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Youjin Jeon - One of the best experts on this subject based on the ideXlab platform.
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Dieckol: an algal polyphenol attenuates urban fine dust-induced inflammation in RAW 264.7 cells via the activation of anti-inflammatory and antioxidant signaling pathways
Journal of Applied Phycology, 2019Co-Authors: K. K. Asanka Sanjeewa, Ginnae Ahn, Wonwoo Lee, Hye-won Yang, I. P.s. Fernando, Hyun-soo Kim, Thilina U. Jayawardena, Bomi Ryu, Youjin JeonAbstract:Fine dust-associated complications related to human health are one of the major issues in the East-Asia region. In the present study, we evaluated anti-inflammatory effect of Dieckol in fine dust-stimulated RAW 264.7 macrophage cells and its biological mechanism. The result showed that the exposure of macrophages to fine dust induced the productions of nitric oxide (NO), prostaglandin E_2 (PGE_2), and the mRNA expression levels of inflammatory mediators such as inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 whereas it was significantly attenuated by the treatment of Dieckol. In addition, fine dust increased the pro-inflammatory cytokines such as interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α that were down-regulated by Dieckol. Interestingly, Dieckol protected macrophages against cell damages via reducing the fine dust-caused intracellular reactive oxygen species (ROS) generation via induction of superoxide dismutase production as well as the HO-1/Nrf2 signaling activation. In conclusion, Dieckol protects RAW 264.7 cells against fine dust-induced inflammation and oxidative stress via inducing anti-inflammatory and antioxidant mechanisms.
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Dieckol Suppresses CoCl2-induced Angiogenesis in
2016Co-Authors: Endothelial Cells, Youjin Jeon, Young-mog Kim, Seung Hyun Jung, In Seung Jang, Sun Joo ParkAbstract:Dieckol is a polyphenol compound isolated from brown algae that has anti-oxidant, anti-inflammatory, and anti-tumor activity. We examined the anti-angiogenic effects of Dieckol in endothelial cells under hypoxic conditions. Treatment with CoCl2, a hypoxic mimetic agent, increased proliferation, adhesion, migration, and tube formation in HUVECs, as well as vessel sprouting in rat aortic rings, which correlated well with increased expression of hypoxia-inducible factor 1-alpha (HIF1α) and β1-integrin. Dieckol suppressed CoCl2-induced adhesion, migration, and tube formation in HUVECs and vessel sprouting in rat aortic rings. Dieckol treatment decreased CoCl2-induced overexpression of HIF1α and its downstream signaling molecules, including β1-integrin/Fak, Akt/eNOS, and p38 MAPK. These results suggest that Dieckol is a novel angiogenesis inhibitor and a potential treatment for angiogenesis-dependent diseases in humans, such as malignant tumors
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Dieckol, an edible seaweed polyphenol, retards rotenone-induced neurotoxicity and α-synuclein aggregation in human dopaminergic neuronal cells
RSC Advances, 2016Co-Authors: Seon-heui Cha, Youjin Jeon, Soojin Heo, Sang Myun ParkAbstract:Dopaminergic neurons are particularly vulnerable to oxidative stress, which may initiate a cascade of intracellular toxic events that lead to protein aggregation and subsequent cell death, causing Parkinson's disease. Here, we investigate the neuroprotective effect of Dieckol, which is a polyphenol isolated from an edible seaweed, Ecklonia cava, on rotenone-induced oxidative stress in SH-SY5Y cells, a human dopaminergic neuronal cell line. Dieckol was found to reduce intracellular reactive oxygen species (ROS) and cytochrome C release induced by treatment with rotenone. Consequently, Dieckol reduced rotenone-induced cell death, and retarded rotenone-induced α-synuclein aggregation in α-synuclein-overexpressing SH-SY5Y cells. These results clearly indicate that Dieckol possesses prominent antioxidant activity in dopaminergic neuronal cells preventing α-synuclein aggregation. Therefore, it could be a potential therapeutic agent for the prevention of neurodegenerative diseases such as Parkinson's disease.
