• Title/Summary/Keyword: degradation pathway

Search Result 432, Processing Time 0.021 seconds

Effect of the Hesperetin and Naringenin on $pp60^{v-src}$-induced $NF-{\kappa}B$ Activation ($pp60^{v-src}$에 의한 $NF-{\kappa}B$ 활성화에 대한 헤스페레틴과 나린제닌의 저해 효과)

  • Kwon, O-Song;Kim, Bo-Yeon;Kim, Kyoung-A;Kim, Min-Soo;Oh, Hyun-Cheol;Kim, Beom-Seok;Kim, Young-Ho;Ahn, Jong-Seog
    • Korean Journal of Pharmacognosy
    • /
    • v.35 no.3 s.138
    • /
    • pp.244-249
    • /
    • 2004
  • The effects of hesperetin and naringenin on $NF-{\kappa}B$ activation were investigated in normal rat kidney cells transformed by temperature sensitive Rous Sarcoma Virus (tsNRK). The flavonoids, naringenin and hesperetin, significantly reduced v-Src-induced $NF-{\kappa}B$ activation as well as phosphorylation of Akt and GSK-3 in tsNRK cells, whereas these compounds did not effect on platelet-derived growth factor (PDGF)-induced $NF-{\kappa}B$ activation in $NIH3T3{\gamma}l$ cells. In addition, the DNA binding activity of SP-I was also reduced but that of AP-1 was not affected by the compounds. Our study suggests that Src-induced $NF-{\kappa}B$ activation could occur via Akt-GSK-3 pathway without $IkB{\alpha}$ degradation and that naringenin and hesperetin could be used in the treatment of cancer through the inhibition of $NF-{\kappa}B$ activation.

Effect of the KH-304 on the Nitric Oxide Synthase Activity and Erectile Dysfunction in Young Rats (KH-304 투여가 흰쥐 음경조직의 Nitric Oxide Synthase활성 및 Erectile dysfunction에 미치는 영향)

  • Lee, Eun-Jeong;Lee, Hyun-Ji;Kim, Hee-Seok;Hwang, Sung-Yeoun
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.20 no.3
    • /
    • pp.680-684
    • /
    • 2006
  • This study was designed to investigate effects of KH-304 in improving erectile dysfunction (ED), particularly in terms of nitric oxide (NO)-cGMP pathways. After oral administration of the KH-304 water extract, 1OOmg, 300mg, 500mg or 700mg per 1 kg of Dody weigh for 10days, We examined the expression and activity of two enzyme: neuronal NO synthase (nNOS), endothelial NO synthase (eNOS) and that act upon the major NO-cGMP signaling pathway in penile tissue. Effect of KH-304 on COMP degradation was also examined using bovine vascular smooth muscle cells pretreated with an NO donor, S-nitroso-N-Acetylpenicillamine (SNAP), Also, it examined the endothelial NO synthase (eNOS) for seaching effecting period (100mg, 300mg/kg for 10 and 30days) and peak intracavernous pressures (ICPS) in penile tissues rabbit copus cavernosum contracted by 10-6 M phenylephrine. The severely reduced peak intracavernous pressures (ICPS) in penile tissues were restored completely after KH-304 treatment, and KH-304 treatment significantly made the latency period earlier. Furthermore, the penile expression levels of nNOS, eNOS dependent NOS activities and COMP concentrations were increased significantly in the KH-304 100, 300mg treated rats. These results suggest that KH-304 with high expression of NOS may be useful in erectile dysfunction.

Induction of Apoptosis and Its Mechanism by Siegesbeckia Glabrescens in HepG2 cells (간암 세포주에서의 희렴의 Apoptosis 유도와 기전)

  • Kim, Yoon-Tae;Lee, Heon-Jae;Kim, Gil-Whon;Shin, Heung-Mook
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.19 no.3
    • /
    • pp.640-646
    • /
    • 2005
  • This study was performed for the investigation of anticancer effects of Siegesbeckia glabrescens(SG) on HepG2 cells, a human hepatoma cell line. In the previous study, we examined the involvement of nitric oxide (NO) on anti-proliferative and apoptotic efficacy of SG in vascular smooth muscle cells. The possible mechanism of the apoptotic effects of SG was investigated in HepG2 cells. SG showed potent cytotoxic activity in HepG2 but not chang cells, liver normal cells. SG treatment caused morphological change such as cell shrinkage, nuclei condensation and cell blebbing in HepG2 cells. SG also increased the nitrite production of HepG2 cells in a dose-dependent manner. Furthermore, L-NNA treatment inhibited the anti-proliferative effect of SG. From RT-PCR, SG decreased Bcl-2 but no affected on Bax. Western blot for procaspase-3 and COX-2 showed that degradation of procaspase-3 protein level or inhibition of COX-2 protein expression by SG treatment. In addition, the apoptotic effect of SG was also demonstrated by DNA laddering. In conclusion, SG-induced HepG2 cells death can occur via apoptosis which was dose-dependent, and associated with apoptosis-related Bcl-2/Bax gene expressions, COX-2 inhibition, caspase-3 activation and NO pathway. These results suggest that SG is potentially useful as a chemotherapeutic/chemopreventive agent in hepatocellular carcinoma.

