chlorogenic acid, (-)-epicatechin, and naringin. In 1,1-diphenyl-2-picrylhydrazyl(DPPH) free radical scavenging assay, the scavenging activities of methanol and hot water extracts were lower than that of positive control, BHT. The chelating effects of methanol and hot water extracts were significantly higher than that of BHT, the positive control at the all concentrations tested. In the reducing power assay, methanol and hot water extracts exhibited the lower activities compared with positive control at the 0.125-0.2 mg/ml. The methanol and hot water extracts of the mushroom inhibited the ${\alpha}$-glucosidase activity by 62.26% and 67.59%, respectively at the 2.0 mg/ml, while acarbose, the positive control, inhibited the ${\alpha}$-glucosidase activity by 81.81% at the same concentration. In the acetylcholinesterase(AChE) inhibitory activity assay, methanol and hot water extracts of the mushroom inhibited the AChE by 94.64% and 74.19%, respectively at 1.0 mg/ml, whereas the galanthamine, standard drug, inhibited the AChE activity by 97.80% at the same concentration. The tyrosinase inhibitory activities of methanol and hot water extracts were 91.33% and 91.99% at 2.0 mg/ml, while the inhibitory activity of kojic acid, the positive control, was 99.61% at the same concentration. Nitric oxide(NO) production in lipopolysaccahride (LPS) activated RAW 264.7 cells were inhibited by the methanol and hot water extracts in a concentration dependent manner. Therefore, it is concluded that fruiting bodies of C. micaceus contained natural antioxidant, anti-acetylcholinesterase and ${\alpha}$-glucosidase inhibitory, anti-inflammatory, anti-tyrosinase substances which might be used for promoting human health.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.1
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• pp.101-108
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• 2014

This study was conducted in order to compare the biological activities of water extracts and sugar immersion extracts of green pepper (Capsicum annuum L.), purslane (Portulaca oleracea L.) and shiitake (Lentinula edodes (Berk.) Pegler) by measuring total polyphenol and flavonoid contents, antioxidant activities and inhibitory effects on ${\alpha}$-amylase and ${\alpha}$-glucosidase. The contents of total polyphenols and flavonoids were higher in water extracts than in sugar immersion extracts. The anti-oxidative activities of water and sugar immersion extracts were measured using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity assay and reducing power assay. All extracts scavenged radicals in a concentration-dependent manner, and water extracts showed stronger radical scavenging activity and reducing power than sugar immersion extract. However, they all exhibited lower activities than ascorbic acid. Compared to the anti-diabetic drug acarbose, which was used as a positive control, the two types of extracts exhibited low ${\alpha}$-glucosidase inhibitory activities, although the activity of sugar immersion extracts were 2-fold higher than that of water extracts. ${\alpha}$-Amylase inhibitory action was not observed for any of the extracts. Finally, by cytotoxicity test, we confirmed that sugar immersion extracts were safer than water extracts. These results indicate that water extracts and sugar immersion extracts of green pepper, purslane and shiitake have different advantages in terms of their antioxidant and anti-diabetic effects, respectively.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.806-813
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• 2013

Agrimonia pilosa Ledeb. is a medicinal plant with anti-tumor, anti-oxidant, anti-inflammatory and anti-hyperglycemic activities. However, few studies of the anti-diabetic effect of A. pilosa on insulin resistance status have been performed. In the present study, the anti-diabetic effect of A. pilosa water extract (AP) was determined by investigating its ${\alpha}$-glucosidase inhibitory property, glucose utilization, and uptake, as well as insulin resistance mechanism of action in C2C12 skeletal muscle cells. Compared to positive control (acarbose), AP ($10mg/m{\ell}$) showed a similar ${\alpha}$-glucosidase inhibitory capacity. Glucose uptake was significantly increased by $1{\mu}m$ insulin treatment (p<0.05). However, palmitic acid (FFA, 1 mM) induced muscle insulin resistance and glucose uptake dysfunction. On the other hand, AP ($10{\mu}g/m{\ell}$) was capable of reversing the FFA-induced insulin resistance in C2C12 myotubes. Compared to control, AP ($100{\mu}g/m{\ell}$ without insulin) significantly increased the utilization of glucose (p<0.05) in C2Cl2 myotubes cultured in normal glucose (7 mM). AP treatment significantly increased the relative mRNA and protein expression levels of Akt. In particular, the effect of A. pilosa on the insulin signaling system is associated with the up-regulation of Akt genes and glucose uptake in C2Cl2 myotubes. These results suggest that A. pilosa is useful in the prevention of diabetes and the treatment of hyperglycemic disorders.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.11
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• pp.1401-1407
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• 2008

