• Title/Summary/Keyword: inhibitory mechanism

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Uptake of Butachlor by Rice Seedlings and Its Phytotoxic Action to the Physiological Activities (수도묘(水稻苗)의 Butachlor 흡수(吸收) 및 약해발생(藥害發生) 특성(特性)에 관한 생리적(生理的) 연구(硏究))

  • Chung, Bong-Jin;Kwon, Yong-Woong
    • Korean Journal of Weed Science
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    • v.1 no.1
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    • pp.57-68
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    • 1981
  • To clarify the mode of uptake of butachlor (2-chloro-2', 6'-diethyl-N-(butoxymethyl) acetanilide) by rice seedlings, its phytotoxic action to growth and physiological activities, studies were conducted with rice seedlings, at the 6th or 7th leaf-stage, which were treated with nutrient solution containing butachlor 0, 1.8, 3.6, 7.2, 10.8 or 14.4 ppm for 1, 2 or 4 days, in other case, the solutions were thereafter renewed with the untreated nutrient solution for further growth. Uptake of butachlor by rice seedlings increased linearly with increase of its concentration and duration of uptake. Butachlor inhibited root growth more than shoot growth, furthermore, the inhibitory effect on the shoot growth was greater in height than in weight or leafing rate. After 4 day-treatment, the rates of shoot growth in weight were delayed for 4 days. Butachlor inhibited water uptake rapidly and linearly with increase of its external concentration. The reduced uptake of water was followed by slow increase in the stomatal resistance of leaves. Upon completion of butachlor treatment, rate of water uptake was recovered rapidly, but the stomatal resistance with lag in time. Butachlor did not affect the uptake of cation such as ammonium, potassium and calcium, but inhibited substantially uptake of nitrate in proportion to its concentration. Especially, butachlor did not affect synthesis and degradation of nitrate reductase. In addition, butachlor has shown much greater binding to the lipidic substances from rice roots than the proteinous material. The primary mechanism of phytotoxic action of butachlor does not seem to be its effect on the protein synthesis, but great affinity to membranes. The inhibition of water uptake, and its subsequent closure of stomates is thought very important for reduced growth under mild phytotoxicity.

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Inhibitory Effects of Asparagus cochinchinensis in LPS-Stimulated BV-2 Microglial Cells through Regulation of Neuroinflammatory Mediators, the MAP Kinase Pathway, and the Cell Cycle (Lipopolysaccharide로 자극된 BV-2 미세교세포에서 신경염증 매개체, MAP kinase경로, 세포주기의 조절에 의한 천문동(Asparagus cochinchinensis)의 저해효과)

  • Lee, Hyun Ah;Kim, Ji Eun;Choi, Jun Young;Sung, Ji Eun;Youn, Woo Bin;Son, Hong Joo;Lee, Hee Seob;Kang, Hyun-Gu;Hwang, Dae Youn
    • Journal of Life Science
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    • v.30 no.4
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    • pp.331-342
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    • 2020
  • The suppression of neuroinflammatory responses in microglial cells can be considered a key target for improving the progression of neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Asparagus cochinchinensis has traditionally been used as a medicine to treat fever, cough, kidney disease, breast cancer, inflammatory diseases, and brain diseases. In this study, we investigated the neuroprotective mechanism of an aqueous extract from A. cochinchinensis root (AEAC), particularly its anti-inflammatory effects on lipopolysaccharide (LPS)-activated BV-2 microglial cells. BV-2 cells were treated with four different concentrations of AEAC. No significant toxicity was detected in BV-2 cells treated with AEAC. Nitric oxide (NO), cyclooxygenase-2 (COX-2) mRNA, and inducible nitric oxide synthase (iNOS) mRNA levels were 21% lower in the AEAC+LPS group than in the Vehicle+LPS group. Lower proinflammatory (TNF-α and IL-1β) and anti-inflammatory cytokine (IL-6 and IL-10) levels were also detected in the AEAC+LPS group than in the Vehicle+LPS group, albeit at varying rates. Moreover, the phosphorylation of mitogen-activated protein kinase (MAPK) members after LPS treatment was significantly recovered in the AEAC-pretreated group compared to the Vehicle+LPS group, enhancement of the phosphorylation of mitogen-activated protein kinase (MAPK) members after LPS treatment was significantly recovered in the AEAC-pretreated group, while cell cycle arrest at the G2/M phase caused by LPS treatment was less severe in the AEAC+LPS group. The increase in reactive oxygen species (ROS) generation induced by LPS treatment was also lower in the AEAC-pretreated group than in the Vehicle+LPS group. This is the first study to show that AEAC exerts anti-neuroinflammatory activity against LPS stimulation by regulating the MAPK signaling pathway, the cell cycle, and ROS production.

