• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.7
• /
• pp.1090-1099
• /
• 2015

Among the four different parts of mulberry (Morus alba L.) tree, ethanol extract of Morus root bark showed the highest ${\alpha}$-glucosidase inhibitory activity ($IC_{50}=12.01{\mu}g/mL$). Bioassay-guided fractionation of the ethanolic extract of root bark by Diaion HP-20, silica gel, ODS-A, and Sephadex LH-20 column chromatographies led to the isolation of four compounds, including Compound (Comp.) 1 ($IC_{50}=5.22{\mu}g/mL$), Comp. 2 ($IC_{50}=1.78{\mu}g/mL$), Comp. 3 ($IC_{50}=2.94{\mu}g/mL$), and Comp. 4 ($IC_{50}=1.54{\mu}g/mL$) with strong ${\alpha}$-glucosidase inhibitory activities. Their chemical structures were elucidated as morusin (Comp. 1), kuwanon H (Comp. 2), chalcomoracin A (Comp. 3), and chalcomoracin B (Comp. 4) by UV and NMR spectral analyses. These results suggest that prenylflavonoid and mulberrofuran of Morus root bark may be useful as potential therapeutic agents for diabetes.

• Korean Journal of Plant Resources
• /
• v.26 no.4
• /
• pp.411-416
• /
• 2013

This study was conducted not only to analyze ${\alpha}$-glucosidase inhibition activity with fronds and rhizomes of nine Pteridophyte species, but also to select the plant materials suitable for natural ${\alpha}$-glucosidase inhibitor. Harvested rhizomes and fronds were washed, freeze-dried and grinded. After conducting ultrasonification extraction for 30 minutes in ultrasonic water tank with 100% methanol solvent, and vacuum filtration, ${\alpha}$-glucosidase inhibition activity was measured. Acarbose was used as the positive control. After mixing $100{\mu}L$ of 0.7 unit ${\alpha}$-glucosidase enzyme solution into $50{\mu}L$ of extract and reacting them at $37^{\circ}C$ for 10 minutes, $50{\mu}L$ of 1.5 mM ${\rho}$-NPG solution was taken and reacted at $37^{\circ}C$ for 20 minutes. The reaction was stopped with 1 mL of 1 M $Na_2CO_3$ and absorbance was measured in 405 nm. With the regression analysis, the content of solubility solids (the value of $IC_{50}$) which can inhibit 50% of 0.7 unit ${\alpha}$-glucosidase solution's activity was investigated. The frond ($IC_{50}=14.00{\sim}913.33{\mu}g{\cdot}mL^{-1}$) and rhizome extracts ($IC_{50}=12.93{\sim}205.84{\mu}g{\cdot}mL^{-1}$) of nine Pteridophyte species showed higher ${\alpha}$-glucosidase inhibition activity in comparison with acarbose ($IC_{50}=1413.70{\mu}g{\cdot}mL^{-1}$). The extracts of fronds and rhizomes showed higher value than acarbose by 1.55~100.98 and 6.87~109.33 times each. Especially, ${\alpha}$-glucosidase inhibition activities of Pyrrosia lingua in fronds and Osmunda cinnamomea var. fokiensis in rhizomes were the highest. The necessary biomass of fronds and rhizomes for inhibiting 50% of ${\alpha}$-glucosidase activity showed the lowest value, 0.35, 0.27 mg each, in O. cinnamomea var. fokiensis. $IC_{50}$ value of P. lingua was the highest among fronds of nine Pteridophyte species, but content of soluble solids was 2.4 times less than O. cinnamomea var. fokiensis. So frond of O. cinnamomea var. fokiensis is more economic in comparison with P. lingua. As the result of this study, O. cinnamomea var. fokiensis showed high ${\alpha}$-glucosidase inhibition activity even with small biomass. Therefore it was considered to be high-valued economic material as natural ${\alpha}$-glucosidase inhibitor.

