• Journal of Life Science
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• v.18 no.7
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• pp.1005-1010
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• 2008

In this study, we investigated the inhibitory effect of four solvent fractions of Alnus firma on ${\alpha}-amylase$, ${\alpha}-glucosidase$ and aldose reductase activities. The inhibitory test showed that methanol (MeOH) extract and hexane (HX) fraction strongly inhibited pork pancreatin and salivary ${\alpha}-amylase$ activity. The MeOH extract and HX fraction of Alnus firma at the concentration of 4 mg/ml inhibited more than 70% of pancreatin and salivary ${\alpha}-amylase$ activity. The inhibitory effect of fractions has different specificities against ${\alpha}-amylase$ from pancreatin and salivary. In addition, the MeOH extract and butanol (BuOH) fraction showed the highest inhibitory activity on yeast ${\alpha}-glucosidase$ at values of $IC_{50}$ $137.36\;{\mu}g/ml$ and $115.14\;{\mu}g/ml$ respectively. The MeOH extract and BuOH fraction showed the highest inhibitory activity on yeast ${\alpha}-glucosidase$ than commercial agent such as 1-deoxynorjirimycin and acarbose. Inhibition kinetics of solvent fractions showed that ${\alpha}-glucosidase$ has been inhibited noncompetitively by the MeOH, EA and BuOH fraction. The aldose reductase from human muscle cell had been inhibited strongly by the MeOH extract and EA fraction at 57.996% and 83.293% at the concentration of $50\;{\mu}g/ml$, respectively. These findings may contribute to biological significance in that ${\alpha}-amylase$, ${\alpha}-glucosidase$ and aldose reductase inhibitory compounds could be used as a functional food and a drug for the symptomatic treatment of antidiabetic disease in the future.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.11
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• pp.1573-1579
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• 2010

This research was performed to determine the antioxidant activity, nitrite scavenging activity, and its inhibitory activity on angiotensin converting enzyme (ACE), xanthine oxidase, $\alpha$-glucosidase, and elastase of hot water extract from pine bud (WPB). Antioxidant activity of WPB was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and superoxide dismutase (SOD)-like activity. DPPH radical scavenging activity and SOD-like activity of WPB were remarkably increased in a dose-dependent manner, and were about 71.4 and 85.4% at 2 mg/mL, respectively. The xanthine oxidase and ACE inhibitory activities were about 70.9 and 51.9% at 2 mg/mL of WPB, respectively. Nitrite scavenging activity of WPB was about 59.1, 53.8, and 39.5% on pH 1.2, 3.0, and 6.0 at 2 mg/mL, respectively. The WPB also showed elastase and $\alpha$-glucosidase inhibitory effects. These results revealed that pine bud have strong antioxidant activity and positive effects on the inhibition of xanthine oxidase, ACE, and elastase.

• Nutrition Research and Practice
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• v.11 no.3
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• pp.180-189
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• 2017

BACKGROUND/OBJECTIVES: Recent living condition improvements, changes in dietary habits, and reductions in physical activity are contributing to an increase in metabolic syndrome symptoms including diabetes and obesity. Through such societal developments, humankind is continuously exposed to metabolic diseases such as diabetes, and the number of the victims is increasing. This study investigated Cordyceps militaris water extract (CMW)-induced glucose uptake in HepG2 cells and the effect of CMW treatment on glucose metabolism. MATERIALS/METHODS: Colorimetric assay kits were used to determine the glucokinase (GK) and pyruvate dehydrogenase (PDH) activities, glucose uptake, and glycogen content. Either RT-PCR or western blot analysis was performed for quantitation of glucose transporter 2 (GLUT2), hepatocyte nuclear factor 1 alpha ($HNF-1{\alpha}$), phosphatidylinositol 3-kinase (PI3k), protein kinase B (Akt), phosphorylated AMP-activated protein kinase (pAMPK), phosphoenolpyruvate carboxykinase, GK, PDH, and glycogen synthase kinase 3 beta ($GSK-3{\beta}$) expression levels. The ${\alpha}-glucosidase$ inhibitory activities of acarbose and CMW were evaluated by absorbance measurement. RESULTS: CMW induced glucose uptake in HepG2 cells by increasing GLUT2 through $HNF-1{\alpha}$ expression stimulation. Glucose in the cells increased the CMW-induced phosphorylation of AMPK. In turn, glycolysis was stimulated, and glyconeogenesis was inhibited. Furthermore, by studying the mechanism of action of PI3k, Akt, and $GSK-3{\beta}$, and measuring glycogen content, the study confirmed that the glucose was stored in the liver as glycogen. Finally, CMW resulted in a higher level of ${\alpha}-glucosidase$ inhibitory activity than that from acarbose. CONCLUSION: CMW induced the uptake of glucose into HepG2 cells, as well, it induced metabolism of the absorbed glucose. It is concluded that CMW is a candidate or potential use in diabetes prevention and treatment.