Inhibition of Cancer Cell Migration by Compounds from Garlic Extracts (마늘추출물에 의한 암세포의 이동 저하)

  • Kim, Eun-Kyoung;Yun, Sung-Ji;Ha, Jung-Min;Jin, In-Hye;Kim, Young-Whan;Kim, Sun-Gun;Park, Da-Jung;Choi, Young-Whan;Yun, Sik;Kim, Chi-Dae;Bae, Sun-Sik
    • Journal of Life Science
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    • v.21 no.6
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    • pp.767-774
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    • 2011
  • Cell migration plays a fundamental role in cancer cell invasion and metastasis as well as in many physiological responses. Here, we screened four different sources of garlic - water extract of normal and black garlic, as well as dried normal and black garlic - for the identification of anti-invasive and anti-metastatic activity on cancer cells. Inhibition of cancer cell migration was observed in the hexane extract of dried-garlic. Inhibitory activity was further purified to near homogeneity by thin layer chromatography and named $\b{i}$nhibitor of $\b{c}$ancer $\b{m}$etastasis from garlic #27 (ICMG-27). ICMG-27 completely blocked insulin-like growth factor-1 (IGF-1)-induced OVCAR-3 cell migration at 6 ${\mu}g/ml$. ICMG-27 completely blocked IGF-1-induced OVCAR-3 and NIH-3T3 cell migration whereas IGF-1-induced mouse embryonic fibroblast (MEF) cell migration was not affected byICMG-27. ICMG-27 inhibited all the tested IGF-1-induced cancer cell migration such as OVCAR-3, SKOV-3, and MDA-MB-231 cells. Finally, ICMG-27 could inhibit IGF-1-, lysophosphatidic acid (LPA)-, sphingosine-1-phosphate (S1P)-, leukotriene B4 (LTB4)-, and angiotensin II (AngII)-induced OVCAR-3 cell migration. These results indicate that ICMG-27 inhibits cancer cell migration by blocking essential steps in many agonists-induced cancer cell migrations. Unveiling an anti-invasive mechanism of ICMG-27 on cancer cells will provide a basis for cancer therapy.

Studies on Effect and its Mechanism of Herbicide Mixture of Cyhalofop-butyl, pyribenzoxim and Pyrazosulfuron-ethyl - II. Effect of Herbicide Mixture on the Activity of ALS, Content of Free Amino Acids and Fatty Acids (Cyhalofop-butyl, Pyribenzoxim 및 Pyrazosulfuron-ethyl의 상호작용효과(相互作用效果) 및 상호작용(相互作用) 기작(機作)에 관(關)하여 - 제(第) 2 보(報) 혼합제초제(混合除草劑) 처리(處理)가 acetolactate synthase 활성(活性) 및 유리(遊離) 아미노산함량(含量)과 지방산함량(脂肪酸含量)에 미치는 영향(影響))

  • Wu, Ming-Gen;Kim, Kil-Ung;Shin, Dong-Hyun
    • Korean Journal of Weed Science
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    • v.18 no.3
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    • pp.197-204
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    • 1998
  • This study was conducted to determine the activity of ALS, content of endogenous free amino acids and fatty acids affected by herbicide mixture of cyhalofop-butyl, pyribenzoxim and pyrazosulfuron-ethyl. $I_{50}$ values (concentration required for 50% inhibition of ALS activity) of pyribenzoxim herbicide on the activity of ALS in Echinochloa crus-galli and Cyperus serotinus in vitro were recorded at 4${\times}$100 nM and 5${\times}$10 nM, respectively, while $I_{50}$ values of pyrazosulfuron against E crus-galli and C. serotinus were 4.5${\times}$10 nM and 4${\times}$10 nM, respectively, and the mixture of two herbicides showed additive effect on ALS activity at the low application rate, and independent effect at the high application rates of two herbicides. The inhibition rates of the three herbicides mixture treatment on the three branch-chain amino acids such as valine, leucine and isoleucine were 74.6%, 66.6% and 57.9% in C. serotinus and 36.6% 51.1% and 48.1% in E. crus-galli, respectively. A little bit higher inhibitory effect on the three branch-chain amino acids in C. serotinus and E. crus-galli seedlings was observed in two herbicide mixture of pyribenzoxim with pyrazosulfuron than three herbicide mixture of cyhalofop with pyribenzoxim and pyrazosulfuron. The interaction among three herbicides showed non-antagonism on the amounts of endogenous free amino acids.

