• Biomolecules & Therapeutics
• /
• 제32권1호
• /
• pp.84-93
• /
• 2024

Rosmarinic acid (RA) is a phenolic ester that protects human keratinocytes against oxidative damage induced by ultraviolet B (UVB) exposure, however, the mechanisms underlying its effects remain unclear. This study aimed to elucidate the cell signaling mechanisms that regulate the antioxidant activity of RA and confirm its cyto-protective role. To explore the signaling mechanisms, we used the human keratinocyte cell line HaCaT and SKH1 hairless mouse skin. RA enhanced glutamate-cysteine ligase catalytic subunit (GCLC) and glutathione synthetase (GSS) expression in HaCaT cells in a dose- and time-dependent manner. Moreover, RA induced nuclear factor erythroid-2-related factor 2 (NRF2) nuclear translocation and activated the signaling kinases protein kinase B (AKT) and extracellular signal-regulated kinase (ERK). Treatment with the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, the ERK inhibitor U0126, and small interfering RNA (siRNA) gene silencing suppressed RA-enhanced GCLC, GSS, and NRF2 expression, respectively. Cell viability tests showed that RA significantly prevented UVB-induced cell viability decrease, whereas the glutathione (GSH) inhibitors buthionine sulfoximine, LY294002, and U0126 significantly reduced this effect. Moreover, RA protected against DNA damage and protein carbonylation, lipid peroxidation, and apoptosis caused by UVB-induced oxidative stress in a concentration-dependent manner in SKH1 hairless mouse skin tissues. These results suggest that RA protects against UVB-induced oxidative damage by activating AKT and ERK signaling to regulate NRF2 signaling and enhance GSH biosynthesis. Thus, RA treatment may be a promising approach to protect the skin from UVB-induced oxidative damage.

• Journal of Ginseng Research
• /
• 제32권1호
• /
• pp.73-78
• /
• 2008

Red ginseng acidic polysaccharide (RGAP), isolated from Korean red ginseng (Panax ginseng C.A. Meyer), has been shown to have a variety of biological functions such as immunostimulating and anti-tumor activities. In the present study, we investigated whether RGAP inhibited ligand-induced platelet aggregation. The washed platelet-rich plasma was prepared from male SD rats with successive centrifugation. The platelets $(10^8/ml)$ were preincubated with 1 mM of $CaCl_2$ for 2 min either in the presence or in the absence of RGAP $(10{\sim}50\;{\mu}g/ml)$ and were stimulated with collagen (2.5 ${\mu}g/ml$) and thrombin (0.1 U/ml). RGAP dose-dependently inhibited thrombin-induced platelet aggregation with $IC_{50}$ value of $26.2{\pm}2.0$ ${\mu}g/ml$. In collagen-induced platelet aggregation, RGAP inhibited the reaction with an $IC_{50}$ value of $31.5{\pm}3.0\;{\mu}g/ml$. RGAP potently suppressed the intracellular calcium ion, which was stimulated by thrombin (0.1 U/ ml). Among mitogen-activated protein kinase (MAPK) subtypes, the extracellular signal-regulated kinase (ERK) 1/2 and p38 MAPK were analyzed in the present study. RGAP inhibited the phosphorylation of ERK2 and p38 MAPK, which was activated by collagen (2.5 ${\mu}g/ml$). Finally, these results suggested that besides saponin fraction, RGAP take an important role in the preventive effect of Korean red ginseng against cardiovascular disease such as thrombosis and atherosclerosis.

• KSBB Journal
• /
• 제28권1호
• /
• pp.7-12
• /
• 2013

Thromboxane $A_2$ ($TXA_2$) is one of major proinflammatory mediators, plays an important role in the development of vascular inflammatory diseases. $TXA_2$ acting through the thromboxane receptor regulates multiple pathways and genes in a variety of cells. In this study, we report that the activation of thromboxane receptor with U46619 increases the interleukin-8 (IL-8) mRNA in vascular endothelial cells. We also demonstrated that U46619 produces the activations of extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK), which is required for endothelial IL-8 production. And U46619 enhanced mRNA stability of IL-8 transcripts in endothelial cells. Moreover, inhibition of ERK1/2 or p38MAPK reduced monocyte adhesion to aortic endothelium stimulated by U46619. Therefore, these results suggest that activation of thromboxane receptor promotes the expression of IL-8 via ERK1/2 and p38MAPK activation in endothelial cells.

