• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.4
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• pp.955-959
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• 2005

We previously demonstrated that the methylene chloride fraction of Scutellaria barbata suppessed human leukemic U937 cell proliferation by inducing apoptosis. In the present study, we have isolated luteolin from Scutellaria barbata and evaluated its apoptotic mechanism in Lewis lung carcinoma cells. Luteolin inhibited the proliferation of Lewis lung carcinoma cells in a concentration-dependent manner. Luteolin effectively increased the portion of $sub-G_1$ DNA content (apoptotic portion) and apoptotic Annexin-V positive cells in a concentration-dependent manner by FACS analysis. Caspase 9 and caspase 3 were activated and PARP was effectively cleaved by luteolin. It also increased the ratio of Bax to Bcl-2 through the decrease of Bcl-2 expression by Western blotting and reduced mitochondrial membrane potential following TMRE staining. These results suggest that luteolin can induce apoptosis through the mitochondrial mediated pathway.

• YAKHAK HOEJI
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• v.40 no.1
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• pp.10-18
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• 1996

Daunirubicin and doxorubicin analogues (5,7,8,9,) in which the natural amino sugar, daunosamine, is replaced by rhamnopyranosyl or 4'-amino rhamnopyranosyl residues have been p repared. The in vitro cytotoxicity of compound 5 or 7 was similar to that of doxorubicin for P388 murine leukemic cell line. But compound 8 or 9 was less cytotoxic than doxorubicin. When administered intravenously on day 1, compound 9 showed antitumor activity comparable to that of doxorubicin against ip-inoculated L1210 murine leukemia and found to be less toxic than doxorubicin. But the in vivo antitumor activity of compound 7 or 8 was inferior to that of doxorubicin.

• Archives of Pharmacal Research
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• v.26 no.5
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• pp.405-410
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• 2003

Vitamin K-related analogs induce growth inhibition in various cancer cell lines. A naphthoquinone analog, termed 2,3-dichloro-5, 8-dihydroxy-1,4-naphthoquinone (DDN), induces apoptosis in human promyeloid leukemic HL-60 cells, and shows antitumor activity in vivo. Following treatment with DDN, evidence of apoptosis, including DNA fragmentation and cleavage of poly ADP ribose polymerase (PARP), was observed. DDN induced an upregulation of proapoptotic Bax protein, and Bid cleavage. Antiapoptotic Bcl-2 protein levels were not changed by DDN, but the expression of Bcl-xL was decreased. In addition, DDN reduced the mass of solid tumor in the Sarcoma 180 tumor-bearing mouse model. These results indicate that DDN exerts antitumor activity, which appears to be related to the induction of apoptosis by regulating Bcl-2 family proteins.

• Archives of Pharmacal Research
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• v.26 no.9
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• pp.731-734
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• 2003

Five known kaurane type diterpenoids, 16$\alpha$H, 17-isovaleryloxy-ent-kauran-19-oic acid (1), 16$\alpha$-hydroxy-17-isovaleryloxy-ent-kauran-19-oic acid (2), paniculoside-IV (3), 16$\alpha$-hydroxy-ent-kauran-19-oic acid (4), and ent-kaur-16-en-19-oic acid (5) were isolated from the root of Acanthopanax koreanum by repeated column chromatography and reversed phase preparative HPLC. The structures of these compounds were established from physicochemical and spectral data. Among the isolated compounds 16$\alpha$H, 17-isovaleryloxy-ent-kauran-19-oic acid (1) showed potent inhibitory activity ($IC_50$ value, 16.2 $\mu$ M) on TNF-$\alpha$ secretion from HMC-1, a trypsin-stimulated human leukemic mast cell line.

• YAKHAK HOEJI
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• v.47 no.1
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• pp.37-45
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• 2003

The present study was undertaken to investigate the anticancer activity of monoterepenes in the animal and the cancer cell line tests. Both of the noncyclic and cyclic monoterpenes showed significant life prolonging effects on ICR mouse with abdominal cancer induced by Sarcoma 180 cells up to 67.4％ and 63.5％ in case of linalool and geraniol, respectively. Linalool and geraniol also exhibited very excellent cytotoxicity against L1210 leukemic cells with $IC_{50}$/ value of 0.32 $\mu\textrm{g}$/mι in 5 days culture condition. In the presence of linalool and geraniol, the generation of $O_2$$^{[-10]}$ ion were found to be increased proportionally to the cytotoxicity arisen from these monoterpenes. Furthermore, the antioxidant enzymes activities such as superoxide dismutase (SOD) and glutathione peroxidase (GPx) responsible for the conversion of $O_2$$^{[-10]}$ ion to $H_2O$$_2$ and then to $H_2O$ augmented remarkably by linalool and geraniol. All data put together it can be postulated that monoterpenes may kill abdominal cancer cells of ICR mouse probably by activating anticancer system of the body, whereas the death of L1210 cells may be due to the detrimental attacks of reactive oxygen species (ROS) including $O_2$$^{[-10]}$ in spite of antioxidant enzymes activities to overcome the ROS attacks.

