Eun-Mi Noh

Emodin suppresses inflammatory responses and joint destruction in collagen-induced arthritic mice

OBJECTIVE Emodin (3-methyl-1,6,8-trihydroxyanthraquinone) is one of the active components present in the root and rhizome of Rheum palmatum. It has been shown to contain biological activity (antitumour, antibacterial, diuretic and vasorelaxant effects). However, the mechanisms underlying the anti-arthritic effect of emodin have not been elucidated. Here we investigated whether emodin treatment would modulate the severity of the disease in an experimental arthritis model. METHODS We evaluated the effects of emodin on CIA mice in vivo. RESULTS The pathological processes of RA are mediated by a number of cytokines and MMPs. Expression of these proinflammatory mediators is controlled by nuclear factor-κB (NF-κB). This study was performed to explore the effect of emodin on control of the NF-κB activation pathway and to investigate whether emodin has anti-inflammatory effects in CIA mice in vivo. Emodin inhibited the nuclear translocation and DNA binding of NF-κB subunits, which were correlated with its inhibitory effect on cytoplasmic IκBα degradation in CIA mice. These events further suppressed chemokine production and MMP expression. In addition, emodin inhibited the osteoclast differentiation induced by M-CSF and receptor activation of NF-κB ligand in bone marrow macrophages. CONCLUSION These findings suggest that emodin exerts anti-inflammatory effects in CIA mice through inhibition of the NF-κB pathway and therefore may have therapeutic value for the treatment of RA.

Guggulsterone blocks IL-1β-mediated inflammatory responses by suppressing NF-κB activation in fibroblast-like synoviocytes

Guggulsterone is a plant sterol that is used to treat hyperlipidemia, arthritis, and obesity. Although its anti-inflammatory and anti-hyperlipidemic effects have been well documented, the effect of guggulsterone on fibroblast-like synoviocytes (FLS) has not yet been reported. Therefore, in this study, the effect of guggulsterone on interleukin (IL)-1beta-induced inflammatory responses in the FLS of rheumatic patients was investigated. Treatment of FLS with IL-1beta induced production of chemokines such as RANTES and ENA-78. In addition, Western blot analysis and gelatin zymography revealed that IL-1beta activated matrix metalloproteinase (MMP)-1 and -3 in FLS. However, pre-incubation with guggulsterone completely inhibited the ability of IL-1beta to induce the production of chemokines and to activate MMPs. Although the NF-kappaB binding activity and nuclear p50 and p65 subunit levels, as well as IkappaBalpha degradation in the cytoplasm was greater in cells stimulated with IL-1beta than in unstimulated cells, treatment with guggulsterone abolished all of these increases. Collectively, these results suggest that guggulsterone would be useful as an inhibitor of joint destruction in patients with rheumatoid arthritis.

Sulforaphane controls TPA-induced MMP-9 expression through the NF-κB signaling pathway, but not AP-1, in MCF-7 breast cancer cells.

Sulforaphane [1-isothiocyanato-4-(methylsulfinyl)-butane] is an isothiocyanate found in some cruciferous vegetables, especially broccoli. Sulforaphane has been shown to display anti-cancer properties against various cancer cell lines. Matrix metalloproteinase-9 (MMP-9), which degrades the extracellular matrix (ECM), plays an important role in cancer cell invasion. In this study, we investigated the effect of sulforaphane on 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced MMP-9 expression and cell invasion in MCF-7 cells. TPA-induced MMP-9 expression and cell invasion were decreased by sulforaphane treatment. TPA substantially increased NF-κB and AP-1 DNA binding activity. Pre-treatment with sulforaphane inhibited TPA-stimulated NF-κB binding activity, but not AP-1 binding activity. In addition, we found that sulforaphane suppressed NF-κB activation, by inhibiting phosphorylation of IκB in TPA-treated MCF-7 cells. In this study, we demonstrated that the inhibition of TPA-induced MMP-9 expression and cell invasion by sulforaphane was mediated by the suppression of the NF-κB pathway in MCF-7 cells. [BMB Reports 2013; 46(4): 201-206]

Brazilin inhibits UVB-induced MMP-1/3 expressions and secretions by suppressing the NF-κB pathway in human dermal fibroblasts.

