• Korean Journal of Microbiology
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• v.11 no.1
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• pp.1-18
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• 1973

A study was made on enzymes of carbohydrate metabolism in T. concretivorus grown with and without glucose. The present results show that T. concretivorus possesses high activities of pentose shunt pathway and related enzymes, glucokinase, G-6-P dehydrogenase, 6-PG dehydrogenase, and phosphoglucoisomerase, but low activities of enzymes unique to EMP(fructose-1, 6-diphosphate aldolase). Although the synthesis of the latter enzymes remains largely unaffected by the growth enviroment, that of the former is stimulated by glucose. And the failure to detect ED pathway enzymes in cells grown in thiosulate or thiosulfate-glucose medium eliminates the ED pathway as a significant route of glucose catabolism in T.concretivorus. These results suggest that pentose shunt pathway performs an energetic role in glucose metabolism by T.concretivorus with EMP as a subway. The absence of ED pathway and the presence of pentose shunt pathway which is the major route of catabolism in T.concretivorus are similar to those of other obligately chemolitho-trophic thiobacilli. The G-6-P and 6-PG dehydrogenase are both NAD and NADP specific, but MAD predominant. However, the 3-PGAL dehydrogenase is only NAD specific. Since the specific activity of 3-PGAL generated from glucose is converted mainly into pyruvate which is channeled into the TCA cycle. All enzymes of the TCA cycle tested and NADH oxidase are detected in the cells of T.concretivorus grown in thiosulfate. The specific activities of fumarase and isocitrate dehydrogenase are high and others are low. The presence of two isocitrate dehydrogenase (NAD-and NADP-linked) may have important regulatory function for this organism. The activity of NAD-oxidase, which is implicated in the energy generating metabolism, was very high in the crude cell-free extract of T.concretivorus, recording 55.11 m$\mu$ mole/min/mg protein. This well coincides with the fact that activities of NAD-linked G-6-P dehydrogenase, 6-PG dehydrogenase and 3-PGAL dehydrogenase were high.

• Biomedical Science Letters
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• v.26 no.2
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• pp.75-84
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• 2020

We evaluated the effect of anti-obesitic activity of MYE (mulberry leaf + Yacon tuber) extracted from Morus alba as muberry leaf and Smallanthus sonchifolia as yacon. 1%, 3%, or 5% of MYE were treated to Sprague-Dawley rats exposed to a high-fat diet. MYE treated rats were suppressed weight during four weeks, and they lost weight significantly after six weeks. Common blood chemistry panels related to liver function revealed significant improvement in the MYE-treated groups. The expression of leptin as indicators for obesity was decreased in perirenal fat. Such results indicate that MYE could be a promising candidate for the improvement of obesity. In addition, MYE effected on deceased glucose metabolism, reducing the activities of glucose-6-phosphate dehydrogenase (G-6-PDH) and glucokinase related to glycogen synthesis. The fatty liver was observed in high-fat diet-treated rats, resulting from increased number of adipose cells and Ito cells. However, this pathologic change was significantly improved by administration of MYE. MYE have significant effects on antioxdative function and glycometabolism against high fat diet. Thereby, it seems that MYE prevent fatty liver by high-fat diet. Thus it is suggested that MYE would be worth being developed as an biofunctional food to prevent undesirable effects caused by obesity.

• Proceedings of the Ginseng society Conference
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• 1988.08a
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• pp.63-69
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• 1988

The effect of $ginsenoside-Rb_2$ purified from ginseng was examined in rats with streptozotocin-induced diabetes. The rats of the $ginsenoside-Rb_2-treated$ group showed a significant decrease in blood glucose level as well as a significant decrease of glucose-6-phosphatase in the liver. whereas a significants rise was observed in the activity of glucokinase. Furthermore, the rats treated with $ginsenoside-Rb_2$ showed a significant decrease of glucose and a slight increase of glycogen in the hepatic tissue. The glucose-6-phosphate level tended to increase, the pyruvate level was unchanged and the lactate level tended to decrease. There was, however. no accumulation of total lipid in hepatic tissue. The serum levels of triglyceride. non-esterified fatty acid. 3-hydroxybutyrate and acetoacetate were markedly decreased, showing a trend toward restoration of the normal state and inducing. an increase in lipids in the adipose tissue. Additional experiments involving long-term administration of $ginsenoside-Rb_2$ produced results suggesting that $ginsenoside-Rb_2$ may improve diabetic symptoms such as overeating, overdrinking. polyuria and glycosuria.

• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.77-81
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• 2009

This study examined the effects of black ginseng (9 times-steamed ginseng) on hypoglycemic action in streptozotocininduced diabetic rats as well as changes in ginsenoside composition by the steaming process. As the number of steaming cycles increased, the amounts of crude saponin and most ginsenoside contents decreased, while the amount of ginsenoside- Rg3 and the ratio of PD/PT (=[$Rb_1+Rb_2+Rc+Rd+Rg_3]/[Re+Rb_1+Rh_1]$) increased. This ginsenoside composition is a unique characteristic compared to other types of ginseng products. In order to investigate the hypoglycemic effect of the black ginseng extract, in vivo studies were performed in rats with streptozotocin-induced diabetes. The studies showed that the administration of the black ginseng extract decreased high blood glucose levels (more than 300 mg/dL) to a normal level (102 mg/dL). These results suggest that this black ginseng extract has a significant hypoglycemic effect and can be used as an anti-diabetic substance for dietary supplements or new drugs.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1148-1161
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• 2016

Lactobacilli are universally recognized as probiotics that are widely used in the adjuvant treatment of inflammatory diseases, such as vaginitis and enteritis. With the overuse of antibiotics in recent years, the lactobacilli in the human body are killed, which could disrupt the microecological balance in the human body and affect health adversely. In this work, cephalosporin-resistant Lactobacillus casei RL20 was obtained successfully from the feces of healthy volunteers, which possessed a stable genetic set. However, the shortage of lactic acid (72.0 g/l at 48 h) by fermentation did not meet the requirement for its use in medicine. To increase the production of lactic acid, the functional genes pfk and glk were introduced into the wild strain. A yield of 144.2 g/l lactic acid was obtained in the transgenic L. casei RL20-2 after fermentation for 48 h in 1 L of basic fermentation medium with an initial glucose concentration of 100 g/l and increasing antibacterial activity. These data suggested that L. casei RL20-2 that exhibited a high yield of lactic acid may be a potential probiotic to inhibit the spread of bacterial infectious diseases and may be used for vaginitis therapy.

• Journal of Nutrition and Health
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• v.43 no.4
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• pp.333-341
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• 2010

The aim of this study was to investigate the hypolgycemic activity of water extract of fermented yacon (Smallanthus sonchifolius) leaves tea (Yacon LWE) in high-fat diet (HFD)/streptozotocin (STZ)-induced diabetic mice. Male ICR mice were fed with a HFD (37% calories from fat) for 4 weeks prior to intraperitoneal injection with STZ (100 mg/kg body weight). Diabetic mice were supplemented with two doses of Yacon LWE (0.16% and 0.8%, wt/wt) for 6 weeks. The supplementation of high-dose Yacon LWE significantly lowered blood glucose levels and plasma ALT and AST activities compared with the control group. High-dose Yacon LWE also improved the insulin tolerance without any changes in plasma and pancreatic insulin concentrations in HFD/STZ-induced diabetic mice. Yacon LWE supplementation increased the insulin staining of pancreatic $\beta$-cells in a dose-dependent manner. Both 0.16% and 0.8% of Yacon LWE significantly elevated plasma leptin concentration, hepatic glucokinase activity and glucokinase/glucose-6-phosphatase ratio compared with the control group. However, glycosylated hemoglobin concentration was not different among the groups. These results suggest that high-dose Yacon LWE lowers the blood glucose level partly by enhancing insulin sensitivity and hepatic glucose metabolism in type 2 diabetic mice.

