• 제목/요약/키워드: Dose enhancement agent

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Enhancement of immunological activity in exo-biopolymer from submerged culture of Lentinus edodes with rice bran

  • Kim, Hwa-Young;Han, Jae-Taek;Hong, Seong-Gil;Yang, Sung-Bum;Hwang, Sung-Joo;Shin, Kwang-Soon;Suh, Hyung-Joo;Park, Mi-Hyoun
    • Natural Product Sciences
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    • 제11권3호
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    • pp.183-187
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    • 2005
  • The objective of the present study was to determine the possible immune-enhancing effects of a substance extracted from a submerged culture of Lentinus edodes with rice bran (SLRB). According to the results obtained by measuring the in vitro macrophage activity of the exo-biopolymer from SLRB, it appears to exhibit activity similar to that of LPS, and this activity seems to occur in a dose-dependent manner. According to the results obtained by measuring splenocyte proliferation, the exo-biopolymer appears to induce an increase in proliferation of approximately 1.4-fold compared to the control group. We measured the proliferation of bone marrow cells in order to evaluate gut immunity and, according to our results, proliferation was increased to 109% that of the control group, and was similar to that associated with LPS. In order to characterize the enhancement of immunological activity in vivo, we orally administered the exo-biopolymer (25, 50, 250 mg/kg bw) to C3H/He mice, and then measured the macrophage activity, determining that the activity was higher than that of the controls at concentrations of 50 and 250 mg/kg. Therefore, the exo-biopolymer from SLRB can be considered to be a useful a BRM agent, as it clearly allows some protection against immunological diseases.

An Animal Model to Evaluate the Protective Efficacy of Haemophilus influenzae Type b Conjugate Vaccines

  • Kim Hyun Sung;Yoo Tae Hyeon;Jang Yang Suk;Kim Hun;Park Jin Yong;Hur Byung Ki;Ryu Yeon Woo;Kim Jong Su
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제9권6호
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    • pp.490-494
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    • 2004
  • An efficacy test of PRP (polyribosylribitol phosphate)-TT (Tetanus toxoid) conjugate vaccines was carried out using BALB/c mice as an animal model by inoculating Haemophilus in­fluenzae type b (Hib) with a virulence enhancement factor (VEF). Three administrations of the conjugate vaccines at 2-week intervals elicited a significantly high level of PRP antibodies (P>0.0001). The protective activity of the PRP immunization was challenged with either Hib with iron dextran (Hib/) or with a combination of mucin and hemoglobin (Hibmh) as a VEF. The me­dium lethal dose $(LD_{50})$ for Hibmh and Hibiwas measured as 10 CFU (Colony Forming Unit) and $2.5{\times}10^{8}$ CFU respectively. Each immunized animal was challenged with five or ten times the $LD_{50}$ level of bacteria with a VEF. A significant difference in mortality between the immunized and control mice (P> 0.01) was observed with the Hibmh challenge inoculation but not with the Hibi challenge inoculation. These results show that a combination of mucin and hemoglobin was able to enhance the virulence of Hib in BALB/c mice to cause a lethal infection, thus suggesting that BALB/c mice introduced to this method can be an effective model animal for testing the protective efficacy of H. influenzae conjugate vaccines.

Effects of Flavonol Derivatives on the Micronudei Formation by N-methyl-N'-nitro-N-nitrosoguanidine and the Enhancement of Bleomycin-induced Chromosome Aberration by N-methyl-N'-nitro-N-nitrosoguanidine