• The Korean Journal of Food And Nutrition
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• v.28 no.2
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• pp.295-301
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• 2015

Biological compounds such as crude saponin and total polyphenol were determined in Allium hookeri roots and leaves. In addition, activities of DPPH radical scavenging activity, hydroxyl radical scavenging activity, ${\alpha}$-amylase inhibition activity and nitrite scavenging were detected in concentrates of 70% ethanol extracts of Allium hookeri roots and leaves. The crude saponin content of the roots and leaves were 4.28 mg/g, and 4.17 mg/g, respectively. Total polyphenol and total flavonoid content was higher in leaves than roots. Furthermore the DPPH radical scavenging activity and hydroxyl radical scavenging activities of leaves was higher than roots. For ${\alpha}$-glucosidase inhibitory activity, 70% ethanol extracts of Allium hookeri roots and leaves showed 60% activity inhibition at a 10 mg/mL concentration. Nitrite scavenging abilities under acidic conditions were most effective for Allium hookeri leaves extracts. These results suggested that Allium hookeri leaves might be used as the components of health functional food.

• Journal of Mushroom
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• v.8 no.1
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• pp.22-26
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• 2010

In this study, for the development of useful food materials, the proximate composition(total carbohydrates, crude fiber, crude protein, fat and ash) and biological activities(electron donating activity, total polyphenol contents, ACE inhibitory and ${\gamma}$-glucosidase inhibitory effects) were determined in the Garlmoe and the four wild Flammulina velutipes. As a results, the dry matter of mushrooms contained large amounts of carbohydrates, from 65.9 to 70.5 g/100g dry weight. the wild collected Flammulina velutipes proved to be an especially good source of crude fiber(7.9~18.1 g/100 g dry weight). Crude protein, fat, and ash contents of the mushrooms ranged 17.1~21.3, 4.1~5.2, and 5.7~8.4 g/100g dry weight, respectively. The electron donating activity ranged from 63.35 to 69.31% and total polyphenol contents ranged from 9.83 to 11.14 mg/g in these mushrooms. ACE inhibitions were high in Garlmoe and CBMFV-02 strain. ${\alpha}$-glucosidase inhibition was the highest in CBMFV-01(46.56%) strain and lowest in Garlmoe(15.91%).

• The Korean Journal of Food And Nutrition
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• v.29 no.4
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• pp.521-528
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• 2016

This study was conducted to investigate changes in the proximate composition, antioxidant activities, and ${\alpha}$-glucosidase inhibitory activity of Opuntia ficus-indica (OFI) cladodes cultivated in Jeju (JJ1, JJ2, JJ3) and Jeonnam (JN1, JN2). The difference in the proximate composition (crude protein, lipid and ash content) of OFI between the two regions was not significant. Ca, Mg and Na were the major mineral components of OFI. The ascorbic acid content of OFI ranged from 57.87 to 143.72 mg/100 g. A 70% ethanol extract was used to investigate the antioxidant content and activity as well as the ${\alpha}$-glucosidase inhibitory activity. The total polyphenol and flavonoid contents of OFI were 38.69~55.29 and 3.33~4.03 mg/g, respectively. The antioxidant activities based on the DPPH and ABTS free radical scavenging assays were 45.19~61.52% and 39.15~51.96%, respectively, at a concentration of 1 mg/mL. The inhibitory activity of OFI extracts against rat intestinal ${\alpha}$-glucosidase was 29.72~45.73% at 1 mg/mL concentration, and JN1 showed the highest ${\alpha}$-glucosidase inhibitory activity. This information could be very useful for authentication of Opuntia species with the highest potential as sources of nutritional and therapeutic elements.

• Food Science and Preservation
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• v.25 no.1
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• pp.124-135
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• 2018

This study investigated the nutritional properties and biological activities of Ganoderma lucidum (GL). The round type of GL contained higher carbohydrate content, while the Nokgak type of GL contained higher crude ash, crude fat, and crude protein content. The most abundant amino acid, fatty acid, mineral, and soluble vitamin observed were valine (round type: 11.90 mg/g and Nokgak type: 17.18 mg/g), linoleic acid (round type: 47.56% and Nokgak type: 75.68%), potassium (round type: 116.50 mg/100 g and Nokgak type: 184.36 mg/100 g), and vitamin B3 (round type: 1.78 mg/100 g and Nokgak type: 1.81 mg/100 g), respectively. In addition, the ${\beta}$-glucan content were 34.15 g/100 g (round type) and 30.07 g/100 g (Nokgak type). The GL 70% ethanol extract at $40^{\circ}C$ showed higher radical scavenging as well as carbohydrate and lipid enzyme inhibition than other conditions. At 1 mg/mL of treatment with the 70% ethanol extract at $40^{\circ}C$ of round type GL, the DPPH, ABTS, hydroxyl radical scavenging, and ${\alpha}$-glucosidase, ${\alpha}$-amylase, and pancreatic lipase inhibition activities obtained were approximately 92.85, 99.74, 58.09, 89.68, 44.68, and 67.56%, respectively.