• Journal of Nutrition and Health
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• v.44 no.4
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• pp.275-283
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• 2011

This study was conducted to evaluate the antihyperglycemic effects of three phytoestrogens, genistein, coumestrol, and enterolactone, in type 2 diabetic animals. Forty male C57BL/KsOlaHsd-db/db mice were used as a diabetic animal model. The animals were divided into four groups and fed a phytoestrogen-free AIN-76 diet (control), or one of three phytoestrogen-supplemented (3.75 mg/100 g diet) AIN-76 diets for six weeks. During the experimental period, fasting blood glucose levels were measured on week 0, 2, 5, and 6 of the experiment, and oral glucose tolerance tests were performed on the 5th week. After the experimental period, blood concentrations of HbA1c, insulin, and glucagon were measured, and hepatic glycogen content and glucose regulating enzyme activities were analyzed. Fasting blood glucose, HbA1c level, and the area under the blood glucose curve in the oral glucose tolerance test were significantly lower in all of the phytoestrogen-supplemented groups compared to the control group. Plasma glucagon levels were also significantly lower in all of the phytoestrogen-supplemented groups compared to the control group. Hepatic glycogen level was significantly higher in the coumestrol-supplemented group compared to the other groups. However, there were no significant differences in the activities of glucokinase and glucose-6-phosphatase between the groups. These results suggest that all of the three major phytoestrogens tested in the present study were effective in lowering blood glucose levels in type 2 diabetic animals. However, further studies need to be conducted to elucidate the exact mechanism for the hypoglycemic effects of phytoestrogens.

• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.272-277
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• 2007

The physiological responses of microorganisms to specific nutrient limitation can be regulated at the transcriptional levels. In this study, in order to develop the Pichia pastoris-derived promoter inducible by nutrient-limited condition, we constructed cDNA libraries using RT-PCR of total RNA from P. pastoris in steady-states of phosphate-limited chemostat with different dilution rates. Various genes were detected from cDNA library. Among these genes, the gene encoding putative sodium/phosphate ($Na^+$/Pi) symporter (NPS), high affinity transporter of phosphate, was detected. It was observed that expression of NPS increased in a manner specific to phosphate-limited condition through Northern blot. Therefore, it is thought that the promoter from NPS gene may have the potential as auto-inducible promoter by phosphate-limited culture condition without inducer.

• Journal of the Korean Chemical Society
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• v.51 no.6
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• pp.543-548
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• 2007

Maturity-onset diabetes of the young (MODY) is a genetically heterogeneous subtype of Type 2 diabetes characterized (non-insulin-dependent) by early onset, usually before 25 years of age, autosomal dominant inheritance and a primary defect in insulin secretion. Mutations in the glucokinase (GCK) and hepatocyte nuclear factor (HNF)-1α genes are the major causes of monogenic forms of Type 2 diabetes mellitus. Therefore it is need to study relation with these polymorphisms by diverse analysis methods. The promotor and coding regions inclusive intron exon boundaries of the GCK, HNF-1α genes were examined by PCR-DHPLC (Polymerase Chain Reaction - Denaturing High Performance Liquid Chromatography) and direct sequencing. We extracted DNA from 11 patients and 20 normals. Then we confirmed a single-nucleotide polymorphism using PCR-DHPLC. As results, we identified one mutation (R135G) in GCK gene and two mutations (I27L, S487N) in HNF-1a and at the same time detected mutation in intron 8.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.630-635
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• 2014

Pine nut oil (PNO) is well known to impart beneficial effects in overweight individuals, but the mechanisms underlying PNO-mediated weight loss remain unclear. To investigate how PNO promotes weight loss, its composition was determined by gas chromatography coupled with mass spectrometry (GC-MS). In addition, the effects of PNO on cytotoxicity, lipid accumulation, expression of lipid metabolism-related biomarkers, and leptin secretion were assessed in 3T3-L1 cells. GC-MS analyses revealed that PNO contains several components, including linoleic acid, oleic acid, palmitic acid, and stearic acid. Moreover, PNO did not have a cytotoxic effect on 3T3-L1 cells. However, it inhibited the expression of peroxisome proliferator-activated receptor (PPAR) and adipocyte protein 2 (aP2). Finally, PNO significantly increased leptin secretion in a dose-dependent manner. Taken together, these results support the notion that PNO is useful for weight management in overweight individuals.