• Title/Summary/Keyword: inhibitory mechanism

Search Result 1,033, Processing Time 0.026 seconds

Anti-inflammatory Effect of Ribes fasciculatum in IFN-${\gamma}$/LPS-stimulated Mouse Peritoneal Macrophage

  • Kim, Jin Kyu;Kim, Ha Na;Kang, Chung Sik;Seo, Je Han;Seo, Hyun Won;Im, Jun Sang;Kim, Bong Seok;Cha, Dong Seok;Kwon, Jin;Oh, Chan Ho;Ma, Sang Yong;Nam, Jung Il;Jeon, Hoon
    • Natural Product Sciences
    • /
    • 제20권2호
    • /
    • pp.113-118
    • /
    • 2014
  • Ribes fasciculatum which belongs to Saxifragaceae has been widely used as a traditional medicine for the treatment of symptoms associated with lacquer poison. However, pharmacological studies on the R. fasciculatum are extremely limited until now. Thus, in this study, we evaluated the possible anti-inflammatory effects of ethyl acetate fraction of R. fasciculatum (ERF) using IFN-${\gamma}$/LPS-stimulated peritoneal macrophage model. We investigated the change in nitrite level in the absence or presence of ERF after LPS stimulation, and we found that ERF effectively attenuates the NO production in a dose dependent manner without notable toxicity. To determine the mechanism of the inhibitory action of ERF on NO production, we performed iNOS enzyme activity assay and Western blotting. Here we showed that both of iNOS enzyme activities and iNOS expressions were significantly down-regulated by ERF, indicating that these dual activities of ERF are responsible for ERF-mediated NO suppression. In addition, ERF inhibitied the expression of cyclooxygenase-2 (COX-2), an another key enzyme in inflammation through suppression of NF-${\kappa}B$ activation. We also tested anti-inflammatory properties of ERF not only in vitro, but in vivo using trypsin-induced paw edema model in mice. Our results revealed that the increased paw volume in response to trypsin injection was recovered by ERF supplement dose dependently.

Inhibitory Activity of Cordyceps bassiana Extract on LPS-induced Inflammation in RAW 264.7 Cells by Suppressing NF-κB Activation

  • Yoon, Deok Hyo;Han, Changwoo;Fang, Yuanying;Gundeti, Shankariah;Han Lee, In-Sook;Song, Won O;Hwang, Ki-Chul;Kim, Tae Woong;Sung, Gi-Ho;Park, Haeil
    • Natural Product Sciences
    • /
    • 제23권3호
    • /
    • pp.162-168
    • /
    • 2017
  • Cordyceps bassiana has long been used as an oriental medicine and reported to possess diverse biological activities. The fruiting bodies of Cordyceps bassiana was extracted with ethanol and then further fractionated with n-hexane, ethyl acetate, n-butanol and water. The butanol fraction from Cordyceps bassiana (CBBF) exhibited the most effective in anti-inflammatory activity in RAW 264.7 macrophages and the roles of CBBF on the anti-inflammation cascade in LPS-stimulated RAW 264.7 cells were studied. To investigate the mechanism by which CBBF inhibits NO, iNOS and COX-2, the activation of $I{\kappa}B$ and MAPKs in LPS-activated macrophage were examined. Our present results demonstrated that CBBF inhibits NO production and iNOS expression in LPS-stimulated RAW 264.7 macrophage cells, and these effects were mediated through the inhibition of $I{\kappa}B-{\alpha}$, JNK and p38 phosphorylation. Also, CBBF suppressed activation of MAPKs including p38 and SAPK/JNK. Furthermore, CBBF significantly suppressed LPS-induced intracellular ROS generation. Its inhibition on iNOS expression, together with its antioxidant activity, may support its anti-inflammatory activity. Thus Cordyceps bassiana can be used as a useful medicinal food or drug for further studies.

