• BMB Reports
• /
• v.34 no.3
• /
• pp.189-193
• /
• 2001

Curcumin a yellow pigment from Curcuma Tonga, has been known to possess antioxidative and anticarcinogenic properties, as well as to induce apoptosis in some cancer cells. There have been, however, several contradictory reports that hypothesized curcumin (a hydrophobic molecule) can bind a membrane Gpid bilayer and induce nonspecific cytotoxicity in some cell lines. Why curcumin shows these contradictory effects is unknown. In A-431 cells, growth inhibition by curcumin is due mostly to the specific inhibition of the intrinsic tyrosine kinase activity of the epidermal growth factor receptor, as reported earlier by Korutla et al. Thus, we assumed that the cell death of A-431 by curcumin might be due to the specific induction of apoptosis. In this paper we clearly show that curcumin induces apoptosis in A-431 cells. The cureumin-induced cell death of A-431 exhibited various apoptotic features, including DNA fragmentation and nuclear condensation. Furthermore, the curcumin-induced apoptosis of A-431 cells involved activation of caspase-3-like cysteine protease. Involvement of caspase-3 was further confirmed by using a caspase-3 specific inhibitor, DEVD-CHO. In another study, decreased nitric oxide (NO) production was also shown in A-431 cells treated with curcumin, which seems to be the result of the inhibition of the iNOS expression by curcumin, as in other cell lines. However, 24 h after treatment of curcumin there was increased NO production in A-431 cells. This observation has not yet been clearly explained. We assumed that the increased NO production may be related to denitrosylation of the enzyme catalytic site in caspase-3 when activated. Taken together, this study shows that the cell death of A-431 by curcumin is due to the induction of apoptosis, which involves caspase-3 activation.

• Biomolecules & Therapeutics
• /
• v.22 no.4
• /
• pp.282-287
• /
• 2014

We show that silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), inhibits cytokine mixture (CM: TNF-${\alpha}$, IFN-${\gamma}$, and IL-$1{\beta}$)-induced production of nitric oxide (NO) in the pancreatic beta cell line MIN6N8a. Immunostaining and Western blot analysis showed that silymarin inhibits iNOS gene expression. RT-PCR showed that silymarin inhibits iNOS gene expression in a dose-dependent manner. We also showed that silymarin inhibits extracellular signal-regulated protein kinase-1 and 2 (ERK1/2) phosphorylation. A MEK1 inhibitor abrogated CM-induced nitrite production, similar to silymarin. Treatment of MIN6N8a cells with silymarin also inhibited CM-stimulated activation of NF-${\kappa}B$, which is important for iNOS transcription. Collectively, we demonstrate that silymarin inhibits NO production in pancreatic beta cells, and silymarin may represent a useful anti-diabetic agent.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.22 no.3
• /
• pp.678-683
• /
• 2008

Aconitum pseudo-laeve var. erectum has traditionally been used for the treatment of water retention in the body. Administration of the aqueous extract of Aconitum pseudo-laeve var. erectum has the efficiency of anti-inflammatory activity and modulates the intestinal immune system. However, the mechanism of anti-inflammatory action of Aconitum pseudo-laeve var. erectum has not been clarified yet. In the present study, the effect of Aconitum pseudo-laeve var. erectum against LPS-stimulated expressions of COX-2 and iNOS in cells of the murine RAW 264.7 macrophages was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, reverse transcription- polymerase chain reaction (RT-PCR), PGE2 immunoassay, and NO detection. The results of the present study indicate that Aconitum pseudo-laeve var. erectum is a potent inhibitor of the LPS-induced NO and $PGE_{2}$ production by blocking iNOS and $NF{\kappa}B$ activation in RAW 264.7 macrophages. These findings suggest that Aconitum pseudo-laeve var. erectum is a potential therapeutic for the treatment of inflammatory syndrome.

