• Korean Journal of Medicinal Crop Science
• /
• v.21 no.4
• /
• pp.301-305
• /
• 2013

This study was performed to select adequate plant materials for developing a natural ${\alpha}$-glucosidase inhibitor by analyzing ${\alpha}$-glucosidase inhibition activity in fronds and rhizomes of three Dryopteridaceae species: Cyrtomium fortunei, Polystichum polyblepharum, and P. lepidocaulon. The highest ${\alpha}$-glucosidase inhibitor obtained from frond of P. lepidocaulon ($4.16{\mu}g{\cdot}mL^{-1}$), and rhizome of C. fortunei ($1.84{\mu}g{\cdot}mL^{-1}$), showed much higher inhibition activity than acarbose ($1413.70{\mu}g{\cdot}mL^{-1}$). The biomass required to inhibit ${\alpha}$-glucosidase by 50% was 0.04 ~ 0.35mg for frond and 0.03 ~ 0.10mg for rhizome, and P. lepidocaulon required the least amount of fronds and P. lepidocaulon the least rhizomes. In frond, ${\alpha}$-glucosidase inhibition activity was the highest in water fraction of C. fortunei ($20.2{\mu}g{\cdot}mL^{-1}$), and n-butanol fraction of P. lepidocaulon ($9.33{\mu}g{\cdot}mL^{-1}$) and P. polyblepharum ($5.10{\mu}g{\cdot}mL^{-1}$). In rhizome, it was the highest in n-butanol fractions of C. fortunei ($19.76{\mu}g{\cdot}mL^{-1}$) and P. polyblepharum ($4.47{\mu}g{\cdot}mL^{-1}$), and ethylacetate fraction of P. lepidocaulon ($5.46{\mu}g{\cdot}mL^{-1}$). The frond biomass required for 50% ${\alpha}$-glucosidase inhibition was the lowest in the water fraction of C. fortunei (1.43mg), and n-butanol fractions of P. lepidocaulon (1.10mg) and P. polyblepharum (0.66mg). The required biomass of rhizome was the lowest in the water fraction of C. fortunei (1.59mg), and n-hexane fractions of P. lepidocaulon (0.04mg) and P. polyblepharum (0.15mg). The result of this study suggested that the three Dryopteridaceae species had high ${\alpha}$-glucosidase inhibition activity with small biomass, which might have high value as materials for economical anti-diabetic medication.

• KSBB Journal
• /
• v.23 no.5
• /
• pp.419-424
• /
• 2008

In this study, we examined the anti-diabetic activity in vitro by the crude extracts of Tetragonia tetragonioides which has been known to superior plants for the traditional prevention and treatment of stomach-related diseases. $\alpha$-Amylase and $\alpha$-glucosidase, the principal enzymes involved in the metabolism of carbohydrates, and aldose reductase, the key enzyme of the polyol pathway, have been shown to play the important roles in the complications associated with diabetes. A hexane (HX) fraction of T. tetragonioides were shown to inhibit more than 50% of salivary and pancreatin $\alpha$-amylase activity at concentration of 2.882 mg/mL and 2.043 mg/mL, respectively. In addition, the HX and ethylacetate (EA) fraction showed the highest inhibitory activity on yeast $\alpha$-glucosidase at values of $IC_{50}$ of 0.723 mg/mL and 1.356 mg/mL respectively. The HX, dichloromethane (DCM) and EA fraction showed more higher inhibitory activity on yeast $\alpha$-glucosidase than commercial agent such as 1-deoxynorjirimycin and acarbose. Also, the aldose reductase from human muscle cell had been inhibited strongly by the DCM fraction and HX fraction at 51.95% and 47.22% at a concentration of 1 mg/mL, respectively. Our study, for the first time, revealed the anti-diabetic potential of T. tetragonioides and this study could be used to develop medicinal preparations or nutraceutical and functional foods for diabetes and related symptoms.

