• Journal of Life Science
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• v.25 no.9
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• pp.984-992
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• 2015

Sanguinarine is a benzophenanthridine alkaloid originally isolated from the roots of Sanguinaria canadensis. It has multiple biological activities (e.g., antioxidant and antiproliferative) and immune-enhancing potential. In this study, we explored the proapoptotic properties and modes of action of sanguinarine in human hepatocellular carcinoma HepG2 cells. Our results revealed that sanguinarine inhibited HepG2 cell growth and induced apoptosis in a dose-dependent manner. The induction of apoptosis by sanguinarine was associated with the up-regulation of Fas and Bax, the release of cytochrome c from the mitochondria to the cytosol, and the loss of the mitochondrial membrane potential. In addition, sanguinarine activated caspase-9 and -8, initiator caspases of the intrinsic and death extrinsic pathways, respectively, and caspase-3, accompanied by proteolytic degradation of poly (ADP-ribose) polymerase. Sanguinarine also triggered the generation of reactive oxygen species (ROS). The elimination of ROS by N-acetylcysteine reversed sanguinarine-induced apoptosis. Furthermore, sanguinarine induced the dephosphorylation of Akt and the phosphorylation of mitogen-activated protein kinases, including extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase (JNK), and p38. The growth inhibition was enhanced by the combined treatment of sanguinarine with a phosphatidylinositol 3'-kinase (PI3K) inhibitor and an ERK inhibitor but not JNK and p38 inhibitors. Overall, our data indicate that the proapoptotic effects of sanguinarine in HepG2 cells depend on ROS production and the activation of both intrinsic and extrinsic signaling pathways, which is mediated by blocking PI3K/Akt and activating the ERK pathway. Thus, our data suggest that sanguinarine may be a natural compound with potential for use as an antitumor agent in liver cancer.

• Biomolecules & Therapeutics
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• v.25 no.4
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• pp.417-426
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• 2017

4-O-methylhonokiol, a neolignan compound from Magnolia Officinalis, has been reported to have various biological activities including hair growth promoting effect. However, although transforming growth factor-${\beta}$ (TGF-${\beta}$) signal pathway has an essential role in the regression induction of hair growth, the effect of 4-O-methylhonokiol on the TGF-${\beta}$ signal pathway has not yet been elucidated. We thus examined the effect of 4-O-methylhonokiol on TGF-${\beta}$-induced canonical and noncanonical pathways in HaCaT human keratinocytes. When HaCaT cells were pretreated with 4-O-methylhonokiol, TGF-${\beta}1$-induced G1/G0 phase arrest and TGF-${\beta}1$-induced p21 expression were decreased. Moreover, 4-O-methylhonokiol inhibited nuclear translocation of Smad2/3, Smad4 and Sp1 in TGF-${\beta}1$-induced canonical pathway. We observed that ERK phosphorylation by TGF-${\beta}1$ was significantly attenuated by treatment with 4-O-methylhonokiol. 4-O-methylhonokiol inhibited TGF-${\beta}1$-induced reactive oxygen species (ROS) production and reduced the increase of NADPH oxidase 4 (NOX4) mRNA level in TGF-${\beta}1$-induced noncanonical pathway. These results indicate that 4-O-methylhonokiol could inhibit TGF-${\beta}1$-induced cell cycle arrest through inhibition of canonical and noncanonical pathways in human keratinocyte HaCaT cell and that 4-O-methylhonokiol might have protective action on TGF-${\beta}1$-induced cell cycle arrest.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.3
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• pp.181-188
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• 2004

The contaminative influence of beef due to the inhalation of air and the ingestion of soil of livestock, both of which are dealt with as minor contaminative pathways in most radioecological models but may not be neglected, was comprehensively investigated with the improvement of the Korean food chain model DYNACON. As the results, it was found that both pathways can not be neglected at all in the contamination of beef in the case of an accidental release during the non-grazing period of livestock. The ingestion of soil was more influential in the contamination of beef than the inhalation of air over most time following an release. If precipitation is encountered during an accidental release, contaminative influence due to the ingestion of soil was far greater compared with the cases of no precipitation. This fact was more distinct for a long-lived radionuclide $^{l37}Cs$ than a short-lived radionuclide $^{131}I$ (elemental iodine). Compared with the results for milk performed prior to this study, the contaminative pathways due to the inhalation of air and the ingestion of soil were more important in beef because of longer biological half-lives. On the other hand, in the case of an accidental release during the grazing period of livestock, radioactive contamination due to the ingestion of pasture was dominant irrespective of the existence of precipitation during an accidental release. It means that contaminative influence due to the inhalation of air and the ingestion of soil is negligible, like the cases of milk.

