• 제목/요약/키워드: Chemical-induced inhibition

검색결과 218건 처리시간 0.027초

인삼 및 인삼 사포닌이 쥐의 건망증 및 신경세포배양에 미치는 영향 (Effects of Ginseng and Its Saponins on Experimental Amnesia in Mice and on Cell Cultures of Neurons)

  • Saito Hiroshi;Nishiyama Nobuyoshi;Iwai Akihiko;Kawajiri Shinichi;Himi Toshiyuki;Sakai Toshimi;Fukunaka Chizu
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 1988년도 학술대회지
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    • pp.92-98
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    • 1988
  • 본 연구는 중앙대서전에 인삼의 주 효과중 건망증 방지작용이라고 수록되어 있는 것을 확인하기 위하여 행하여졌다. Step through 시험에서 $GRb_1$$GRg_1$은 기억력 획득을 용이하게 하였으며 전기충격 쇼크에 의해 야기되는 기억상실 효과를 억제하였다. 게대가 $Rg_1$은 에타놀 야기 기억재생 저해작용을 방지하였다. Stepdown test에 있어서 $Rb_1,\;Rb_2,\;Rg_1$은 전기충격쇼크에 의해 야기되는 기억보지 저해효과를 방지하였다. 또한 $Rg_1$은 에타놀에 의해 야기되는 기억재생 저해효과를 방지하였으며 단기적 기억력 획득을 용이케 하였다. Shuttle box와 lever press 시험에서도 $Rb_1$을 제외하고 나머지는 기억획득과 재생에 효과를 미치지 못했다. $Rb_1$은 shuttle box 시험에서 조건회피반응의 재생 (retrieval)을 억제하였다. 이와 같은 4가지 시험이 끝난후에 인삼의 구강투여가 진정, 진통, 해열, 진경효과와 자발 및 탐색활동에 미치는 영향을 500 mg/kg 투여 범위내에서 조사하였으나 아무런 반응도 관찰되지 않았다. 현재까지 연구결과는 $Rg_1$이 기억의 재생 및 학습반응의 획득과정에 대하여 효과가 있다는 것을 의미한다. 최근의 신경성장인자(NGF)가 성숙동물에 있어 뇌신경세포의 생존, 재생 및 조절에 미치는 작용에 관한 연구결과는 지능장해와 건망증에 대한 신경성장인자의 중요성을 시사했다. NGF에 의해 야기된 신경세포돌기 성장의 특이성에 관한 연구결과를 병아리 배배근 신경절에 있어서 NGF의 영향은 $Rh_1$에 의해 증가되었다. 다음으로 $Rb_1$은 병아리 배의 감각 및 교감신경단위에 있어서 NGF-관련 신경섬유 증가를 강화시켰다. NGF와 $Rb_1$을 함께 했을 때도 역시 쥐 대뇌피질의 신경세포 생존수를 증가시키는 경향을 보였다. NGF는 쥐의 배격부 부근의 신경세포를 배양했을 때 cholineacetyl transferase 활성을 증가시키지 않았다. 이러한 결과로 $Rb_1$은 뇌에 있어서 신경세포의 생존이나 재생에 중요한 역활을 한다는 것은 알 수 있었다.

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염산-에탄올에 의해 유발된 흰쥐 위염에 대한 마치현의 억제 작용 (The Inhibitory Effects of Portulaca oleracea L. on HCl-ethanol Induced Gastritis in Rats)

  • 김재현
    • 대한본초학회지
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    • 제24권1호
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    • pp.41-47
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    • 2009
  • Objectives : The objective of this study was to examine the effects of P. oleracea into the HCl-ethanol induced gastritis in rats, and to isolate and determine the chemical compounds from P. oleracea. Methods : The rats were orally administered with crude extract or fractions or isolated compounds of P. oleracea 30 mins before the induction of gastric lesion by oral administration of HCl-ethanol. The gastric lesional area was measured using pixel counting software. Then the chemical compounds from P. oleracea was isolated and determined by LC-MS and NMR. Results : The inhibition effect of oral administration of crude extract of P. oleracea at a dose of 500 mg/kg in HCl-ethanol induced gastritis was similar to cimetidine. Then, aqueous fraction at a dose of 240 mg/kg exhibited the effects similar to cimetidine. Then, the aqueous fraction was further separated by MPLC and yielded four sub fractions. Among those sub fractions, agent II at a dose of 40 mg/kg possessed the strongest effect in the HCl-ethanol induced gastritis. The water fraction yielded-Uridine, Adenosine, Guanosine, which were characterized by Mass, 1H-NMR, 13C-NMR. Conclusions : This study suggest that a P. oleracea and its compounds showed potent efficacy on the development of HCl-ethanol induced gastritis. Thus, P. olaracea can be a potential natural resource for the management of gastritis although the mechanism of action involved in the treatment remains to be explored.

