• Title, Summary, Keyword: ${\alpha}$-glucosidase

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Inhibition of α-Glucosidase by a Semi-Purified Ethyl Acetate Fraction from Submerged-Liquid Culture of Agaricus blazei Murill (신령버섯균사체 액체배양물의 α-glucosidase 저해 효과)

  • Jung, Kwan-Ju;Moon, Yeon-Gyu;Kwon, Jung-Min;Ahn, Chae-Rin;Kim, Jeong-Ok;Ha, Yeong-Lae
    • Journal of Life Science
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    • v.21 no.11
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    • pp.1579-1585
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    • 2011
  • Natural anti-diabetic semipurified ethyl acetate fraction was isolated from the submerged-liquid culture of Agaricus blaze Murill (AB) in a medium containing soybean flakes. Hot-water extract of AB (HEAB) was prepared by extraction at $121^{\circ}C$ for 60 min, followed by filtering through a filter presser filled with diatomate. The ${\beta}$-glucan-free HEAB, which was a supernatant fraction from HEAB by precipitation in an 80% ethanol solution, was fractionated into hexane, chloroform, ethyl acetate, and butanol fractions. The inhibition of the ${\alpha}$-glucosidase activity by fractions was 59.0, 17.0, 61.6, and 37.9%, respectively, suggesting that ethyl acetate fraction was the most active. A subfraction having a strong ${\alpha}$-glucosidase inhibitory activity (80.4%) was isolated from the ethyl acetate fraction. This subfraction contained isoflavones (genistin and daidzin) and their conjugates with sugars as potent inhibiters of ${\alpha}$-glucosidase activity. These results suggest that the ethyl acetate fraction or HEAB containing isoflavones and their sugars conjugates could be useful sources for controlling blood sugar levels in humans.

Isolation and Identification of α-Glucosidase Inhibitory Compounds, Hyperoside, and Isoquercetin from Eleutherococcus senticosus Leaves (가시오갈피(Eleutherococcus senticosus) 잎으로부터 α-Glucosidase의 저해 활성 물질, Hyperoside와 Isoquercetin의 분리 및 구조·동정)

  • Lee, Ki Yeon;Hong, Soo Young;Jeong, Hye Jeong;Lee, Jae Hyoung;Lim, Sang Hyun;Heo, Nam-Kee;Kim, Songmun;Kim, Hee-Yeon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.12
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    • pp.1858-1864
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    • 2014
  • In the present investigation, the anti-diabetic potential of 80% ethanol extract of Eleutherococcus senticosus leaves (EEES) was examined based on ${\alpha}$-glucosidase inhibitory activities. EEES was sequentially fractionated with n-hexane, chloroform, ethyl acetate (EtAOc), n-butanol, and $H_2O$. Of the various fractions, EtAOc fraction effectively inhibited ${\alpha}$-glucosidase activity by 68.05%. Therefore, EtAOc fraction was selected for further isolation and identification studies. EtAOc fraction was separated by medium pressure liquid chromatography with silica and ODS gel to yield eight fractions (EAA~EAH). Based on the results of ${\alpha}$-glucosidase inhibitory activity, EAH fraction was re-chromatographed to yielded four more fractions (EAHA~EAHD). Of these, EAHC fraction showed higher ${\alpha}$-glucosidase inhibitory activity of 93.60%. EAHC fraction was re-chromatographed and yielded EAHCA and EAHCB fractions. Further, identification and chemical structures of these two fractions were analyzed using $^1H$-NMR, $^{13}C$-NMR, and mass spectra data. Based on the results of the spectral data, the isolated compounds were identified as hyperoside and isoquercetin. Results of the present study indicate that the isolated compounds, hyperoside, and isoquercetin from leaves of E. senticosus could be used for the development of new anti-diabetic drugs.

