• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.898-904
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• 2019

This study was carried to investigate the antidiabetic effect of ethanol extract of Astragali Radix(A.R) in Streptozotocin(STZ) induced diabetic rats. Diabetes was induced by intravenous injection of STZ at a dose of 45mg/kg dissolved in citrate buffer. The ethanol extract of A. R was orally administrated once a day for 7 days at a dose of 1,000mg/kg. The contents of serum glucose, triglyceride(TG), total cholesterol were significantly decreased in A.R treated group compared to the those of STZ-control group. The content of hepatic glycogen and activities of glucokinase(GK) and glucose-6-phosphate dehydrogenase(G-6-PDH) were significantly increased, and activity of glucose-6-phoshatase(G-6-Pase) was significantly decreased in A.R treated group compared to the those of STZ-control group, These results indicated that ethanol extract of A.R would have antidiabetic effect in STZ-induced diabetic rats.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.1-3
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• 2015

This study investigated the inhibitory activities of 2-hydroxyquinoline and its analogs against ${\alpha}$-glucosidase and ${\alpha}$-amylase. Based on the $IC_{50}$ values of 2-hydroxyquinoline analogs tested against ${\alpha}$-glucosidase and ${\alpha}$-amylase, 2-hydroxyquinoline had potent inhibitory activity (64.4 and $130.5{\mu}g/mL$, respectively), while 2-methyl-8-hydroxyquinoline showed weakly inhibitory activity (90.7 and $215.4{\mu}g/mL$, respectively). 2-Methylquinoline demonstrated no activity against ${\alpha}$-glucosidase and ${\alpha}$-amylase. In conclusion, 2-hydroxyquinoline analogs, with the existence of a methyl group and hydroxyl on quinoline, can be useful as a new diabetes treatment.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3772-3776
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• 2012

Mitogen-activated protein kinase phosphatase 4 (MKP4) has proved to be a promising target for the development of therapeutics for the treatment of diabetes and the other metabolic diseases. Here, we report an example for a successful application of the structure-based virtual screening to identify three novel inhibitors of MKP4. These inhibitors have desirable physicochemical properties as a drug candidate and reveal a moderate potency with $IC_{50}$ values ranging from 4.9 to $32.3{\mu}M$. Therefore, they deserve consideration for further development by structure-activity relationship studies to optimize the inhibitory and antidiabetic activities. Structural features relevant to the stabilization of the newly identified inhibitors in the active site of MKP4 are discussed in detail.

• Archives of Pharmacal Research
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• v.24 no.3
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• pp.214-218
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• 2001

The mechanisms responsible for the antidiabetic activity of both the white ginseng radix (Ginseng Radix Alba, GRA) and the rootlet (Cinseng Radix Palva, GRP) were investigated. After a four week oral administration, the fasting blood glucose levels in the GRA- and GRP-treated groups were lower when compared to the control group. To elucidate the hypoglycemic mechanism(s) of the ginseng radices, glucose absorption from the small intestine, hepatic hexokinase and glucose-6-phosphatase activities, in addition to PPAR-${\gamma}$ expression in adipose tissue were examined. The results strongly suggest that GRA can improve hyperglycemia in KKAy mice, possibly by blocking intestinal glucose absorption and inhibiting hepatic glucose-6-phosphatase, and GRP through the upregulation of adipocytic PPAR-$\gamma$ protein expression as well as inhibiting intestinal glucose absorption.