Pulegone Exhibits Anti-inflammatory Activities through the Regulation of NF-κB and Nrf-2 Signaling Pathways in LPS-stimulated RAW 264.7 cells

  • Roy, Anupom;Park, Hee-Juhn;Abdul, Qudeer Ahmed;Jung, Hyun Ah;Choi, Jae Sue
    • Natural Product Sciences
    • /
    • 제24권1호
    • /
    • pp.28-35
    • /
    • 2018
  • Pulegone is a naturally occurring organic compound obtained from essential oils from a variety of plants. The aim of this study was to investigate the anti-inflammatory effects through the inhibitory mechanism of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX-2), nuclear factor kappa B ($NF-{\kappa}B$), mitogen-activated protein kinases (MAPK) pathways and the activation of nuclear factor erythroid 2-related factor 2 (Nrf2)/ heme oxygenase (HO)-1 pathways in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Results revealed that pulegone significantly inhibited NO production as well as iNOS and COX-2 expressions. Meanwhile, western blot analysis showed that pulegone down-regulated LPS-induced $NF-{\kappa}B$ and MAPKs activation in RAW 264.7 cells. Furthermore, the selected compound suppressed LPS-induced intracellular ROS production in RAW 264.7 cells, while the expression of stress response gene, HO-1, and its transcriptional activator, Nrf-2 was upregulated upon pulegone treatment. Taking together, these findings provided that pulegone inhibited the LPS-induced expression of inflammatory mediators via the down-regulation iNOS, COX-2, $NF-{\kappa}B$, and MAPKs signaling pathways as well as up-regulation of Nrf-2/HO-1 indicating that pulegone has a potential therapeutic and preventive application in various inflammatory diseases.

RNAi Suppression of RPN12a Decreases the Expression of Type-A ARRs, Negative Regulators of Cytokinin Signaling Pathway, in Arabidopsis

  • Ryu, Moon Young;Cho, Seok Keun;Kim, Woo Taek
    • Molecules and Cells
    • /
    • 제28권4호
    • /
    • pp.375-382
    • /
    • 2009
  • The 26S proteasome is a 2-MDa complex with a central role in protein turn over. The 26S proteasome is comprised of one 20S core particle and two 19S regulatory particles (RPs). The RPN12a protein, a non-ATPase subunit of the 19S RP, was previously shown to be involved in cytokinin signaling in Arabidopsis. To further investigate cellular roles of RPN12a, RNAi transgenic plants of RPN12a were constructed. As expected, the 35S:RNAi-RPN12a plants showed cytokinin signaling defective phenotypes, including abnormal formation of leaves and inflorescences. Furthermore, RNAi knock-down transgenic plants exhibited additional unique phenotypes, including concave and heart-shape cotyledons, triple cotyledons, irregular and clustered guard cells, and defects in phyllotaxy, all of which are typical for defective cytokinin signaling. We next examined the mRNA level of cytokinin signaling components, including type-A ARRs, type-B ARRs, and CRFs. The expression of type-A ARRs, encoding negative regulators of cytokinin signaling, was markedly reduced in 35S:RNAi-RPN12a transgenic plants relative to that in wild type plants, while type-B ARRs and CRFs were unaffected. Our results also indicate that in vivo stability of the ARR5 protein, a negative regulator of cytokinin signaling, is mediated by the 26S proteasome complex. These results suggest that RPN12a participates in feedback inhibitory mechanism of cytokinin signaling through modulation of the abundance of ARR5 protein in Arabidopsis.

A Protein Tyrosine Phosphatase Inhibitor, Pervanadate, Inhibits Angiotensin II-Induced β-Arrestin Cleavage

  • Jang, Sei-Heon;Hwang, Si Ae;Kim, Mijin;Yun, Sung-Hae;Kim, Moon-Sook;Karnik, Sadashiva S.;Lee, ChangWoo
    • Molecules and Cells
    • /
    • 제28권1호
    • /
    • pp.25-30
    • /
    • 2009
  • ${\beta}$-Arrestins turn off G protein-mediated signals and initiate distinct G protein-independent signaling pathways. We previously demonstrated that angiotensin $AT_1$ receptorbound ${\beta}$-arrestin 1 is cleaved after $Phe^{388}$ upon angiotensin II stimulation. The mechanism and signaling pathway of angiotensin II-induced ${\beta}$-arrestin cleavage remain largely unknown. Here, we show that protein Tyr phosphatase activity is involved in the regulation of ${\beta}$-arrestin 1 cleavage. Tagging of green fluorescent protein (GFP) either to the N-terminus or C-terminus of ${\beta}$-arrestin 1 induced conformational changes and the cleavage of ${\beta}$-arrestin 1 without angiotensin $AT_1$ receptor activation. Orthovanadate and molybdate, inhibitors of protein Tyr phosphatase, attenuated the cleavage of C-terminal GFP-tagged ${\beta}$-arrestin 1 in vitro. The inhibitory effects of okadaic acid and pyrophosphate, which are inhibitors of protein Ser/Thr phosphatase, were less than those of protein Tyr phosphatase inhibitors. Cell-permeable pervanadate inhibited angiotensin II-induced cleavage of ${\beta}$-arrestin 1 in COS-1 cells. Our findings suggest that Tyr phosphorylation signaling is involved in the regulation of angiotensin II-induced ${\beta}$-arrestin cleavage.