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first evidence that ecklonia cava derived Dieckol attenuates mcf 7 human breast carcinoma cell migration
Marine Drugs, 2015Co-Authors: Eunkyung Kim, Youjin Jeon, Ji-hyeok Lee, Seung-hong Lee, Yujiao Tang, Yonsuk Kim, Jinwoo Hwang, Eunju Choi, Pyojam ParkAbstract:We investigated the effect of Ecklonia cava (E. cava)-derived Dieckol on movement behavior and the expression of migration-related genes in MCF-7 human breast cancer cell. Phlorotannins (e.g., Dieckol, 6,6′-biecko, and 2,7″-phloroglucinol-6,6′-bieckol) were purified from E. cava by using centrifugal partition chromatography. Among the phlorotannins, we found that Dieckol inhibited breast cancer cell the most and was selected for further study. Radius™-well was used to assess cell migration, and Dieckol (1–100 µM) was found to suppress breast cancer cell movement. Metastasis-related gene expressions were evaluated by RT-PCR and Western blot analysis. In addition, Dieckol inhibited the expression of migration-related genes such as matrix metalloproteinase (MMP)-9 and vascular endothelial growth factor (VEGF). On the other hand, it stimulated the expression of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2. These results suggest that Dieckol exerts anti-breast cancer activity via the regulation of the expressions of metastasis-related genes, and this is the first report on the anti-breast cancer effect of Dieckol.
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efficacy and safety of a Dieckol rich extract ag Dieckol of brown algae ecklonia cava in pre diabetic individuals a double blind randomized placebo controlled clinical trial
Food & Function, 2015Co-Authors: Seung-hong Lee, Youjin JeonAbstract:The effects of 12 weeks of supplementation with a Dieckol-rich extract (AG-Dieckol) from brown algae, Ecklonia cava, on glycemic parameters, serum biochemistry, and hematology were investigated in this study. Eighty pre-diabetic male and female adults were enrolled in a randomized, double-blind, placebo-controlled trial with parallel-group design. Subjects were randomly allocated into two groups designated as placebo and AG-Dieckol (1500 mg per day). Compared with the placebo group, the AG-Dieckol group showed a significant decrease in postprandial glucose levels after 12 weeks. The AG-Dieckol group also showed a significant decrease in insulin and C-peptide levels after 12 weeks, but there was no significant difference between the AG-Dieckol and placebo groups. There were no significant adverse events related to the consumption of AG-Dieckol, and biochemical and hematological parameters were maintained within the normal range during the intervention period. In conclusion, these results demonstrate that AG-Dieckol supplementation significantly contributes to lowering postprandial hyperglycemia and in reducing insulin resistance. Furthermore, we believe that based on these results the consumption of phlorotannin-rich foods such as marine algae may be useful for the treatment of diabetes.
Sun Joo Park - One of the best experts on this subject based on the ideXlab platform.
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Inhibitory effects of Dieckol on hypoxia-induced epithelial-mesenchymal transition of HT29 human colorectal cancer cells
Molecular medicine reports, 2016Co-Authors: Seung‑hyun Jeong, You‑jin Jeon, Sun Joo ParkAbstract:Hypoxia-induced epithelial-mesenchymal transition (EMT) has been identified as essential for tumor progression and metastasis. The present study examined the effects of an antioxidant, Dieckol, on hypoxia‑induced EMT in HT29 human colorectal cancer cells. HT29 cells were treated with a hypoxia‑inducing agent, CoCl2, and an increase in the levels of intracellular reactive oxygen species (ROS) and various morphological changes, such as loss of cell‑cell contact and aggressive cell migration were observed. CoCl2 also induced an increase in the expression of hypoxia‑inducible factor 1α (HIF1α) and various mesenchymal‑specific markers, including vimentin and snail family transcriptional repressor 1 (Snail1), and a decrease in the expression of E‑cadherin, thus suggesting that CoCl2 induced EMT in HT29 cells. Conversely, the CoCl2‑induced EMT of HT29 cells was suppressed following treatment with Dieckol. In addition, ROS generation, EMT marker protein expression and intracellular localization, cell migration and cell invasion were attenuated following Dieckol treatment. The findings of the present study suggested that Dieckol may inhibit hypoxia‑induced EMT in HT29 cells by regulating the levels of cellular ROS and protein expression levels downstream of the HIF1α signaling pathway. Therefore, Dieckol has the potential to become an attractive therapeutic agent for the treatment of colorectal cancer.
