• Journal of Microbiology and Biotechnology
• /
• v.17 no.8
• /
• pp.1338-1343
• /
• 2007

Angiogenesis is an essential step in tumor progress and metastasis. Accordingly, small molecules that inhibit angiogenesis would appear to be a promising way to cure angiogenesis-related diseases, including cancer. In the present study, we report that streptochlorin, a small molecule from marine actinomycete, exhibits a potent antiangiogenic activity. The compound potently inhibited endothelial cell invasion and tube formation stimulated with vascular endothelial cell growth factor (VEGF) at low micromolar concentrations where it showed no cytotoxicity to the cells. In addition, streptochlorin inhibited TNF-${\alpha}$-induced $NF-{\kappa}B$ activation in the newly developed cell-based reporter gene assay. These data demonstrate that streptochlorin is a new inhibitor of $NF-{\kappa}B$ activation and can be a basis for the development of novel anti-angiogenic agents.

• Archives of Pharmacal Research
• /
• v.11 no.3
• /
• pp.197-202
• /
• 1988

A new saponin, 3-O-[${\alpha}$-L-rhamnopyranosyl$(1{\rightarrow}2)$-${\beta}$-D-glucopyranosyl$(1{\rightarrow}2)$-${\beta}$-D-glucuronopyranosyl]soyasapogenol B carboxylate (6) has been isolated from the medicinal plant yellow sweetclover together with azukisaponin II(7), robinin(8), and clovin(9). 7,8, and 9 are reported for the first time from this plant. The new saponin(6) exhibited inhibitory action on leucocyte migration in inflammation.

• Archives of Pharmacal Research
• /
• v.11 no.3
• /
• pp.230-239
• /
• 1988

Thirty kinds of medicinal plants were screened to examine inhibitory activities on rat brain monoamine oxidase A, using serotonin as a substrate. As active principles, various kinds of stilbenes were isolated from Veratri Rhizoma, Reynoutriae Radix and Rhei undulati Rhizoma, and several kinds of flavonoids from Sophorae Flos, Chrisanthemi Flos and Glycine max. Among the compounds isolated, resveratrol(I) strongly inhibited MAO-A competitively, and its $IC_{50}$ and Ki values were 2 ${\mu}M$ and 2.5 ${\mu}M$, respectively. Inhibitory potencies towards MAO-A of some stilbenes and flavonoids were also compared.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2003.05a
• /
• pp.77-77
• /
• 2003

We have previously shown that 2, 3' , 4, 5' -tetramethoxystilbene(TMS), a trans-stilbene analogue, is one of the most potently selective inhibitor of recombinant human cytochrome P450 1B1 in vitro. In the present studies, the effects of TMS on the expression of cytochrome P450 1B1 were investigated in human mammary cell lines such as MCF-7 and MCF-10A. (omitted)

• YAKHAK HOEJI
• /
• v.43 no.4
• /
• pp.481-486
• /
• 1999

Excessive or long term ingestion of alcohol may cause hepatitis, cirrhosis, hepatic tumor and so on. Aldehyde and active form of free oxygen that are metabolites of alcohol in liver are the cause of liver cell damage. The main system of alcohol metabolism is composed of alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH) and cytochrome P450. In connection with in vivo alcohol metabolism, more than one hundred natural products were screened for inhibition or activation of alcohol dehydrogenase. As a results, we found significant inhibition ($IC_50$) of ADH by methanolic extracts of Puerariae Radix ($61.2{\;}\mu\textrm{g}/ml$), Glycyrrhizae Radix ($105.0{\;}\mu\textrm{g}/ml$), Cinnamomi Ramulus ($7.0{\;}\mu\textrm{g}/ml$), Rhei Rhizoma ($36.7{\;}\mu\textrm{g}/ml$), Mori Cortex Radicis ($106.2{\;}\mu\textrm{g}/ml$), Chrysanthemi Flos ($112.2{\;}\mu\textrm{g}/ml$), Erycibes Caulis ($36.7{\;}\mu\textrm{g}/ml$), and Scutellariae Radix ($122.5{\;}\mu\textrm{g}/ml$)

• Archives of Pharmacal Research
• /
• v.16 no.3
• /
• pp.209-212
• /
• 1993

The anti-coagulant activity of ilexoside D isolated from the roots of ilex pubescens Hook. et Am. was investigated in in vivo models of blood coagulation in rats. On oral administration, ilexoside D prolonged the bleeding time and the whole blood recalcified clotting time, but not the plasma recalcified clotting time. In vitor, ilexoside D did not affect the recalciffed clotting times of whole blood, platelet-rich plasma(PRP), and platelet-poor plasma(PPP), while in the presence of tissue factor the compound prologed the reduced proth-rombin times of whole blood, PRP and PPP in the dose-dependent manner. These results indicate that ilexoside D has the anit-tissue factor activity as well as the antithromobotic activity.

