• Proceedings of the PSK Conference
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• 2003.04a
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• pp.276.1-276.1
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• 2003

This study describes a simple and sensitive semi-micro HPLC method with UV detection and direct deproteinization. The plasma protein was precipitated using perchloric acid (60％) and the supernatant was directly injected onto the semi-micro HPLC system. The separation was achieved on a C18 (25 mm ${\times}$ 2.0 mm I.D) analytical column with a mobile phase of sodium acetate buffer (pH 3.5, 50 mmol) - acetonitrile (60:40, V/V). (omitted)

• Natural Product Sciences
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• v.29 no.2
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• pp.74-82
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• 2023

Nepeta sibirica L. or Siberian catmint is a medicinal plant species used in Mongolian traditional medicine for curing human different disorders and veterinary practices. The previous study of the whole plant concentrated on the determination of its essential oil composition and reported that the major ones are sesquiterpenes, including nepetalactone. The aim of this study was to reveal a new biological activity of the above-ground parts of N. sibirica L. and compare the activity of different extracts correlating with the content of biologically active compounds and evaluate their toxicity. For this purpose, anti-oxidative and acetylcholinesterase inhibitory activities of the above-ground parts of N. sibirica L. aqueous and ethanol (EtOH) (40%, 70%) extracts were assayed spectrophotometrically. The aqueous extract showed positive anti-oxidative activity by both tested DPPH and FRAP assays with IC₅₀ 134.24 ± 1.42 mg/mL and FRAP value 1385.15 ± 8.12 µmol/L at 200 ㎍/mL, in contrast to 40% and 70% EtOH extracts. The 70% EtOH extract presented the highest acetylcholinesterase inhibitory activity (IC₅₀ 77.29 ± 0.38 mg/mL) followed by 40% EtOH extract (176.72 ± 0.35 mg/mL) and aqueous extract (275.41 ± 0.23 mg/mL). Total phenolics were found to be gallic acid equivalent, % 3.74 ± 0.05 (70% EtOH), 3.94 ± 0.04 (40% EtOH), and 3.79 ± 0.16 (aqueous), whereas the total flavonoids as a rutin equivalent, % as 2.01 ± 0.12, 1.44 ± 0.17 and 1.99 ± 0.02, each. The aqueous extract showed the best anti-oxidative and lowest activity against the acetylcholinesterase; however, the 70% EtOH extract showed the opposite effects than that of the aqueous. No mortality incidence was visible at various doses, indicating that the oral median lethal dose of aqueous and 70% EtOH extracts were considered greater than 5000 mg/kg. N. sibirica L. belongs to the non-toxic category of the OECD 423 classification.

• Journal of Pharmaceutical Investigation
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• v.39 no.1
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• pp.29-36
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• 2009

Since the quality of final products is significantly affected by the homogeneity of powder mixture, the powder blending process has been regarded as one of the critical pharmaceutical unit processes, especially for solid dosage forms. Accordingly, the monitoring to determine a blending process' end-point based on a faster and more accurate in-line/on-line analysis has attracted enormous attentions recently. Among various analytical tools, NIR (near-infrared) spectroscopy has been extensively studied for PAT (process analytical technology) system due to its many advantages. In this study, NIR spectroscopy was employed with an optical fiber probe for the in-line monitoring of fluid-bed blending process. The position of the probe, the ratio of binary powder mixture, the powder size differential and the back-flush period of the shaking bag were examined as principal process parameters. During the blending process of lactose and mannitol powders, NIR spectra were collected, corrected, calibrated and analyzed using MSC and PLS method, respectively. The probe position was optimized. A reasonable end-point was predicted as 1,500 seconds based on 5% RSD value. As a consequence, it was demonstrated that the blending process using a fluid-bed processor has several advantages over other methods, and the application of NIRS with an optical fiber probe as PAT system for a fluid-bed blending process could be high feasible.

• KSBB Journal
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• v.25 no.1
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• pp.11-17
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• 2010

Here, we evaluated the effect of thrombin on the interleukin-6 production induced by tumor-necrosis-factor-$\alpha$ in endothelial cells. It is well known that tumor-necrosis-factor-$\alpha$ mediates inflammatory responses by activation of nuclear factor-kappa-B in endothelial cells. Here, we showed that lower concentration of thrombin decreased the production of interleukin-6 induced by tumor-necrosis-factor-$\alpha$ and this inhibitory effect of thrombin on interleukin-6 production was mediated by interacting with protease-activated-receptor-1. In addition, phosphoinositide-3-kinase was also involved the anti-inflammatory responses by lower concentration of thrombin in endothelial cells. These results suggested that lower concentration of thrombin mediated anti-inflammatory responses by interacting with protease-activated-receptor-1 on the cell membrane and phosphoinositide-3-kinase in the cell. These findings will provide the important evidence in the development of new medicine for the treatment of severe sepsis and inflammatory diseases and good clue for understanding unknown mechanisms by which thrombin showed the pro-inflammatory or anti-inflammatory activities in endothelial cells.