Alleviating Effects of Baechu Kimchi Added Ecklonia cava on Postprandial Hyperglycemia in Diabetic Mice

  • Lee, Hyun-Ah;Song, Yeong-Ok;Jang, Mi-Soon;Han, Ji-Sook
    • Preventive Nutrition and Food Science
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    • v.18 no.3
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    • pp.163-168
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    • 2013
  • In this study, we investigated the inhibitory effects of Baechu kimchi added Ecklonia cava on the activities of ${\alpha}$-glucosidase and ${\alpha}$-amylase and its alleviating effect on the postprandial hyperglycemia in STZ-induced diabetic mice. Baechu kimchi added Ecklonia cava (BKE, 15%) was fermented at $5^{\circ}C$ for 28 days. Optimum ripened BKE was used in this study as it showedthe strongest inhibitory activities on ${\alpha}$-glucosidase and ${\alpha}$-amylaseby fermentation time among the BKEs in our previous study. The BKE was extracted with 80% methanol and the extract solution was concentrated, and then used in this study. The BKE extract showed higher inhibitory activities than Baechu kimchi extract against ${\alpha}$-glucosidase and ${\alpha}$-amylase. The $IC_{50}$ values of the BKE extract against ${\alpha}$-glucosidase and ${\alpha}$-amylase were 0.58 and 0.35 mg/mL, respectively; BKE exhibited a lower ${\alpha}$-glucosidase inhibitory activity but a higher ${\alpha}$-amylase inhibitory activity than those of acarbose. The BKE extract alleviated postprandial hyperglycemia caused by starch loading in normal and streptozotocin- induced diabetic mice. Furthermore, the BKE extract significantly lowered the incremental area under the curve in both normal and diabetic mice (P<0.05). These results indicated that the BKE extract may delay carbohydrate digestion and thus glucose absorption.

Inhibitory Effect of Bacillus subtilis Y3-7 Culture Broth on $\alpha$-Glucosidase Activity (Bacillus subtilis Y3-7 배양액의 $\alpha$-glucosidase 활성 억제 효과)

  • Myoung, Kil-Sun;Heo, Gun;Yoon, Suck-Yong;Shim, Jae-Jung;Lee, Jung-Hee;Lim, Kwang-Sei;Huh, Chul-Sung
    • Korean Journal of Food Science and Technology
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    • v.40 no.5
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    • pp.558-561
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    • 2008
  • Culture broth of Bacillus subtilis Y3-7 in tryptic soy broth (TSB) isolated from Korean traditional fermented food was evaluated for the inhibition of $\alpha$-glucosidase. The results of in vitro studies using the yeast $\alpha$-glucosidase demonstrated that the culture broth exerted inhibitory effects on $\alpha$-glucosidase with $IC_{50}$ value of 1.62 mg/mL, and functioned as a competitive inhibitor. Furthermore, the culture broth of B. subtilis Y3-7 significantly improved glucose tolerance in normal and streptozotocin-induced diabetic mice. The blood glucose levels in the mice receiving sucrose supplementation in the culture broth (1 g/kg, 2 g/kg) were measured at 48.7%, which corresponded to 22.2% of the levels measured in the control mice. These results indicated that the culture broth of B. subtilis Y3-7 in TSB might be considered as a useful compound for the preparation of functional foods for diabetic patients.

Hypoglycemic Effect of Sargassum ringgoldianum Extract in STZ-induced Diabetic Mice

  • Lee, Chae-Won;Han, Ji-Sook
    • Preventive Nutrition and Food Science
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    • v.17 no.1
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    • pp.8-13
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    • 2012
  • This study was designed to investigate whether Sargassum ringgoldianum extract may inhibit ${\alpha}$-glucosidase and ${\alpha}$-amylase activities, and alleviate postprandial hyperglycemia in streptozotocin-induced diabetic mice. The $IC_{50}$ values of Sargassum ringgoldianum extract against ${\alpha}$-glucosidase and ${\alpha}$-amylase were 0.12 mg/mL and 0.18 mg/mL, respectively, which evidenced higher activities than those of acarbose. The blood glucose levels of the Sargassum ringgoldianum extract administered group were significantly lower compared to the control group in the streptozotocin-induced diabetic mice. Moreover, the area under the two-hour blood glucose response curve was significantly reduced and the absorption of dietary carbohydrates was delayed after administration of Sargassum ringgoldianum extract in the diabetic mice. Therefore, these results indicated that Sargassum ringgoldianum extract may help decrease the postprandial blood glucose level via inhibiting ${\alpha}$-glucosidase.

