• Journal of Ginseng Research
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• v.40 no.4
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• pp.437-444
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• 2016

Background: Although Korean Red Ginseng (KRG) has been traditionally used for a long time, its anti-inflammatory role and underlying molecular and cellular mechanisms have been poorly understood. In this study, the anti-inflammatory roles of KRG-derived components, namely, water extract (KRG-WE), saponin fraction (KRG-SF), and nonsaponin fraction (KRG-NSF), were investigated. Methods: To check saponin levels in the test fractions, KRG-WE, KRG-NSF, and KRG-SF were analyzed using high-performance liquid chromatography. The anti-inflammatory roles and underlying cellular and molecular mechanisms of these components were investigated using a macrophage-like cell line (RAW264.7 cells) and an acute gastritis model in mice. Results: Of the tested fractions, KGR-SF (but not KRG-NSF and KRG-WE) markedly inhibited the viability of RAW264.7 cells, and splenocytes at more than 500 mg/mL significantly suppressed NO production at $100{\mu}g/mL$, diminished mRNA expression of inflammatory genes such as inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor-${\alpha}$, and interferon-${\beta}$ at $200{\mu}g/mL$, and completely blocked phagocytic uptake by RAW264.7 cells. All three fractions suppressed luciferase activity triggered by interferon regulatory factor 3 (IRF3), but not that triggered by activator protein-1 and nuclear factor-kappa B. Phospho-IRF3 and phospho-TBK1 were simultaneously decreased in KRG-SF. Interestingly, all these fractions, when orally administered, clearly ameliorated the symptoms of gastric ulcer in HCl/ethanol-induced gastritis mice. Conclusion: These results suggest that KRG-WE, KRG-NSF, and KRG-SF might have anti-inflammatory properties, mostly because of the suppression of the IRF3 pathway.

• Journal of Yeungnam Medical Science
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• v.14 no.1
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• pp.53-66
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• 1997

Insulin resistance is a prominent feature of diabetic state and has heterogeneous nature. However, the pathogenetic sequence of events leading to the emergence of the defect in insulin action remains controversial. It is well-known that prolonged hyperglycemia and hyperinsulinemia are one of the causes of development of insulin resistance, but both hyperglycemia and hyperinsulinemia stimulate glucose uptake in peripheral tissue. Therefore, it is hypothesized that insulin resistance may be generated by a kind of protective mechanism preventing cellular hypertrophy. In this study, to evaluate whether the acutely increased glucose uptake inhibits further glucose transport stimulated by insulin, insulin sensitivity was measured after preloaded glucose infusion for 2 hours at various conditions in rats. And also, to evaluate the mechanism of decreased insulin sensitivity, insulin receptor binding affinity and glucose transporter 4 (GLUT4) protein of plasma membrane of gastrocnemius muscle were assayed after hyperinsulinemic euglycemic clamp studies. Experimental animals were divided into five groups according to conditions of preloaded glucose infusion: group I, basal insulin ($14{\pm}1.9{\mu}U/ml$) and basal glucose ($75{\pm}0.7mg/dl$), by normal saline infusion; group II, normal insulin ($33{\pm}3.8{\mu}U/ml$) and hyperglycemia ($207{\pm}6.3mg/dl$), by somatostatin and glucose infusion; group III, hyperinsulinemia ($134{\pm}34.8{\mu}U/ml$) and hyperglycemia ($204{\pm}4.6mg/dl$), by glucose infusion; group IV, supramaximal insulin ($5006{\pm}396.1{\mu}U/ml$) and euglycemia ($l00{\pm}2.2mg/dl$), by insulin and glucose infusion; group V, supramaximal insulin ($4813{\pm}687.9{\mu}U/ml$) and hyperglycemia ($233{\pm}3.1mg/dl$), by insulin and glucose infusion. Insulin sensitivity was assessed with hyperinsulinemic euglycemic clamp technique. The amounts of preloaded glucose infusion(gm/kg) were $1.88{\pm}0.151$ in group II, $2.69{\pm}0.239$ in group III, $3.54{\pm}0.198$ in group IV, and $4.32{\pm}0.621$ in group V. Disappearance rates of glucose (Rd, mg/kg/min) at steady state of hyperinsulinemic euglycemic clamp studies were $16.9{\pm}3.88$ in group I, $13.5{\pm}1.05$ in group II, $11.2{\pm}1.17$ in group III, $13.2{\pm}2.05$ in group IV, and $10.4{\pm}1.01$ in group V. A negative correlation was observed between amount of preloaded glucose and Rd (r=-0.701, p<0.001) when all studies were combined. Insulin receptor binding affinity and content of GLUT4 were not significantly different in all experimental groups. These results suggest that increased glucose uptake may inhibit further glucose transport and lead to decreased insulin sensitivity.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.6
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• pp.506-513
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• 2004