  • Heo, Moon-Young;Kwon, Chang-Ho;Sohn, Dong-Hun;Lee, Su-Jun;Kim, Sung-Wan;Kim, Jung-Han;William W. Au
    • Archives of Pharmacal Research
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    • 제16권3호
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    • pp.196-204
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    • 1993
  • Flavonol derivatives were tested for their anticlastogenic effect against induction of micronuclei by n-methyl-n'-nitor-n-nitorsoguanidine(MNNG), and against induction of chromosome aberration by bleomycin or MNNG.belomycin. For micronudeus assay, each flavonol derivative (0, 0.001, 0.01, 0.1, 1, 10 and 100 mg/kg) was administered orally twice with 24 h interval, together with intraperitioneally administered MNNG(150 mg/kg). The result showed that msot flavonol derivatives tested were effective in suppresing the frequencies of micronude induced by MNNG. For chromosome aberration assy, each flavonol derivative (0, 0.1, 1, 10m and 100 mg/kg)was administered to mice orally in vivo, and then mice were sacrificed and spleen lymphocyte cultures were made. Bleomycin $(3\;\mu$g/ml) was treated to the mouse spleen hymphocyte cultures at 24 h after con A initiation. There wre nomarked decrease tendencies in chromosome aberration unless all doses of galangin and some doses of several flavonol derivatives tested. In the another experiment, we have evaluated the effect of flavonol derivatives on the enhancement of bleomycin-induced chromsome aberration by MNNG. Most of flavonol derivtives reduced the incidence of chromosome aberration induced by in vitro treatment of bleomycin followed by in vivo treatment of MNNG. Galangin particulary showed a dose-dependent decrease tendency. Other flavonol derivative showed slightly suggest that most of flavonol derivatives may be capable of protecting the inhibition of suggest that most of flavonol derivatives may be capable of protecting the inhibition of DNA-repair by MNNG. Our data indicate clearly that flavonol derivatives can suppress MNNG-induced genotoxicity such as an induction of MNPCEs. Therfore, our results could suggest that flavonol derivtives may be useful as a chemopreventive agent of MNNG.

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Effect of Sodium Butyrate on the Production of IDS by CHO-DG44 Cell

  • Jeon, Ok-Seon;Kang, Seon-Ah;Kim, Myoung-Hwa;Jeong, Yeon-Ho
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2005년도 생물공학의 동향(XVI)
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    • pp.214-217
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    • 2005
  • 본 연구에서는 재조합 단백질 IDS의 생산성을 향상시키기 위한 방법으로 혈청이 첨가되거나 첨가되지 않은 배지에서 세포를 배양하는 동안 sodium butyrate를 첨가하였다. 두 배양 배지에서 모두 비록 세포 농도나 생존률이 감소되긴 했지만 생산성에서 상당히 높은 효과를 보였다.

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흰쥐에 경구 투여시 히드록시프로필-베타-시클로덱스트린과 니트렌디핀 고체분산에 의한 생체이용률 증가 (Enhancement of Nitrendipine Bioavailability in Rats by its Solid Dispersion with $Hydroxypropyl-{\beta}-Cyclodextrin$ after Oral Administration)

  • 용철순
    • Journal of Pharmaceutical Investigation
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    • 제27권4호
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    • pp.295-301
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    • 1997
  • Nitrendipine, a slightly soluble calcium channel blocking agent forms a solid dispersion system with $hydroxypropyl-{\beta}-cyclodextrin$, which exhibits better dissolution characteristics than the uncomplexed drug. The dissolution rate of nitrendipine was markedly increased in solid dispersion system in pharmacopeial disintegration media at pH 1.2 and pH 6.8. Four different dosage forms of nitrendipine were administered to rats: (a) nitrendipine in the solution of PEG 400; (b) nitrendipine solid dispersion system with $hydroxypropyl-{\beta}-cyclodextrin$ in a molar ratio of 1:2 by solvent evaporation method and administered in capsule form; (c) physical mixture of nitrendipine with $hydroxypropyl-{\beta}-cyclodextrin$ in a molar ratio of 1:2 and administered in capsule form; (d) nitrendipine alone administered in capsule form. Relative bioavailability after the oral administration of various dosage forms to rats with a dose of 10 mg/kg equivalent to nitrendipine was compared with that of nitrendipine in the solution of PEG 400. The AUC of solid dispersion was significantly bigger than that of nitrendipine powder. $T_{max}$ of solid dispersion was significantly shorter and $C_{max}$ was higher than that of nitrendipine powder. These results indicate that the bioavailability of nitrendipine could be improved markedly by inclusion complexation. An interesting correlation also appears to exist between the in vitro dissolution data and the area under the plasma concentration-time curves.