• Journal of Applied Biological Chemistry
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• v.44 no.1
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• pp.1-5
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• 2001

The methanol extracts of 25 leguminous seeds in vitro was evaluated for inhibitory activities against the small intestinal $\alpha$-glucosidase of Sprague Dawley male rats. The responses varied both with leguminous seed types and concentrations used. At the concentration of 0.5 mg/ml, the methanol extracts of Cassia obtusifolia, Glycine max var. yagkong, Glycine max var. hooktae, Glycine max var. geumdu, Glycine max var. mejukong, Glycine soja, Phaseolus multiflorus, Pisum sativum, and Vigna sinensis inhibited over 50% of the enzyme activity. The extracts of G. max var. yagkong and V. sinensis showed relatively strong inhibitory activities against $\alpha$-glucosidase at the concentration of 0.1 mg/ml. The activity of each solvent fraction from G. max var. yagkong and V. sinensis was determined, and potent activities were detected from chloroform and butanol fractions, respectively. $IC_{50}$ values of G. max var. yagkong and V. sinensis were 0.06 and 0.19 mg/ml, respectively. As a naturally occurring therapeutic agents, leguminous seeds examined could be useful for developing new types of antidiabetic agents.

• Journal of Ginseng Research
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• v.20 no.4
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• pp.389-415
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• 1996

Panax ginseng C.A. Meyer(Araliaceae) has been traditionally used as an expensive and precious medicine in oriental countries for more than 5, 000 years. Ginseng saponin isolated from the root of Panax ginseng have been regarded as the main effective components responsible for the pharmacological and biological activities. Such as antiaging effects. antidiabetic effects anticancer effects. Protection against physical and chemical stress. Analgesic and antipyretic effects. Effects on the central nervous system, tranquilizing action and others. Thirty kinds of ginsenosides have been so far isolated from ginseng saponin and their chemical structures have been elucidated since 1960's. Among which protopanaxadiol type is 19 kinds. protopanaxatriol type. 10 kinds and oleanane type, one. Since ginsenosides are generally labile under acidic conditions ordinary acid hydrolysis is always accompanied by many side reactions, such as epimerization. hydroxylation and cyclization of side chain of the sapogenins Especially. it is well known that C-20 glycosyl linkage of ginsenoside was hydrolysed on heating with acetic acid to give an equilibrated mixture of 20(S) and 20(R) epimers. And also, the chemical transformations of the secondary metabolites have appeared during the steaming process to prepare red ginseng. Indicating demalonylation of malonyl ginsenosides, elimination of glycosyl residue at C-20 and isomerization of hydroxyl configuration at C-20. But these studies have not provided a comprehensive picture in explaning how these ginsenosides showed val'iotas pharmacological activities of ginseng. Though some of them have been involved in the mechanism of pharmacological actions. Recently, non-saponin components have received a great deal of attention for their antioxidant, anticancer antidiabetic, immunomodulating. anticomplementary activities and so on. To meet the demand for such wide applications, studies on the non-saponin components play an important role in providing a good evidence of pharmacological and biol ogical activities. Among the non-saponin constituents of Korean ginseng, polyacetylenes, phenols. Sesquiterpenes, alkaloids. polysaccharides oligosaccharides, oligopeptides and aminoglycosides together with ginsenosides of terrestrial part are mainly described.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.2
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• pp.270-277
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• 2015

This study was performed to investigate the antidiabetic and antioxidant activities of Crataegus pinnatifida which was extracted with water and different concentrations of EtOH (0~100%). The extraction yield of 70% EtOH (33.16%) was higher than that of 50% EtOH (27.79%), water (21.71%), 30% EtOH (21.88%) and 100% EtOH (19.03%). Total polyphenol contents of 50% EtOH extract from C. pinnatifida were the highest. DPPH and ABTS radical scavenging activities were $80.79{\pm}0.83%$ and $34.92{\pm}0.97%$ in 50% EtOH extract, respectively, which were higher than those of other extracts. The inhibitory activities of 50% ethanol extract from C. pinnatifida against advanced glycation end products (AGEs) formation and ${\alpha}$-glucosidase were determined to be $27.09{\pm}2.27%$ and $58.87{\pm}0.70%$, respectively. The inhibitory activity of water extract from C. pinnatifida against aldose reductase was higher ($30.68{\pm}1.41%$) than those of other extracts. Overall, 50% EtOH extract from C. pinnatifida showed the highest antidiabetic and antioxidant effects. These results suggest that 50% ethanol extracts from C. pinnatifida have potential as a useful ingredient with antidiabetic and antioxidant effects.