Corrosion Inhibition of Steel Rebar in Concrete with the Coated MCI 2022

  • Bezad Bavarian;Lisa Reiner;Kim, Chong Y.
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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    • pp.63-67
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    • 2002
  • The induced chemical and salt solution in water or admixture are originated to the corrosion process of the steeo rebar. These liquids penetrate into concrete as the accompanied by the chemical reaction and cause to attack the steel rebar in concrete. Concrete surfaces which it exposed to deicing, water and sea water is allowed to enter the chlorides in the structures. To prevent from the source of corrosion and deterioration Is subjected to put an end to corrode or reduce to contaminate on the steel rebar. As this reason the MCI 2022 products are applied to the surface of concrete and steel rebar. The concrete samples were made of to the kind of four, i.e. RF, MR, MS, and MM. Corrosion inhibitor is applied to coat on the surface of concrete after it had been cured for 28days. Specimen were immersed in a 3.5% sodium chloride solution. Concrete specimen were tested to determine the changes of the resistance polarization, Rp, over a 22 weeks period. MCI 2022 is significantly shown the corrosion inhibition of steel rebar in 3.5% NaCl solution. In the each different concrete sample, MS and MM is seemed to be better than others. The results are proofed that MCI 2022 is promised to maintain the inhibition of corrosion with high resistance polarization of the steel rebar in concrete.

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Regulatory Mechanism of L-Alanine Dehydrogenase from Bacillus subtilis

  • 김수자;김유진;서미란;전봉숙
    • Bulletin of the Korean Chemical Society
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    • 제21권12호
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    • pp.1217-1221
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    • 2000
  • L-alanine dehydrogenase from Bacillus subtilis exhibits allosteric kinetic properties in the presence of $ZN^{2+}$. $ZN^{2+}$ induces the binding of substrate (L-alanine) to be cooperative at pH 8.0. The effect of pH variation between pH 7.0 and pH 10.0 on the inhibition by $ZN^{2+}$ correlates with the pH effect on the $K_m$ values for L-alanine within these pH range indicating that $ZN^{2+}$ and substrate compete for the same site. No such cooperativity is induced by $ZN^{2+}$ when the reaction is carried out at pH 10. At this higher pH, $ZN^{2+}$ binds with the enzyme with lower affinity and noncompetitive with respect to L-alanine. Inhibition of L-alanine dehydrogenase by $ZN^{2+}$ depends on the ionic strength. Increase in KCI concentration reduced the inhibition, but allosteric property in $ZN^{2+}$ binding is conserved. A model for the regulatory mechanism of L-alanine dehydrogenase as a noncooperative substrate-cooperative cofactor allosteric enzyme, which is compatible in both concerted and the sequential allosteric mechanism, is proposed.

Anti-allergic Actions of the Leaves of Castnea crenata and Isolation of an Active Component Responsible for the Inhibition of Mast Cell Degranulation

  • Lee, Eun;Choi, Eun-Ju;Cheong, Ho;Kim, Young-Ran;Ryu, Shi-Yong;Kim, Kyeong-Man
    • Archives of Pharmacal Research
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    • 제22권3호
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    • pp.320-323
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    • 1999
  • The anti-allergic actions of the leaves of Castanea crenata (Fagaceae) were studied. The water extract demonstrated potent anti-allergic actions in in vivo and in vitro experiments. The oral or intraperitoneal administration of the extract (100 or 200 mg/kg) caused a significant inhibition of the 48 hr-PCA (up to 90%) and the vascular permeability induced by histamine or serotonin in rats (about 80%). The anaphylactic release of ${\beta}$-hexosaminidase for RBL-2H3 cells was also significantly inhibited by the extract in as dose-dependent manner with an IC50 value of 230 $\mu\textrm{g}$/ml. The activity-guided fractionation of the extract, based on the determination of inhibitor effect upon the release of ${\beta}$-hexosaminidase, led to the isolation of quercetin as an active principle responsible for the inhibition of degranulation.

