• 한국자원식물학회지
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• 제25권3호
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• pp.339-345
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• 2012

The marine carotenoid fucoxanthin can be found in marine brown seaweeds, macroalgae, diatoms, and microalgae, and has remarkable biological properties. Numerous studies have shown that fucoxanthin has considerable potential and promising applications in human health, but the underlying mechanisms involved in its anti-allergic activity are not fully understood. We here investigated the mechanisms by anti-allergic activity of fucoxanthin fraction from Eisenia bicyclis in immunoglobulin E-antigen complex (IgE/DNP-BSA)-stimulated RBL-2H3 mast cells. This study we found that the fucoxanthin inhibits the release of ${\beta}$-hexosaminidase and suppressed not only transcriptional activation of NF-${\kappa}B$, but also phosphorylation of ERK and JNK in IgE/DNP-BSA-treated RBL-2H3 cells. Fucoxanthin may be useful for preventing allergic diseases, including asthma and atopic dermatitis.

• Molecules and Cells
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• 제22권3호
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• pp.291-299
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• 2006

Vitexin, a natural flavonoid compound identified as apigenin-8-C-${\beta}$-D-glucopyranoside, has been reported to exhibit antioxidative and anti-inflammatory properties. In this study, we investigated its effect on hypoxiainducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) in rat pheochromacytoma (PC12), human osteosarcoma (HOS) and human hepatoma (HepG2) cells. Vitexin inhibited HIF-$1{\alpha}$ in PC12 cells, but not in HOS or HepG2 cells. In addition, it diminished the mRNA levels of hypoxia-inducible genes such as vascular endothelial growth factor (VEGF), smad3, aldolase A, enolase 1, and collagen type III in the PC12 cells. We found that vitexin inhibited the migration of PC12 cells as well as their invasion rates, and it also inhibited tube formation by human umbilical vein endothelium cells (HUVECs). Interestingly, vitexin inhibited the hypoxia-induced activation of c-jun N-terminal kinase (JNK), but not of extracellular-signal regulated protein kinase (ERK), implying that it acts in part via the JNK pathway. Overall, these results suggest the potential use of vitexin as a treatment for diseases such as cancer.

• Biomolecules & Therapeutics
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• 제20권3호
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• pp.352-356
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• 2012

The present study was undertaken to determine whether ethanol influences on the agonist-induced vascular smooth muscle contraction and, if so, to investigate the related mechanism. The measurement of isometric contractions using a computerized data acquisition system was combined with molecular experiments. Ethanol significantly inhibited thromboxane $A_2$ mimetic-induced contraction with intact endothelial function, but there was no relaxation on thromboxane $A_2$ mimetic U-46619-induced contraction irrespective of endothelium suggesting that the pathway such as Rho-kinase activation, $Ca^{2+}$ entry or thin filament regulation was not affected. In addition, ethanol didn't decrease thromboxane $A_2$ mimetic-induced increase of phospho-myosin phosphatase targeting subunit protein 1 (pMYPT1) or pERK1/2. Interestingly, ethanol didn't inhibit significantly phorbol ester-induced contraction in denuded muscles suggesting that thin filament regulation is less important on the ethanol-induced regulation in the muscle than endothelial NO synthesis. In conclusion, this study provides the evidence and possible related mechanism concerning the effect of ethanol on the agonist-dependent contraction in rat aortic rings with regard to endothelial function.