1-Deoxynojirimycin (DNJ) is a strong $\alpha$-glucosidase inhibitor which inhibits hyperglycemia in animals. To select the Bacillus strains highly producing DNJ, 4,000 strains were isolated from soil and grain samples. By the inhibitory activity against $\alpha$-glucosidase, nine Bacillus strains were selected and then identified by 16S rDNA sequencing. B. subtilis S10 was finally selected as the best strain for the production of DNJ. Various carbon sources and nitrogen sources in culture medium were evaluated for the highest production of DNJ. As the results, the optimized concentration of carbon source and nitrogen source was 1.0% galactose and 1.6% polypeptone and the concentration of DNJ produced was 0.75 g/L. The effect of culture supernatant of B. subtilis S10 on lowering blood glucose level was investigated in streptozotocin (STZ)-induced diabetic mice model. Mice were randomly assigned to control group (saline) and three test groups such as acarbose group, silkworm powder group and B. subtilis S10 group. After eight-week oral feeding, blood glucose levels of the B. subtilis S10 and silkworm powder groups were respectively $209.1{\pm}19.6\;mg/dL$ (59.1%) and $208.6{\pm}39.8\;mg/dL$ (59.0%) lower than $510{\pm}10\;mg/dL$ of the control group. These results indicated that the culture supernatant of B. subtilis S10 was able to reduce the blood glucose level in STZ-induced diabetic mice.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.571-577
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• 2010

Korean traditional medicinal herbs have been reported to possess antioxidant and anti-hyperglycemic activities. We tested the antioxidant and anti-hyperglycemic activities of 6 kinds of medicinal herbs: Angelica gigas N., Poria cocos, Mori radicis Cortex, Mori folium, Aralia elata Cortex, and Panax ginseng, prepared as hot water, ethanol, and sonication extracts. The antioxidant activities of the extracts were examined by performing total polyphenol, total flavonoid, and ${\alpha}$,${\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) assays. For M. folium, the ethanol extract showed the strongest effects in DPPH radical scavenging activity among the three extraction methods. In addition, sonication extracts of M. radicis Cortex and M. folium showed the highest inhibitory activities for ${\alpha}$-glucosidase among the different extracts. The ethanol extracts of M. folium had the highest inhibition effects against ${\alpha}$-amylase. A direct correlation between antioxidant and anti-hyperglycemic inhibition activity was found in the ethanol and sonication extracts. From the results, it is considered that these six medicinal herbal extracts have antioxidative, anti-hyperglycemic, and correlation effects based on different extraction methods.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.22 no.2
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• pp.58-62
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• 2022

Pompe disease (PD) is an autosomal recessive genetic disorder caused by a deficiency of the lysosomal enzyme acid α-glucosidase (GAA). It is easy to hastily diagnose as patients if they have two pathogenic variants. Clinical pathologists misdiagnosed our infant and her mother as PD. Here, we report a case of pseudodeficiency in a potential late-onset Pompe disease (LOPD) carrier with a double dual variant, each in cis formation in a 3-month infant. The person who has two pathogenic variants was diagnosed as a carrier, not a patient. It was first reported in Korea. The patient had: two likely pathogenic heterozygous mutations on exon #4: c.752C>T (p.Ser251Leu), c.761C>T (p.Ser254Leu), and a heterozygous mutation on exon #12: c.1726G>A (p.Gly576Ser), also with a heterozygous mutation on exon #15: c.2065G>A (p.Glu689Lys). By presenting this case we emphasize the possibility of cis formation of genes which may cause pseudodeficiency, and potential LOPD carrier form. Hereby we suggest that thorough evaluation of GAA gene is essential among whom initially diagnosed as PD.