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Dieckol Suppresses CoCl2-induced Angiogenesis in
2016Co-Authors: Endothelial Cells, Youjin Jeon, Young-mog Kim, Seung Hyun Jung, In Seung Jang, Sun Joo ParkAbstract:Dieckol is a polyphenol compound isolated from brown algae that has anti-oxidant, anti-inflammatory, and anti-tumor activity. We examined the anti-angiogenic effects of Dieckol in endothelial cells under hypoxic conditions. Treatment with CoCl2, a hypoxic mimetic agent, increased proliferation, adhesion, migration, and tube formation in HUVECs, as well as vessel sprouting in rat aortic rings, which correlated well with increased expression of hypoxia-inducible factor 1-alpha (HIF1α) and β1-integrin. Dieckol suppressed CoCl2-induced adhesion, migration, and tube formation in HUVECs and vessel sprouting in rat aortic rings. Dieckol treatment decreased CoCl2-induced overexpression of HIF1α and its downstream signaling molecules, including β1-integrin/Fak, Akt/eNOS, and p38 MAPK. These results suggest that Dieckol is a novel angiogenesis inhibitor and a potential treatment for angiogenesis-dependent diseases in humans, such as malignant tumors
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original article Dieckol suppresses cocl2 induced angiogenesis in endothelial cells
Fisheries and Aquatic Sciences, 2014Co-Authors: Seung Hyun Jung, Young-mog Kim, Youjin Jeon, In Seung Jang, Sun Joo ParkAbstract:Dieckol is a polyphenol compound isolated from brown algae that has anti-oxidant, anti-inflammatory, and anti-tumor activity. We examined the anti-angiogenic effects of Dieckol in endothelial cells under hypoxic conditions. Treatment with CoCl2, a hypoxic mimetic agent, increased proliferation, adhesion, migration, and tube formation in HUVECs, as well as vessel sprouting in rat aortic rings, which correlated well with increased expression of hypoxia-inducible factor 1-alpha (HIF1α) and β1-integrin. Dieckol suppressed CoCl2-induced adhesion, migration, and tube formation in HUVECs and vessel sprouting in rat aortic rings. Dieckol treatment decreased CoCl2-induced overexpression of HIF1α and its downstream signaling molecules, including β1-integrin/Fak, Akt/eNOS, and p38 MAPK. These results suggest that Dieckol is a novel angiogenesis inhibitor and a potential treatment for angiogenesis-dependent diseases in humans, such as malignant tumors.
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anti hiv 1 activity of phlorotannin derivative 8 4 Dieckol from korean brown alga ecklonia cava
Bioscience Biotechnology and Biochemistry, 2014Co-Authors: Fatih Karadeniz, Sun Joo Park, Kyong-hwa Kang, Jae W. Park, Se-kwon KimAbstract:8,4‴-Dieckol is a natural product which has been isolated from brown alga, Ecklonia cava. This polyphenolic compound is a phlorotannin derivative with a broad range of bioactivities. Its inhibitory activity on human immunodeficiency virus type-1 (HIV-1) was tested and the results indicated that 8,4‴-Dieckol inhibited HIV-1 induced syncytia formation, lytic effects, and viral p24 antigen production at noncytotoxic concentrations. Furthermore, it was found that 8,4‴-Dieckol selectively inhibited the activity of HIV-1 reverse trancriptase (RT) enzyme with 91% inhibition ratio at the concentration of 50 μM. HIV-1 entry was also inhibited by 8,4‴-Dieckol. According to data from this study, 8,4‴-Dieckol is an effective compound against HIV-1 with high potential for further studies. These results suggest that it might be used as a drug candidate for the development of new generation therapeutic agents, although further studies on the mechanism of inhibition should be addressed.