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Potentiating Effect of Prostagliandin $E_1$ on the Action of Sympathomimetics in the Isolated Vas Deferens of Guinea-Pig (적출(摘出) 기니아-픽 정관(精管)에 있어서 교감신경효능제(交感神經效能劑)의 作用(작용)에 대(對)한 Prostaglindin $E_1$의 강화작용(强化作用))

  • Hong, Ki-Whan;Kang, Young-Soo
    • The Korean Journal of Pharmacology
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    • v.10 no.1 s.15
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    • pp.31-40
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    • 1974
  • 1. The authors investigated the effects of $PGE_1$ on the action of sympathomimetics in the vas deferens of guinea-pig, comparing with those in the rat vas deferens, and also the action of $PGE_1$ on the motility of nerve-free smooth muscle of chick amnion. 2. In the isolated guinea-pig vas deferens, the actions of phenylephrine and norepinephrine were much potentiated by pretreatment with $PGE_1$. Futher, in the isolated hypogastric nerve-vas deferens preparation of guinea-pig, effects of phenylephrine, norepinephrine and tyramine on the contractile response of vas to the hypogastric nerve stimulation and to the transmural stimulation were also augumented especially in tension by $PGE_1$-pretreatment. 3. In the isolated hypogastric nerve-vas preparation of rat, both contractile responses to hypogastric nerve and transmural stimulation were slowly reduced by treatment with $PGE_1$ and the potentiated effect of phenylephrine or norepinephrine was not observed in spite of pretreatment with $PGE_1$. 4. The actions of phenylephrine and norepinephrine on the denervated vas deferens of guinea-pig were also enhanced by $PGE_1$ as it were in the intact vas deferens, but there was no significant effect by $PGE_1$ on the action of norepinephrine in the denervated rat vas deferens. 5. $PGE_1$ in low concentration $(10^{-8}g/ml)$ did not affect the spontaneous motility of nerve-free smooth muscle of chick amnion ($9{\sim}11$ th day incubated chick), but in large concentration $(5{\times}10^{-8}g/ml)$ it caused irregular and slightly inhibitory movement. Pretreatment with $PGE_1$ on chick amnion did not exert any change on the action of phenylephrine applied. However, the stimulatory action of physostigmine on the chick amnion was a little antagonized by the low concentration of $PGE_1$. 6. It might be summarized that there is species difference between the actions of $PGE_1$ on the vas deferens of guinea-pig and that of rat, and the action of $PGE_1$ on the guinea-pig vas deferens might be mediated by the other mechanism rather than by direct action on the vas musculature.

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Extract from Prunus mume Sieb. et Zucc. Fruit Prevents LPS-induced Homotypic Aggregation of Monocytic THP-1 Cells via Suppression of Nitric Oxide Production and NF-κB Activation (매실 추출물의 산화질소 생성과 NF-κB 활성 조절을 통한 LPS유도성 THP-1 세포 동형성 응집의 억제 효과)