Brazilin (7, 11b-dihydrobenz[b]indeno[1,2-d]pyran-3,6a,9,10 (6H)-tetrol), the major component of Caesalpinia sappan L., is a natural red pigment used for histological staining. Recent studies have shown that brazilin exhibits distinct biological effects, including anti-hepatotoxicity, antiplatelet activity, and anti-inflammatory activities. In the present study, we evaluated the effects of brazilin on MMP-1 and -3 expressions in human dermal fibroblasts exposed to ultraviolet B (UVB) irradiation. Brazilin showed protective effect on UVB-induced loss of cell viability of fibroblasts. Brazilin also blocked significantly UVB-induced Reactive Oxygen Species generation in fibroblasts. Brazilin inhibited UVB-induced MMP-1/3 expressions and secretions in a dose-dependent manner. Moreover, UVB-induced NF-κB activation was completely blocked by treatment with brazilin. These findings suggest that brazilin inhibits UVB-induced MMP-1/3 expressions and secretions by suppressing of NF-κB activation in human dermal fibroblasts. Thus, brazilin might be used as a potential agent for treatment of UV-induced skin photoaging.

Peroxisome Proliferator-Activated Receptor γ and Retinoic Acid Receptor Synergistically Up-Regulate the Tumor Suppressor PTEN in Human Promyeloid Leukemia Cells

Peroxisome proliferator-activated receptor γ (PPARγ) and retinoic acid receptors (RARs) have been a focus in chemotherapy for human cancers. The tumor suppressor PTEN plays a pivotal role in the growth of human cancer cells. We investigated whether costimulation of PPARγ and RAR could synergistically up-regulate PTEN in human leukemia cells and consequently potentiate the inhibition of growth and cell cycle progression of these cells. We found that overexpression of PTEN with the adenoviral vector Ad/PTEN caused growth arrest at the G1 phase of the cell cycle of HL-60 cells. HL-60 cells treated with either a PPARγ ligand (ciglitazone) or a RAR ligand(all-trans retinoic acid [ATRA]) up-regulated PTEN in HL-60 cells. The 2 compounds in combination showed synergistic effects on PTEN expression at the protein and messenger RNA levels. Moreover, the combination of ciglitazone and ATRA synergistically reduced cell growth rates and cell cycle arrest at the G1 phase. Our results suggest that, PPARγ and RAR play an important role in controlling the growth of leukemia cells via the up-regulation of PTEN.

Induction of G1 phase arrest and apoptosis in MDA-MB-231 breast cancer cells by troglitazone, a synthetic peroxisome proliferator-activated receptor γ (PPARγ) ligand

Peroxisome proliferator‐activated receptor γ (PPARγ) ligands inhibit cell proliferation and induce apoptosis in cancer cells. Here we wished to determine whether the PPARγ ligand induces apoptosis and cell cycle arrest of the MDA‐MB‐231 cell, an estrogen receptor α negative breast cancer cell line. The treatment of MDA‐MB‐231 cell with PPARγ ligands was shown to induce inhibition of cell growth in a dose‐dependent manner as determined by MTT assay. Cell cycle analysis showed a G1 arrest in MDA‐MB‐231 cells exposed to troglitazone. An apoptotic effect by troglitazone demonstrated that apoptotic cells elevated by 2.5‐fold from the control level at 10 μM, to 3.1‐fold at 50 μM and to 3.5‐fold at 75 μM. Moreover, troglitazone treatment, applied in a dose‐dependent manner, caused a marked decrease in pRb, cyclin D1, cyclin D2, cyclin D3, Cdk2, Cdk4 and Cdk6 expression as well as a significant increase in p21 and p27 expression. These results indicate that troglitazone causes growth inhibition, G1 arrest and apoptotic death of MDA‐MB‐231 cells.