Aromadendrin Inhibits Lipopolysaccharide-Induced Nuclear Translocation of NF-κB and Phosphorylation of JNK in RAW 264.7 Macrophage Cells

  • Lee, Jae-Won;Kim, Nam Ho;Kim, Ji-Young;Park, Jun-Ho;Shin, Seung-Yeon;Kwon, Yong-Soo;Lee, Hee Jae;Kim, Sung-Soo;Chun, Wanjoo
    • Biomolecules & Therapeutics
    • /
    • v.21 no.3
    • /
    • pp.216-221
    • /
    • 2013
  • Aromadendrin, a flavonol, has been reported to possess a variety of pharmacological activities such as anti-inflammatory, antioxidant, and anti-diabetic properties. However, the underlying mechanism by which aromadendrin exerts its biological activity has not been extensively demonstrated. The objective of this study is to elucidate the anti-inflammatory mechanism of aromadedrin in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. Aromadendrin significantly suppressed LPS-induced excessive production of pro-inflammatory mediators such as nitric oxide (NO) and $PGE_2$. In accordance, aromadendrin attenuated LPS-induced overexpression iNOS and COX-2. In addition, aromadendrin significantly suppressed LPS-induced degradation of $I{\kappa}B$, which sequesters NF-${\kappa}B$ in cytoplasm, consequently inhibiting the nuclear translocation of pro-inflammatory transcription factor NF-${\kappa}B$. To elucidate the underlying signaling mechanism of anti-inflammatory activity of aromadendrin, MAPK signaling pathway was examined. Aromadendrin significantly attenuated LPS-induced activation of JNK, but not ERK and p38, in a concentration-dependent manner. Taken together, the present study clearly demonstrates that aromadendrin exhibits anti-inflammatory activity through the suppression of nuclear translocation of NF-${\kappa}B$ and phosphorylation of JNK in LPS-stimulated RAW 264.7 macrophage cells.

Biodegradation of Fungicide Tolclofos-methyl by Sphingomonas sp. 224 (Sphingomonas sp. 224 균주에 의한 살균제 tolclofos-methyl의 분해)

  • Kwak, Yun-Young;Shin, Kab-Sik;Lee, Sang-Man;Kim, Jang-Eok;Rhee, In-Koo;Shin, Jae-Ho
    • Korean Journal of Environmental Agriculture
    • /
    • v.29 no.4
    • /
    • pp.388-395
    • /
    • 2010
  • In order to decrease level of an organophosphorus fungicide, tolclofos-methyl, from in situ ginseng cultivating soil, we isolated a tolclofos-methyl degrading bacteria from ginseng cultivating soil samples. The bacterial strain removed tolclofos-methyl around 95% after 3 days incubation with complete liquid media. The strain was identified as Sphingomonas sp. by 16S rDNA sequence comparison, and designated as Sphingomonas sp. 224. Through the GC-MS analysis, Sphingomonas sp. 224 was proposed to have an initiative degradation pathway generating the metabolite such as 2,6-dichloro-4-methyl phenol compound from tolclofos-methyl. In addition, Sphingomonas sp. 224 was confirmed representing the effective degrading capability to tolclofosmethyl in situ soil.

Study on the Anti-inflammatory Effect and Mechanism of Prunus mume Extract Regarding NF-κB (NF-κB 조절을 통한 오매추출물의 항염효과 및 작용기작에 관한 연구)

