Seok Bean Song

Inhibition of TNF-α-mediated NF-κB Transcriptional Activity in HepG2 Cells by Dammarane-type Saponins from Panax ginseng Leaves

Panax ginseng (PG) is a globally utilized medicinal herb. The medicinal effects of PG are primarily attributable to ginsenosides located in the root and leaf. The leaves of PG are known to be rich in various bioactive ginsenosides, and the therapeutic effects of ginseng extract and ginsenosides have been associated with immunomodulatory and anti-inflammatory activities. We examined the effect of PG leaf extract and the isolated ginsenosides, on nuclear factor (NF)-κB transcriptional activity and target gene expression by applying a luciferase assay and reverse transcription polymerase chain reaction in tumor necrosis factor (TNF)-α-treated hepatocarcinoma HepG2 cells. Air-dried PG leaf extract inhibited TNF-α-induced NF-κB transcription activity and NF-κB-dependent cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) gene expression more efficiently than the steamed extract. Of the 10 ginsenosides isolated from PG leaves, Rd and Km most significantly inhibited activity in a dose-dependent manner, with IC50 values of 12.05±0.82 and 8.84±0.99 μM, respectively. Furthermore, the ginsenosides Rd and Km inhibited the TNF-α-induced expression levels of the COX-2 and iNOS gene in HepG2 cells. Air-dried leaf extracts and their chemical components, ginsenoside Rd and Km, are involved in the suppression of TNF-α-induced NF-κB activation and NF-κB-dependent iNOS and COX-2 gene expression. Consequently, air-dried leaf extract from PG, and the purified ginsenosides, have therapeutic potential as anti-inflammatory.

A large population genetic study of 15 autosomal short tandem repeat loci for establishment of Korean DNA profile database.

Genotyping of highly polymorphic short tandem repeat (STR) markers is widely used for the genetic identification of individuals in forensic DNA analyses and in paternity disputes. The National DNA Profile Databank recently established by the DNA Identification Act in Korea contains the computerized STR DNA profiles of individuals convicted of crimes. For the establishment of a large autosomal STR loci population database, 1805 samples were obtained at random from Korean individuals and 15 autosomal STR markers were analyzed using the AmpFlSTR Identifiler PCR Amplification kit. For the 15 autosomal STR markers, no deviations from the Hardy-Weinberg equilibrium were observed. The most informative locus in our data set was the D2S1338 with a discrimination power of 0.9699. The combined matching probability was 1.521 × 10−17. This large STR profile dataset including atypical alleles will be important for the establishment of the Korean DNA database and for forensic applications.

Cytotoxic and anti-inflammatory cembranoids from the Vietnamese soft coral Lobophytum laevigatum

Four new cembranoids, namely laevigatol A-D (1-4), and six known metabolites (5-10), were isolated from the Vietnamese soft coral Lobophytum laevigatum. The structures of these compounds were elucidated by extensive spectroscopic analyses, and the absolute stereochemistry of 1 was determined using the modified Moshers method. Compounds 5, and 7-10 exhibited cytotoxic activity against selected human cancer cell lines. Compounds 1, 2, 8, and 9 showed dose-dependent inhibitory effects on the TNFα-induced NF-κB transcriptional activity in Hep-G2 cells. Moreover, compounds 1, 2, 8, and 9 significantly inhibited the induction of COX-2 and iNOS mRNA dose-dependently, indicating that these compounds attenuated the synthesis of these transcripts at the transcriptional level.

Oleanane-type triterpene saponins from the bark of Aralia elata and their NF-κB inhibition and PPAR activation signal pathway.

Two new oleanane-type triterpene saponins, tarasaponin IV (1) and elatoside L (2), and four known; stipuleanoside R(2) (3), kalopanax-saponin F (4), kalopanax-saponin F methylester (5), and elatoside D (6) were isolated from the bark of Aralia elata. Kalopanax-saponin F methyl ester was isolated from nature for the first time. Their chemical structures were elucidated using the chemical and physical methods as well as good agreement with those of reported in the literature. Oleanane-type triterpene saponins are the main component of A. elata. All compounds were investigated the anti-inflammatory activity. We measured their inhibition of NF-κB and activation of PPARs activities in HepG2 cells using luciferase reporter system. As results, compounds 2 and 4 were found to inhibit NF-κB activation stimulated by TNFα in a dose-dependent manner with IC(50) values of 4.1 and 9.5 μM, respectively, when compared with that of positive control, sulfasalazine (0.9 μM). Compounds 2 and 4 also inhibited TNFα-induced expression of iNOS and COX-2 mRNA. Furthermore, compounds 1-6 were evaluated PPAR activity using PPAR subtype transactivation assays. Among of them, compounds 4-6 significantly increased PPARγ transactivation. However, compounds 4-6 did not activate in any other PPAR subtypes.

Erythroid differentiation regulator 1 (Erdr1) is a proapototic factor in human keratinocytes.