• Food Science and Preservation
• /
• v.18 no.4
• /
• pp.620-625
• /
• 2011

This is a part of the study on the food materials that are effective for diabetes treatment and for use in the development of functional bread products. In this study, various commercially available Oriental medicines with the intestinal absorption enzyme called ${\alpha}$-glucosidase, which is known to be effective for diabetes treatment, were explored. According to the research results on the water and methanol in 200 kinds of Oriental medicines, which were separated by layer to investigate the inhibitory activity of ${\alpha}$-glucosidase, Astragalus membranaceus (70.9%) in the water layer and Pericaeta communissima (72.9%) in the MeOH layer showed a strong inhibitory effect of over 70%. Myristica fragrans (69%), Morus alba (66.9%), Schisandra chinensis (65%), Panax notoginsens (63.9%), Anthriscus sylvestris (62.9%), Asparagus cochinchinensis (62.1%), Erycibe obtusifolia (60.9%), Polygonum cuspidatum (60.7%), Atractylodes lancea (60.2%), and Perilla frutescens (60.2%) in the water layer, and Codonopsis pilosula (67.8%), Prunus persica batsch (67.6%), Sinomenium acutum (63.5%), and Malvae semen (61.6%) in the MeOH layer, showed a more than 60% inhibitory effect. Thirty one species, including Polygonatum sibiricum (59.8%), Medicata fementata (59.7%), Alisma canaliculatum (59.5%), Coix lacryma-jobi (59.2%), Asiasarum sieboldi (59.0%), and Bupleurum falcatum (53.0%), in the water layer, and 10 species [Quisqualis indica (58.8%), Lycium chinense (58.3%), Trichosanthes kirilowii (58.0%), Thuja orientalis (55.9%), Bombyx mori (55.6%), Gallus domesticus (55.4%), Aralia continentalis (55.3%), Cibotium barometz (52.7%), Euphorbia pekinensis (52.7%), and Dolichos lablab (52.5%)] in the MeOHlayer, showed a more than 50% inhibitory effect. Therefore, such materials are expected to be the basic materials that will be used for the development of functional materials for diabetes treatment.

• Korean Journal of Food Science and Technology
• /
• v.42 no.5
• /
• pp.571-577
• /
• 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 Applied Biological Chemistry
• /
• v.65 no.1
• /
• pp.75-79
• /
• 2022

Antioxidant, α-glucosidase inhibition, and anticoagulant effects of 80% ethanolic extract from mistletoe (Viscum album var. coloratum) were investigated. The yield and polyphenol content of the mistletoe extract were 30.9±0.4% and 57.6±1.5 mg gallic acid equivalents/g, respectively. The antioxidant effects of the mistletoe extract such as free and cationic radical scavenging ability, nitrite scavenging ability, and reducing power increased in proportion to its concentration. Also the mistletoe extract inhibited the activity of α-glucosidase, and delayed plasma coagulation mainly by inhibiting the extrinsic and common pathways in blood coagulation system.

• Journal of Plant Biotechnology
• /
• v.46 no.1
• /
• pp.45-55
• /
• 2019

TheCitrus grandis Osbeck is a special product in the Jeju island. The product has been as a remedy for liver damage and hang over. This study demonstrates how to investigate and compare the antioxidant, phenol content, tyrosinase and ${\alpha}$-glucosidase inhibitory activity, antimicrobial, and alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activity with the C. grandis leaves extracted in different ethanol concentrations. From the yield, a 20% ethanol extract demonstrated the highest results among the other extracts. The distilled water extract showed the most abundant in a total phenol content and highest ABTS radical scavenging activity and reducing power assay. In the DPPH radical scavenging activity, ${\alpha}$-glucosidase and tyrosinase inhibitory assay (used ${\text\tiny{L}}$-tyrosine as substrate), the 80% ethanol extract exhibited a higher value than other extracts. The 60% ethanol extract showed prominent activities in the tyrosinase inhibitory (used ${\text\tiny{L}}$-dopa as substrate), ADH and ALDH activity assay. In the minimum inhibitory concentration (MIC) assay, 60% and 80% ethanol extracts inhibited the bacterial growth almost similarly. Moreover, the gram-positive bacteria was more restrained than the gram-negative bacteria. The resultsrevealed that the distilled water and 80% ethanol extract showed a relatively higher antioxidant activity compared to other extracts. The 60 ~ 80% ethanol extracts demonstrated potential tyrosinase, ${\alpha}$-glucosidase inhibitory, antimicrobial, ADH and ALDH activities. Therefore, the C. grandis is suggested to be considered as a functional material for various proposes.