• Journal of Ginseng Research
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• v.45 no.4
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• pp.482-489
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• 2021

Background: Asthma is an incurable hyper-responsive disease of the pulmonary system that is caused by various allergens, including indoor and outdoor stimulators. According to the Global Asthma Network, 339 million people suffered from asthma in 2018, with particularly severe forms in children. Numerous treatments for asthma are available; however, they are frequently associated with adverse effects such as growth retardation, neurological disorders (e.g., catatonia, poor concentration, and insomnia), and physiological disorders (e.g., immunosuppression, hypertension, hyperglycemia, and osteoporosis). Methods: Korean Red Ginseng has long been used to treat numerous diseases in many countries, and we investigated the anti-asthmatic effects and mechanisms of action of Korean Red Ginseng. Eighty-four BALB/c mice were assigned to 6 treatment groups: control, ovalbumin-induced asthma group, dexamethasone treatment group, and 3 groups treated with Korean Red Ginseng water extract (KRGWE) at 5, 25, or 50 mg/kg/day for 5 days. Anti-asthmatic effects of KRGWE were assessed based on biological changes, such as white blood cell counts and differential counts in the bronchoalveolar lavage fluid, serum IgE levels, and histopathological changes in the lungs, and by examining anti-asthmatic mechanisms, such as the cytokines associated with Th1, Th2, and Treg cells and inflammation pathways. Results: KRGWE affected ovalbumin-induced changes, such as increased white blood cell counts, increased IgE levels, and morphological changes (mucous hypersecretion, epithelial cell hyperplasia, inflammatory cell infiltration) by downregulating cytokines such as IL-12, IL-4, and IL-6 via GATA-3 inactivation and suppression of inflammation via NF-κB/COX-2 and PGE₂ pathways. Conclusion: KRGWE is a promising drug for asthma treatment.

• Journal of Ginseng Research
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• v.45 no.3
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• pp.408-419
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• 2021

Background: The decreased renal function is known to be associated with biological aging, of which the main pathological features are chronic inflammation and renal interstitial fibrosis. In previous studies, we reported that total saponins from Panax japonicus (SPJs) can availably protect acute myocardial ischemia. We proposed that SPJs might have similar protective effects for aging-associated renal interstitial fibrosis. Thus, in the present study, we evaluated the overall effect of SPJs on renal fibrosis. Methods: Sprague-Dawley (SD) aging rats were given SPJs by gavage beginning from 18 months old, at 10 mg/kg/d and 60 mg/kg/d, up to 24 months old. After the experiment, changes in morphology, function and fibrosis of their kidneys were detected. The levels of serum uric acid (UA), β2-microglobulin (β2-MG) and cystatin C (Cys C) were assayed with ELISA kits. The levels of extracellular matrix (ECM), matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), inflammatory factors and changes of oxidative stress parameters were examined. Results: After SPJs treatment, SD rats showed significantly histopathological changes in kidneys accompanied by decreased renal fibrosis and increased renal function; As compared with those in 3-month group, the levels of serum UA, Cys C and β2-MG in 24-month group were significantly increased (p < 0.05). Compared with those in the 24-month group, the levels of serum UA, Cys C and β2-MG in the SPJ-H group were significantly decreased. While ECM was reduced and the levels of MMP-2 and MMP-9 were increased, the levels of TIMP-1, TIMP-2 and transforming growth factor-β1 (TGF-β1)/Smad signaling were decreased; the expression level of phosphorylated nuclear factor kappa-B (NF-κB) was down-regulated with reduced inflammatory factors; meanwhile, the expression of nuclear factor erythroid 2-related factor 2-antioxidant response element (Nrf2-ARE) signaling was aggrandized. Conclusion: These results suggest that SPJs treatment can improve age-associated renal fibrosis by inhibiting TGF-β1/Smad, NFκB signaling pathways and activating Nrf2-ARE signaling pathways and that SPJs can be a potentially valuable anti-renal fibrosis drug.