• Biomolecules & Therapeutics
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• 제25권2호
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• pp.158-164
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• 2017

Methylglyoxal (MGO) is a highly reactive metabolite of glucose which is known to cause damage and induce apoptosis in endothelial cells. Endothelial cell damage is implicated in the progression of diabetes-associated complications and atherosclerosis. Hypericin, a naphthodianthrone isolated from Hypericum perforatum L. (St. John's Wort), is a potent and selective inhibitor of protein kinase C and is reported to reduce neuropathic pain. In this work, we investigated the protective effect of hypericin on MGO-induced apoptosis in human umbilical vein endothelial cells (HUVECs). Hypericin showed significant anti-apoptotic activity in MGO-treated HUVECs. Pretreatment with hypericin significantly inhibited MGO-induced changes in cell morphology, cell death, and production of intracellular reactive oxygen species. Hypericin prevented MGO-induced apoptosis in HUVECs by increasing Bcl-2 expression and decreasing Bax expression. MGO was found to activate mitogen-activated protein kinases (MAPKs). Pretreatment with hypericin strongly inhibited the activation of MAPKs, including P38, JNK, and ERK1/2. Interestingly, hypericin also inhibited the formation of AGEs. These findings suggest that hypericin may be an effective regulator of MGO-induced apoptosis. In conclusion, hypericin downregulated the formation of AGEs and ameliorated MGO-induced dysfunction in human endothelial cells.

• Biomolecules & Therapeutics
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• 제25권3호
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• pp.337-343
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• 2017

Kahweol as a coffee-specific diterpene has been reported to induce apoptosis in human cancer cells. Although some molecular targets for kahweol-mediated apoptosis have been elucidated, the further mechanism for apoptotic effect of kahweol is not known. Activating transcription factor 3 (ATF3) has been reported to be associated with apoptosis in colorectal cancer. The present study was performed to investigate the molecular mechanism by which kahweol stimulates ATF3 expression and apoptosis in human colorectal cancer cells. Kahweol increased apoptosis in human colorectal cancer cells. It also increased ATF3 expression through the transcriptional activity. The responsible cis-element for ATF3 transcriptional activation by kahweol was CREB located between -147 to -85 of ATF3 promoter. ATF3 overexpression increased kahweol-mediated cleaved PARP, while ATF3 knockdown attenuated the cleavage of PARP by kahweol. Inhibition of ERK1/2 and $GSK3{\beta}$ blocked kahweol-mediated ATF3 expression. The results suggest that kahweol induces apoptosis through ATF3-mediated pathway in human colorectal cancer cells.

• 한국자원식물학회지
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• 제31권6호
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• pp.634-640
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• 2018

Aralia cordata (A. cordata), which belongs to Araliaceae, is a perennial herb widely distributed in East Asia. We evaluated the anti-inflammatory effect of stems (AC-S), roots (AC-R) and leaves (AC-L) extracted with 100% methanol of A. cordata and elucidated the potential signaling pathway in LPS-stimulated RAW264.7 cells. The AC-L showed a strong anti-inflammatory activity through inhibition of NO production. AC-L dose-dependently inhibited NO production by suppressing iNOS, COX-2 and $IL-{\beta}$ expression in LPS-stimulated RAW264.7 cells. AC-L inhibited the degradation and phosphorylation of $I{\kappa}B-{\alpha}$, which donated to the inhibition of p65 nuclear accumulation and $NF-{\kappa}B$ activation. Furthermore, AC-L suppressed the phosphorylation of ERK1/2 and p38. These results suggested that AC-L may utilize anti-inflammatory activity by blocking $NF-{\kappa}B$ and MAPK signaling pathway and indicated that the AC-L can be used as a natural anti-inflammatory drugs.

• Journal of Microbiology and Biotechnology
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• 제29권7호
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• pp.1053-1060
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• 2019

Thermal drying is a common process used in the food industry for the modification of agricultural products. However, while various studies have investigated the alteration in physiochemical properties and chemical composition after drying, research focusing on the relationship between different dehydration conditions and bioactivity is scarce. In the current study, we prepared dried ginger under nine different conditions by varying the processing time and temperature and compared their immunomodulatory effects. Interestingly, depending on the drying condition, there were significant differences in the immunestimulating activity of the dried ginger samples. Gingers processed at $50^{\circ}C$ 1h displayed the strongest activation of macrophages measured by $TNF-{\alpha}$ and IL-6 levels, whereas, freezedried or $70^{\circ}C$- and $90^{\circ}C$-dried ginger showed little effect. Similar results were recapitulated in primary bone marrow-derived macrophages, further confirming that different dehydration conditions can cause significant differences in the immune-stimulating activity of ginger. Induction of ERK, p38, and JNK signaling was found to be the major underlying molecular mechanism responsible for the immunomodulatory effect of ginger. These results highlight the potential to improve the bioactivity of functional foods by selectively controlling processing conditions.