• KSBB Journal
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• v.27 no.6
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• pp.361-366
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• 2012

We investigated the anti-diabetic activity and enzymatic activity of 24 commercial doenjang samples certified for traditional foods. Twenty four doenjang samples showed the wide ranges in enzymatic activities (protease activities 0-50.45 unit/g, ${\alpha}$-amylase activities 0-675.9 unit/g, ${\beta}$-amylase 13.6-308.6 unit/g), and there were no difference in enzymatic activity by the producing region. To evaluate the potential anti-diabetic activity of 24 doenjang samples, we examined the effect of doenjang methanol extract (DME) on 2-[n-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amyno]-2-deoxy-d-glucose (2-NBDG) uptake. Ten samples among 24 samples significantly stimulated the uptake of 2-NBDG. When the cells were treated with DME at 400 ug/mL, No. 17 and 23 specially stimulated 2-NBDG uptake by 1.23-fold and 1.25-fold, respectively, compared with untreated control cell. And there were no cytotoxicity in the C2C12 cells treated with DME at concentration of 500 ug/mL. Among 24 samples, No. 6, 7, 12, 21 and 24 showed the ${\alpha}$-glucosidase inhibitor activity at concentration of 10 mg/mL; however, they were less effective than acarbose which is a commercial ${\alpha}$-glucosidase inhibitor.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1531-1535
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• 2005

The present study was designed to investigate the antidiabetic effect of Cordyceps militaris on activities of hepatic glucose-regulating enzymes, such as glucokinase (GK), pyruvate dehydrogenase (PDH) and acetyI-CoA carboxylase (ACC). We have isolated the active compounds, CM-A and CM-B from C. militaris and the extracts are under investigation to determine their mechanism of action. Hepatic GK, PDH and ACC activities were significantly (p < 0.05) increased compared with the control. Treatment with CM-A led to a rise in percentage of enzymes by 380$\%$,396$\%$ and 286$\%$, respectively, relative to control levels. CM-B were 329$\%$, 312$\%$ and 239$\%$, respectively. The increase in GK and ACC activities was linearly proportional with increased ratio of CM-A. Our findings suggest that C. militaris exerted antihyperglycemic potency, which is thought to be mediated through activation of GK, PDH and ACC enzymes related to glucose metabolism directly or indirectly and therefore C. militaris is promising as antidiabetic functional foods.

• Journal of Life Science
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• v.25 no.6
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• pp.638-645
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• 2015

This study analyzed the physiological quality of Mesembryanthemum crystallinum (ice plant) extract. M. crystallinum is a succulent plant found in Africa, southern Europe, North America, South America, and Australia. It has known antidiabetic, antioxidant, and activation of lipid metabolism effects. Extracts from M. crystallinum were prepared with methanol (MCM), ethanol (MCE), hot water (MCHW), and methanol after hot water (MCHM) extractions. The yields of MCM, MCE, MCHW, and MCHM were 0.37, 0.33, 0.50, and 0.07%, respectively. To determine the biological activities of the extracts, mushroom tyrosinase, pancreatic lipase, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging, nitric oxide (NO) production, and α-glucosidase assays were conducted. The DPPH radical scavenging activity of the MCHW extract was 62.9% at a concentration of 400 μg/ml, which was the highest of all the extracts. The MCM extract showed the highest inhibition activity of α-glucosidase and NO production (56.6 and 57.2%, respectively). The pancreatic lipase inhibition of the MCE extract was similar to that of the MCM extract, with significant inhibition of 90%. The mushroom tyrosinase inhibition of all the extracts was very low (approximately 30%). These results suggest that extracts from M. crystallinum have antioxidant, anti-inflammatory, antiobesity, and antidiabetic activities. Thus, it may have potential as a functional food product and therapeutic potential as an antidiabetic or antiobesity agent.