• Korean Journal of Pharmacognosy
• /
• v.36 no.4 s.143
• /
• pp.338-343
• /
• 2005

Inflammatory mediators such as interleukin-1 (IL-1), tumor necrosis $factor-{\alpha}\;(TNF-{\alpha}),\;interferon-{\gamma}\;(IFN-{\gamma})$ and lipopolysaccharide (LPS) are thought to play major roles in joint diseases such as a rheumatoid arthritis (RA), and there is considerable evidence playing a role for these cytokines in osteoarthritis (OA). Therefore, we have studied the effects on anti-inflammation and analgesic by ethyl acetate fraction from 70% ethanol extract of Artemisia capillaries (EAC). As a positive control, apigenin, which is known as an anti-inflammatory agent as an iNOS inhibitor, was used and showed the dose-dependent inhibitory effect. EAC showed strong inhibitory efficacy against cytokine-induced proteoglycan degradation, $PGE_2$ production, nitric oxide (NO) production, and matrix-matalloproteinases (MMPs) expression in rabbit articular chondrocyte. In the writhing test induced by acetic acid, EAC $(200{\sim}400\;mg/kg)$ exhibited a dose-dependent inhibition of writhing. The results indicate that EAC have anti-inflammatory and analgesic activities, and could be a good herbal medicine candidate for curing of RA and/or OA.

• The Journal of Internal Korean Medicine
• /
• v.28 no.3
• /
• pp.442-452
• /
• 2007

Objectives : The purpose of this study was to investigate the toll-like receptor (TLR)-4 mediated anti-inflammatory effects of extract from Shigyungbanha-tang (SBT) on the peritoneal macrophage. Methods : To evaluate of TLR-4 mediated inflammatory of SBT. we examined NO and cytokine production in TRL-4 ligand (LPS : lipopolysaccharide) induced macrophages. Furthermore, we examined its molecular mechanism using western blot. Results : Extract from SBT itself does not have any cytotoxic effect in the peritoneal macrophages. Extract from SBT reduced LPS-induced nitric oxide (NO). tumor necrosis factor-alpha ($TNF-{\alpha}$), interleukin (IL)-6 and IL-12 production in peritoneal macrophages. SBT inhibited degradation of inhibitor kappa B-alpha ($I{\kappa}B-{\alpha}$) in the TLR-4 mediated peritoneal macrophages. Conclusions : These results suggest that SBT inhibits NO and cytokines production through inhibiting nuclear factor-kappaB (NF-${\kappa}$B) activation in peritoneal macrophage and that SBT may be beneficial oriental medicine for inflammation.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.19 no.6
• /
• pp.1647-1655
• /
• 2005

Gamimahaenggamsuk-tang (GMHGST) is used for treatment of inflammatory diseases including rheumatoid arthritis (RA). Here, regulatory activity of GMHGST on RA-mediated inflammatory responses was investigated in cultured human fiDroblast-like synoviocytes (FLS), Levels of mRNAs encoding for inflammatory cytokines such as $IL-1{\beta}$, IL-6 and IL-8 and NOS-II enzyme, which had been induced by $TNF-{\alpha}$ and $IL-1{\beta}$ cotreatment, were decreased to the similar levels as those in cells treated with anti-inflammatory agent MTX. mRNA expressions of matrix metalloproteinase-3 (MMP-3) and tissue inhibitor of metalloproteinases (TIMPs) as well as intercellular adhesion molecule (ICAM) were also downregulated by increasing doses of GMHGST in activated FLS. Moreover, GMHGST appeared to protect cells by decreasing NO levels, and inhibited cell proliferation which had been induced by inflammatory stimulation by $TNF-{\alpha}$ and IL-1. These results suggest that GMHGST is effective as an inhibitory agent for regulating inflammatory responses in activated FLS.

• Molecules and Cells
• /
• v.23 no.2
• /
• pp.198-206
• /
• 2007

Hydroquinone is a toxic compound and a major benzene metabolite. We report that it strongly inhibits the activation of macrophages and associated cells. Thus, it suppressed the production of proinflammatory cytokines [tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-$1{\beta}$, IL-3, IL-6, IL-10, IL-12p40, IL-23], secretion of toxic molecules [nitric oxide (NO) and reactive oxygen species (ROS)] and the activation and expression of CD29 as judged by cell-cell adhesion and surface staining experiments. The inhibition was due to the induction of heme oxygenase (HO)-1 in LPS-activated macrophages, since blocking HO-1 activity with ZnPP, an HO-1 specific inhibitor, abolished hydroquinone's NO inhibitory activity. In addition, hydroquinone and inhibitors (wortmannin and LY294002) of the phosphatidylinositol-3 kinase (PI3K)/Akt pathway had very similar inhibitory effects on LPS-induced and CD29-mediated macrophage responses, including the phoshorylation of Akt. Therefore, our data suggest that hydroquinone inhibits macrophage-mediated immune responses by modulating intracellular signaling and protective mechanisms.