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7, 12-dimethylbenz[a]anthracene(DMBA)로 유발된 햄스터 협낭암에서 chlorophylln의 암예방효과에 관한 실험적 연구 (AN EXPERIMENTAL STUDY ON THE CHEMOPREVENTIVE EFFECT OF CHLOROPHYLLIN IN HAMSTER CHEEK POUCH TUMOR INDUCED BY 7, 12-DIMETHYLBENZ[A]ANTHRACENE)

  • 윤규호
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제26권2호
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    • pp.137-145
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    • 2000
  • Carcinogenesis is a multi-stage process that generally consists of at least three steps; initiation, promotion, and progression. If one of these carcinogenic steps were suppressed or delayed, the cancer could be prevented. Cancer chemoprevention is defined to be inhibition or reversal of the carcinogenic process by the specific chemical agents and is a novel approach to cancer management alternative to conventional chemotherapy. Chlorophylln(CHL), a water-soluble derivative of chlorophyll, containing sodium and copper, has been known to be strong antimutagen in several test systems, but its mechanism of antimutagenic action is unknown. In the present experiment, the possibility of CHL as chemopreventive drugs on 7,12-dimethylbenz[a]anthracene(DMBA)-induced hamster buccal pouch carcinogenesis was investigated by mutagenicity test, carcinogenicity test, and frequency or spectrum of H-ras mutations in the both of DMBA-induced and chlorophylln-pretreated-DMBA induced tumor by polymerase chain reaction and non-isotopic restriction fragment length polymorphism. The treatment of CHL reduced the yields and multiplicity of the 0.5% DMBA-induced tumor, 86% to 62.5% and $3.7{\pm}0.6$ to $1.4{\pm}0.3$, respectively. The occurrence of histidine revertant by $20{\mu}mole$ DMBA was inhibited 25.6 to 81.7% by 1 to $5{\mu}M$ CHL in a dose-dependent manner. The mutation rates of H-ras gene in DMBA-induced and CHL-pretreated-DMBA induced tumor were 96%, 94% of which the most mutations were in codon 12/13. These results suggest that CHL inhibits the carcinogenic action of DMBA by the formation of complex between CHL and DMBA or the inhibition of the activation of DMBA in vivo. But CHL did not affect the mutation rates or its spectrum in already formed tumor.

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Development of TPA-induced Ornithine Decarboxylase (ODC) Inhibitors from Plants as Cancer Chemopreventive Agents

  • Kim, Soo-Jeong;Lee, Ik-Soo;Chang, Il-Moo;Mar, Woong-Chon
    • Natural Product Sciences
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    • 제2권2호
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    • pp.123-129
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    • 1996
  • Chemical carcinogenesis is associated with the increase of intracellular polyamine levels, and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse epidermal ODC activity are essential to skin tumor promotion by TPA. Therefore, for the discovery of new cancer chemopreventive agents, we have evaluated about 73 kinds of natural products to study inhibitory effects against ODC activity induced by TPA in T24 cell culture system. The total methanol extracts of plants fractionated into three layers (hexane, ethyl acetate and water layer) were tested and the hexane fraction of Angelica gigas $(root\;bark,\;IC_{50}:\;7.4\;{\mu}g/ml)$ and the ethyl acetate fraction of Corydalis ternata $(root,\;IC_{50}:\;7.5\;{\mu}g/ml)$ were the most effective on the inhibition of TPA-induced ODC activity, These active fractions are under investigation with further sequential fractionation using column chromatography.

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Flow Cytometric Analysis of the Effect of Silkworm Hemolymph on the Baculovirus-Induced Insect Cell Apoptosis

  • Rhee, Won-Jong;Park, Tai-Hyun
    • Journal of Microbiology and Biotechnology
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    • 제11권5호
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    • pp.853-857
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    • 2001
  • The effect of silkworm hemolymph on the inhibition of baculovirus-induced insect cell apoptosis was quantitatively investigated using a flow cytometric analysis. Spodoptera frugiperda (Sf9) cell and Autographa californica nuclear polyhedrous virus (AcNPV) were used as a model for insect cell and baculovirus in this study, respectively. Compared with a mammalian cell cycle, the fraction of G1 cells was relatively small in the Sf9 cell cycle. Silkworm hemolymph did not affect the Sf9 cell-cycle distribution before the baculovirus infection. However, the fraction of cells which are not in the sub-G1 phase remained at a high level for 3 days after the infection in the medium without silkworm hemolymph, while it remained at a high level for 7 days after the infection in the medium supplemented with silkworm hemolymph. The fractions of apoptotic cells in the sub-G1 phase were $4.7\%$, and 4 days after infection, $22.7\%$, in the media with and without silkworm hemolymph, respectively.