  • Seo, Won-Sang;Oh, Han-Na;Park, Woo-Jung;Um, Sang-Young;Lee, Dae-Woo;Kang, Sang-Mo
    • KSBB Journal
    • /
    • v.29 no.1
    • /
    • pp.50-57
    • /
    • 2014
  • NF-${\kappa}B$ is a transcriptional factor which is involved in many biological processes including immunity, inflammation, and cell survival. Many investigators studied on the mechanism involved in activation of NF-${\kappa}B$ signalling pathway via ubiquitination and degradation of $I{\kappa}B$ regarding skin disease. Some specific molecules including Akt, MEK, p38 MAP Kinase, Stat3, et al. represent convergence points and key regulatory proteins in signaling pathways controlling cellular events such as growth and differentiation, energy homeostasis, and the response to stress and inflammation. Ultraviolet (UV) irradiation has many adverse effects on skin, including inflammation, alteration in the extracellular matrix, cellular senescence, apoptosis and skin cancer. Prunus mume, a naturally derived plant extract, has beneficial biological activities as blood fluidity improvement, anti-fatigue action, antioxidative and free radical scavenging activities, inhibiting the motility of Helicobacter pyolri. Previous reports on various beneficial function prompted us to investigate UVB-induced or other immunostimulated biological marker regarding P. mume extract. P. mume extract suppresses UVB-induced cyclooxygenase-2 (COX-2) expression in mouse skin epidermal JB6 P+ cells. The activation of activator protein-1 and nuclear factor-${\kappa}B$ induced by UVB was dose-dependently inhibited by P. mume extract treatment. This results suggest that P. mume extracts might be used as a potential agents for protection of inflammation or UVB induced skin damage.

Protective Effects of Isorhamnetin against Hydrogen Peroxide-Induced Apoptosis in C2C12 Murine Myoblasts (C2C12 근아세포에서 산자나무 유래 Isorhamnetin의 산화적 스트레스에 의한 Apoptosis 유발 억제 효과)

  • Choi, Yung Hyun
    • Journal of Korean Medicine for Obesity Research
    • /
    • v.15 no.2
    • /
    • pp.93-103
    • /
    • 2015
  • Objectives: It was investigated the cytoprotective efficacies of isorhamnetin, a flavonoid originally derived from Hippophae rhamnoides L., against oxidative stress-induced apoptosis in C2C12 myoblasts. Methods: The effects of isorhamnetin on cell growth, apoptosis and reactive oxygen species (ROS) generation were evaluated by trypan blue dye exclusion assay, 4',6-diamidino-2-phenylindole staining and flow cytometry. The levels of apoptosis-regulatory and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway-related proteins, and caspase activities (caspase-3 and -9) were determined by Western blot analysis and colorimetric assay, respectively. Results: Our results revealed that treatment with isorhamnetin prior to hydrogen peroxide ($H_2O_2$) exposure significantly increased the C2C12 cell viability and, indicating that the exposure of C2C12 cells to isorhamnetin conferred a protective effect against oxidative stress. Isorhamnetin also effectively attenuated $H_2O_2$-induced apoptosis and ROS generation, which was associated with the restoration of the upregulation of Bax and downregulation of Bcl-2 induced by $H_2O_2$. In addition, $H_2O_2$ enhanced the activation of caspase-9 and -3, and degradation of poly (ADP-ribose)-polymerase, a typical substrate protein of activated caspase-3; however, these events were almost totally reversed by pretreatment with isorhamnetin. Moreover, isorhamnetin increased the levels of heme oxygenase-1, a potent antioxidant enzyme, associated with the induction of Nrf2. Conclusions: Our data indicated that isorhamnetin may potentially serve as an agent for the treatment and prevention of muscle disorders caused by oxidative stress.

Cancer Chemoprevention by Tea Polyphenols Through Modulating Signal Transduction Pathways

  • Lin, Jen-Kun
    • Archives of Pharmacal Research
    • /
    • v.25 no.5
    • /
    • pp.561-571
    • /
    • 2002
  • The action mechanisms of several chemopreventive agents derived from herbal medicine and edible plants have become attractive issues in cancer research. Tea is the most widely consumed beverage worldwide. Recently, the cancer chemopreventive actions of tea have been intensively investigated. It have been demonstrated that the active principles of tea were attributed to their tea polyphenols. Recently, tremendous progress has been made in elucidating the molecular mechanisms of cancer chemoprevention by tea and tea polyphenols. The suppression of various tumor biomarkers including growth factor receptor tyrosine kinases, cytokine receptor kinases, P13K, phosphatases, ras, raf, MAPK cascades, NㆍFB, IㆍB kinase, PKA, PKB, PKC, c-jun, c-fos, c-myc, cdks, cyclins, and related transducing proteins by tea polyphenols has been studied in our laboratory and others. The IㆍB kinase (IKK) activity in LPS-activated murine macrophages (RAW 264.7 cells) was found to be inhibited by various tea polyphenols including (-) epigallocatechin-3-gallate (EGCG), theaflavin (TF-1), theaflavin-3-gal-late (TF-2) and theaflavin-3,3'-digallate (TF-3). TF-3 inhibited IKK activity in activated macrophages more strongly than did the other tea polyphenols. TF-3 inhibited both IKK1 and IKK2 activity and prevented the degradation of IㆍBㆍand IㆍBㆍin activated macrophage cells. The results suggested that the inhibition of IKK activity by TF-3 and other tea polyphenols could occur by a direct effect on IKKs or on upstream events in the signal transduction pathway. TF-3 and other tea polyphenols blocked phosphorylation of IB from the cytosolic fraction, inhibited NFB activity and inhibited increases in inducible nitric oxide synthase levels in activated macrophage. TF-3 and other tea polyphenols also inhibited strongly the activities of xanthine oxidase, cyclooxygenase, EGF-receptor tyrosine kinase and protein kinase C. These results suggest that TF-3 and other tea polyphenols may exert their cancer chemoprevention through suppressing tumor promotion and inflammation by blocking signal transduction. The mechanisms of this inhibition may be due to the blockade of the mitogenic and differentiating signals through modulating EGFR function, MAPK cascades, NFkB activation as wll as c-myc, c-jun and c-fos expression.