The Inhibitory Effect of Cornus walteri Extract Against ${\alpha}-amylase$ (말채나무 추출물의 ${\alpha}-amylase$ 저해 활성)

  • Lim, Chae-Sung;Li, Chun-Ying;Kim, Yong-Mu;Lee, Wi-Young;Rhee, Hae-Ik
    • Applied Biological Chemistry
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    • v.48 no.1
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    • pp.103-108
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    • 2005
  • ${\alpha}-Amylase$ inhibitor is used to control blood glucose level by inhibiting starch digestion in the small intestine and delaying the absorption of glucose. In this study, we investigated the effect of the ethanol extracts from more than 1400 species of plants against ${\alpha}-amylase$ with the aim of developing a new ${\alpha}-amylase$ inhibitor. In the results, Cornus walteri extracts showed the highest inhibition activity. The inhibitory effect of Cornus walteri extract on the carbohydrate hydrolysis enzymes has different sensitivities against ${\alpha}-amylase$ from salivary and pancreatin and against ${\alpha}-glucosidase$ from yeast and porcine small intestine. In the study of inhibition kinetics of ${\alpha}-amylase$ and ${\alpha}-glucosidase$, Cornus walteri extract showed competitive inhibition against salivary and pancreatin while showing the combination of uncompetitive and noncompetitive inhibition against ${\alpha}-glucosidase$. The Cornus walteri extract was stable at acidic and thermal conditions. As for the blood glucose and body weight levels of Cornus walteri extract, we confirmed anti-hyperglycemic and anti-obesity effects. Also, in the investigation of the mRNA lever, Cornus walteri extract upregulated the level of GLUT4 mRNA in the quadriceps muscle.

Production of Ascorbic acid-2-Glucoside from Ascorbic acid with Rice ${\alpha}-Glucosidase$ (벼의 ${\alpha}-Glucosidase$에 의한 Ascorbic acid로부터 Ascorbic acid-2-Glucoside의 생산)

  • Kim, Sung-Kyoon;Hwang, Ki-Chul;Bang, Won-Gi
    • Applied Biological Chemistry
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    • v.43 no.1
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    • pp.12-17
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    • 2000
  • For the enzymatic production of $2-O-{\alpha}-D-glucopyranosyl-L-ascorbic$ acid (AA-2G) from ascorbic acid, rice seed was used as the source of ${\alpha}-glucosidase$ having transglucosylation activity. Among six rice varieties, cultivated in Korea, ${\alpha}-glucosidase$ activity of Oryza savita L. cv. Ilpumbyeo was the highest with 125.03 unit/ml and it had maximum specific activity with 8.52 unit/mg protein when rice seeds were grown for 3 days after germination. For the production of AA-2G using crude extract of O. savita L. cv. Ilpumbyeo, maltose was most effective glucose donor. The optimum concentration of maltose and ascorbic acid were 125 mM and 175 mM, respectively. The optimum concentration of ${\alpha}-glucosidase$ was 100 unit. The most effective buffer was 100 mM sodium citrate. The optimum pH and temperature were 5.0 and $60^{\circ}C$, respectively. Under the optimum condition, $108.43\;{\mu}M/unit$ of AA-2G was produced from ascorbic acid after 35 minutes of reaction, which corresponds to 6.2% of conversion ratio based on the amount of ascorbic acid used.