• Journal of Nutrition and Health
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• v.53 no.3
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• pp.244-254
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• 2020

Purpose: Ixeris strigosa (IS) is a perennial plant that commonly grows in meadows. The leaves and roots of IS have been used in medicine as a sedative. This study evaluated the antioxidant and carbohydrate-digestive-enzyme inhibitory effects of IS to determine its potential as an essential antioxidant and glycemic inhibitor for type 2 diabetics. Methods: The antioxidative and α-amylase and α-glucosidase inhibitory activities were examined using the water extracts (ISW), ethanol extracts (ISE), and solvent fractions from IS. The antioxidative activities were measured using in vitro methods by measuring the 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activity. Results: Investigations of the total polyphenol, flavonoid content, in vitro antioxidant activity, and α-amylase and α-glucosidase inhibitory activities of the IS extract showed that the ISE had higher total phenolic and flavonoid contents than the ISW, as well as high antioxidant activity. The ethanolic extracts of IS (70%) had an α-amylase inhibitory activity of 78.55%. The ethyl acetate fraction (90.56%) showed higher α-glucosidase inhibitory activity than the positive control, acarbose (83.01%). Conclusion: Among the ISE fractions, the ethyl acetate and butanol fractions showed the best digestive enzyme inhibitory activity. Moreover, the antioxidant activity of the extract and the carbohydrate, α-amylase, and α-glucosidase inhibitory effects showed a stronger correlation with the total phenol and flavonoid contents compared to the ISW. As a result, the antioxidant and digestive enzyme inhibitory activities of high ISE are due to the phenolic compounds, particularly the flavonoid compounds. Therefore, ethyl acetate and butanol fractions of the 70% ethanol extract are excellent anti-diabetic functional materials.

• Journal of Life Science
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• v.30 no.1
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• pp.18-25
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• 2020

This study was designed to investigate whether Loranthus parasiticus extract (LPE) could inhibit the activities of carbohydrate digestive enzymes and alleviate postprandial hyperglycemia in diabetic mice. Lyophilized L. parasiticus was extracted with 80% ethanol and concentrated. The inhibitory effects of LPE on carbohydrate digestive enzymes were evaluated by examining α-glucosidase and αamylase, and it was seen to inhibit the activities of both enzymes in a dose-dependent manner. More specifically, the IC50 values of LPE against α-glucosidase and α-amylase were 0.121±0.007 and 0.157±0.004 mg/ml, respectively, significantly lower than those of acarbose, showing that LPE has stronger inhibitory effects than the positive control. These results suggest that LPE strongly inhibits the activities of these digestive enzymes. Blood glucose levels in the control group of diabetic mice increased to 490.00±28.52 mg/dl and 474.60±25.30 mg/dl at 60 and 120 min after a meal, respectively. However, when LPE was added to starch, postprandial blood glucose levels were significantly reduced (463.0±23.73 and 418.5±24.50 mg/dl at 60 and 120 min, respectively; p<0.05). The area under the curve also significantly decreased following administration of LPE, with no cytotoxicity. These results therefore indicate that LPE could be used as an α-glucosidase and α-amylase inhibitor and delay carbohydrate digestion and, thus, glucose absorption after a meal.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.6
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• pp.1049-1057
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• 2015

This study investigated the physicochemical properties of Dioscorea batatas for improvement of biological activities during a three-step steaming process, steaming $120^{\circ}C$ for 30 min and hot air drying at $60^{\circ}C$ for 8 hrs. Samples were extracted with 70% ethanol and analyzed for free sugars, and organic acids were analyzed by HPLC. The DPPH & ABTS radical scavenging activities, crude saponin, water binding capacity, oil absorption, and ${\alpha}$-glucosidase activity were measured. The major free sugars in all samples were fructose, maltose, and sucrose, and the free sugar contents increased to 157~235% after the three-step steaming process compared to the control. Organic acid contents of samples treated by steaming increased to greater than 55.8 mg/100g. The ABTS radical scavenging activity significantly increased with repeated steaming process, especially after the three-step process. As the time of steaming process increased, DPPH radical scavenging activity increased from 26.99% fresh Dioscorea batatas to 80.46~97.79% after the three-step process. Crude saponin content increased rapidly as steaming time increased, but decreased after the three-step process steaming process. The water-binding capacities of the samples treated by steaming process were higher than that of the control, whereas oil absorption decreased as steaming time increased. From the results, steaming process could be suggested as beneficial for controlling fat intake. Compared to acarbose, a known antidiabetic drug, used as a positive control, ${\alpha}$-glucosidase inhibitory activity of samples treated by two-step steaming was among the samples. The results suggest that Dioscorea batatas treated by steaming process has antioxidative and anti-diabetis activities and can be used as a natural health product.