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Hung T.M.,Catholic University of Daegu | Van Thu C.,Hanoi University of Pharmacy | Cuong T.D.,Catholic University of Daegu | Hung N.P.,Chosun University | And 6 more authors.
Journal of Natural Products | Year: 2010

Two new dammarane-type glycosides, 2α,3β,12β,20S- tetrahydroxydammar-24-ene-3-O-[β-D-glucopyranosyl(1→'4) -sβ-D-glucopyranosyl]-20-O-[β-D-xylopyranosyl-(1→6) -β-D-glucopyranoside] (1) and 2α,3β,12β,20S- tetrahydroxydammar24-ene-3-O-β-D-glucopyranosyl-20-O-[β-D-6-O- acetylglucopyranosyl-(l-→2)-β-D-glucopyranoside] (2), were isolated from a MeOH extract of the leaves of Gynostemma pentaphyllum. Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The isolated compounds showed potential inhibitory effects on eotaxin expression in BEAS-2B bronchial epithelial cells. © 2010 American Chemical Society and American Society of Pharmacognosy.

Kim J.S.,Seoul National University | Kim J.-M.,Seoul National University | O J.-J.,National Institute of Toxicological Research | Jeon B.S.,Seoul National University
Journal of Clinical Neuroscience | Year: 2010

The aim of this study was to investigate the involvement of inducible nitric oxide synthase (iNOS) in the action of (-)-epigallocatechin-3-gallate (EGCG), a potential neuroprotective agent against Parkinson's disease (PD), and to test for toxicity resulting from high doses of EGCG. EGCG was administered to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mice at two different doses (10 mg/kg and 50 mg/kg). EGCG treatment reduced the neuronal death rate to less than 50%. The level of iNOS expression in the MPTP group was 20% higher than that seen in the control group, but in the EGCG groups, iNOS expression was reduced to the level observed in the negative control group. The two doses of EGCG were equally beneficial for cell rescue, and no toxicity was observed with the higher dose. Inhibition of iNOS may be an important mechanism underlying the prevention of MPTP toxicity, and EGCG may potentially be a neuroprotective agent against PD. © 2010 Elsevier Ltd. All rights reserved.

Choi B.-S.,Chung - Ang University | Choi S.-J.,Chung - Ang University | Kim D.-W.,Chung - Ang University | Huang M.,Chung - Ang University | And 9 more authors.
Archives of Environmental Contamination and Toxicology | Year: 2010

Arsenic (As) is a known human carcinogen and widely distributed in the environment. The main route of As exposure in the general population is through food and drinking water. Seafood harvested in Korea contains high-level organoarsenics such as arsenobetaine, arsenocholine, and arsenosugars, which are much less harmful than inorganic arsenics. However, for those who eat large amounts of seafood it is important to understand whether seafood consumption affects urinary levels of inorganic As metabolites such as arsenite, arsenate, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). In this study we investigated urinary As metabolites (inorganic As, MMA[V], DMA[V]) and some biological indexes such as AST, GSH, GPX, lipid peroxidation, and uric acid in volunteer study subjects (seven males and nine females). Total urinary As metabolites were analyzed by the hydride generation method, followed by arsenic speciation using HPLC with ICP-mass spectrometry. Study subjects refrained from eating seafood for 3 days prior to the first urine collection and then ingested seafood daily for 6 consecutive days. The first voided urine of the morning was collected from each subject the first day of the consecutive 6 days of seafood ingestion but prior to the first seafood meal. The first voided urine of the morning was also collected on days 1, 2, 3, 4, 5, 6, 7, 10, and 14 after seafood ingestion. The daily mean intake of total As was 6.98 mg, comprised of 4.71 mg of seaweed (67%), 1.74 mg of flat fish (25%), and 0.53 mg of conch (8%). We observed a substantial increase in total urinary As metabolites for subjects consuming seafood from day 1, which recovered to control level at day 10. The increase in total urinary As metabolites was attributed to the increase in DMA, which is a more harmful metabolite than organoarsenics. However, no significant changes in response biological indexes were observed. These results suggest that it is necessary to evaluate As metabolism when assessing the exposure to inorganic As and potential chronic health effects of seafood consumption in Korea. © 2009 Springer Science+Business Media, LLC.

Van L.T.K.,Catholic University of Daegu | Hung T.M.,Catholic University of Daegu | Kim S.H.,Korea Research Institute of Bioscience and Biotechnology | Kim J.C.,Korea Research Institute of Chemical Technology | And 8 more authors.
Helvetica Chimica Acta | Year: 2010

A new stereoisomer of a tetrahydrofuranoid lignan, acerifuranoidA (1), and two new oleanane-type triterpenoids, aceriphyllic acids J and K (2 and 3), were isolated from the roots of Aceriphyllum rossii. Their structures were elucidated on the basis of spectroscopic analyses and chemical evidence. These isolated compounds exhibited weak cytotoxic activity against various cancer cell lines with IC50>150 μm. © 2010 Verlag Helvetica Chimica Acta AG.

Jeong S.H.,Laboratory of Cell Signaling and Nanomedicine | Kim J.H.,Laboratory of Cell Signaling and Nanomedicine | Yi S.M.,Laboratory of Cell Signaling and Nanomedicine | Lee J.P.,National Institute of Toxicological Research | And 5 more authors.
Biochemical and Biophysical Research Communications | Year: 2010

Quantum dots (QDs) are rapidly emerging as an important class of nanoparticles (NPs) with potential applications in medicine. However, little is known about penetration of QDs through human skin. This study investigated skin penetration of QDs in both in vivo and in vitro human skin. Using the tape stripping method, this study demonstrates for the first time that QDs can actually penetrate through the stratum corneum (SC) of human skin. Transmission electron microscope (TEM) and energy diverse X-ray (EDX) analysis showed accumulation of QDs in the SC of a human skin equivalent model (HSEM) after dermal exposure to QDs. These findings suggest possible transdermal absorption of QDs after dermal exposure over a relatively long period of time. © 2010 Elsevier Inc. All rights reserved.

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