• BMB Reports
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• 제52권6호
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• pp.385-390
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• 2019

Leptin, an adipokine regulating energy metabolism, appears to be associated with breast cancer progression. Insulin-like growth factor-1 (IGF-1) mediates the pathogenesis of breast cancer. The regulation of IGF-1 expression by leptin in breast cancer cells is unclear. Here, we found that leptin upregulates IGF-1 expression at the transcriptional level in breast cancer cells. Activating protein-1 (AP-1)-binding element within the proximal region of IGF-1 was necessary for leptin-induced IGF-1 promoter activation. Forced expression of AP-1 components, c-FOS or c-JUN, enhanced leptin-induced IGF-1 expression, while knockdown of c-FOS or c-JUN abrogated leptin responsiveness. All three MAPKs (ERK1/2, JNK1/2, and p38 MAPK) mediated leptin-induced IGF-1 expression. These results suggest that leptin contributes to breast cancer progression through the transcriptional upregulation of leptin via the MAPK pathway.

• 대한한의학회지
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• 제41권4호
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• pp.12-26
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• 2020

Objectives: The aim of this study is to investigate the mechanisms involved in the anti-inflammatory and anti-tumor effects of Rhus verniciflua Stokes (RVS) on PMA-differentiated human monocytic leukemia THP-1 cells. Methods: Cells were treated with various concentrations of RVS decoction (0-300㎍/ml) for 24, 48, and 72h. Cell viability was evaluated by MTS/PMS assay. The expressions of MMP-2, MMP-9, TIMP-1, TIMP-2, iNOS and COX-2 mRNA and proteins were measured using RT-PCR and western blotting, respectively. Results: RVS suppressed expression of MMP-2 and MMP-9 mRNA. It also down-regulated iNOS and COX-2 mRNA and protein expression. RVS inhibited NF-𝜅B p65 activity and the phosphorylation of Akt and MAPK (ERK and p38 MAPK). Instead, the phosphorylation of JNK is increased at a very low concentration but decreased at higher concentrations. Conclusion: RVS is regarded to inhibit the expression of MMP and TIMP as well as iNOS and COX-2 gene expression via directly inhibiting the activation of NF-𝜅B and phosphorylation of MAPK pathway in THP-1 cells. This suggests RVS have potential to be used as a therapeutic agent for acute myeloid leukemia (AML).

• 한국식품과학회지
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• 제52권6호
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• pp.622-626
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• 2020

Recent studies have suggested that Canavalia gladiate, a dietary food and traditional folk medicine, has promising pharmaceutical potential, but the effects have mostly been demonstrated using its organo-soluble extract. To date, its immunomodulatory effect depending on the extraction method is unclear. Here, the immune responses of macrophages to C. gladiate and the underlying mechanisms were studied. C. gladiate hot water extract (CGW) induced cytokine production in bone marrow-derived macrophages (BMDMs) in a dose-dependent manner, whereas its ethanolic extract (CGE) did not. Immunoblotting analysis also showed that CGW activated nuclear factor (NF)-κB and mitogen-activated protein kinases (MAPKs). Moreover, an inhibitor assay revealed the involvement of NF-κB, p38, and JNK, but not ERK, in CGW-induced cytokine production. CGE inhibited lipopolysaccharide-stimulated production of pro-inflammatory cytokines and activation of NF-κB and MAPKs in BMDMs. The results suggest that C. gladiate regulates the immune responses of macrophages differently depending on the extraction method.