• Korean Journal of Plant Resources
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• v.33 no.4
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• pp.279-286
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• 2020

Purple loosestrife-Lythrum anceps (Koehne) Makino is a herbaceous perennial plant belonging to the Lythraceae family. It has been used for centuries in Korea and other Asian traditional medicine. It has been showed pharmacological effects, including anti-oxidant and anti-microbial effects. However, the mechanisms underlying its anti-cancer effect are not yet understood. In this study, we investigated the mechanism of apoptosis signaling pathways by ethanol extract of Lythrum anceps (Koehne) Makino (ELM) in human leukemia U937 cells. Treatment with ELM significantly inhibited cell growth in a dose-dependent manner by inducing apoptosis, as evidenced by the formation of apoptotic bodies (ApoBDs), DNA fragmentation and increased populations of sub-G1 ratio. Induction of apoptosis by ELM was connected with up-regulation of death receptor (DR) 4 and DR5, pro-apoptotic Bax protein expression and down-regulation of anti-apoptotic Bcl-2 protein, and inhibitor of apoptosis protein (IAP) family proteins, depending on dosage. This induction was associated with Bid truncation, mitochondrial dysfunction, proteolytic activation of caspases (-3, -8 and -9) and cleavage of poly(ADP-ribose) polymerase protein. Therefore, our data indicate that ELM suppresses U937 cell growth by activating the intrinsic and extrinsic apoptosis pathways, and thus may have applications as a potential source for an anti-leukemic chemotherapeutic agent.

• Journal of Life Science
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• v.26 no.7
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• pp.764-771
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• 2016

Extracts from Artemisia annua Linné (AAE) have been known to possess various functions, including anti-bacterial, anti-virus, and anti-oxidant effects. However, the mechanism of those effects of AAE is not well-known. The aim of this study was to analyze the inhibitory effects of AAE on cell proliferation of the human hepatoma cell line (Hep3B) and to examine its effects on apoptosis. Activation by phosphorylation of Akt is cell proliferation through the phosphorylation of TSC2, mTOR, and GSK-3β. We suggested that AAE may exert cancer cell apoptosis through Akt/mTOR/GSK-3β signal pathways and mitochondria-mediated apoptotic proteins. For this, we examined the effects of extracts of AAE on cell proliferation according to treatment concentration. Treatment with AAE not only reduced cell viability, but also resulted in the induced release of lactate dehydrogenase (LDH). These results were determined with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and a lactate dehydrogenase (LDH) assay. Furthermore, we determined the effects of apoptosis through Hoechst 33342 staining, annexinⅤ-propidium iodide (PI) staining, 5,5′, 6,6′-tetrachloro-1,1′,3,3′-tetraethyl-imidacarbocyanine iodide (JC-1) staining, and Western blotting. Our study showed that the treatment of liver cancer cells with AAE resulted in the inhibition of Akt, TSC2, GSK-3β-phosphorylated, Bcl-2, and pro-caspase 3 and the activation of Bim, Bax, Bak, and cleaved PARP expressions. These results indicate that AAE induced apoptosis by means of a mitochondrial event through the regulate of Akt/mTOR/GSK-3β signaling pathways.

• Journal of Life Science
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• v.32 no.11
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• pp.833-840
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• 2022