• 한국식품영양과학회지
• /
• 제43권2호
• /
• pp.224-230
• /
• 2014

항암, 항염증 및 비만억제 등의 생리활성을 지닌 해조류는 최근 건강기능 식품, 기능성 화장품 그리고 의약품 산업 분야에서 미용과 건강식품 소재로 각광받고 있다. 본 연구에서는 10종의 갈조류 메탄올 추출물을 이용하여 1,1-diphenyl-2-picrylhydrazyl(DPPH) 라디칼 소거능과 아밀로이드 베타 단백질($A{\beta}$)의 신경독성에 대한 HT-22 신경세포 보호효과를 조사함으로써 천연물로부터 안전하고 새로운 신경세포 보호소재를 개발해내고자 한다. DPPH 라디칼 소거능의 경우 미역쇠를 포함한 8종의 갈조류에서는 비교적 낮은 활성산소 소거능을 보인 반면, 감태와 패에서 강력한 활성산소 소거능이 나왔다. $A{\beta}$의 신경독성에 대해 10종의 갈조류 추출물이 갖는 HT-22 신경세포 보호효과를 검증하기 위해 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) 분석과 APP, BACE1, iNOS 단백질의 발현양상 및 ERK1/2, p38, JNK1/2 단백질의 활성화 양상을 분석했다. MTT 분석 결과, $A{\beta}$의 신경독성으로부터 미역쇠가 $25{\mu}g/mL$의 농도에서 가장 효과적으로 세포를 보호하고 있는 것으로 나타났고, 알쏭이모자반, 불레기말, 바위수염, 짝잎모자반도 세포 보호효과가 있는 것으로 나타났다. 세포 보호효과가 있는 것으로 밝혀진 5종의 갈조류를 가지고 수행한 단백질 발현분석 결과, 미역쇠는 $A{\beta}$의 신경독성에 의해 HT-22 신경세포에서 발현되는 단백질인 BACE1과 iNOS의 발현을 저해하였다. 이는 미역쇠의 세포보호효과가 $A{\beta}$의 신경독성으로부터 일어난 ERK와 p38의 활성화에 연관된 세포신호전달 경로를 억제하는 것으로 보인다. 그러므로 특히 식용 갈조류인 미역쇠는 $A{\beta}$에 의해 유도된 신경독성에 대해서 신경세포 보호효과를 갖는 건강기능 식품 소재로서의 가치가 충분한 것으로 사료된다.

• The Korean Journal of Physiology and Pharmacology
• /
• 제17권3호
• /
• pp.189-195
• /
• 2013

Amyloid-${\beta}$ peptide ($A{\beta}$), generated by proteolytic cleavage of the amyloid precursor protein (APP), plays a pivotal role in the pathogenesis of Alzheimer's disease (AD). The key step in the generation of $A{\beta}$ is cleavage of APP by beta-site APP-cleaving enzyme 1 (BACE1). Levels of BACE1 are increased in vulnerable regions of the AD brain, but the underlying mechanism is unknown. In the present study, we reported the effects of ferrous ions at subtoxic concentrations on the mRNA levels of BACE1 and a-disintegrin-and-metalloproteinase 10 (ADAM10) in PC12 cells and the cell responses to ferrous ions. The cell survival in PC12 cells significantly decreased with 0 to 0.3 mM $FeCl_2$, with 0.6 mM $FeCl_2$ treatment resulting in significant reductions by about 75%. 4,6-diamidino-2-phenylindole (DAPI) staining showed that the nuclei appeared fragmented in 0.2 and 0.3 mM $FeCl_2$. APP-${\alpha}$-carboxyl terminal fragment (APP-${\alpha}$-CTF) associations with ADAM10 and APP-${\beta}$-CTF with BACE1 were increased. Levels of ADAM10 and BACE1 mRNA increased in response to the concentrations of 0.25 mM, respectively. In addition, p-ERK and p-Bad (S112, S155) expressions were increased, suggesting that APP-CTF formation is related to ADAM10/ BACE1 expression. Levels of Bcl-2 protein were increased, but significant changes were not observed in the expression of Bax. These data suggest that ion-induced enhanced expression of AMDA10/BACE1 could be one of the causes for APP-${\alpha}/{\beta}$-CTF activation.

• The Korean Journal of Physiology and Pharmacology
• /
• 제21권1호
• /
• pp.117-124
• /
• 2017

The present study aimed to show that pro-inflammatory cytokines [tumor necrosis factor (TNF)-${\alpha}$, interferon (IFN)-${\gamma}$, and interleukin (IL)-$1{\beta}$] synergistically induce the production of nitric oxide (NO) production in mouse mesangial cells, which play an important role in inflammatory glomerular injury. We also found that co-treatment with cytokines at low doses (TNF-${\alpha}$; 5 ng/ml, IFN-${\gamma}$; 5 ng/ml, and IL-$1{\beta}$; 1.25 U/ml) synergistically induced NO production, whereas treatment with each cytokine alone did not increase NO production at doses up to 100 ng/ml or 50 U/ml. Silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), attenuates cytokine mixture (TNF-${\alpha}$, IFN-${\gamma}$, and IL-$1{\beta}$)-induced NO production. Western blot and RT-PCR analyses showed that silymarin inhibits inducible nitric oxide synthase (iNOS) expression in a dose-dependent manner. Silymarin also inhibited extracellular signal-regulated protein kinase-1 and -2 (ERK1/2) phosphorylation. Collectively, we have demonstrated that silymarin inhibits NO production in mouse mesangial cells, and may act as a useful anti-inflammatory agent.