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Anti-HIV-1 activity of phlorotannin derivative 8,4‴-Dieckol from Korean brown alga Ecklonia cava
Bioscience Biotechnology and Biochemistry, 2014Co-Authors: Fatih Karadeniz, Sun Joo Park, Kyong-hwa Kang, Jae W. Park, Se-kwon KimAbstract:8,4‴-Dieckol is a natural product which has been isolated from brown alga, Ecklonia cava. This polyphenolic compound is a phlorotannin derivative with a broad range of bioactivities. Its inhibitory activity on human immunodeficiency virus type-1 (HIV-1) was tested and the results indicated that 8,4‴-Dieckol inhibited HIV-1 induced syncytia formation, lytic effects, and viral p24 antigen production at noncytotoxic concentrations. Furthermore, it was found that 8,4‴-Dieckol selectively inhibited the activity of HIV-1 reverse trancriptase (RT) enzyme with 91% inhibition ratio at the concentration of 50 μM. HIV-1 entry was also inhibited by 8,4‴-Dieckol. According to data from this study, 8,4‴-Dieckol is an effective compound against HIV-1 with high potential for further studies. These results suggest that it might be used as a drug candidate for the development of new generation therapeutic agents, although further studies on the mechanism of inhibition should be addressed.
Yong Tae Kim - One of the best experts on this subject based on the ideXlab platform.
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Antioxidant Dieckol downregulates the Rac1/ROS signaling pathway and inhibits Wiskott-Aldrich syndrome protein (WASP)-family verprolin-homologous protein 2 (WAVE2)-mediated invasive migration of B16 mouse melanoma cells
Molecules and Cells, 2012Co-Authors: Sun Joo Park, Yong Tae Kim, Youjin JeonAbstract:Reactive oxygen species (ROS) generation is linked to dynamic actin cytoskeleton reorganization, which is involved in tumor cell motility and metastasis. Thus, inhibition of ROS generation and actin polymerization in tumor cells may represent an effective anticancer strategy. However, the molecular basis of this signaling pathway is currently unknown. Here, we show that the Ecklonia cava -derived antioxidant Dieckol downregulates the Rac1/ROS signaling pathway and inhibits Wiskott-Aldrich syndrome protein (WASP)-family verprolin-homologous protein 2 (WAVE2)-mediated invasive migration of B16 mouse melanoma cells. Steady-state intracellular ROS levels were higher in malignant B16F10 cells than in parental, nonmetastatic B16F0 cells. Elevation of ROS by H_2O_2 treatment increased migration and invasion ability of B16F0 cells to level similar to that of B16F10 cells, suggesting that intracellular ROS signaling mediates the prometastatic properties of B16 mouse melanoma cells. ROS levels and the cell migration and invasion ability of B16 melanoma cells correlated with Rac1 activation and WAVE2 expression. Overexpression of dominant negative Rac1 and depletion of WAVE2 by siRNA suppressed H_2O_2-induced cell invasion of B16F0 and B16F10 cells. Similarly, Dieckol attenuates the ROS-mediated Rac1 activation and WAVE2 expression, resulting in decreased migration and invasion of B16 melanoma cells. In addition, we found that Dieckol decreases association between WAVE2 and NADPH oxidase subunit p47^phox. Therefore, this finding suggests that WAVE2 acts to couple intracellular Rac1/ROS signaling to the invasive migration of B16 melanoma cells, which is inhibited by Dieckol.