Abstract:  Skin is constantly exposed to physical and chemical stressors. The exposure of keratinocytes to ultraviolet B (UVB) irradiation causes epidermal damage via induction of apoptosis. Erythroid differentiation regulator 1 (Erdr1) modulates growth and survival of cells under various stressful conditions, but the function of Erdr1 in human keratinocyte apoptosis has not been investigated so far. Here, we investigated the effect of Erdr1 on UVB‐induced apoptosis in human keratinocytes and also examined the underlying regulatory mechanism. First, Erdr1 expression was detected in human primary keratinocytes and normal human skin tissues. Expression of Erdr1 was enhanced in human keratinocytes following UVB irradiation. Knock‐down of Erdr1 led to resistance to UVB‐induced apoptosis. Also, Erdr1 overexpression increased UVB‐induced apoptosis and induced caspase‐3 activation. Furthermore, the extracellular signal‐regulated kinase (ERK) inhibitor PD98059 and the p38 mitogen‐activated protein kinase (MAPK) inhibitor SB203580 significantly reduced Erdr1 expression following UVB irradiation. These results indicate that UVB induces Erdr1 via a MAPK‐dependent mechanism. Taken together, these findings suggest that Erdr1 has a role as a proapoptotic factor in human keratinocytes and acts via ERK and p38 MAPK pathways. Therefore, Erdr1 may be a potential therapeutic target to reduce apoptosis in keratinocytes in conditions such as psoriasis and skin cancer.

Osteonectin-expressing cells in human stomach cancer and their possible clinical significance

The clinical significance of osteonectin in human stomach cancer was examined immunohistochemically and molecular biologically in 31 differentiated and eight undifferentiated stomach adenocarcinomas and 19 non-cancer stomach tissues. Osteonectin-mAb-stained cells were observed in stroma of 90% differentiated and 63% undifferentiated adenocarcinomas, and of 26% non-cancer stomach tissues. Competitive reverse transcriptase polymerase chain reaction results generally coincided with immunohistochemical data. The present results suggest that osteonectin is highly expressed in reactive stroma associated with invasive differentiated adenocarcinomas and that it may serve as a useful clinical diagnostic marker for stomach cancer.

New anti-inflammatory cembranoid diterpenoids from the Vietnamese soft coral Lobophytum crassum.

Four new cembranoid diterpenes lobocrasols A-D (1-4), were isolated from the methanol extract of the soft coral Lobophytum crassum. Their structures were elucidated by spectroscopic analysis and by comparison of the spectroscopic data with those of similar compounds previously reported in literature. The anti-inflammatory effects of isolated compounds were evaluated using NF-κB luciferase and reverse transcription polymerase chain reaction (RT-PCR). Compounds 1 and 2 significantly inhibited TNFα-induced NF-κB transcriptional activity in HepG2 cells in a dose-dependent manner, with IC50 values of 6.30±0.42 and 6.63±0.11μM, respectively. Furthermore, the transcriptional inhibition of these compounds was confirmed by a decrease in cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) gene expression levels in HepG2 cells.

Anti-inflammatory Triterpenoid Saponins from the Stem Bark of Kalopanax pictus

Five new compounds, 16,23,29-trihydroxy-3-oxo-olean-12-en-28-oic acid (1), 4,23,29-trihydroxy-3,4-seco-olean-12-en-3-oate-28-oic acid (2), 3β,6β,23-trihydroxyolean-12-en-28-oic acid 28-O-β-D-glucopyranoside (3), 3-O-[2,3-di-O-acetyl-α-L-arabinopyranosyl]hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (4), and 3-O-[3,4-di-O-acetyl-α-L-arabinopyranosyl]hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (5), as well as 10 known compounds (6-15), were isolated from the stem bark of Kalopanax pictus. Compounds 1-5 and 7-14 inhibited TNFα-induced NF-κB transcriptional activity in HepG2 cells in a dose-dependent manner, with IC50 values ranging from 0.6 to 16.4 μM. Furthermore, the transcriptional inhibitory function of these compounds was confirmed on the basis of decreases in COX-2 and iNOS gene expression in HepG2 cells. The structure-activity relationship of the compounds with respect to anti-inflammatory activity is also discussed.

Effects of impressic acid from Acanthopanax koreanum on NF-κB and PPARγ activities

Impressic acid, 3α,11α-dihydroxylup-20(29)-en-28-oic acid, is a lupane-type triterpenoid isolated from Acanthopanax koreanum, which has been used as a Korean folk medicine for rheumatism, hepatitis, diabetes, and inflammatory disorders. Recently, it was reported that impressic acid has inhibitory effects on the LPS-stimulated pro-inflammatory cytokine production in bone marrow-derived dendritic cells and on the nuclear factor of activated T-cells transcription factor activity. Thus, to investigate whether impressic acid has effects on the inhibition of nuclear factor kappa B (NF-κB) and activation of peroxisome proliferator-activated receptor gamma (PPARγ), luciferase reporter assays were used. The effects on the expression of NF-κB and PPARγ target genes were also examined by reverse transcription-polymerase chain reaction. In this study, impressic acid was found to inhibit tumor necrosis factor (TNF)-α induced NF-κB activity and to up-regulate transcriptional activity of PPARγ.

Oleanane-triterpenoids from Panax stipuleanatus inhibit NF-κB

In continuation of our research to find biological components from Panax stipuleanatus, four oleanane-type triterpenes (12 to 15) were isolated successively. Fifteen oleanane-type saponins (1 to 15) were evaluated for nuclear factor (NF)-κB activity using a luciferase reporter gene assay in HepG2 cells. Compounds 6 to 11 inhibited NF-κB, with IC50 values between 3.1 to 18.9 μM. The effects on inducible nitric oxide synthase and cyclooxygenase-2 by compounds 8, 10, and 11 were also examined using reverse transcription-polymerase chain reaction. Three compounds (8, 10, and 11) inhibited NF-κB activity by reducing the concentration of inflammatory factors in HepG2 cells.