Chronic inflammation has been shown to be closely associated with tumor development and progression. Nuclear factor kappa B (NF-κB) is composed of a family of five transcription factors. NF-κB signaling plays a crucial role in the inflammatory response and is often found to be dysregulated in various types of cancer, making it an attractive target in cancer therapeutics. In this study, CDC-like kinase 3 (CLK3) was identified as a novel kinase that regulates the NF-κB signaling pathway. Our data demonstrate that CLK3 inhibits the canonical and non-canonical NF-κB pathways. Luciferase assays following the transient or stable expression of CLK3 indicated that this kinase inhibited NF-κB activation mediated by Tumor necrosis factor-alpha (TNFα) and Phorbol 12-myristate 13-acetate (PMA), which are known to activate NF-κB signaling via the canonical pathway. Consistent with data on the ectopic expression of CLK3, CLK3 knockdown using shRNA constructs increased NF-κB activity 1.5-fold upon stimulation with TNFα in HEK293 cells compared with the control cells. Additionally, overexpression of CLK3 suppressed the activation of this signaling pathway induced by NF-κB-inducing kinase (NIK) or CD40, which are well-established activators of the non-canonical pathway. To further examine the negative impact of CLK3 on NF-κB signaling, we performed Western blotting following the TNFα treatment to directly identify the molecular components of the NF-κB pathway that are affected by this kinase. Our results revealed that CLK3 mitigated the phosphorylation/activation of transforming growth factor-α-activated kinase 1 (TAK1), inhibitor of NF-κB kinase alpha/beta (IKKα/α), NF-κB p65 (RelA), NF-κB inhibitor alpha (IκBα), and Extracellular signal-regulated kinase 1/2-Mitogen-activated protein kinase (ERK1/2-MAPK), suggesting that CLK3 inhibits both the NF-κB and MAPK signaling activated by TNFα exposure. Further studies are required to elucidate the mechanism by which CLK3 inhibits the canonical and non-canonical NF-κB pathways. Collectively, these findings reveal CLK3 as a novel negative regulator of NF-κB signaling.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1708-1716
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• 2016

The Akt/mammalian target of the rapamycin (mTOR) pathway is activated in the majority of human cancers. Activation of the Akt/mTOR pathway confers resistance to many types of cancer therapy. In this study, we evaluated the apoptotic effect of ethanol extract of Artemisia annua L. through down-regulation of Akt signal pathways and the mitochondrial pathway in hepato-carcinoma cells (HepG2). A. annua extract is known as a medicinal herb that is effective against cancer. We evaluated anti-proliferative activity by MTT-based viability assay and apoptotic effect by Annexin-V/PI staining, mitochondrial membrane potential (MMP), and caspase-3/7 activity as determined by flow cytometry. A. annua treatment led to loss of MMP, resulting in cytochrome c-inducible activation of caspase-3/7. Treatment with A. annua extract reduced activities of Akt/mTOR/anti-apoptotic proteins (such as Bcl-2 and $Bcl-X_L$), leading to increased activation of tumor suppressor p53 and pro-apoptotic proteins (such as Bax and Bak). We applied LY294002 (inhibitor of Akt) and rapamycin (inhibitor of mTOR) to determine the relationship between signal transduction of proteins associated with apoptosis. LY294002 and rapamycin significantly reduced cell viability and increased apoptosis. These results indicate that Bcl-2 and caspase-3 are key regulators in A. annua extract-induced apoptosis in HepG2 cells and are controlled through the Akt/mTOR signaling pathway.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.122-126
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• 2010

RAD53 functions as an effector kinase of checkpoint pathways in Saccharomyces cerevisiae, which plays a central role to regulate many downstream cellular processes in response to DNA damage. It also involves in transcriptional activation of various genes including RNR genes which encode the key enzyme required for dNTP synthesis. In this study, we identified CYC8 as a suppressor for the hydroxyurea sensitivity of $rad53{\Delta}$ mutation. $Rad53{\Delta}$ mutant transformed with a multi-copy plasmid containing CYC8 showed increased hydroxyurea resistance. In contrast, TUP1 which forms a complex with CYC8 did not function as a suppressor. In the case of mutations, both $cyc8{\Delta}$ and $tup1{\Delta}$ suppressed hydroxyurea sensitivity of $rad53{\Delta}$. Since CYC8 can propagate as a prion in yeast, overexpression of CYC8 induced misfolding of the normal CYC8 proteins, resulting in dominant cyc8-phenotype. Therefore, it is suggested that CYC8 can act as a multi-copy suppressor due to its prion property. It was observed that the levels of RNR transcription were increased in the yeast strains containing either multi-copies of CYC8 gene or $cyc8{\Delta}$ mutation, suggesting that the increased level of RNR will elevate the intracellular pools of dNTPs, which, in turn, suppress the phenotype of $rad53{\Delta}$ mutation.