Time filter

Source Type

Anyang, South Korea

Jayasooriya R.G.P.T.,Jeju National University | Kang C.-H.,Jeju National University | Park S.-Y.,Ottogi Corporation | Choi Y.H.,Korea University | Kim G.-Y.,Jeju National University
Tropical Journal of Pharmaceutical Research | Year: 2012

Purpose: This study is aimed at identifying the anti-inflammatory mechanisms of a methanol extract of Polyopes lancifolius (MEPL) in lipopolysaccharide (LPS)-stimulated BV2 microglia cells. Methods: The expression of mRNA and protein were investigated RT-PCR and western blot analyses in LPS-stimulated BV2 microglial cells. The level of nitric oxide (NO) production was analyzed using Griess reaction. The release of prostaglandin E2 (PGE2) and tumor necrosis factor-α (TNF-α) were determined using sandwich ELISA. NF-κB activation was detected using EMSA methods. Results: MEPL significantly suppressed NO production in LPS-stimulated BV2 cells without any cytotoxicity. The results also indicate that MEPL decreased the production of PGE2 and TNF-α in LPSstimulated BV2 cells. Furthermore, pretreatment with MEPL resulted in a downregulation of LPSinduced mRNA and protein expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2) and TNF-α. Investigation of the effect of MEPL on nuclear factor-κB (NF-κB) activity, which is a potential transcriptional factor for regulating inflammatory genes such as iNOS, COX-2 and TNF-α, showed that MEPL substantially inhibited the LPS-induced DNA-binding activity of NF-κB. MEPL also suppressed the LPS-induced degradation and phosphorylation of IκB α, and it consequently blocked p65 translocation from the cytosol to the nucleus. Conclusion: These data show that MEPL may regulate LPS-induced NO, PGE2, and TNF-α production by suppressing NF-κB activity. All rights reserved. © Pharmacotherapy Group. All rights reserved. Source

Kang C.-H.,Jeju National University | Kang S.-H.,Jeju National University | Boo S.-H.,Jeju National University | Park S.-Y.,Ottogi Corporation | And 3 more authors.
Tropical Journal of Pharmaceutical Research | Year: 2011

Purpose: Hizikia fusiforme is renowned for the possession of anti-inflammatory and anti-oxidant properties. In this study, the role of the ethyl alcohol extract of H. fusiforme (EAHF) in the induction of apoptosis in human leukemia U937 cells was investigated. Methods: Protein expression was investigated by Western blot analysis. Cell viability and apoptosis were analyzed by an MTT assay and flow cytometric analysis. Caspase activity was analyzed using a caspase-specific kit. Results: EAHF suppressed the proliferation of U937 cells in a dose-dependent manner. This effect was closely related to the induction of apoptosis via the downregulation of IAP family members such as IAP- 1, IAP-2 and XIAP, as well as Bcl-2 proteins. The results also showed that caspases play an essential role in EAHF-induced apoptosis by generating of reactive oxygen species (ROS). In addition, ROS scavenging by N-acetyl-L-cysteine (NAC) and glutathione (GSH) decreased EAHF-induced apoptosis via the suppression of caspase activity. Although EAHF induced the phosphorylation of mitogenactivated protein kinases (MAPKs), treatment with MAPK inhibitors did not affect EAHF-induced apoptosis. Conclusion: These results suggest that EAHF induces apoptosis in U937 cells via ROS-dependent caspase activation. © Pharmacotherapy Group. Source

Jayasooriya R.G.P.T.,Jeju National University | Lee Y.-G.,Yonsei University | Kang C.-H.,Jeju National University | Lee K.-T.,Korea forest Research Institute | And 4 more authors.
Oncology Letters | Year: 2012

Piceatannol has potent anti-inflammatory, immunomodulatory, anticancer and antiproliferative effects. However, little is known about the mechanism by which piceatannol inhibits invasion and metastasis. The aim of the current study was to investigate the effects of piceatannol on the expression of matrix metalloproteinase-9 (MMP-9) in DU145 human prostate cancer cells. The results revealed that MMP-9 activity was significantly increased in response to tumor necrosis factor-α (TNF-α). However, treatment with piceatannol reversed TNF-α- and MMP-9-induced gelatin zymography and its gene expression. In addition, a Matrigel invasion assay determined that piceatannol reduces the TNF-α-induced invasion of DU145 cells. Nuclear factor-κ B (NF-κB) is a significant transcription factor that regulates numerous genes involved in tumor cell invasion and metastasis. Therefore, whether piceatannol acts on NF-κB to regulate MMP-9 gene expression was analyzed. The results revealed that piceatannol attenuates MMP-9 gene expression via the suppression of NF-κB activity. Using a specific NF-κB inhibitor, pyrrolidine dithiocarbamate, it was confirmed that TNF-α-induced MMP-9 gene expression is primarily regulated by NF-κB activation. Piceatannol inhibited NF-κB activity by suppressing nuclear translocation of the NF-κB p65 and p50 subunits. Furthermore, TNF-α-induced Akt phosphorylation was significantly downregulated in the presence of piceatannol. The Akt inhibitor LY294002 caused a significant decrease in TNF-α-induced NF-κB activity and MMP-9 gene expression. Overall, these data suggest that piceatannol inhibits TNF-α-induced invasion by suppression of MMP-9 activation via the Akt-mediated NF-κB pathway in DU145 prostate cancer cells. Source