Anti-Helicobacter pylori Compounds from Polygonum cuspidatum

  • Khalil, Atif Ali Khan;Park, Woo Sung;Kim, Hye Jin;Akter, Kazi Marjahan;Ahn, Mi-Jeong
    • Natural Product Sciences
    • /
    • 제22권3호
    • /
    • pp.220-224
    • /
    • 2016
  • Anti-Helicobacter pylori activity guided fractionation led to the isolation of five anthraquinones, two stilbenes and one naphthoquinone from the EtOAc fraction of Polygonum cuspidatum, using silica gel column chromatography, Sephadex-LH20, MPLC and recrystallization. The chemical structures were identified to be physcion (1), emodin (2), anthraglycoside B (3), trans-resveratrol (4), anthraglycoside A (5), polydatin (6), 2-methoxy-6-acetyl-7-methyljuglone (7) and citreorosein (8) by UV, $^1H$-NMR, $^{13}C$-NMR and mass spectrometry. Anti-Helicobacter pylori activity including MIC values of each compound was evaluated. All of the isolates exhibited anti-H. pylori activity of which MIC values were lower than that of a positive control, quercetin. Compounds 2 and 7 showed potent growth inhibitory activity. Especially, a naphthoquinone, compound 7 displayed most potent antibacterial activity with $MIC_{50}$ value of $0.30{\mu}M$ and $MIC_{90}$ value of $0.39{\mu}M$. Although anti-H. pylori activity of this plant was previously reported, this is the first report on that of compounds isolated from this species. From these findings, P. cuspidatum roots or its isolates may be useful for H. pylori infection and further study is needed to elucidate mechanism of action.

까마귀쪽나무(Litsea japonica)의 HL-60/ADR 세포 Apoptosis 유도효과 (The Effects of Litsea japonica on the Induction of Apoptosis in HL-60/ADR)

  • 김엘비라;부혜진;현재희;김상철;강정일;김민경;유은숙;강희경
    • 생약학회지
    • /
    • 제40권1호
    • /
    • pp.65-69
    • /
    • 2009
  • The present study investigated the antiproliferative effect of Litsea japonica in HL-60/ADR, adriamycin resistant human promyelocytic leukemia cells. The 80% ethanol extract of L. japonica markedly inhibited the growth of HL-60/ADR cells. When HL-60/ADR cells were treated with the extract, several apoptosis events like as DNA fragmentation, chromatin condensation and the increase of the population of sub-G1 hypodiploid cells were observed. In the mechanism of apoptosis induction by L. japonica, we examined the changes of Bcl-2 and Bax protein expression levels, and activation of caspases. After the HL-60/ADR cells were treated with the extract, the Bcl-2 expression was decreased, whereas the expression of Bax was increased in a time-dependent manner compared to the control. In addition, the active forms of caspase-9 and -3 were increased and the cleavage of poly (ADP-ribose) polymerase, a vital substrate of effector caspase, was observed. The results suggest that the inhibitory effect of L. japonica on the growth of the HL-60/ADR appears to arise from the induction of apoptosis via the down-regulation of Bcl-2 and the activation of caspases.

대황이 자궁상종세포의 세포자멸사에 미치는 영향 (Growth Inhibition of Uterine Leiomyoma Cells Using Rhubarb)

