• Title/Summary/Keyword: Suppressive activity

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2-Acetylaminofluorene의 면역독성 기작에 대한 연구

  • 이미가엘;양규환
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.318-318
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    • 1994
  • Addition of AAF to murine splenocytes culture produced a dose-related suppression of lymphoproliferative response to lipopolysaccharide (LPS). The time course of the suppression showed that a significant inhibition was occured after a 18 hr AAF treatment. Total protein kinase C activity in splenocytes was decreased to 72% of control level after a 18 hr AAF treatment. Phosphorylation of a PKC specific 80 kDa protein was increased by LPS and AAF down-regulated LPS-induced PKC activity. LPS-induced phosphorylation of overall proteins in membrane and cytosolic fraction were also decreased by the treatment of AAF. A significant increase of PKC activity in membrane fraction was noticed within 10 min of AAF treatment compared to LPS alone and then gradually decreased to LPS level in 60 min. Meanwhile, PKC activity in cytosolic fraction was increased slightly in 10 min by the treatment of AAF and then decrease to 80% LPS level in 30 min. These results suggested that suppressive effect of AAF on LPS-induced lymphoproliferative response may be associated with the down-regulation of PKC and other susceptible kinases in spleen cells.

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Immunomodulatory Function of Murine NK Cell Activity by Alginate

  • Son Eun-Wha;Yang Kwang-Hee;Rhee Dong-Kwon;Pyo Suhkneung
    • Archives of Pharmacal Research
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    • v.28 no.11
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    • pp.1282-1286
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    • 2005
  • The in vivo immunomodulatory function of the activity of murine natural killer (NK) cells induced by high mannuronic acid-containing alginate (HMA) was examined. HMA was injected i.p at doses of 25 and 100 mg/kg. The NK activity was 3 times higher with 100 mg/kg HMA than the baseline. In addition, in vitro studies of splenocytes cultured with HMA for 20 h showed a significant increase in NK activity at E:T ratio of 100: 1; a 160$\%$ and 210$\%$ increase at 10 and 100 $\mu$g/mL, respectively. There was a six fold increase in interferon-$\gamma$ production in a postculture of splenocytes with 100 $\mu$g/mL HMA. HMA had no suppressive effects on the lymphocyte function in the presence or absence of mitogens. This suggests that HMA is useful in cancer immunotherapy.

Effect of DDT on Testosterone Production by Modulator Aromatase (CYP 19) in R2C

  • Lee, Kyung-Jin;Lee, Jong-Bin;Jeong, Hye-Gwang
    • Korean Journal of Environmental Biology
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    • v.21 no.3
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    • pp.308-312
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    • 2003
  • Various pesticides known or suspected to interfere with steroid hormone function were screened toy effects in leydig cells on catalytic activity and mRNA expression of aromatase. Dichlorodiphenyltrichloroethane (DDT) is a widespread environmental pollutant. In this study, we investigated the effect of DDT on testosterone production through aromatase activity and its molecular mechanism in testicular leydig cell, R2C by using radioimmunoassay (RIA). As the results, the potent leydig: cell activator LH increased testosterone production compared to the control. DDT exposure significantly decreased testosterone production in R2C cell. In addition, DDT was found to increase aromatase gene expression and activity in R2C cell in a dose dependent manner. In order to assess whether the suppressive effects of DDT on LH-inducible testosterone (T) production might be influenced by the ER, ICI 182.780 was used, and it was found that these inhibitory effects of DDT were antagonized by ICI 182.780, implying that the estrogen receptor (ER) mediates the suppressive effects of DDT. Furthermore, the inducible effects of DDT on aromatase gene expression might be influenced by the ER, ICI 182.780 was used, and it was found that these enhancing effects of DDT were antagonized by ICI 182.780, implying that the ER mediates the inducible effects of DDT. Our results indicated that DDT inhibition of luteinizing hormone (LH) -inducible T production in R2C cell is mediated through aromatase. However, the precise mechanisms by which DDT enhance in R2C cell remains unknown. The current study suggests the possibility that DDT might act as a modulator aromatase gene transcription.

Suppressive Effects of Coumarins on Pumpkin Seedling Growth and Glutathione S-Transferase Activity

  • Hossain, Md. Daud;Li, Jing;Guo, Shirong;Fujita, Masayuki
    • Journal of Crop Science and Biotechnology
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    • v.11 no.3
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    • pp.187-192
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    • 2008
  • The effects of some coumarins(coumarin, 7-hydroxycoumarin, scopoletin and esculetin) were investigated on pumpkin(Cucurbita maxima Duch.) seedlings and on pumpkin glutathione S-transferases(GSTs). Coumarin and esculetin suppressed the growth of seedlings, especially the elongation of roots as well as hypocotyls. Among the compounds tested, only esculetin inhibited the activity of a particular pumpkin GST by 50%, CmGSTU3 toward 1-chloro-2, 4- dinitrobenzene(CDNB) and at a concentration of 22 ${\mu}M$. Both ethylacetae(EtOAc) and water fractions in pumpkin seedlings and different organs of one-month-old pumpkin plants contained esculetin or similar hydrophobic fluorescent substances as well as hydrophilic substances, which showed different degrees of inhibitory effects on CmGSTU3 activity.