• Molecules and Cells
• /
• v.22 no.1
• /
• pp.113-118
• /
• 2006

Thioredoxin reductase (TrxR), a component of the redox control system involving thioredoxin (Trx), is implicated in defense against oxidative stress, control of cell growth and proliferation, and regulation of apoptosis. In the present study a stable transfectant was made by introducing the vector pcDNA3.0 harboring the fission yeast TrxR gene into COS-7 African green monkey kidney fibroblast cells. The exogenous TrxR gene led to an increase in TrxR activity of up to 3.2-fold but did not affect glutathione (GSH) content, or glutaredoxin and caspase-3 activities. Levels of reactive oxygen species (ROS), but not those of nitric oxide (NO), were reduced. Conversely, 1-chloro-2,4-dinitrobezene (CDNB), an irreversible inhibitor of mammalian TrxR, enhanced ROS levels in the COS-7 cells. After treatment with hydrogen peroxide, the level of intracellular ROS was lower in the transfectants than in the vector control cells. These results confirm that TrxR is a crucial determinant of the level of cellular ROS during oxidative stress as well as in the normal state.

• Journal of Veterinary Clinics
• /
• v.17 no.2
• /
• pp.305-314
• /
• 2000

Recombinant inteileukin-2 (IL-2) is a potent inductive stimulus for nitric oxide synthesis (NO.) and has been demonstrated as an antineoplastic agent in mice and human. But it is not let clear whether NO. can contribute to IL-2-induced therapeutic responses. Therefore, the current experiment was undertaken to clarify the effect of IL-2 on antitumor response against subcutaneous Meth-A tumor in mice. At the beginning of each experiment, normal BALB/c mice were injected subcuta-neously with $5{\times}10^6 Meth-A$ tumor cells. Some mice were implanted with osmotic minipumps con- taining 225 $\mu$l of 3.38 M $N^{\gamma}$ -monomethyl-L-arginine (MLA. an NOS inhibitor). Beginning on day 7, experimental groups were treated with a f-day course of IL-2 (50,000 lU,75,000 nJ,100,0007, 50,000 IU+MLA, 75,000 IU+MLA, 100,000 IU+MLA intraperitoneal injection every 12 hours for 5 days). The result of this experiment revealed that Meth-A tumor grew progressively in control mice. Intraperitoneal IL-2 treatment decreased tumor growth and prolonged survival. compared with con-trol mice. But no significant differences among 50.000 lU.75.000 lU and 100,000 lU of 7-2 treat-ment were observed. MLA administration prevented partially the decrease tumor growth and prolong survival of IL-2 treated mice compared with mice receiving IL-2 alone.

• Biomedical Science Letters
• /
• v.15 no.1
• /
• pp.61-66
• /
• 2009

Leflunomide is an immunomodulatory agent used for the treatment of rheumatoid arthritis (RA). Leflunomide known as a regulator of iNOS synthesis which largely decreases NO production in diverse cell type. However, the effect of leflunomide on chondrocyte is still poorly understood. In our previous studies, we have shown that direct production of Nitric oxide (NO) by treating chondrocytes with NO donor, sodium nitroprusside (SNP), causes apoptosis via p38 mitogen-activated protein kinase in association with elevation of p53 protein level, caspase-3 activation. In this study, we characterized the molecular mechanism by which A77 1726 inhibit apoptosis. We found that A77 1726 inhibit NO-induced apoptosis as determined by MTT (Thiazolyl Blue Tetrazolium Bromide) assay and DNA fragmentation. The inhibition of apoptosis by A77 1726 was accompanied by increased PI-3 kinase and AKT activities. So, inhibition of phosphatidylinositol (PI)-3kinase with LY294002 rescued apoptosis. Triciribine, the specific inhibitor of AKT, also abolished anti-apoptotic effect. Our results indicate that A77 1726, the active metabolite of leflunomide, mediates NO-induced apoptosis in chondrocytes by modulating up-regulation of PI-3 kinase and AKT.