• Journal of Pharmaceutical Investigation
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• v.41 no.3
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• pp.153-159
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• 2011

This study was designed to investigate the effects of silibinin on the pharmacokinetics of carvedilol after oral administration of carvedilol in rats. Carvedilol was administered orally (3 mg/kg) with oral silibinin (0.3, 1.5 or 6 mg/kg) and intravenously (1 mg/kg) to rats. The effects of silibinin on P-glycoprotein (P-gp) and cytochrome P450 (CYP) 2C9 and CYP2D6 activity were also evaluated. Silibinin inhibited CYP2C9 and CYP2D6 enzyme activity with 50% inhibition concentration ($IC_{50}$) of 5.2 ${\mu}M$ and 85.4 ${\mu}M$, respectively. In addition, silibinin significantly enhanced the cellular accumulation of rhodamine-123 in MCF-7/ADR cells overexpressing P-gp. Compared with the control group, the area under the plasma concentration-time curve was significantly increased by 36.3-57.1%, and the peak concentration was significantly increased by 51.1-88.5% in the presence of silibinin after oral administration of carvedilol. Consequently, the relative bio-availability of carvedilol was increased by 1.13- to 1.57-fold and the absolute bioavailability was significantly increased by 38.6-59.7%. The time to reach peak concentration and the terminal half-life were not significant. The enhanced oral bio-availability of carvedilol may result from inhibition of CYP2C9-mediated metabolism and P-gp-mediated efflux of carvedilol rather than inhibition of CYP2D6-mediated metabolism in the intestine and/or in the liver by silibinin.

• Journal of the Korean Society of Food Culture
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• v.34 no.5
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• pp.645-650
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• 2019

Skin plays important roles in protecting the internal organs from the chemical-biological risk factors and ultraviolet light. Exposure to the chemical and biological stimuli has a detrimental effect on skin's structure and physiological regulation. Therefore, much attention has been paid to natural products that show biological activities such as anti-oxidation, anti-aging and anti-bacterial activities. In this study, we investigated the skin-related biological activities of Oenothera lamarckiana aerial part extract. The extract contained 229.35 mg TAE (tannic acid equivalents)/g total polyphenolic compounds and the extract showed relative high antioxidant activity ($SC_{50}$ value: $8.52{\mu}g/mL$). The $IC_{50}$ value against tyrosinase and elastase were 307.94 and $181.51{\mu}g/mL$, respectively. This suggested that O. lamarckiana can be applied to whiten skin and slow the aging of skin. O. lamarckiana extract showed a growth inhibitory effect on Staphylococcu epidermidis (minimum inhibitory concentration: $250{\mu}g/mL$). Interestingly, O. lamarckiana extract showed no inhibitory effect on Pseudomonas aeruginosa on the paper disc assay. Yet the extract inhibited the growth of Pseudomonas aeruginosa on the broth dilution assay in a dose-dependent manners. Taken together, O. lamarckiana could have good potential for development as an additive in the cosmetic industry.

• Journal of Biomedical and Translational Research
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• v.19 no.4
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• pp.130-139
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• 2018

This study aimed to analyze a high-performance liquid chromatography (HPLC) separation using a pentafluorophenyl column of parent drug hydroxychloroquine (HCQ) and its active metabolite, desethylhydroxchloroquine (DHCQ) applying to determine bioequivalence of two different formulations administered to patients. A rapid, simple, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for bioanalysis of HCQ and its metabolite DHCQ in human whole blood using deuterium derivative $hydroxychloroquine-D_4$ as an internal standard (IS). A triple-quadrupole mass spectrometer was operated using electrospray ionization in multiple reaction monitoring (MRM) mode. Sample preparation involves a two-step precipitation of protein techniques. The removed protein blood samples were chromatographed on a pentafluorophenyl (PFP) column ($50mm{\times}4.6mm$, $2.6{\mu}m$) with a mobile phase (ammonium formate solution containing dilute formic acid) in an isocratic mode at a flow rate of 0.45 mL/min. The standard curves were found to be linear in the range of 2 - 500 ng/mL for HCQ; 2 - 2,000 ng/mL for DHCQ in spite of lacking a highly sensitive MS spectrometry system. Results of intra- and inter-day precision and accuracy were within acceptable limits. A run time of 2.2 min for HCQ and 2.03 min for DHCQ in blood sample facilitated the analysis of more than 300 human whole blood samples per day. Taken together, we concluded that the assay developed herein represents a highly qualified technology for the quantification of HCQ in human whole blood for a parallel design bioequivalence study in a healthy male.

• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.131-137
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• 2021

This study aimed at isolating lactic acid bacteria with anti-MRSA (methicillin-resistant Staphylococcus aureus) bacteriocin activity from fermented shrimp. We selected three strains, named Weissella sp. S1, S2, and S3, using analysis based on 16S rRNA gene sequences. All strains showed appropriate growth in an MRS medium containing 5% (w/v) NaCl and showed antibacterial activities against Bacillus cereus, Escherichia coli, Staphylococcus aureus, and MRSA. The strains exhibited similar growth rates at 0-5% NaCl, with approximate reduction in growth rate observed at 9% NaCl. Weissella sp. S1, S2, and S3 exhibited maximum growth rates at pH 7, 9, and 8, respectively. The crude bacteriocin was prepared from Weissella sp. S3 and subjected to characterization. The remaining activities after 30 min of exposure at each temperature were 100%, beyond 75%, and 49% at 4℃ and 37℃, 50℃ and 70℃, and 100℃, respectively. The remaining activities after 24 h of exposure at each pH were 100%, 75%, and 49% at pH 3 and 5, 7 and 9, and 10, respectively. Use of 50% (v/v) ethanol or isopropanol treatment did not diminish the antibacterial activity of the bacteriocin, while the 50% (v/v) hexane treatment reduced the activity by 51%. The molecular weight of the bacteriocin was nearly 6 kDa that was quantified using tricine-SDS-PAGE. Our findings suggest that Weissella sp. S3 may be considered a probiotic and useful source of antimicrobial substances in the development of bio-preservatives for food or in MRSA treatment.

• BMB Reports
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• v.53 no.5
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• pp.272-277
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• 2020

Protein kinase CK2 downregulation induces premature senescence in various human cell types via activation of the reactive oxygen species (ROS)-p53-p21^Cip1/WAF1 pathway. The transcription factor "nuclear factor erythroid 2-related factor 2" (Nrf2) plays an important role in maintaining intracellular redox homeostasis. In this study, Nrf2 overexpression attenuated CK2 downregulation-induced ROS production and senescence markers including SA-β-gal staining and activation of p53-p21^Cip1/WAF1 in human breast (MCF-7) and colon (HCT116) cancer cells. CK2 downregulation reduced the transcription of Nrf2 target genes, such as glutathione S-transferase, glutathione peroxidase 2, and glutathione reductase 1. Furthermore, CK2 downregulation destabilized Nrf2 protein via inhibiting autophagic degradation of Kelch-like ECH-associated protein 1 (Keap1). Finally, CK2 downregulation decreased the nuclear import of Nrf2 by deactivating AMP-activated protein kinase (AMPK). Collectively, our data suggest that both Keap1 stabilization and AMPK inactivation are associated with decreased activity of Nrf2 in CK2 downregulation-induced cellular senescence.

• CELLMED
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• v.1 no.1
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• pp.7.1-7.9
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• 2011

Bioelectric impedance measurements have been reported to show significant variation between individuals. Different physiological conditions like thickened skin, obesity, and fluid retention can affect the impedance measurement. Therefore, it is important to learn what other factors can affect the measurements of impedance even in healthy individuals. Such information is a prerequisite for understanding the changes in impedance associated with acupuncture treatment. This study investigated the bio-impedance properties of tissue segments in the arms of a number of healthy subjects, so as to define the factors that might influence the variation of the bio-impedance data in acupuncture meridians studies. 51 healthy subjects were recruited through Liverpool Hospital, Sydney. Demographic data was collected from each subject including the age, sex, BMI, and time since most recent meal. Electrodes were applied to the forearms of each test subject. Measurements were done by a purpose-built Bio-Impedance Research Device (BIRD-I) which allowed the determination of core resistance (Rc) and core reactance (Xc) of each of the three meridian tissue segments on the anterior surface of the forearm. No significant difference was found in the core resistance attributable to age group, gender, BMI or meal intake. However, a statistically significant trend in increasing resistance from the radial to ulnar aspect of the forearm (p < 0.001) was found. No significant difference was found in the core resistance of test tissue segments among the 51 healthy subjects measured in this study. However, the trend of increasing core resistance from the radial to ulnar aspects of the arm deserves further investigation.