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Antifungal Activity of Root Colonizing Pseudomonas fluorescens MC07 is Responsible for Its Disease Suppression Ability (근권 정창 세균 Pseudomonas fluorescens MC07의 항진균 활성과 병 억제 능력)

  • 김진우;박병근;황인규;박창석
    • Korean Journal Plant Pathology
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    • v.14 no.6
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    • pp.606-611
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    • 1998
  • An antagonistic bacterium, Pseudomonas flurorescens MC07 inhibited the mycelial growth of Rhizoctonia solani, Pythium ultimum, Fusarium oxysporum, and Phytophthora capsici in on potato dextrose agan (PDA) and other media. The strain MC07 conlonizes various plant roots and possesses antifungal activity. To determine the role of antifungal activity of the bacterium in disease suppression, a mutant Okm3-4 which lost its activity was isolated after screening 2,500 colonies generated by Omegon-Km insertions. The mutant Okm3-4 showed diminished growth inhibition of R. solani, P. ultimum, F. oxysporum, and Ph. capsici in vitro and had reduced suppressive effects on sesame damping.-off compared to the parental strain. In soils, accumulation of the pathogens by continuous cropping, 90% of sesame plants were killed by natural infection of damping-off whereas, only 29% of plants grown from seeds treated with MC07 were killed. On the other hand, 85% of plants died when sesame seeds were treated with the Okm3-4 cells. This indicated that antifungal activity of MC07 in vitro is directly responsible for the suppression of damping-off disease. Emergence rates of sesame seeds in pots containing diseased soil were 33%. However, MC07 treatments on seeds significantly improved emergence rates, which has similar effects of Benomyl treatment. The mutant Okm3-4 exhibited 53% of emergence rate. This indicated that antifungal activity of MC07 also affects the emergence rate of sesame seeds.

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Body-fat Suppressive Effects of Capsaicin through $\beta$-adrenergic Stimulation in Rats Fed a High-fat Diet (고지방식이를 섭취시킨 흰쥐에서 $\beta$-adrenergic 활성의 증가에 의한 Capsaicin의 체지방 감소효과)

  • 주종재
    • Journal of Nutrition and Health
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    • v.32 no.5
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    • pp.533-539
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    • 1999
  • The effects of capsaicin, a pungent principle of hot red pepper, on body fat gain, balance serum lipid values were investigated in rats fed a high-fat(30%) diet. Administration of capsaicin by dietary administration caused a complete cessation of increased in body weight and fat gain induced by the high-fat diet. However, energy intake and body protein gain were not affected by capsaicin. Therefore, the suppression of body fat gain by capsaicn was believed due to an increased in energy expenditure. Simultaneous administration of capsaicin and a $\beta$-adrenergic blocker, propranolo, resulted in the inhibition of changes in body fat gain by capsaicin without remained unchanged, indicating an increase in the number of mitochondria in brown adipose tissue. Therefore, it appears that capsaicin possesses potent body fat suppressive effects mediated by $\beta$-adrenergic stimulation in which brown adipose tissue may be involved. On the other hand, capsaicin had no effects on serum triglyceride, total cholesterol or HDL-cholesterol levels. These results are in contrast to those reported by other investigators. Perhaps expression of the effects of capsaicin on plasma lipids is a rather complicated process, dependent on the type of diet administered, fat content of the diet, period and route of capsaicin administration, and species and strain of animals used.

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Suppressive Effects of Korean Indigenous Acanthopanax divaritacus on the Allergic Inflammation

  • Park, Seul-Ki;Kim, Jum-Ji;Jeon, Yu-Mi;Lee, Mi-Young
    • Journal of Applied Biological Chemistry
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    • v.50 no.3
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    • pp.155-159
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    • 2007
  • The water extracts of root, stem, and leaf from Korean indigenous Acanthopanax divaritacus were examined for their suppressive effects against allergic inflammations such as lipoxygenase activity, ${\beta}-hexosaminidase$ release, inflammatory cytokine production, and serum IgE level. The root extract inhibited the release of ${\beta}-hexosaminidase$, a degranulation marker, from rat basophilic leukemia cells (RBL-2H3) much more potently than the stem and leaf extracts. The root extract also significantly reduced the expression of $TNF-{\alpha}\;and\;IL-1{\beta}$ in the RBL-2H3 cells challenged with antigen. Moreover, there was a significant fall in the serum IgE level by the treatment of the root extract. Taken together, the root extract could be the most potent inhibitor of allergic inflammation, suppressing ${\beta}-hexosaminidase$ release and inflammatory cytokine expression, as well as reducing the rise of serum IgE level.