• Microbiology and Biotechnology Letters
• /
• v.38 no.2
• /
• pp.183-189
• /
• 2010

In the course of screening for anti-acidosis and anti-diabetes agent from natural products, the inhibitory activities of Nepales plant extracts against microbial $\alpha$-amylase and $\alpha$-glucosidase were evaluated. Among the 100 different kinds of ethanol extracts, Cedrus deodara (Roxb.) G. Don and Myrica nagi Thunb showed strong inhibition activities against $\alpha$-amylase. The $IC_{50}$ values of C. deodara (Roxb.) G. Don, M. nagi Thunb and acarose, a commercial available anti-diabetes agent, were 44.5, 47.5 and $50.5\;{\mu}g/mL$, respectively. Considering the crude extract of C. deodara (Roxb.) G. Don, and M. nagi Thunb, these extracts have strong potentials as anti-acidosis or anti-diabates agent. In a while, Cleistocalyx operculatus (Roxb.) extract showed a good inhibition activity to $\alpha$-amylase and $\alpha$-glucosidase, even it was recently reported. The selected three extracts did not show any hemolysis activity against human red blood cell up to 1 mg/mL, and the inhibition activities were maintained by heat or acid treatment. Moreover, treatment of HCl (0.01N) for 1 h into C. operculatus (Roxb.) and M. nagi Thunb increased the inhibition activity from 50% to 70%. Our results suggest that C. deodara (Roxb.) G. Don, M. nagi Thunb, and C. operculatus (Roxb.) are potential as anti-acidosis and anti-diabetes agents.

• Journal of Applied Biological Chemistry
• /
• v.62 no.1
• /
• pp.81-86
• /
• 2019

A yellow resin (gamboge) from Garcinia hanburyi has been widely used as folk medicine due to its antibacterial and antitumor activities. We isolated four ${\alpha}$-glucosidase inhibitory compounds from the methanol extract of gamboge. The compounds (1-4) were identified as gambogoic acid (1), moreollic acid (2), gambogic acid (3), and 10-methoxygambogenic acid (4), respectively through spectroscopic data including 2D-NMR and HREIMS. All compounds were examined in the enzyme inhibition assay against ${\alpha}$-glucosidase to identify their inhibitory potencies and kinetic behavior. All compounds (1-4) showed enzyme inhibition against ${\alpha}$-glucosidase, but the activity was significantly affected by the methoxy group on C-10 of ring A and pentenyl pyran moiety of ring D. For example, compound 1 ($IC_{50}=41.4{\mu}M$) bearing pyran ring eight times effective that 4 ($IC_{50}=350.6{\mu}M$) having geranyl group itself. Most active compound was found out to be gambogoic acid (1) which was analyzed most abundant metabolite in gamboge by LC-ESI-MS/MS. In kinetic study, compounds 1 and 2 were proved as noncompetitive inhibitors.

• Korean Journal of Plant Resources
• /
• v.23 no.5
• /
• pp.423-429
• /
• 2010

In this study, we examined the anti-diabetic activity in vitro by the mixed Korean herb water extracts(JDG) composed of Lycium chinense, Cordyceps militaris, and Acanthopanax senticosus on hepatic glucose-regulating enzyme activities such as glucokinase(GK), acetyl-CoA carboxylase(ACC), and inhibition activity of $\alpha$-glucosidase. The hepatic cytosol fraction of a type II diabetic animal(Goto-Kakizaki rat) was used in GK and ACC activity assays. JDG mixed water extracts significantly increased the hepatic GK and ACC activity. The highest anti-$\alpha$-glucosidase activity was observed in JDG 5 water extract when compared to the acarbose control, inhibitor of $\alpha$-glucosidase. We suggest that Lycium chinense, Cordyceps militaris, and Acanthopanax senticosus mixed water extracts may exert an anti-diabetic activity by enhancing the glucose metabolism and may be used as natural $\alpha$-glucosidase inhibitors in type 2 diabetic conditions.