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Synthesis and Activity of a Potent ${\alpha}$-glucosidase inhibitor, (1R, 6R, 8S)-cis-1,6-dihydroxypyrrolizidine, and its isomer

  • Jung, Kyeong-Eun;Kang, Yong-Koo;Kim, Dong-Jin;Park, Sang-Woo
    • Archives of Pharmacal Research
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    • v.20 no.4
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    • pp.346-350
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    • 1997
  • The synthesis of cis- and trans-1,6-dihydroxypyrrolizidine starting from trans-4-hydroxy-L-proline and their evaluation as glycosidase inhibitors are reported. The cis-isomer was found to be a potent inhibitor against .alpha.-glucosidase and showed weak inhibitory effect against other glycosidases. The trans-isomer exhibited weak inhibitions of b-glucosidase and amylo-glucosidase and poor inhibition of other glycosidases.

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Gelidium amansii Extract, a Potent α-glucosidase and α-amylase Inhibitor, Alleviates Postprandial Hyperglycemia in Diabetic Mice (당뇨 마우스에서 우뭇가사리(Gelidium amansii)의 식후 고혈당 완화 효과)

  • Park, Jae-Eun;Kim, Jung-Min;Han, Ji-Sook
    • Journal of Life Science
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    • v.27 no.9
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    • pp.1052-1058
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    • 2017
  • Gelidium amansii shows antioxidant and anti-obesity effects; however, the effect on postprandial blood glucose levels is not known. The objective of the present study was to investigate the inhibitory effect of Gelidium amansii extract (GAE) on carbohydrate-digesting enzymes and its ability to alleviate postprandial hyperglycemia in streptozotocin (STZ)-induced diabetic mice. Gelidium amansii was extracted with 80% ethanol and concentrated for use in this study. The ${\alpha}-glucosidase$ and ${\alpha}-amylase$ inhibition assays were performed using the colorimetric method. ICR normal and STZ-induced diabetic mice were orally administered GAE (300 mg/kg body weight) or acarbose (100 mg/kg body weight) alone or soluble starch (2 g/kg body weight). Blood samples were taken from the tail vein at 0, 30, 60 and 120 min. Our results indicated that GAE markedly inhibited ${\alpha}-glucosidase$ and ${\alpha}-amylase$ activities with $IC_{50}$ values of $0.099{\pm}0.009mg/ml$ and $0.178{\pm}0.038mg/ml$, respectively, and was a more effective inhibitor than acarbose, the positive control. Further, the postprandial blood glucose levels of STZ-induced diabetic mice in the GAE-administered group were significantly lower than those of control group mice (p<0.05). Moreover, the area under the curves (AUC) significantly decreased with GAE administration in STZ-induced diabetic mice (p<0.05). These results indicate that GAE may be effective in decreasing postprandial blood glucose levels by inhibiting carbohydrate-digesting enzymes such as ${\alpha}-amylase$ and ${\alpha}-glucosidase$. Therefore, GAE could be used as a potential functional food for alleviating postprandial hyperglycemia.

Inhibitory Effect of Extracts from Paeoniae radix on Postprandial Hyperglycemia (작약(Paeoniae radix) 추출물의 식후 과혈당 억제작용)

  • 지승택;이성진;이강은;손용태;정요경
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.31 no.1
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    • pp.131-135
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    • 2002
  • This study was carried out to investigate the inhibitory effect of extracts from Paeoniae radix on postprandial hyperglycemia. Organic solvent (hexane, ethyl acetate, butanol, water) extracts from Paeoniae radix were fractionated by high performance liquid chromatography. These fractions were used to screen $\alpha$-glucosidase (EC 3.2.1.20) inhibitors by microplate colorimetric assay. The fractions 11, 12, 18, 19 of ethyl acetate extract from Paeoniae radix showed inhibitory activity by 85%, 84%, 77%, 77% at concentration of 20 $\mu\textrm{g}$/mL, respectively. The selected fractions (no. 10~no. 19) significantly reduced by 22% the blood glucose elevation in comparison with positive control in mice loaded with maltose. The fractions of Paeoniae radix were determined in vitro inhibitory activity on $\alpha$-glucosidase and in vivo inhibition effect on blood glucose elevation in mice. Therefore, these results suggest that the extract of Paeoniae radix can be used as a new nutraceutial for inhibition on postprandial hyperglycemia as well as resource pool for lead compounds as a $\alpha$-glucosidase inhibitor.