• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.11
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• pp.1401-1407
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• 2008

1-Deoxynojirimycin (DNJ) is a strong $\alpha$-glucosidase inhibitor which inhibits hyperglycemia in animals. To select the Bacillus strains highly producing DNJ, 4,000 strains were isolated from soil and grain samples. By the inhibitory activity against $\alpha$-glucosidase, nine Bacillus strains were selected and then identified by 16S rDNA sequencing. B. subtilis S10 was finally selected as the best strain for the production of DNJ. Various carbon sources and nitrogen sources in culture medium were evaluated for the highest production of DNJ. As the results, the optimized concentration of carbon source and nitrogen source was 1.0% galactose and 1.6% polypeptone and the concentration of DNJ produced was 0.75 g/L. The effect of culture supernatant of B. subtilis S10 on lowering blood glucose level was investigated in streptozotocin (STZ)-induced diabetic mice model. Mice were randomly assigned to control group (saline) and three test groups such as acarbose group, silkworm powder group and B. subtilis S10 group. After eight-week oral feeding, blood glucose levels of the B. subtilis S10 and silkworm powder groups were respectively $209.1{\pm}19.6\;mg/dL$ (59.1%) and $208.6{\pm}39.8\;mg/dL$ (59.0%) lower than $510{\pm}10\;mg/dL$ of the control group. These results indicated that the culture supernatant of B. subtilis S10 was able to reduce the blood glucose level in STZ-induced diabetic mice.

• International Journal of Industrial Entomology and Biomaterials
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• v.21 no.2
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• pp.163-167
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• 2010

[ $\alpha$ ]Glucosidase (EC 3.2.1.20) is a glycosidase that hydrolyzes disaccharides, oligosaccharides, and polysaccharides resulting in the release of α-D-glucose. In this study, $\alpha$-glucosidase activity in the hemolymph and midgut of the mulberry silkworm Bombyx mori and Japanese oak silkmoth Antheraea yamamai was measured using maltose, sucrose, trehalose, and p-nitrophenyl $\alpha$-D-glucopyranoside as substrates. In general, hemolymph $\alpha$-glucosidase activity was higher in B. mori than in A. yamamai. In contrast, midgut $\alpha$-glucosidase activity was higher in A. yamamai than in B. mori for all of the substrates tested. $\alpha$-Glucosidase activity in the midgut of both B. mori and A. yamamai showed similar responses to changes in pH and temperature for all of the substrates tested. Native (7.5%) PAGE of hemolymph and midgut proteins from B. mori and A. yamamai followed by staining with 4-methylumbelliferyl $\alpha$-D-glucoside (MUG) indicated that the $\alpha$-glucosidases of these related lepidopterans are functionally similar but structurally different. In comparison to $\alpha$-glucosidase activity from A. yamamai, $\alpha$-glucosidase activity from B. mori was generally less sensitive to the $\alpha$-glucosidase inhibitors, 1-deoxynojirimycin (DNJ), acarbose, and voglibose when the activity was determined using maltose, sucrose, and trehalose.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.2
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• pp.161-164
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• 2003

Several polyhydroxylated alkaloids were isolated from the extracts of freeze-dried silkworm powder, and purified by ion exchange chromatographic analysis. Through the HPLC analysis, we could identify 1-deoxynojirimycin (DNJ) and a kind of calystegin $B_2$ (HS-58) as well as a noble compound (HS-74) from the purified polyhydroxylated alkaloids. In order to know the characteristics of these isolated alkaloids as enzyme inhibitors, glycosidase inhibition activities of these identified alkaloids including other two non-purified alkaloids (SWP 3-1 and SWP 3-2) were investigated.

• Korean Journal of Medicinal Crop Science
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• v.20 no.6
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• pp.472-478
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• 2012