Spirulina produces $\gamma$-linolenic acid (GLA), an important pharmaceutical substance, in a relatively low level compared with fungi and plants, prompting more research to improve its GLA yield. In this study, metabolic flux analysis was applied to determine the cellular metabolic flux distributions in the GLA synthetic pathways of two Spiru/ina strains, wild type BP and a high­GLA producing mutant Z19/2. Simplified pathways involving the GLA synthesis of S. platensis formulated comprise of photosynthesis, gluconeogenesis, the pentose phosphate pathway, the anaplerotic pathway, the tricarboxylic cycle, the GLA synthesis pathway, and the biomass syn­thesis pathway. A stoichiometric model reflecting these pathways contains 17 intermediates and 22 reactions. Three fluxes - the bicarbonate (C-source) uptake rate, the specific growth rate, and the GLA synthesis rate - were measured and the remaining fluxes were calculated using lin­ear optimization. The calculation showed that the flux through the reaction converting acetyl­CoA into malonyl-CoA in the mutant strain was nearly three times higher than that in the wild­type strain. This finding implies that this reaction is rate controlling. This suggestion was sup­ported by experiments, in which the stimulating factors for this reaction $(NADPH\;and\;MgCl_{2})$ were added into the culture medium, resulting in an increased GLA-synthesis rate in the wild type strain.

• Journal of Ginseng Research
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• v.24 no.3
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• pp.138-142
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• 2000

Effects of ginsenosides (Rb$_1$, Rb$_2$, Rc, Re, Rg$_1$, Rf) on L-glutamate (glutamate)-induced swelling of cultured astrocytes from rat brain cerebral cortex were studied. Following the exposure to 0.5mM glutamate for 1 hr, the intracellular water space (as measured by [$^3$H]O-methyl-D-glucose uptake) of astrocytes increased by about two-fold. Simultaneous addition of ginsenosides Rb$_2$ and Rc with glutamate reduced the astrocytic swelling in a dose-dependent manner. These ginsenosides at 0.5 mg/ml did not affect the viability of astrocytes for up to 24 hr which was determined by a colorimetric assay (MTT assay) for cellular growth and survival. These ginsenosides at 0.3 mg/ml inhibited the increase of intracellular Ca$\^$2+/ concentration ([Ca$\^$2+/]$\_$i/) induced by glutamate. These data suggest ginsenosides Rb$_2$ and Rc prevent the cell swelling of astrocytes induced by glutamate, maybe via inhibition of Ca$\^$2+/ influx.

• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.3893-3898
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• 2011

Cellular uptake of double-stranded DNA (dsDNA) triggers strong innate immune responses via activation of NF-${\kappa}B$ transcription factor. However, the detailed mechanism of dsDNA-mediated innate immune response remains yet to be elucidated. Here, we show that the expression of tazarotene-induced gene 3 (TIG3) is dramatically induced by dsDNA stimulation, and the siRNA-mediated down-regulation of TIG3 mRNA results in significant suppression of dsDNA-triggered cytokine expression. Because TIG3 has been previously shown to physically interact with transglutaminase (TG) 1 to activate TG activity, and TG2 has been shown to induce NF-${\kappa}B$ activity by inducing $I{\kappa}B{\alpha}$ polymerization, we tested whether TG also plays a role in dsDNA-mediated innate immune response. Pre-treatment of TG inhibitors dramatically reduces dsDNA-triggered cytokine induction. We also show that, in HeLa cells, TG2 is the major TG, and TIG3 physically interacts with TG2. Combined together, our results suggest a novel mechanism of dsDNA-triggered innate immune response which is critically dependent on TIG3 and TG2.

• Molecules and Cells
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• v.38 no.6
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• pp.573-579
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• 2015

Apolipoprotein A-I and A-IV are protein constituents of high-density lipoproteins although their functional difference in lipoprotein metabolism is still unclear. To compare anti-atherogenic properties between apoA-I and apoA-4, we characterized both proteins in lipid-free and lipidbound state. In lipid-free state, apoA4 showed two distinct bands, around 78 and $67{\AA}$ on native gel electrophoresis, while apoA-I showed scattered band pattern less than $71{\AA}$. In reconstituted HDL (rHDL) state, apoA-4 showed three major bands around $101{\AA}$ and $113{\AA}$, while apoA-I-rHDL showed almost single band around $98{\AA}$ size. Lipid-free apoA-I showed 2.9-fold higher phospholipid binding ability than apoA-4. In lipid-free state, $BS_3$-crosslinking revealed that apoA-4 showed less multimerization tendency upto dimer, while apoA-I showed pentamerization. In rHDL state (95:1), apoA-4 was existed as dimer as like as apoA-I. With higher phospholipid content (255:1), five apoA-I and three apoA-4 were required to the bigger rHDL formation. Regardless of particle size, apoA-I-rHDL showed superior LCAT activation ability than apoA-4-rHDL. Uptake of acetylated LDL was inhibited by apoA-I in both lipid-free and lipid-bound state, while apoA-4 inhibited it only lipid-free state. ApoA-4 showed less anti-atherogenic activity with more sensitivity to glycation. In conclusion, apoA-4 showed inferior physiological functions in lipid-bound state, compared with those of apoA-I, to induce more pro-atherosclerotic properties.

• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.85-91
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• 2016

Exosomes are homogenous vesicles of 40-100 nm diameter produced endogenously. Exosomes are generated by inward budding into multi-vesicular bodies (MVB) and then released to extracellular space. Exosomes contain various nucleic acid and protein cargoes from their cells of origin and this endosomal cellular molecules are used for intracellular communication and for both promotion and suppression of immune responses. Recently, they are also considered as delivery vehicle for therapeutic proteins due to their characteristics of stability in body fluids and ability for target uptake. Also, they show less immune reactivity because the isolated exosome harboring therapeutic proteins can be from the same host. White-spotted flower chafer, Protaetia brevitarsis is one of the major insect commercially reared in Korea. There are bacterial and fungal pathogens causing diseases in the beetle, and these diseases incur economic loss to the larva-rearing farms. Due to their endosomal cargoes, exosomes are good candidates in use of disease diagnosis. In this study, we isolated insect exosome from the hemolymph of P. brevitarsis, and verified it by analysis of the exosome-specific surface proteins and RNA.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2003.10a
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• pp.251-257
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• 2003

Metabolic engineering has become a new paradigm for the more efficient production of desired bioproducts. Metabolic engineering can be defined as directed modification of cellular metabolism and properties through the introduction, deletion, and modification of metabolic pathways by using recombinant DNA and other molecular biological tools. During the last decade, metabolic flux analysis(MFA) has become an essential tool fur metabolic engineering. By MFA, the intracellular metabolic fluxes can be quantified by the measurement of extracellular metabolite concentrations in combination with the stoichiometry of intracellular reactions and mass balances. The usefulness and functionality of MFA are demonstrated by applying to metabolic pathways in E. coli. First, a large-scale in silico E. coli model is constructed, and then the effects of carbon sources on intracellular flux distributions and succinic acid production were investigated on the basis of the uptake and secretion rates of the relevant metabolites. The results indicated that succinic acid yields increased in order of gluconate, glucose and sorbitol. Acetic acid and lactic acid were produced as major products rather than when gluconate and glucose were used carbon sources. The results indicated that among three carbon sources available, the most reduced substrate is sorbitol which yields efficient succinic acid production.

• The Korean Journal of Nuclear Medicine
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• v.22 no.1
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• pp.65-76
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• 1988

High affinity complexes for the tumor were obtained by changing pH and composition in the preparation of $^{99m}Tc-DMSA$. The purpose of this study was to investigate the tumor affinity, and in vitro and in vivo characteristics of these complexes. The results obtained were as follows; 1) Tumor imaging agent was formed successfully at pH $6.0\sim9.0$ and renal imaging agent at pH $2.0\sim5.0$. 2) The serum protein binding of $^{99m}Tc-DMSA$ was $89.1\sim92.8%$ at pH $2.0\sim5.0$ and $11.8\sim30.5%$ at pH $6.0\sim9.0$ respectively, and it was not changed with time. 3) The T 1/2 of tumor affinity complex in blood between 3 and 6 hours after injection was $187{\pm}29$ minutes $(mean{\pm}SD)$. 4) In the blood, the radioactivity was mainly in the plasma, and less than 1% was in the cellular components. 5) In the Walker carcinosarcoma 256 bearing Wistar rats, the radioactivity in the kidney increased, and decreased in the skeleton with time. The radioactivity in the tumor showed the peak in 6 hours after injection and decreased thereafter. 6) In the tumor cell, the radioactivity localized mainly in the cytosol, the soluble fraction of the cytoplasm. This study provides the basic knowledge about tumor affinity and usefulness of $^{99m}Tc-DMSA$ in the diagnosis of malignant disease.

• Biomolecules & Therapeutics
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• v.19 no.3
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• pp.364-370
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• 2011

The purpose of this study was to investigate the effects of curcumin on the pharmacokinetics of loratadine in rats. The effect of curcumin on P-glycoprotein (P-gp) and cytochrome P450 (CYP) 3A4 activity was evaluated. Pharmacokinetic parameters of loratadine were also determined after oral and intravenous administration in the presence or absence of curcumin. Curcumin inhibited CYP3A4 activity with an IC50 value of 2.71 ${\mu}M$ and the relative cellular uptake of rhodamine-123 was comparable. Compared to the oral control group, curcumin significantly increased the area under the plasma concentration-time curve and the peak plasma concentration by 39.4-66.7% and 34.2-61.5%. Curcumin also significantly increased the absolute bioavailability of loratadine by 40.0-66.1% compared to the oral control group. Consequently, the relative bioavailability of loratadine was increased by 1.39- to 1.67-fold. In contrast, curcumin had no effect on any pharmacokinetic parameters of loratadine given intravenously, implying that the enhanced oral bioavailability may be mainly due to increased intestinal absorption caused via P-gp and CYP3A4 inhibition by curcumin rather than to reduced renal and hepatic elimination of loratadine. Curcumin enhanced the oral bioavailability of loratadine in this study. The enhanced bioavailability of loratadine might be mainly attributed to enhanced absorption in the gastrointestinal tract via the inhibition of P-gp and reduced fi rst-pass metabolism of loratadine via the inhibition of the CYP3A subfamily in the small intestine and/or in the liver by curcumin.