  • Lee, Hye-Rim;Park, Youngsook;Kim, Hyun Jeong;Lee, Aram;Choi, Jihea;Pyee, Jaeho;Park, Heonyong;Kim, Jongmin
    • Journal of Life Science
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    • v.25 no.7
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    • pp.801-809
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    • 2015
  • Homotypic cell adhesion (homotypic aggregation) in activated monocytes plays a central role in physiological and pathological processes including inflammatory responses, differentiation and migration. The extract of the Prunus mume Sieb. et Zucc. fruit (Maesil) has potential benefits to human health; such as anti-viral, anti-microbial, and anti-cancer activities. Indeed, Maesil extract may modulate inflammatory responses via interference with homotypic aggregation in monocytes. In the present study, the molecular mechanisms underpinning the therapeutic efficacy of Maesil extract in inflammatory diseases were investigated. It was found that Maesil extract inhibited homotypic aggregation in lipopolysaccharide (LPS)-activated monocytes. This was mediated by reduction of nitric oxide (NO) production, partly via inhibition of inducible nitric oxide synthase (iNOS) expression in LPS-activated THP-1 cells. It was confirmed that NO inhibition is a key mechanism in Maesil induced blockade of monocyte aggregation through identification of reversal of this inhibitory effect by the NO-producing agent S-nitroso-N-acetyl penicillamine (SNAP). In addition, Maesil extract significantly attenuated LPS-induced IκB-α phosphorylation and NF-κB translocation into the nucleus. In conclusion, Maesil extract exerts anti-inflammatory effects via inhibition of homotypic aggregation of LPS-activated monocytes through mechanisms involving the suppression of NO production and NF-κB activity, suggesting Maesil extract as a potential therapeutic candidate for the prevention and treatment of chronic inflammatory diseases.

An Investigation of Glyceollin I's Inhibitory Effect on The Mammalian Adenylyl (글리세올린 I의 아데니닐 고리화 효소 활성 억제 효능과 결합 부위 비교 분석)

  • Kim, Dong-Chan;Kim, Nam Doo;Kim, Sung In;Jang, Chul-Soo;Kweon, Chang Oh;Kim, Byung Weon;Ryu, Jae-Ki;Kim, Hyun-Kyung;Lee, Suk Jun;Lee, Seungho;Kim, Dongjin
    • Journal of Life Science
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    • v.23 no.5
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    • pp.609-615
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    • 2013
  • Glyceollin I has gained attention as a useful therapy for various dermatological diseases. However, the binding property of glyceollin I to the mammalian adenylyl cyclase (hereafter mAC), a critical target enzyme for the down-regulation of skin melanogenesis, has not been fully explored. To clarify the action mechanism between glyceollin I and mAC, we first investigated the molecular docking property of glyceollin I to mAC and compared with that of SQ22,536, a well-known mAC inhibitor, to mAC. Glyceollin I showed superiority by forming three hydrogen bonds with Asp 1018, Trp 1020, and Asn 1025, which exist in the catalytic site of mAC. However, SQ22,536 formed only two hydrogen bonds with Asp 1018 and Asn 1025. Secondly, we confirmed that glyceollin I effectively inhibits the formation of forskolin-induced cAMP and the phosphorylation of PKA from a cell-based assay. Long term treatment with glyceollin I had little effect on the cell viability. The findings of the present study also suggest that glyceollin I may be extended to be used as an effective inhibitor of hyperpigmentation.

Angiotensin Converting Enzyme Inhibition and Antihypertensive Effects of Phyllostachys pubescens Culm Extracts in Spontaneously Hypertensive Rats (맹종죽 줄기 추출물을 투여한 본태성 고혈압 쥐(SHR)의 ACE 저해 활성 및 혈압 강하 효과)

  • Kim, Jung-Suk;Kim, Mi-Jeong;Park, Min-Hee;Ryu, Bog-Mi;Moon, Gap-Soon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.1
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    • pp.27-34
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    • 2008
  • This study investigated the anti-hypertensive effect of Phyllostachys pubescens culm extract (PCE) by examining its effects on renal angiotensin-converting enzyme (ACE) inhibition and blood pressure using the spontaneously hypertensive rat (SHR) system. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured weekly for 8 weeks. Also, total antioxidant capacity and protein oxidation of tissues were examined by plasma Trolox Equivalent Antioxidant Capacity assay (TEAC) and hepatic protein carbonyl values, respectively. Twenty male SHR were randomly divided into four groups: PCE50, PCE100, and PCE500 (50, 100, and 500 mg of PCE per kilogram bodyweight daily, respectively), and control group. At week 2, the SBP in all PCE groups appeared to be significantly lower than the control (p<0.05), whereas the DBP were not different until week 4 (p<0.05). At week 8, SBP in the PCE500 was lower by 20% than the control. PCE groups considerably suppressed ACE dose-dependently compared with the control. Plasma TEAC and hepatic protein carbonyl values indicated increased antioxidative activity due to the PCE feed. No adverse effect was observed on the liver of SHR as there was no difference for the GOT and GPT values among the groups. Results of this study suggest that ACE inhibition may be one possible mechanism for the blood pressure lowering effect of PCE; thus, long term consumption of PCE may be beneficial in preventing high blood pressure along with the increased antioxidative status.