• 한국독성학회:학술대회논문집
• /
• 한국독성학회 2003년도 추계학술대회
• /
• pp.175-175
• /
• 2003

In the present study, we show the inhibitory effect of anethole, a substituted alkenylbenzene found in a variety of foods and essential oils, on T lymphocyte functions. Anethole produced an inhibition of concanavalin A-induced lymphoproliferation in B6C3F1 mouse splenocytes.(omitted)

• BMB Reports
• /
• 제48권3호
• /
• pp.184-189
• /
• 2015

Src homology 2-containing protein tyrosine phosphatase 2 (SHP-2) is known to protect neurons from neurodegeneration during ischemia/reperfusion injury. We recently reported that ROS-mediated oxidative stress promotes phosphorylation of endogenous SHP-2 in astrocytes and complex formation between caveolin-1 and SHP-2 in response to oxidative stress. To examine the region of SHP-2 participating in complex formation with caveolin-1, we generated three deletion mutant constructs and six point mutation constructs of SHP-2. Compared with wild-type SHP-2, binding of the N-SH2 domain deletion mutant of SHP-2 to p-caveolin-1 was reduced greatly, using flow cytometric competitive binding assays and surface plasmon resonance (SPR). Moreover, deletion of the N-SH2 domain of SHP-2 affected $H_2O_2$-mediated ERK phosphorylation and Src phosphorylation at Tyr 419 in primary astrocytes, suggesting that N-SH2 domain of SHP-2 is responsible for the binding of caveolin-1 and contributes to the regulation of Src phosphorylation and activation following ROS-induced oxidative stress in brain astrocytes.

• 동의생리병리학회지
• /
• 제36권2호
• /
• pp.79-87
• /
• 2022

In this study, extracts of Boswellia serrata gum resin, Curcuma longa rhizome, and Terminalia chebula fruit were combined in different ratios, and their anti-osteoarthritis effects were compared to determine which combination had the best synergistic effect. B. serrata, C. longa, and T. chebula extracts in a 2:1:2 ratio exhibited higher antioxidative activity in scavenging DPPH radicals than did the individual extracts alone or the other extract combinations. Additionally, the 2:1:2 combination significantly improved the levels of enzymatic antioxidants and antioxidant-related proteins. Moreover, this same combination ratio decreased the protein levels of matrix metalloproteinase (MMP) 3 and MMP13 in interleukin-1β-stimulated human articular chondrocytes (HCHs) and increased those of aggrecan and collagen type II alpha 1 chain (COL2A1). Analysis of the underlying mechanisms revealed that the 2:1:2 combination significantly inhibited the phosphorylation of nuclear factor kappa B (NF-κB) p65, extracellular regulated protein kinase (ERK), and p38 mitogen-activated protein kinase (MAPK). Therefore, the 2:1:2 combination of these three plant extracts has the best potential for use as an effective dietary supplement for improving joint health compared with the individual extracts and their other combination ratios.

• Preventive Nutrition and Food Science
• /
• 제22권1호
• /
• pp.9-15
• /
• 2017

Vaccinium angustifolium, commonly known as the lowbush blueberry, is a rich source of flavonoids, with which various human physiological activities have been associated. The present study focuses on the investigation of the effect of the methanolic extract of V. angustifolium root extract (VAE) on high affinity immunoglobulin E receptor ($Fc{\varepsilon}RI$) ${\alpha}$ chain antibody (CRA-1)-induced allergic reaction in human basophilic KU812F cells. The total phenolic content of VAE was found to be $170{\pm}1.9mg$ gallic acid equivalents/g. Flow cytometry analysis revealed that the cell surface expression of $Fc{\varepsilon}RI$ was suppressed in a concentration-dependent manner upon culture with VAE. Reverse-transcriptase polymerase chain reaction analysis showed that the mRNA level of the $Fc{\varepsilon}RI$ ${\alpha}$ chain was reduced in a concentration-dependent manner as a result of VAE treatment. Western blot analysis revealed that the protein expression of $Fc{\varepsilon}RI$ and the phosphorylation of extracellular signal-regulated kinases (ERK) 1/2 were concentration-dependently inhibited by VAE. We determined that VAE inhibited anti-CRA-1-induced histamine release, in addition to the elevation of intracellular calcium concentration ([$Ca^{2+}$]i), in a concentration-dependent manner. These results indicate that VAE may exert an anti-allergic effect via the inhibition of calcium influx and histamine release, which occurs as a result of the down-regulation of $Fc{\varepsilon}RI$ expression through inhibition of ERK 1/2 activation.