TNF-α upregulates PTEN via NF-κB signaling pathways in human leukemic cells

TNF-α plays a variety of biological functions such as apoptosis, inflammation and immunity. PTEN also has various cellular function including cell growth, proliferation, migration and differentiation. Thus, possible relationships between the two molecules are suggested. TNF-α has been known to downregulate PTEN via NF-κB pathway in the human colon cell line, HT-29. However, here we show the opposite finding that TNF-α upregulates PTEN via activation of NF-κB in human leukemic cells. TNF-α increased PTEN expression at HL-60 cells in a time- and dose-dependent manner, but the response was abolished by disruption of NF-κB with p65 anisense phosphorothioate oligonucleotide or pyrrolidine dithiocarbamate. We found that TNF-α activated the NF-κB pathways, evidenced by the translocation of p65 to the nucleus in TNF-α-treated cells. We conclude that TNF-α induces upregulation of PTEN expression through NF-κB activation in human leukemic cells.

Curcumin inhibits UVB‐induced matrix metalloproteinase‐1/3 expression by suppressing the MAPK‐p38/JNK pathways in human dermal fibroblasts

Curcumin (diferuloylmethane) is a polyphenol derived from turmeric (Curcuma longa), which is commonly used as a spice. Recent studies have shown that curcumin has a wide range of pharmacological activities, including anticarcinogenic, antioxidant, anti‐inflammatory and antiangiogenic activities. However, the antiphotoageing effects of curcumin have yet to be characterized. In this study, we investigated the inhibitory effects of curcumin on matrix metalloproteinase (MMP)‐1 and MMP‐3 expression in human dermal fibroblast cells. Western blot analysis revealed that curcumin inhibited ultraviolet (UV) B‐induced MMP‐1 and MMP‐3 expression. Furthermore, curcumin significantly blocked UVB‐induced reactive oxygen species generation in fibroblasts. Curcumin treatment significantly blocked the UVB‐induced activation of nuclear factor (NF)‐κB and activator protein (AP)‐1. Additionally, curcumin strongly repressed the UVB‐induced phosphorylation of p38 and c‐Jun N‐terminal kinase. Curcumin prevented UVB‐induced MMP expression through mitogen‐activated protein kinase/NF‐κB inhibition and AP‐1 activation. In conclusion, curcumin may be useful for preventing and treating skin photoageing.

Dihydroavenanthramide D inhibits human breast cancer cell invasion through suppression of MMP-9 expression.

Dihydroavenanthramide D (DHAvD) is a synthetic analog to naturally occurring avenanthramide, which is the active component of oat. Previous study demonstrates that DHAvD strongly inhibits activation of nuclear factor-kappa B (NF-κB), which is a major component in cancer cell invasion. The present study investigated whether DHAvD can modulate MMP-9 expression and cell invasion in MCF-7 human breast cancer cells. MMP-9 expression and cell invasion in response to 12-O-tetradecanoylphorbol-13-acetate (TPA) was increased, whereas these inductions were muted by DHAvD. DHAvD also suppressed activation of mitogen-activated protein kinase (MAPK), and MAPK-mediated nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1) activations in TPA-treated MCF-7 cells. The results indicate that DHAvD-mediated inhibition of TPA-induced MMP-9 expression and cell invasion involves the suppression of the MAPK/NF-κB and MAPK/AP-1 pathways in MCF-7 cells. DHAvD may have potential value in breast cancer metastasis.

Decursin inhibits UVB-induced MMP expression in human dermal fibroblasts via regulation of nuclear factor-κB

Decursin, a coumarin compound, was originally isolated from the roots of Angelica gigas almost four decades ago, and it was found to exhibit cytotoxicity against various types of human cancer cells and anti-amnesic activity in vivo through the inhibition of AChE activity. However, the anti-skin photoaging effects of decursin have not been reported to date. In the present study, we investigated the inhibitory effects of decursin on the expression of matrix metalloproteinase (MMP)-1 and MMP-3 in human dermal fibroblast (HDF) cells. Western blot analysis and real-time PCR revealed that decursin inhibited the ultraviolet (UV)B-induced expression of MMP-1 and MMP-3 in a dose-dependent manner. Decursin significantly blocked the UVB-induced activation of nuclear factor-κB (NF-κB). However, decursin showed no effect on MAPK or AP-1 activity. In this study, decursin prevented the UVB-induced expression of MMPs via the inhibition of NF-κB activation. In conclusion, decursin may be a potential agent for the prevention and treatment of skin photoaging.