• BMB Reports
• /
• v.50 no.7
• /
• pp.355-360
• /
• 2017

Mutations in Ras GTPase are among the most common genetic alterations in human cancers. Despite extensive research investigating Ras proteins, their functions still remain a challenge over a long period of time. The currently available data suggests that solving the outstanding issues regarding Ras could lead to development of effective drugs that could have a significant impact on cancer treatment. Developing a better understanding of their biochemical properties or modes of action, along with improvements in their pharmacologic profiles, clinical design and scheduling will enable the development of more effective therapies.

• Archives of Pharmacal Research
• /
• v.18 no.2
• /
• pp.65-68
• /
• 1995

The methanol extract from the whole parts of the flowers of Chrysanthemum boreals was found to exhibit a significant inhibition of a rat lens aldose reductase (RLAR) activity in vitro. Bioassay guided systematic fractionation of the methanol extract led to the isolation of four flavonoids which were identified as acacetin (1), apigenin (II), luteolin (III) and linarin (IV). Compounds I-III were demonstrated to exhibit a significant inhibition of RLAR. Luteolin (II) was found to be the most potent AR inhibitor with $IC_{50}$ value of $5{\times}10^{-7}M$.

• Journal of Life Science
• /
• v.22 no.6
• /
• pp.788-793
• /
• 2012

High concentration of antibiotics has been used to treat the outbreak of edwardsiellosis caused by Edwardsiella tarda in aquaculture. However, not all of the bacteria have been killed with high concentrations of antibiotics treatment by the formation of persister cells with a dormant state. The main objective of this study was to kill persister cell using antibiotics with the addition of natural plant compounds. Antibiotics used in this study consist of 100 mg/ml florfenicol and 100 mg/ml amoxicillin. Ten natural plant compounds with persister cell inhibitor activity to E. coli were obtained from Protein Engineering and Systems Biology Lab. of Sungkyunkwan University. The persister cell inhibition activities of those natural plant compounds were evaluated in test tube. Concentrations of the antibiotics were in the ranges of 25~200 ${\mu}g/ml$. The persister cell formation was observed after 16 hours of culture. Persister cells were killed by antibiotics with natural plant compounds. Among ten natural plant compounds, Gynostemma pentaphyllum, Mallotus japonicus, and Orixa japonica showed persister cell formation inhibition activities. The optimal concentrations of G. pentaphyllum, M. japonicus, and O. japonica for the inhibitor of persister cell formation were 100 ${\mu}g/ml$, 100 ${\mu}g/ml$, and 200 ${\mu}g/ml$, respectively. In vivo study was carried out to evaluate the effect of the antibiotics with natural plant compounds using aquacultural fish, olive flounder, as test animals. G. pentaphyllum, M. japonicus, and O. japonica of 30 ${\mu}g/ml$, 10 ${\mu}g/ml$, and 10 ${\mu}g/ml$ with antibiotics reduced cumulative mortalities, showing the effectiveness of persister cell inhibition.

• BMB Reports
• /
• v.56 no.2
• /
• pp.114-119
• /
• 2023

Liver fibrosis is caused by chronic liver damage and results in the aberrant accumulation of extracellular matrix during disease progression. Despite the identification of the HAT enzyme p300 as a major factor for liver fibrosis, the development of therapeutic agents targeting the regulation of p300 has not been reported. We validated a novel p300 inhibitor (A6) on the improvement of liver fibrosis using two mouse models, mice on a choline-deficient high-fat diet and thioacetamide-treated mice. We demonstrated that pathological hall-marks of liver fibrosis were significantly diminished by A6 treatment through Masson's trichrome and Sirius red staining on liver tissue and found that A6 treatment reduced the expression of matricellular protein genes. We further showed that A6 treatment improved liver fibrosis by reducing the stability of p300 protein via disruption of p300 binding to AKT. Our findings suggest that targeting p300 through the specific inhibitor A6 has potential as a major therapeutic avenue for treating liver fibrosis.