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antioxidant Dieckol downregulates the rac1 ros signaling pathway and inhibits wiskott aldrich syndrome protein wasp family verprolin homologous protein 2 wave2 mediated invasive migration of b16 mouse melanoma cells
Molecules and Cells, 2012Co-Authors: Sun Joo Park, Yong Tae Kim, Youjin JeonAbstract:Reactive oxygen species (ROS) generation is linked to dynamic actin cytoskeleton reorganization, which is involved in tumor cell motility and metastasis. Thus, inhibition of ROS generation and actin polymerization in tumor cells may represent an effective anticancer strategy. However, the molecular basis of this signaling pathway is currently unknown. Here, we show that the Ecklonia cava-derived antioxidant Dieckol downregulates the Rac1/ROS signaling pathway and inhibits Wiskott-Aldrich syndrome protein (WASP)-family verprolin-homologous protein 2 (WAVE2)-mediated invasive migration of B16 mouse melanoma cells. Steady-state intracellular ROS levels were higher in malignant B16F10 cells than in parental, nonmetastatic B16F0 cells. Elevation of ROS by H2O2 treatment increased migration and invasion ability of B16F0 cells to level similar to that of B16F10 cells, suggesting that intracellular ROS signaling mediates the prometastatic properties of B16 mouse melanoma cells. ROS levels and the cell migration and invasion ability of B16 melanoma cells correlated with Rac1 activation and WAVE2 expression. Overexpression of dominant negative Rac1 and depletion of WAVE2 by siRNA suppressed H2O2-induced cell invasion of B16F0 and B16F10 cells. Similarly, Dieckol attenuates the ROS-mediated Rac1 activation and WAVE2 expression, resulting in decreased migration and invasion of B16 melanoma cells. In addition, we found that Dieckol decreases association between WAVE2 and NADPH oxidase subunit p47phox. Therefore, this finding suggests that WAVE2 acts to couple intracellular Rac1/ROS signaling to the invasive migration of B16 melanoma cells, which is inhibited by Dieckol.
Jung Hye Choi - One of the best experts on this subject based on the ideXlab platform.
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Dieckol, isolated from the edible brown algae Ecklonia cava, induces apoptosis of ovarian cancer cells and inhibits tumor xenograft growth
Journal of Cancer Research and Clinical Oncology, 2015Co-Authors: Ji-Hye Ahn, Yeong-In Yang, Kyung Tae Lee, Jung Hye ChoiAbstract:PurposeEcklonia cava is an abundant brown alga and has been reported to possess various bioactive compounds having anti-inflammatory effect. However, the anticancer effects of Dieckol, a major active compound in E. cava, are poorly understood. In the present study, we investigated the anti-tumor activity of Dieckol and its molecular mechanism in ovarian cancer cells and in a xenograft mouse model .MethodsMTT assay, PI staining, and PI and Annexin double staining were performed to study cell cytotoxicity, cell cycle distribution, and apoptosis. We also investigated reactive oxygen species (ROS) production and protein expression using flow cytometry and Western blot analysis, respectively. Anti-tumor effects of Dieckol were evaluated in SKOV3 tumor xenograft model.ResultsWe found that the E. cava extract and its phlorotannins have cytotoxic effects on A2780 and SKOV3 ovarian cancer cells. Dieckol induced the apoptosis of SKOV3 cells and suppressed tumor growth without any significant adverse effect in the SKOV3-bearing mouse model. Dieckol triggered the activation of caspase-8, caspase-9, and caspase-3, and pretreatment with caspase inhibitors neutralized the pro-apoptotic activity of Dieckol. Furthermore, treatment with Dieckol caused mitochondrial dysfunction and suppressed the levels of anti-apoptotic proteins. We further demonstrated that Dieckol induced an increase in intracellular ROS, and the antioxidant N-acetyl-l-cysteine (NAC) significantly reversed the caspase activation, cytochrome c release, Bcl-2 downregulation, and apoptosis that were caused by Dieckol. Moreover, Dieckol inhibited the activity of AKT and p38, and overexpression of AKT and p38, at least in part, reversed Dieckol-induced apoptosis in SKOV3 cells.ConclusionThese data suggest that Dieckol suppresses ovarian cancer cell growth by inducing caspase-dependent apoptosis via ROS production and the regulation of AKT and p38 signaling.
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Dieckol, isolated from the edible brown algae Ecklonia cava, induces apoptosis of ovarian cancer cells and inhibits tumor xenograft growth
Journal of Cancer Research and Clinical Oncology, 2014Co-Authors: Ji-Hye Ahn, Yeong-In Yang, Kyung Tae Lee, Jung Hye ChoiAbstract:Purpose Ecklonia cava is an abundant brown alga and has been reported to possess various bioactive compounds having anti-inflammatory effect. However, the anticancer effects of Dieckol, a major active compound in E. cava, are poorly understood. In the present study, we investigated the anti-tumor activity of Dieckol and its molecular mechanism in ovarian cancer cells and in a xenograft mouse model .