Transcriptome Analyses for the Anti-Adipogenic Mechanism of an Herbal Composition (생약복합물의 지방세포형성억제 기전규명을 위한 전사체 분석)

  • Lee, Hae-Yong;Kang, Ryun-Hwa;Bae, Sung-Min;Chae, Soo-Ahn;Lee, Jung-Ju;Oh, Dong-Jin;Park, Suk-Won;Cho, Soo-Hyun;Shim, Yae-Jie;Yoon, Yoo-Sik
    • Journal of Life Science
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    • v.20 no.7
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    • pp.1054-1065
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    • 2010
  • SH21B is a natural composition composed of seven herbs: Scutellaria baicalensis Georgi, Prunus armeniaca Maxim, Ephedra sinica Stapf, Acorus gramineus Soland, Typha orientalis Presl, Polygala tenuifolia Willd and Nelumbo nucifera Gaertner (Ratio 3:3:3:3:3:2:2). In our previous study, we reported that SH21B inhibited adipogenesis and fat accumulation in 3T3-L1 cells through modulation of various regulators in the adipogenesis pathway. The aim of this study was to analyze the transcriptome profiles for the anti-adipogenic effects of SH21B in 3T3-L1 cells. Total RNAs from SH21B-treated 3T3-L1 cells were reverse-transcribed into cDNAs and hybridized to Affymetrix Mouse Gene 1.0 ST array. From microarray analyses, we identified 2,568 genes of which expressions were changed more than two-fold by SH21B, and the clustering analyses of these genes resulted in 9 clusters. Three clusters among the 9 showed down-regulation by SH21B (cluster 4, cluster 6 and cluster 9), and two clusters showed up-regulation by SH21B (cluster 7 and cluster 8) during the adipogenesis of 3T3-L1 cells. It was found that many genes related to cell proliferation and adipogenesis were included in these clusters. Clusters 4, 6 and 9 included genes which were related with adipogenesis induction and cell cycle arrest. Clusters 7 and 8 included genes related to cell proliferation as well as adipogenesis inhibition. These results suggest that the mechanisms of the anti-adipogenic effects of SH21B may be the modulation of genes involved in cell proliferation and adipogenesis.

Vibrio Vulnificus Induces the Inflammation of Mouse Ileal Epithelium: Involvement of Protein Kinase C and Nuclear Factor-Kappa B (회장 상피세포에서 비브리오균(Vibrio vulnificus)의 염증 유도 기작 연구: protein kinase C와 nuclear factor kappa-B의 관련성)

  • Han, Gi Yeon;Jung, Young Hyun;Jang, Kyung Ku;Choi, Sang Ho;Lee, Sei-Jung
    • Journal of Life Science
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    • v.24 no.6
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    • pp.664-670
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    • 2014
  • In the present study, we investigate the role of V. vulnificus in promoting the inflammation of mouse ileal ephitelium and its related signaling pathways. ICR mice were infected orally with V. vulnificus ($1{\times}10^9CFU$) for 16 h as a representative model of food-borne infection. To find the major portal of entry of V. vulnificus in mouse intestine, we have measured the levels of bacterial colonization in small intestine, colon, spleen, and liver. V. vulnificus appeared to colonize in intestine and colon in the order of ileum >> jejunum> colon, but lack in the duodenum, spleen, and liver. V. vulnificus in ileum caused severe necrotizing enteritis and showed shortened villi heights accompanied by an expanded width and inflammation, compared with the control mice. V. vulnificus induced ileal epithelium inflammation by activating phosphorylation of PKC and membrane translocation of $PKC{\alpha}$. V. vulnificus induced the phosphorylation of ERK and JNK, but did not affect p38 MAPK phosphorylation. Notably, V. vulnificus stimulated the I-${\kappa}B$-dependent phosphorylation of NF-${\kappa}B$ in mouse ileal epithelium. Finally, the ileal infection of V. vulnificus resulted in a significant increase in expression of proinflammatory cytokines and Toll-like receptors, respectively, compared to the control. Collectively, our results indicate that V. vulnificus induces ileal epithelium inflammation by increasing NF-${\kappa}B$ phosphorylation via activation of PKC, ERK, and JNK, which is critical for host defense mechanism in food-borne infection by V. vulnificus.