Suppressive Effects of Potato (Solanum tuberlosum) on Type II Collagen-Induced Arthritis in DBA/1J Mice

  • Choi, Eun-Mi
    • Food Science and Biotechnology
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    • v.16 no.1
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    • pp.43-48
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    • 2007
  • Collagen-induced arthritis (CIA) is a model for some types of human autoimmune rheumatoid arthritis (RA). In this study, we examined whether ethanol extract of potato (Solanum tuberosum) is efficacious against CIA in mice. Potato extracts (100 and 200 mg/kg) were orally administered to DBA/1J mice once daily for 49 day after initial immunization with type II collagen. Clinical assessment of disease and measurement of paw edema were conducted throughout the study. The production of CIA-related rheumatoid factor, anti-type II collagen antibody, and cytokines were examined in DBA/1J mice. Serum levels of AST, ALT, creatinine, and lipids were measured, and antioxidant enzyme activity in the spleen was also determined. The arthritis score and paw edema were markedly suppressed in the groups treated with potato extract. Levels of rheumatoid factor, anti-type II collagen antibody, interleukin (IL)-1, IL-6, LDL-cholesterol, and malondialdehyde in sera were also reduced by potato extract treatment. The activities of glutathione peroxidase and glutathione reductase were increased in the spleens of CIA mice treated with potato extract. These findings suggest that potato extract has suppressive effects on type II collagen-induced arthritis, an animal model for human RA.

Microscopic Examination of the Suppressive Action of Antifungal Substances from Pseudomonas aeruginosa on Asexual Sporulation of Fungi

  • Kwon S. Yoon;Bu Y. Min;Park, Hyoung T.;Lee, Jong K.;Kim, Kun W.
    • Journal of Microbiology
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    • v.37 no.1
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    • pp.27-34
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    • 1999
  • Two fractions with unusual antifungal activity that suppress asexual sporulation of several fungi were obtained from culture filtrate of Pseudomonas aeruginosa and were partially purified through the repeated silicagel flash column chromatographies. The sporulation-suppressive actions of these fractions in Aspergillus nidulans, Rhizopus stolonifer, and Coprinus cinereus, were analyzed by light and electron microscopes. The germination ability of the spores produced in the presence of these fractions were also checked to determine the persistent effects of these antifungal substances on the next generation. Light microscopic observation of developing sporangia of R. stolonifer grown in the presence of both fractions revealed that the significant number of sporangia failed to reach maturity, and frequently, uncontrolled growths of hyphae and rhizoids from the sporangiophores were found. In A. nidulans addition of these fractions appeared to cause different classes of morphological abnormality in conidia development, which included aborted formation of conidiogenous cells from the apex of conidiophores and enhanced hyphal growths either at the tip or middle of the conidiophores. Germination abilities of spores obtained from the cultures grown in the presence of antifungal fractions were 40∼60% in Aspergillus, 50∼80% in Coprinus (thallic spores), and 30∼40% in Rhizopus compared to those of normal spores.

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Suppressive Effects of Vitamin E on the Induction of Placental Glutathione S-transferase(GST-P) Positive foci and Antioxidant Enzyme Activity in Rat Hepatocarcinogenesis (비타민 E가 쥐간 세포의 암화과정에서 태반형 Glutathione S-transferase(GST-P) 양성 병소와 항산화요소계에 미치는 영향)

  • 최혜미
    • Journal of Nutrition and Health
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    • v.30 no.7
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    • pp.803-812
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    • 1997
  • The influences of dietary supplements of vitamin E on hepatocellular chemical carcinogenesis have been studied, Placental glutathione S-transferase(GST-P) positive foci area, antioxidant enzymes(superoxide dismutase(SOD), catalase, glutathione reductase, glutathione peroxidase, glutathione S-transferase(GST)), glucose 6-phosphatase(G6Pase) activities, and lipid peroxidation of mecrosomes(thiobarbituric acid reactive substances(TBARS) contents) were investigated. For is purpose , we used the murine chemical hepatocardinogenic procedure induced by modified Ito model, which consists of 200mg/kg body weight diethylinitrosamine (DEN) injection, 0.01% 2-acethlaminoflurene(2-AAF) feeding for 6 weeks, and partial hepatectomy on week 3. Weanling Sprague-Dawley male rats were fed pulverized Purina rat chow with 15, 000IU/kg diet vitamin E from initiation or promotion stages. We found that vitamin E supplement decreased the area of GST-P positive foci. Catalase, glutathione peroxidase, glutathione reductase. GST activities, and TBARS contents were decreased. On the other hand G6Pase activities were increased by vitamin E supplement. It seemed that vitamin E supplements helped endogenous defense systems against carcinogenesis by decreasing TBARS contents, $H_2O$$_2$ and organic peroxides. So, vitamin E seemed to protect cell from free radical damage in carcinogenesis. Anticarcinogenic effects of vitamin E were more effective at intiation that at promotion stage. These results suggest that vitamin E has suppressive effects on hepatocellular chemical carcinogenesis, probably through antioxidant effects against TBARS contents $H_2O$$_2$ and orgainc peroxides.

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