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6 6 bieckol isolated from marine alga ecklonia cava suppressed lps induced nitric oxide and pge2 production and inflammatory cytokine expression in macrophages the inhibition of nfκb
International Immunopharmacology, 2012Co-Authors: Yeong-In Yang, Hyeon Cheol Shin, Kyung Tae Lee, Seong Ho Kim, Woongyang Park, Jung Hye ChoiAbstract:Abstract Ecklonia cava is an edible brown alga that contains high levels of phlorotannins, which are unique marine polyphenolic compounds. In the present study, we investigated the anti-inflammatory effects and the underlying molecular mechanism of phlorotannin 6,6′-bieckol, which is an active component isolated from E. cava , on lipopolysaccharide (LPS)-stimulated primary macrophages and RAW 264.7 macrophage cells. 6,6′-Bieckol was found to inhibit nitric oxide (NO) and prostaglandin E 2 (PGE 2 ) production and to suppress the LPS-induced expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the mRNA and protein levels. In addition, 6,6′-bieckol downregulated the production and mRNA expression of the inflammatory cytokines TNF-α and IL-6. Moreover, pretreatment with 6,6′-bieckol decreased LPS-induced transactivation of nuclear factor-kappa B (NFκB) and nuclear translocation of p50 and p65 subunits of NFκB. Furthermore, chromatin immunoprecipitation assay revealed that 6,6′-bieckol inhibited LPS-induced NFκB binding to the TNF-α and IL-6 promoters. Taken together, these data suggest that the anti-inflammatory properties of 6,6′-bieckol are related to the down-regulation of iNOS, COX-2, and pro-inflammatory cytokines through the negative regulation of the NFκB pathway in LPS-stimulated macrophages.
Seung-hong Lee - One of the best experts on this subject based on the ideXlab platform.
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Correction: A marine algal polyphenol, Dieckol, attenuates blood glucose levels by Akt pathway in alloxan induced hyperglycemia zebrafish model
RSC Advances, 2016Co-Authors: Eun-a Kim, Ginnae Ahn, Ji-hyeok Lee, Seung-hong Lee, Nalae Kang, Seon-heui Cha, Shanura P. Fernando, Seo-young KimAbstract:Correction for ‘A marine algal polyphenol, Dieckol, attenuates blood glucose levels by Akt pathway in alloxan induced hyperglycemia zebrafish model’ by Eun-A Kim et al., RSC Adv., 2016, 6, 78570–78575.
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first evidence that ecklonia cava derived Dieckol attenuates mcf 7 human breast carcinoma cell migration
Marine Drugs, 2015Co-Authors: Eunkyung Kim, Youjin Jeon, Ji-hyeok Lee, Seung-hong Lee, Yujiao Tang, Yonsuk Kim, Jinwoo Hwang, Eunju Choi, Pyojam ParkAbstract:We investigated the effect of Ecklonia cava (E. cava)-derived Dieckol on movement behavior and the expression of migration-related genes in MCF-7 human breast cancer cell. Phlorotannins (e.g., Dieckol, 6,6′-biecko, and 2,7″-phloroglucinol-6,6′-bieckol) were purified from E. cava by using centrifugal partition chromatography. Among the phlorotannins, we found that Dieckol inhibited breast cancer cell the most and was selected for further study. Radius™-well was used to assess cell migration, and Dieckol (1–100 µM) was found to suppress breast cancer cell movement. Metastasis-related gene expressions were evaluated by RT-PCR and Western blot analysis. In addition, Dieckol inhibited the expression of migration-related genes such as matrix metalloproteinase (MMP)-9 and vascular endothelial growth factor (VEGF). On the other hand, it stimulated the expression of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2. These results suggest that Dieckol exerts anti-breast cancer activity via the regulation of the expressions of metastasis-related genes, and this is the first report on the anti-breast cancer effect of Dieckol.