• Korean Journal of Radiology
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• v.2 no.4
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• pp.222-230
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• 2001

Central diabetes insipidus (DI) can be the outcome of a number of diseases that affect the hypothalamic-neurohypophyseal axis. The causes of the condition can be classified as traumatic, inflammatory, or neoplastic. Traumatic causes include postoperative sella or transection of the pituitary stalk, while infectious or inflammatory causes include meningitis, lymphocytic hypophysitis, and granulomatous inflammations such as sarcoidosis and Wegener's granulomatosis. Various neoplastic conditions such as germinoma, Langerhans cell histiocytosis, metastasis, leukemic infiltration, lymphoma, teratoma, pituitary adenoma, craniopharyngioma, Rathke cleft cyst, hypothalamic glioma, and meningioma are also causes of central DI. In affected patients, careful analysis of these MR imaging features and correlation with the clinical manifestations can allow a more specific diagnosis, which is essential for treatment.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.5
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• pp.1226-1232
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• 2007

Phellinus linteus is a well-known Oriental medicinal fungus that has various biological activities, including immunomodulatory and anti-tumor activities, the mechanisms of which are poorly understood. In the present study, we investigated the anti-proliferative activity of the methanol extract of P. linteus-Barley corn (MEPLB) in human lekemic U937 cells. It was found that exposure of U937 cells to MEPLB resulted morphological change and growth inhibition in a dose-dependent manner as measured by trypan blue count and MTT assay. Upon treatment with MEPLB, U937 cells developed many of the hallmark features of apoptosis, including condensation of chromatin and an increase in the sub-G1 population suggesting that the anti-proliferative effect of MEPLB is associated with the induction of apoptosis. The anti-proliferative and apoptotic effects of MEPLB were connected with a marked induction of the pro-apoptotic Bax and cyclin-dependent kinase (Cdk) inhibitor p21 in a p53-independent manner. Additionally, MEPLB treatment significantly induced the caspase-3 activity in U937 cells. Taken together, the present results suggest that apoptotic signals evoked by MEPLB in human leukemic U937 cells may converge caspase-3 activation through an up-regulation of Bax rather than a down-regulation of Bcl-2 or Bel-xL.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.2
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• pp.63-70
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• 2006

Natural product compounds are the source of numerous therapeutic agents. The marine environment produces natural products from a variety of structural classes exhibiting activity against numerous disease targets including anticancer agents. Among these, pectenotoxin-2 (PTX-2), which was first identified as a cytotoxic entity in marine sponges, which depolymerizes actin filaments, was found to be highly effective and more potent to activate an intrinsic pathway of apoptosis in p53-deficient tumor cells compared to those with functional p53 both in vitro and in vivo. However, the anti-proliferative mechanism of the compound at non-cytotoxic concentrations has not yet been explored. In the current study, we sought to investigate anti-proliferation and apoptosis of PTX-2 against U937 human leukemic cells and its underlying molecular mechanism. Exposure of U937 cells to PTX-2 resulted in growth inhibition and induction of apoptosis in dose- and time-dependent manner as measured by MTT assay, fluorescent microscopy and flow cytometric analysis. The anti-proliferative effect of PTX-2 was associated with a marked increase in the expression of cyclin-dependent kinase p21 (WAF1/CIP1) mRNA which was tumor suppressor p53-independent. The increase in apoptosis was connected with a time-dependent down-regulation of anti-apoptotic Bcl-XL and inhibitor of apoptosis proteins (IAPs) family such as XIAP and cIAP-2. Though additional studies are needed, these findings suggested that PTX-2-induced inhibition of U937 cells was associated with the induction of apoptotic cell death and the results provided important new insights into the possible molecular mechanisms of the anti-cancer activity of PTX-2.

• Natural Product Sciences
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• v.10 no.1
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• pp.48-53
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• 2004

Two galloyl monosaccharides, 1,2,6-trigalloylglucose (1, TRgG) and 1,2,3,6- tetragalloylglucose (2, TEgG), were isolated from the stem-bark of Juglans mandshurica. Two galloylglucoses showed cytotoxic effects on human promyelocytic leukemia HL-60 cells. In order to elucidate their mechanism of action, we have investigated the flow cytometric analysis after Annexin V-FITC and PI staining, caspase-3 activity, and internucleosomal DNA fragmentation in HL-60 cells. HL-60 cells treated with both compounds 1 and 2 at 150 and $100\;{\mu}M$, respectively, led to a morphological features of apoptosis, such as plasma membrane blebbing and cell shrinkage. TRgG (1) and TEgG (2) increased the percentage of $FITC^+\;and\;FITC^+PI^+$ cells in flow cytometry after Annexin V-FITC and PI staining. The increase of apoptotic cells was preceded by the activation of caspase-3 reported to play a central role in apoptotic process and inducing internucleosomal DNA fragmentation. TEgG (2) showed to have stronger apoptosis inducing activity in HL-60 cell lines as compared with TRgG (1).

• Journal of Life Science
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• v.18 no.1
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• pp.96-102
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• 2008

Piceatannol is a polyphenol that is found in abundant quantities in grapes and wine. Although recent experimental data revealed the anti-cancer potency of piceatannol, the molecular mechanisms underlying the antileukemic activity have not yet been studied in detail. In the present study, we investigated further possible mechanisms by which piceatannol exerts its anti-proliferative action in cultured human leukemia U937 cells. Exposure of U937 cells to piceatannol resulted in growth inhibition and induction of apoptosis as measured by MTT assay and flow cytometry analysis, which was associated with S phase arrest of the cell cycle. Piceatannol treatment markedly inhibited the activity of telomerase, and the levels of human telomerase reverse transcriptase (hTERT) and telomerase-associated protein-1 (TEP-1), main determinants of the telomerase enzymatic activity, were progressively down-regulated by piceatannol treatment in a dose-dependent fashion. However, the levels of cyclooxygenases (COXs) expression and prostaglandin E2 (PGE2) release were not changed in piceatannol-treated U937 cells. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of piceatannol.