• Journal of Nutrition and Health
• /
• v.46 no.4
• /
• pp.315-323
• /
• 2013

This study was conducted in order to compare the biological activities of leaf and root water extracts of Smilax china L. (SC) by measuring the total polyphenol and flavonoid contents, anti-oxidant activity, inhibitory effect on ${\alpha}$-glucosidase, and anti-inflammatory gene expression. The total polyphenol and flavonoid contents of SC leaf (SCLE) and root (SCRE) water extracts were 127.93 mg GAE/g and 39.50 mg GAE/g and 41.99 mg QE/g and 1.25 mg QE/g, respectively. The anti-oxidative activities of SCLE and SCRE 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. Both SCLE and SCRE scavenged radicals in a concentration-dependent manner, and SCLE showed stronger radical scavenging activity and reducing power than SCRE; however, both SCLE and SCRE exhibited lower activities than ascorbic acid. Compared to the anti-diabetic drug acarbose, which was used as a positive control, SCLE and SCRE exhibited low ${\alpha}$-glucosidase inhibition activities; nevertheless, the activity of SCLE was 3.7 fold higher than that of SCRE. Finally, SCLE caused significantly decreased expression of the LPS-induced cytokines, iNOS, and COX-2 mRNA in RAW264.7 cells, indicating anti-inflammatory activity. These results indicate that SCLE might be a potential candidate as an anti-oxidant, anti-diabetic, and anti-inflammatory agent.

• Journal of Applied Biological Chemistry
• /
• v.60 no.3
• /
• pp.241-244
• /
• 2017

The antioxidant activity of various solvent extracts from Jeju camellia mistletoe (Korthalsella japonica (Thunb.) Engl.) was investigated using various in vitro assays as the 1,1-diphenyl-2-picrylhydrazyl radical scavenging, ferrous ion chelating and reducing power assays. Methanol and ethanol extracts showed the most potent antioxidant activity in all assays tested followed by water extract. The inhibitory effect of the Jeju camellia mistletoe extracts on pancreatic lipase and $\acute{a}$-glucosidase was also evaluated and the results showed that methanol and ethanol extracts markedly reduced both enzyme activities. Therefore, the methanol and ethanol extracts of Jeju camellia mistletoe is definitely worthy of further investigation for these beneficial effects on nutraceutical medicine.

• Journal of Life Science
• /
• v.27 no.1
• /
• pp.32-37
• /
• 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.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.6
• /
• pp.1643-1650
• /
• 2013

A non linear QSAR model was constructed on a series of 57 xanthone and curcuminoide derivatives as ${\alpha}$-glucosidase inhibitors by back-propagation neural network method. The neural network architecture was optimized to obtain a three-layer neural network, composed of five descriptors, nine hidden neurons and one output neuron. A good predictive determination coefficient was obtained (${R^2}_{Pset}$ = 86.7%), the statistical results being better than those obtained with the same data set using a multiple regression analysis (MLR). As in the MLR model, the descriptor MATS7v weighted by Van der Waals volume was found as the most important independent variable on the ${\alpha}$-glucosidase inhibitory.

• 한국약용작물학회:학술대회논문집
• /
• 2010.10a
• /
• pp.430-430
• /
• 2010

In this study ethanol extracts of aerial part of Geranium thunbergii Sieb. et Zucc. was investigated for their ability to inhibit a-glucosidase, and thus was fractionated using two organic solvents, including dichloromethane, ethyl acetate. The ethyl acetate-soluble fraction, which manifested potent enzyme inhibitory properties, was then followed by tracking down the active compound by combining HPLC micro-fractionation to an enzyme assay in 96-well plate. The ${\alpha}$-glucosidase inhibitory activity profile showed that two peaks exhibited potent inhibitory activity, and then the structural analyses of the two peaks were carried out by HPLC-UV-MS. The main ${\alpha}$-glucosidase inhibitory compounds in the ethyl acetate-soluble fractions of ethanol extracts of Geranium thunbergii Sieb. et Zucc. were tentatively identified as geraniin and kaempferol-7-rhamnoside.