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efficacy and safety of a Dieckol rich extract ag Dieckol of brown algae ecklonia cava in pre diabetic individuals a double blind randomized placebo controlled clinical trial
Food & Function, 2015Co-Authors: Seung-hong Lee, Youjin JeonAbstract:The effects of 12 weeks of supplementation with a Dieckol-rich extract (AG-Dieckol) from brown algae, Ecklonia cava, on glycemic parameters, serum biochemistry, and hematology were investigated in this study. Eighty pre-diabetic male and female adults were enrolled in a randomized, double-blind, placebo-controlled trial with parallel-group design. Subjects were randomly allocated into two groups designated as placebo and AG-Dieckol (1500 mg per day). Compared with the placebo group, the AG-Dieckol group showed a significant decrease in postprandial glucose levels after 12 weeks. The AG-Dieckol group also showed a significant decrease in insulin and C-peptide levels after 12 weeks, but there was no significant difference between the AG-Dieckol and placebo groups. There were no significant adverse events related to the consumption of AG-Dieckol, and biochemical and hematological parameters were maintained within the normal range during the intervention period. In conclusion, these results demonstrate that AG-Dieckol supplementation significantly contributes to lowering postprandial hyperglycemia and in reducing insulin resistance. Furthermore, we believe that based on these results the consumption of phlorotannin-rich foods such as marine algae may be useful for the treatment of diabetes.
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Dieckol a phlorotannin isolated from a brown seaweed ecklonia cava inhibits adipogenesis through amp activated protein kinase ampk activation in 3t3 l1 preadipocytes
Environmental Toxicology and Pharmacology, 2013Co-Authors: Myoungsook Lee, Seung-hong Lee, Ji-hyeok Lee, Yunsook Lim, Youjin JeonAbstract:In this study, we assessed the potential inhibitory effect of 5 species of brown seaweeds on adipogenesis the differentiation of 3T3-L1 preadipocytes into mature adipocytes by measuring Oil-Red O staining. The Ecklonia cava extract tested herein evidenced profound adipogenesis inhibitory effect, compared to that exhibited by the other four brown seaweed extracts. Thus, E. cava was selected for isolation of active compounds and finally the three polyphenol compounds of phlorotannins were obtained and their inhibitory effect on adipogenesis was observed. Among the phlorotannins, Dieckol exhibited greatest potential adipogenesis inhibition and down-regulated the expression of peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer-binding proteins (C/EBPα), sterol regulatory element-binding protein 1 (SREBP1) and fatty acid binding protein 4 (FABP4) in a dose-dependent manner. The specific mechanism mediating the effects of Dieckol was confirmed by AMP-activated protein kinase (AMPK) activation. These results demonstrate inhibitory effect of Dieckol compound on adipogenesis through the activation of the AMPK signal pathway.
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Dieckol isolated from brown seaweed ecklonia cava attenuates type іі diabetes in db db mouse model
Food and Chemical Toxicology, 2013Co-Authors: Min Cheol Kang, W. A J P Wijesinghe, Xiudong Yang, Sung-myung Kang, Seung-hong Lee, Byong-tae Jeon, Nalae Kang, Jaell Kim, Daeho Lee, Youjin JeonAbstract:In the present study, the attenuation of type ІІ diabetes by Dieckol, a phlorotannin derivative isolated from brown seaweed, Ecklonia cava was investigated in C57BL/KsJ-db/db, a type ІІ diabetes mouse model. Dieckol was administered intraperitoneal injection at doses of 10 and 20 mg/kg body weight diabetes mice for 14 days. The blood glucose level, serum insulin level and body weight were significantly reduced in the Dieckol administered group, compared to that of the saline administered group. Furthermore, reduced thiobarbituric acid reactive substraces (TBARS), as well as increased activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-px) in liver tissues were observed in the Dieckol administered group. In addition, increased levels of the phosphorylation of AMPK and Akt were observed in the muscle tissues of the Dieckol administered group in a Western blotting analysis. According to the findings of this study, it could be suggested that, Dieckol can be developed as a therapeutic agent for type ІІ diabetes.