This study was carried out to investigate solid-state fermentation method using cellulolytic lactic acid bacteria Lactobacillus plantarum TO-2100 in order to increase piperidine alkaloid contents in mulberry leaves. Piperidine alkaloid, one type of which include 1-deoxynojirimycin (1-DNJ), is known to inhibit ${\alpha}$-glycosidase activities. Using this strain, the optimal solid-state fermentation conditions on mulberry leaves powder were found as the following: initial moisture content, temperature and relative humidity were 20%, $30{\sim}35^{\circ}C$ and 60 ~ 70%, respectively, and the fermentation time was 72 hrs. The piperidine alkaloid contents in the fermented mulberry leaves were 2.86% on dry powder, which is 7-fold increase from that of non-fermented mulberry leaves. The 1-deoxynojirimycin contents after applying preparative thin layer chromatography were 2.02% on dry powder, which is 8 times higher than that of non-fermented mulberry leaves. ${\alpha}$-Glycosidase activities was inhibited by 65.7 ~ 84.7% with 3 ~ 5% treatments of hot-water extracts of the fermented mulberry leaves, compared to 16.2 ~ 40.2% with 3 ~ 5% treatments of hot-water extracts of non-fermented mulberry leaves. Therefore, the results suggest that solid-state fermentation method does indeed increase of piperidine alkaloid contents on mulberry leaves.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2001.04a
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• pp.32-32
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• 2001

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2001.04a
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• pp.33-33
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• 2001

No Abstract. See Full-text

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2001.10a
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• pp.55-55
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• 2001

no Abstract, See Full Text

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.2
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• pp.139-144
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• 2003

Over 350 million people worldwide are chronic carriers of hepatitis B virus (HBV). Chronic viral infections of the liver can progress to cirrhosis, which may ultimately lead to hepatic failure or the development of hepatocellular carcinoma. There are two antiviral drugs on the market approved for clinical management of chronic HBV infections; interferon-alpha and the nucleoside analog lamivudine. However, they showed adverse side-effects. In the rational drug design for such therapies we would like to utilize antiviral drugs that inhibit the HBV replication in the liver. Investigation of natural extracts of silkworm exhibiting antiviral potential was held in the functional HBV polymerase activity and the release of virion particle in the HepG2.2.15 cell lines. HBV-producing transgenic mouse fed with silkworm DNJ molecule was shown as an inhibitor of serum HBV particles. We could represent this DNJ molecule as an antiviral potential complementing conventional therapies after preclinical tests against WHBV-infected animal model, woodchuck.

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.191-199
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• 2020

The purpose of this study was to isolate novel lactic acid bacteria to ferment mulberry leaf extract (MLE) and to investigate its anti-diabetic effect. Lactobacillus plantarum SG-053 isolated from gatkimchi was selected to ferment MLE because it exhibited high α-glucosidase inhibitory activity (96.8%) and enhanced the content of 1-deoxynojirimycin (DNJ), an anti-diabetic substance, in fermented MLE up-to 2.2 times. MLE fermented with L. plantarum SG-053 (FMLE) showed growth promoting activity against L6 myotubes and increased the gene expressions of IRS-1, PI3K p85α, and GLUT-4 up-to 1.4, 2.2, and 1.4 times, respectively, and 2-deoxyglucose uptake up-to 40.7%. In rat skeletal muscle tissue, the expressions of PI3K p85α and GLUT-4 increased by 6.4 and 2.1 times, respectively. These results suggest that L. plantarum SG-053 could enhance the DNJ content of MLE by fermentation and that FMLE is effective in ameliorating insulin resistance via activation of the insulin signaling pathway.

• Nutrition Research and Practice
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• v.12 no.6
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• pp.469-478
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• 2018

BACKGROUND/OBJECTIVES: Mulberry leaf (ML) has been shown to have an inhibitory effect on ${\alpha}$-glucosidase, and suppresses postprandial hyperglycemia, which may be related to its deoxynojirimycin (DNJ) content. This study was conducted to investigate the hypoglycemic and dyslipidemic effects of rice coated with ML rich in DNJ in a type 2 diabetes mouse model. MATERIALS/METHODS: The mice were divided into four groups (n = 8 each): non-diabetic normal control (NC); diabetic control (DM-C), fed with 10% polished rice powder (DM-R); and fed with 10% polished rice powder coated with DNJ-rich ML (DM-DNJR). RESULTS: Supplementation with DNJR for six weeks decreased levels of fasting blood glucose, plasma insulin, triglyceride, total cholesterol, and blood glycosylated hemoglobin; conversely, levels of glucagon-like peptide-1 and high-density lipoprotein-cholesterol showed an increase in the same treatment. In addition, weights of mesenteric, epididymal, and total adipose tissues decreased with DNJR supplementation, when compared with diabetic control db/db mice, while maltase, lactase, and sucrase activity in the small intestine were inhibited. The anti-diabetic effects were marginally greater in the DM-DNJR group than in the DM-R group. CONCLUSIONS: These results suggest that rice coated with ML rich in DNJ can reduce hyperglycemia and hyperlipidemia in db/db mice, and may prove useful for individuals with diabetes.