Regulations of Reversal of Senescence by PKC Isozymes in Response to 12-O-Tetradecanoylphorbol-13-Acetate via Nuclear Translocation of pErk1/2

  • Lee, Yun Yeong;Ryu, Min Sook;Kim, Hong Seok;Suganuma, Masami;Song, Kye Yong;Lim, In Kyoung
    • Molecules and Cells
    • /
    • v.39 no.3
    • /
    • pp.266-279
    • /
    • 2016
  • The mechanism by which 12-O-tetradecanoylphorbol-13-acetate (TPA) bypasses cellular senescence was investigated using human diploid fibroblast (HDF) cell replicative senescence as a model. Upon TPA treatment, protein kinase C (PKC) ${\alpha}$ and $PKC{\beta}1$ exerted differential effects on the nuclear translocation of cytoplasmic pErk1/2, a protein which maintains senescence. $PKC{\alpha}$ accompanied pErk1/2 to the nucleus after freeing it from $PEA-15pS^{104}$ via $PKC{\beta}1$ and then was rapidly ubiquitinated and degraded within the nucleus. Mitogen-activated protein kinase docking motif and kinase activity of $PKC{\alpha}$ were both required for pErk1/2 transport to the nucleus. Repetitive exposure of mouse skin to TPA downregulated $PKC{\alpha}$ expression and increased epidermal and hair follicle cell proliferation. Thus, $PKC{\alpha}$ downregulation is accompanied by in vivo cell proliferation, as evidenced in 7, 12-dimethylbenz(a)anthracene (DMBA)-TPA-mediated carcinogenesis. The ability of TPA to reverse senescence was further demonstrated in old HDF cells using RNA-sequencing analyses in which TPA-induced nuclear $PKC{\alpha}$ degradation freed nuclear pErk1/2 to induce cell proliferation and facilitated the recovery of mitochondrial energy metabolism. Our data indicate that TPA-induced senescence reversal and carcinogenesis promotion share the same molecular pathway. Loss of $PKC{\alpha}$ expression following TPA treatment reduces pErk1/2-activated SP1 biding to the $p21^{WAF1}$ gene promoter, thus preventing senescence onset and overcoming G1/S cell cycle arrest in senescent cells.

Reductive Degradation Kinetics and Pathways of Chlorophenolic Organic Pollutants by Nickel-Coated Zero Valent Iron (니켈로 코팅된 영가금속을 이용한 염소계 페놀화합물의 반응경로 및 반응율 평가)

  • Shin, Seung-Chul;Kim, Young-Hun;Ko, Seok-Oh
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.28 no.5
    • /
    • pp.487-493
    • /
    • 2006
  • Reductive dechlorination of chlorophenols by nickel coated iron was investigated to understand the feasibility of using Ni/Fe for the in situ remediation of contaminated groundwater. Zero Valent Iron(ZVI) was amended with Ni(II) ions to form bimetal(Ni/Fe). Dechlorination of five chlorophenol compounds and formation of intermediates were examined using Ni/Fe. Rate constant for each reaction pathway was quantified by the numerical integration of a series of differential rate equation. Experimental results showed that the sequence of hydrodechlorination rate constant was in the order of 2-CP>4-CP>2,4-DCP>2,4,6-TCP>2,6-DCP. The hydrodechlorination pathways for the conversion of each chlorophenol compound involves a full dechlorination to phenol via both concerted and stepwise mechanisms. Reaction pathways and corresponding kinetic rate constants were suggested based on the experiments and numerical simulations.