Moon D.-O.,Daegu University | Park S.-Y.,Ottogi Corporation | Choi Y.H.,Korea University | Ahn J.S.,Korea Research Institute of Bioscience and Biotechnology | Kim G.-Y.,Jeju National University
Biochemical Pharmacology | Year: 2011

Guggulsterone (GGS) has anti-tumor and anti-angiogenesis potential by suppressing nuclear factor-κB and STAT3 activity. Although GGS has been suggested as a potential therapeutic agent for treating various cancers, the underlying molecular mechanisms are unknown. Therefore, we investigated whether GGS sensitizes hepatocellular carcinoma cells (HCC) to apoptosis mediated by tumor necrosis factor-related apoptosis inducing ligand (TRAIL). The apoptotic mechanism induced by treatment with a GGS/TRAIL combination involved the loss of mitochondrial transmembrane potential and consequent activation of caspases. GGS also induced upregulation of the death receptor DR5 for TRAIL. The effects seemed to be associated with eIF2α and CHOP activation, which are related to the endoplasmic reticulum (ER) stress response and apoptosis. This relationship was suggested by the observation that CHOP downregulation by specific siRNA attenuated both GGS-mediated DR5 upregulation and the cytotoxicity induced by GGS/TRAIL co-treatment. Moreover, salubrinal, a specific eIF-2α phosphorylation-inducing agent, enhanced the expression of CHOP and DR5 induced by GGS and sensitized cells to GGS/TRAIL-induced apoptosis. Thus, GGS-induced eIF2α phosphorylation seems to be important for CHOP and DR5 upregulation. Furthermore, these events were accompanied by an increase in the generation of reactive oxygen species. Pretreatment with N-acetyl-l-cysteine and glutathione inhibited GGS-induced ER-stress, and CHOP and DR5 upregulation and almost completely blocked GGS/TRAIL-induced apoptosis. These results collectively indicate that DR5 induction via eIF-2α and CHOP is crucial for the marked synergistic effects induced by TRAIL and GGS. Taken together, these results indicate that a GGS/TRAIL combination could represent a novel important tool for cancer therapy. © 2011 Elsevier Inc. Source

Kang C.-H.,Jeju National University | Choi Y.H.,Korea University | Park S.-Y.,Ottogi Corporation | Kim G.-Y.,Jeju National University
Journal of Medicinal Food | Year: 2012

The methanol extract of Codium fragile (MECF) has been reported to possess bioactive properties such as antidegranulation in eosinophils, as well as anti-edema, antibacterial, and antiviral activities. However, little is known about the molecular effects of MECF on lipopolysaccharide (LPS)-induced inflammation. Therefore, we investigated whether MECF affects the expression of inflammatory mediators in LPS-stimulated RAW 264.7 cells. To evaluate the anti-inflammatory effects of MECF, the cells were pretreated with MECF for 1 hour and then cultured with LPS for 24 hours. Our results indicate that MECF significantly attenuated secretion of LPS-induced inflammatory mediators nitric oxide (NO), prostaglandin E 2 (PGE 2), and tumor necrosis factor (TNF)-α in RAW 264.7 cells. Additionally, LPS-induced mRNA and protein expression of inducible NO synthase (iNOS), cyclooxygenase (COX)-2, and TNF-α was decreased by pretreatment with MECF. These data indicate that MECF attenuates the expression of these inflammatory mediators at the transcriptional level. Therefore, we also investigated the effects of MECF on nuclear factor-κB (NF-κB) activity, which may be an important transcriptional factor for regulating the expression of iNOS, COX-2, and TNF-α mRNA. Our results showed that MECF reduced LPS-induced NF-κB activity via the suppression of nuclear translocation of the p50 and p65 NF-κB subunits and degradation of inhibitor of κB. In conclusion, we propose that MECF treatment down-regulates the expression and secretion of LPS-induced inflammatory mediators by inhibiting NF-κB activity. © Copyright 2012, Mary Ann Liebert, Inc. Source

Discover hidden collaborations