• The Korean Journal of Food And Nutrition
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• v.29 no.1
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• pp.128-133
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• 2016

This study aimed to evaluate the efficacy of the antioxidative and antidiabetic activities of the flowers, leaves, and roots of the Jerusalem artichoke (Helianthus tuberosus L.). The total polyphenol and flavonoid contents of the leaves were higher than those of the flowers and roots. However, the DPPH radical-scavenging and hydroxyl radical-scavenging activities of the flowers were higher than those of the leaves and roots. The nitrite-scavenging ability under acidic conditions was high in Jerusalem artichoke flower extracts. The ${\alpha}-glucosidase$ inhibitory activity and ${\alpha}-amylase$ inhibitory activity of a methanol extract of Jerusalem artichoke roots were about 60% (5 mg/mL concentration). Based on these experiments, it can be concluded that the flowers leaves, and roots of the Jerusalem artichoke can be used as natural preservatives. Therefore, they can be developed as functional foods, to take advantage of their antioxidant activity and abundant polyphenols. This study suggests that the whole Jerusalem artichoke, including roots, leaves, and flowers, is useful as a functional, nutritious food product.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.783-788
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• 2010

The purpose of this study is to investigate the antioxidative activity and digestive enzyme inhibition of grape seed extract (GSE). The GSE was tested for its effect on various antioxidative potentials (scavenging activities of DPPH radical, superoxide anion radical and hydroxyl radical) and inhibitory effect of various digestive enzymes (trypsin, $\alpha$-chymotrypsin, $\alpha$-amylase, $\beta$-glucosidase and lipase). DPPH radical scavenging activity ($SC_{50}$, 50% scavenging concentration) of GSE was 4.76${\pm}$0.27 ppm while those of positive controls (EGCG and vitamin C) were 2.22${\pm}$0.12 ppm and 9.50${\pm}$0.72 ppm, respectively. $SC_{50}$ value of GSE against superoxide anion radical and hydroxyl radical were 3.82${\pm}$0.07 ppm and 803.23${\pm}$27.16 ppm, respectively. In addition, $IC_{50}$ values of GSE against trypsin, $\alpha$-chymotrypsin, $\alpha$-amylase, $\alpha$-glucosidase and lipase were 2.17${\pm}$0.59 ppm, 7.46${\pm}$1.25 ppm, 18.25${\pm}$3.54 ppm, 12.30${\pm}$1.12 ppm, and 653.23${\pm}$79.34 ppm, respectively. These results suggest that GSE may be useful for the prevention or treatment of obesity.

• Journal of Life Science
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• v.33 no.10
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• pp.783-790
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• 2023

Modern people have an increased incidence of metabolic diseases due to changed eating habits, and diabetes is considered the most significant metabolic disease. Given that existing diabetes treatments are accompanied by side effects, the aim of this study was to identify traditional natural products that have anti-diabetic activity. The potential anti-diabetic and antioxidant activities of natural products were examined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, α-glucosidase assay, and protein tyrosine phosphatase 1B (PTP1B) inhibition assay. Methanol extracts of Ulmus davidiana var. japonica, Acer tegmentosum branches, Nelumbo nucifera seeds, and Carthamus tinctorius seeds were found to have high anti-diabetic activity and further fractionated with solvents using ethyl acetate and butanol. Consequently, the ethyl acetate fraction of C. tinctorius seeds (MG-11-E) with high α-glucosidase and PTP1B inhibitory activity was selected. MG-11-E was subjected to preparative thin layer chromatography, and fraction #6 showed high α-glucosidase and PTP1B inhibitory activity. Fraction #6 was analyzed and fractionated via high performance liquid chromatography with 50% methanol as the mobile phase, and anti-diabetic activity was observed in the sample that eluted after 4 min as a single peak. The α-glucosidase inhibitory activity exhibited by this sample seemed to be greater than the PTP1B inhibitory activity; thus, it was concluded that a greater anti-diabetic therapeutic effect may be achieved by combining this agent with natural products that inhibit PTP1B activity.