• Korean Journal of Korean Medical Institute of Dermatology and Aesthetics
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• v.1 no.1
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• pp.53-90
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• 2005

Purpose: Contents of astragaloside I, II and IV, cytotoxicity, anticancer activity, immunomodulatory activity and antioxidant capacity were to be compared as a function of the cultivated years as one, three, five and seven years. Method: Major components of Astragali membranacei Radix were separated as astragaloside I, astragaloside II, astragaloside IV by HPLC analysis. Cytotoxicity and anticancer activities were measured by MTT and SRB assay. For immunomodulatory activity, the secretion of IL -6 and $TNF-{\alpha}$, NK cell activation and macrophage activation were observed as well as kinetics of responding to human T cells by a microphysiometer. In vitro antioxidant activities were measured by several radical scavenging activities of superoxide anion radican, DPPH, LDL and linoleic acid. For in vivo activity, the activation of SOD, GSH-px, catalase, ALDH and ADH was measured as well the relative weight of liver. Result : 1. For HPLC analysis, the contents of all of astragaloside I, astragaloside II, astragaloside IV were in order of three, five, one and seven years. 2. The cytotoxicity of normal human lung cell line, HEL299 showed lower than 18% in adding 0.25 mg/ml, and 28.9% in adding 1.0 mg/ml of water extract of seven year root. For methanol extracts, three year root showed highest cytotoxicity as 35.2 % and there was no difference between the cultivated years. 3. For anticancer activities, methanol extracts of one and three year roots showed relatively high inhibition of human stomach cancer cells, AGS, breast cancer cells, MCF-7, lung cancer cells, A549 and liver cancer cell, Hep3B as well as high selectivities. 4. The water extract of seven year root could yield high secretion of IL-6 from both human Band T cells while the methanol extracts of three and five year roots secreted high amounts of IL-6 and $TNF-{\alpha}$ from both Band T cells. 5. As a result of in vitro antioxidant activities, both water and methanol extracts from five and seven year roots showed high activities for superoxide anion radical scavenging activity, inhibiting linoleic acid peroxide and contents of total phenols. 6. For in vivo tests, Mn-SOD and GSH-px activities and weight of liver were better in adding seven year root. For ALDH activity one year root was better and for ADH activity five year root. Overall speaking, seven year root showed relatively better antioxidant activities. Conclusion:There was difference of the contents of astragaloside I, astragaloside II, astragaloside IV according to cultivation year. Methanol extract showed better activities of anticancer and immune activation rather than water extract Interestingly enough, for methanol extracts, overall activities were improved as the cultivation year increased. There might be further investigation required for the clinical uses of the results as several biological activities varied according to the cultivated year of Astragali membranacei Radix.

• Natural Product Sciences
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• v.14 no.1
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• pp.47-50
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• 2008

To evaluate the antiallergic effect of the dried root of Astragalus membranaceus Bunge (AM) (Leguminosae), which inhibited the mouse passive cutaneous anaphylaxis (PCA) reaction in a preliminary experiment, its main constituents, astragalosides I and IV, were isolated and their antiallergic effects were investigated. Astragalosides I and IV inhibited the PCA reaction induced by the IgE-antigen complex, and the scratching behaviors induced by compound 48/80. These constituents reduced the protein expressions of $TNF-{\alpha}$ and IL-4 in IgE-induced RBL-2H3 cells. These findings suggest that astragalosides I and IV as well as AM can improve IgE-induced anaphylaxis and scratching behaviors.

• Molecules and Cells
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• v.41 no.3
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• pp.244-255
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• 2018

Low-grade pro-inflammatory state and leptin resistance are important underlying mechanisms that contribute to obesity-associated hypertension. We tested the hypothesis that Astragaloside IV (As IV), known to counteract obesity and hypertension, could prevent obesity-associated hypertension by inhibiting pro-inflammatory reaction and leptin resistance. High-fat diet (HFD) induced obese rats were randomly assigned to three groups: the HFD control group (HF con group), As IV group, and the As IV + ${\alpha}$-bungaratoxin (${\alpha}-BGT$) group (As IV+${\alpha}-BGT$ group). As IV ($20mg{\cdot}Kg^{-1}{\cdot}d^{-1}$) was administrated to rats for 6 weeks via daily oral gavage. Body weight and blood pressure were continuously measured, and NE levels in the plasma and renal cortex was evaluated to reflect the sympathetic activity. The expressions of leptin receptor (LepRb) mRNA, phosphorylated signal transducer and activator of transcription-3 (p-STAT3), phosphorylated phosphatidylinositol 3-kinase (p-PI3K), suppressor of cytokine signaling 3 (SOCS3) mRNA, and protein-tyrosine phosphatase 1B (PTP1B) mRNA, pro-opiomelanocortin (POMC) mRNA and neuropeptide Y (NPY) mRNA were measured by Western blot or qRT-PCR to evaluate the hypothalamic leptin sensitivity. Additionally, we measured the protein or mRNA levels of ${\alpha}7nAChR$, inhibitor of nuclear factor ${\kappa}B$ kinase subunit ${\beta}/nuclear$ factor ${\kappa}B$ ($IKK{\beta}/NF-KB$) and pro-inflammatory cytokines ($IL-1{\beta}$ and $TNF-{\alpha}$) in hypothalamus and adipose tissue to reflect the anti-inflammatory effects of As IV through upregulating expression of ${\alpha}7nAChR$. We found that As IV prevented body weight gain and adipose accumulation, and also improved metabolic disorders in HFD rats. Furthermore, As IV decreased BP and HR, as well as NE levels in blood and renal tissue. In the hypothalamus, As IV alleviated leptin resistance as evidenced by the increased p-STAT3, LepRb mRNA and POMC mRNA, and decreased p-PI3K, SOCS3 mRNA, and PTP1B mRNA. The effects of As IV on leptin sensitivity were related in part to the up-regulated ${\alpha}7nAchR$ and suppressed $IKK{\beta}/NF-KB$ signaling and pro-inflammatory cytokines in the hypothalamus and adipose tissue, since co-administration of ${\alpha}7nAChR$ selective antagonist ${\alpha}-BGT$ could weaken the improved effect of As IV on central leptin resistance. Our study suggested that As IV could efficiently prevent obesityassociated hypertension through inhibiting inflammatory reaction and improving leptin resistance; furthermore, these effects of As IV was partly related to the increased ${\alpha}7nAchR$ expression.