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위령선약침이 Collagen, Adjuvant, LPS 및 PLA2 유발 류머티스성 관절염에 미치는 영향 (The Effect of $Clematidis$ Radix Herbal-acupuncture Solution, on Collagen, Adjuvant, Lipopolysaccharide and Phospholipase $A_2$ Induced Rheumatoid Arthritis in Mice)

  • 이진석;김경호;이승덕;김갑성
    • Journal of Acupuncture Research
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    • 제29권1호
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    • pp.127-137
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    • 2012
  • Objectives : The purpose of this study is to investigate the effect of $Clematidis$ radix herbal-acupuncture solution, on collagen, adjuvant, lipopolysaccharide and phospholipase A2 induced rheumatoid arthritis in mice. Methods : Arthritis index was measured for mouse that was injected subcutaneously in solution mixed chicken type II collagen with Freund's complete adjuvant. We injected Freund's complete adjuvant into right posterior part of the sole of a ICR mouse foot, which was measured by plethysmometer. The solution mixed $CRHS$ with Tris-HCI, $CaCl_2$, substrate, enzyme was done a chemical action for thirty minutes, and then inhibitory activity of PLA2 enzyme was expressed with inhibition percentage by utilizing isolated arachidonic acid. COX-2 was induced by adding LPS to RAW 264.7 cell, and COX-2 activity was measured by western blot analysis and $PGE_2$ Biotrak kit. Results : $CRHS$ also inhibited Freund's complete adjuvant induced chronic rheumatoid arthritis in mice. $CRHS$ showed significant inhibition of type I and type II $PLA_2$ activities in a dose dependent manner. Furthermore, $PGE_2$ production was decreased with $CRHS$ and lipopolysaccharide-induced COX-2 protein expression was significantly inhibited by $CRHS$. Conclusions : These results suggest that $CRHS$ has an therapeutic effect on drug induced-rheumatoic arthritis by inhibiting $PLA_2$ and COX-2 activities.

The effect of L-carnitine in the expression of matrix metalloproteinases by human dermal fibroblasts

  • Yoon, Eun-Jeong;Lee, Kyoung-Eun;Sim, Kwan-Sup;Lee, Bum-Chun;Pyo, Hyeong-Bae;Choe, Tae-boo
    • 대한화장품학회:학술대회논문집
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    • 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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    • pp.12-25
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    • 2003
  • L-camitine ($\beta$ -hydroxy-${\gamma}$ -trimethyl-ammoniumbutyric acid) is a small water-soluble molecule important in mammalian fat metabolism. It is essential for the normal oxidation of fatty acids by the mitochondria, and is involved in the trans-esterification and excretion of acyl-CoA esters. In this paper, to investigate the relationship between aging and L-camitine, we investigated the effects of in vitro MMP inhibition and activity and expression of UVA-induced MMP 1 in human skin fibroblasts. Fluorometric assays of the proteolytic activities of MMP-l were performed using fluorescent collagen substrates. ELISA (enzyme linked immuno sorbent assay), gelatin-substrate zymography, and RT-PCR ELISA techniques were used for the effects of L-camitine on MMP expression and activity, MMP mRNA expression in UVA irradiated fibroblast. L-camitine inhibited the activities of MMP-l in a dose-dependent manner and the $IC_{50}$/ values calculated from semi-log plots were 2.45mM, and L-carnitine showed strong inhibition on MMP-2 (gelatinase) activity in UVA irradiated fibroblast by zymography. Also, UVA induced MMP expression was reduced 40% by treated with L-carnitine, and MMP-l mRNA expression was reduced dose-dependent manner. Therefore L-carnitine was able to significantly inhibition the MMP activity, regulation of MMP expression in protein and mRNA level. All these results suggest that L-carnitine may be useful as new anti-aging cofactor for protection against UVA induced MMP expression and activity.

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