• Journal of Applied Biological Chemistry
• /
• v.64 no.2
• /
• pp.121-125
• /
• 2021

Antioxidative, anticoagulant, and α-glucosidase inhibitory effects of 60% (v/v) ethanolic extract from lotus (Nelumbo nucifera) leaves were investigated in vitro. The yield and polyphenol content of the lotus leaves extract were 35.3±1.1% and 186.2±5.2 ㎍ gallic acid equivalents/mg, respectively. The lotus leaves extract effectively scavenged free and cation radicals, and nitrite in a concentration-dependent manner, and possessed potent reducing power. The lotus leaves extract had remarkable anticoagulant and α-glucosidase inhibitory activities as a function of the extract concentration.

• Korean Journal of Food Science and Technology
• /
• v.46 no.1
• /
• pp.44-50
• /
• 2014

We evaluated the enzyme inhibitory activity of germinated rough rice (Oryza sativar L.) treated by high pressure (30MPa) for 24 h (HP24) and 48 h (HP48). In rice germinated for 1 day, the ${\alpha}$-glucosidase inhibitory activity reached its highest level, 68.32%, at HP48. The ${\alpha}$-amylase inhibitory activity increased from 32.66-57.00% at HP0, to 43.67-74.82% at HP48. On the other hand, the inhibitory activity of angiotensin-converting enzyme increased from 27.98% to 49.42% over the course of the second day of HP48. The inhibitory activity of xanthine oxidase peaked of 67.51% at HP48 and subsequently decreased. Lipase inhibitory activity increased from 24.04-47.91% at HP0, to 29.62-64.63% at HP48. These results provide useful information for the use of germinated rough rice as a functional food material and demonstrate that high-pressure treatment during the germination process efficiently increase enzyme inhibitory activity.

• Microbiology and Biotechnology Letters
• /
• v.34 no.4
• /
• pp.368-372
• /
• 2006

Quercetin is a flavonoid molecule that is known to tie in various sources of natural products such as vegetables and fruits. It has been proven that quercetin plays a crucial role in the prevention of colon cancer as well as homeostasis as radical scavenger in human body. It is also well-known that glycosidases, including $\alpha$-glucosidase, are involved in a variety of degenerative metabolic disorders. In the course of screening useful $\alpha$-glucosidase inhibitors, we screened out quercetin as a $\alpha$-glucosidase inhibitor from chemical libraries. Quercetin was shown to be a reversible, slow-binding, and noncompetitive inhibitor of yeast a-glucosidase with a K$_i$ value of $6.3\times10^{-8}$ M when it was included with an enzyme mixture. Together, these results show that quercetin has potential in treating disorders including diabetes, although the further mechanistic study is needed.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.1
• /
• pp.39-45
• /
• 2017

This study investigated the glycyrrhizic acid content and anti-diabetic activities of Glycyrrhiza uralensis (GU) depending on the cultivation region (Jecheon, Youngju, Gokseong, China, and Uzbekistan). Glycyrrhizic acid accuracy recovery and intra- and inter-day precisions (RSD%) of the method were calculated at 99.10~107.07% and 3.92 and 6.31% for GU samples, respectively, whereas the limits of detection and quantitation were 0.14 and $0.20{\mu}g/mL$. Anti-diabetic activity was measured by ${\alpha}-glucosidase$ and glucose uptake. GU (20 g) was extracted with 70% ethanol at $70^{\circ}C$ for 6 h. The Jecheon and Gokseong GU showed good inhibitory activity compared to the control. The Jecheon, Youngju, and Uzbekistan GU ethanol extracts ($100{\mu}g/mL$) showed glucose uptakes (in $C_2C_{12}$ myotube) of 124.19, 127.18, and 126.92%, respectively, compared to the positive control. In conclusion, these methods were validated for detection of glycyrrhizic acid in GU, and the results indicate that GU might have potential anti-diabetic activities.