• Natural Product Sciences
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• v.14 no.1
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• pp.37-46
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• 2008

From the 70% EtOH extract of the roots of Astragalus membranaceus (Leguminosae), fifteen saponins were isolated and identified as astragaloside I (1), isoastragaloside II (2), astragaloside II (3), agroastragaloside I (4), cyclogaleginoside B (5), cycloaraloside A (6), brachyoside B (7), agroastragaloside II (8), astragaloside III (9), astragaloside IV (10), astramembranoside A (11), astramembranoside B (12), cylocanthoside E (13), cyclounifolioside B (14) and azukisaponin V methyl ester (15) by spectroscopic methods. Ten compounds 1 - 3, 5 - 7, 9 - 11 and 14 have cycloastragenol as an aglycon, and four compounds 4, 8 , 12, and 13 have cyclocanthogenin as an aglycon. The hairy roots of A. membranaceus were shown to produce previously unreported cycloartane-type saponins such as agroastragalosides I (4) and II (8) and cycloastragenol $3-O-{\beta}-D-xyloside$ (5), together with the known saponins. This is the first report of these saponins (4, 5, and 8) from the intact plant. Although the occurrence of the oleanane-type triterpene saponin, azukisaponin V methyl ester (15), in Astragalus plants has been demonstrated by others, this is the first report of the azukisaponin V methyl ester (15) from the Astragalus plants.

• Journal of Microbiology and Biotechnology
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• v.29 no.12
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• pp.1882-1893
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• 2019

β-Glucosidases and β-xylosidases are two categories of enzymes that could cleave out non-reducing, terminal β-D-glucosyl and β-D-xylosyl residues with release of D-glucose and D-xylose, respectively. In this paper, two functional β-glucosidase Dth3 and β-xylosidase Xln-DT from Dictyoglomus thermophilum were heterologously expressed in E.coli BL21 (DE3). Dth3 and Xln-DT were relatively stable at 75℃ and were tolerant or even stimulated by glucose and xylose. Dth3 was highly tolerant to glucose with a K_i value of approximately 3 M. Meanwhile, it was not affected by xylose in high concentration. The activity of Xln-DT was stimulated 2.13-fold by 1 M glucose and 1.29-fold by 0.3 M xylose, respectively. Furthermore, the βglucosidase Dth3 and β-xylosidase Xln-DT showed excellent selectivity to cleave the outer C-6 and C-3 sugar moieties of ASI, which established an effective and green method to produce the more pharmacologically active CAG, an exclusive telomerase activator. We measured temperature, pH and dosage of enzyme using a single-factor experiment in ASI biotransformation. After optimization, the optimal reaction conditions were as follows: 75℃, pH 5.5, 1 U of Dth3 and 0.2 U of Xln-DT, respectively. Under the optimized conditions, 1 g/l ASI was transformed into 0.63 g/l CAG with a corresponding molar conversion of 94.5% within 3 h. This is the first report to use the purified thermostable and sugar-tolerant enzymes from Dictyoglomus thermophilum to hydrolyze ASI synergistically, which provides a specific, environment-friendly and cost-effective way to produce CAG.

• Bulletin of the Korean Chemical Society
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• v.28 no.7
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• pp.1187-1194
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• 2007

The three major active isoflavonoids (calycosin-7-O-β -glucoside, isomucronulatol 7-O-β-glucoside, formononetin) and two main saponins (astragaloside I, astragaloside IV) in an extract of Radix Astragali were determined using rapid, sensitive, reliable HPLC/UV and LC-ESI-MS/MS methods. The separation conditions employed for HPLC/UV were optimized using a phenyl-hexyl column (4.6 × 150 mm, 5 μm) with the gradient elution of acetonitrile and water as the mobile phase at a flow rate of 1.0 mL/min and a detection wavelength of 230 nm. The specificity of the peaks was determined using a triple quadrupole tandem mass spectrometer equipped with an electrospray ionization (ESI) source that was operated in multiple reaction monitoring (MRM) in the positive mode. These methods were fully validated with respect to the linearity, accuracy, precision, recovery and robustness. The HPLC/UV method was applied successfully to the quantification of three major isoflavonoids in the extract of Radix Astragali. The results indicate that the established HPLC/UV and LC-ESI-MS/MS methods are suitable for the quantitative analysis and quality control of multi-components in Radix Astragali.