  • 양영필;김현태;김상찬;백승희;김미려;권영규
    • 동의생리병리학회지
    • /
    • 제18권1호
    • /
    • pp.200-205
    • /
    • 2004
  • Uterine leiomyoma is the most common tumor in the female genital tract. Although the tumor is benign, it is of paramount importance since it often causes profuse menstrual bleeding, pressure symptoms, and infertility. Nevertheless, the etiology and patholphysiology of this abnormality remain poorly understood. The traditional definitive treatment for uterine leiomyomas is hysterectomy and, even today, symptomatic leiomyomas are the leading cause of hysterectomy in Korea. Clearly, the development of a safe, effective, and nonsurgical method of treatment for leiomyoma would be of great benefit to many women. The present study was designed to investigate the effect of Rhubarb on apoptosis in uterine leiomyoma cells. Results demonstrate that Rhubarb inhibited cell growth in dose-dependent manner. Cell growth significantly decreased to 60% of control in the treatment of Rhubarb (300㎍/㎖). Associated with the decreased response, there was a concomitant and significant delay of subG1 8.32% above baseline in the treatment of Rhubarb (300㎍/㎖). The delay of subG1 showed a dose-dependent manner, as evidenced by the flow cytometry. The reduced cellular viability on exposure to Rhubarb may represent the induction of apoptosis, at least in part, as concomitantly evidenced by enhanced DNA fragmentation, PARP cleavage and caspase 9 and decreased pro-caspase 3. In addition, Rhubarb decreased clAP1 expression levels in dose-dependent manner. Talcen together, there results suggest that Rhubarb can produce a potent inhibition effect of apoptosis and implicate the delay of G1 phase in the cell cycle and pathways of caspase 3 and 9 in the mechanism underlying inhibitory apoptosis effect of Rhubarb.

백혈병 세포주 HL-60에서 과루실 세포고사 유도 효과 (Apoptosis-inducing Effect of Fructus Trichosanthis in HL-60 Leukemic Cells)

  • 권강범;김은경;한미정;류도곤
    • 동의생리병리학회지
    • /
    • 제19권4호
    • /
    • pp.903-907
    • /
    • 2005
  • Many naturally occurring plant extracts are studied for their beneficial effects for health and particularly on cancer. Apoptosis, or programmed cell death, occurs in both normal and pathological conditions, including cancer Dysregulation of apoptosis allows transformed cells to continually and uninhibitedly enter the cell cycle, thus perpetuating the sequence of mutation, genomic instability and, finally, oncogenesis. To investigate the apoptosis-inducing effect of the extract of Fructus Trichosanthis (EFT) on leukemic HL-60 cells and its mechanism, HL-60 cells in vitro in culture medium were given different doses of the extract. The inhibitory rate of cells were measured by microculture tetrazolium assay, cell apoptotic rate was detected by flow cytometry, morphology of cell apoptosis was observed by DAPI fluorescence staining, and the activations of caspases and PARP were detected using Western blotting analysis. The extract could activate the caspase-3 and caspase-8, induce PARP cleavage, inhibit growth of HL-60 cells, and cause apoptosis significantly The suppression was in dose-dependent manner. Marked morphological changes of cell apoptosis including condensation of chromatin and nuclear fragmentation were observed clearly by DAPI fluorescence staining especially. These results will provide strong laboratory evidence of EFT for clinical treatment of acute leukemia.

Inhibition of Inducible Nitric Oxide Synthase and Cyclooxygenase-2 by Gamijihwang-tang Via Suppression of Nuclear Factor-B Activation in RAW 264.7 cells

  • Jang Du-Hyun;Kim Ji-Young;Han Eun-Hee;Park Hee-Ok;Kim Dong-Hee;Jeong Hye-Gwang;Yoo Dong-Yeol
    • 동의생리병리학회지
    • /
    • 제19권5호
    • /
    • pp.1405-1410
    • /
    • 2005
  • Asthma is recognized today as an inflammatory disease of the lung characterized by acute non-specific airway hypersensitiveness in association with chronic pulmonary inflammation. Gamijihwang-tang(GJT), a fortified prescription of YMJHT, is applied for the treatments of chronic coughing and asthma, and post-delivery coughing and asthma in the gynecology. Also in the clinical practice, GJT is known to be very effective for controlling coughing and asthma as a cold sequoia. In this study, we investigated the effects of GJT on the lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) production, and on the level of inducible nitric oxide synthase (iNOS) and Cyclooxygenase-2 expression in murine macrophage RAW 264.7 cells. We found that GJT inhibited LPS-induced NO and $PGE_2$ production in a dose dependent manner. Furthermore, GJT inhibited the expression of LPS-induced iNOS and COX-2 protein and mRNA expression in RAW 264.7 macrophages. Treatment with GJT of RAW 264.7 cells transfected with a reporter construct indicated a reduced level of LPS-induced nuclear factor-KB (NF-kB) activity and effectively lowered NF-kB binding as measured by transient transfection assay. These results suggest that the main inhibitory mechanism of the GJT may be the reduction of iNOS and COX-2 gene expression through blocking of NF-kB activation.