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chemopreventive Effects of 2-(Allylthio) pyrazine

  • Kim, Nak-Doo;Kim, Sang-Geon
    • Archives of Pharmacal Research
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    • 제22권2호
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    • pp.99-107
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    • 1999
  • A series of organosulfur compounds were synthesized with the aim of developing chemopreventive compounds active against hepatotoxicity and chemical carcinogesis. 2-(Allylthio) prazine (2-AP) was effective in inhibiting cytochrome P450 2E1-mediated catalytic activities and protein expression, and in inducing microsomal epoxide hydrolase and major glutathione S-transferases. 2-AP reduced the hepatotoxicity caused by toxicant sand elevated cellular GSH content. Development of skin tumors, pulmonary adenoma and aberrant crypt foci in colon by various chemical carcinogens was inhibited by 2-AP pretreatment. Anticarcinogenic effects of 2-AP at the stage of initiation of tumors were also observed in the aflatoxin B1 ($AFB_1$)-induced three-step medium-term hepatocarcinogenesis model. Reduction of $AFB_1$-DNA adduct by 2-AP appeared to result from the decreased formation of $AFB_1$-8,9-epoxide via suppression of cytochrome P450, while induction of GST 2-AP increases the excretion of glutathione-conjugated $AFB_1$ . 2-AP was a radioprotective agent effective against the lethal dose of total body irradiation and reduced radiation-induced injury in association with the elevation of detoxifying gene expression. 2-AP produces reactive oxygen species in vivo, which is not mediated with the thiol-dependent production of oxidants and that NF-KB activation is not involved in the induction of the detoxifying enzymes. the mechanism of chemoprotection by 2-AP may involve inhibition of the P450-mediated metabolic activation of chemical carcinogens and enhancement of electrophilic detoxification through induction of phase II detoxification enzymes which would facilitate the clearance of activated metabolites through conjugation reaction.

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Cyclophosphamide가 마우스의 면역기억에 미치는 영향 (Effects of Cyclophosphamide on Immunological Memory in Mice)

  • 박영민;박윤규;안우섭;하대유
    • 대한미생물학회지
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    • 제22권2호
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    • pp.175-184
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    • 1987
  • The use of alkylating agent cyclophosphamide(CY), a widely used antitumor drug is well known as a potent immunosuppressant and has been used as a probe for investigating the functional capabilities of lymphocyte subsets of both T and B cells that play an important role in the regulation of the immune response. The present study was undertaken in an effort to assess the effects of CY on immunological memory in murine model. CY, given as a single dose of CY(250mg/kg) before sensitization with sheep red blood cells(SRBC) enhanced the primary response of Arthus and delayed-type hypersensitivity(DTH), as measured by footpad swelling reaction, but suppressed their tertiary DTH response. The similar CY pretreatment enhanced both the primary and tertiary hemagglutinin(HA) responses to SRBC, and the tertiary antibody response against polyvinylpyrroridone(PVP), a thymus-independent antigen but not the primary response against PVP. CY, given as a single dose of 250mg/kg 2 days before the primary immunization and two doses of 100mg/kg 2 days before the secondary and tertiary immunization, markedly suppressed the tertiary DTH and HA responses to SRBC. However, CY, given as small multiple daily doses(10mg/kg) over 4 days before sensitization but not after sensitization, enhanced the secondary HA response to SRBC. Contact sensitivity to dinitrofluorobenzene(DNFB) was suppressed by the drug, given either as a single large dose(300mg/kg) or as multiple dose(10mg/kg) administered 2 days before, together with or after DNFB sensitization. This suppression was more pronounced and more significant when CY was given as multiple dose. However, the enhancement of the secondary contact sensitivity to DNFB by CY was not clear-cut. The splenectomy appears to increase the enhancing effect of CY on contact sensitivity. These results suggest that CY selectively influences the immune response depending on the time of the drug administration relative to immunization and that the secondary or tertiary immune response involve memory cells with different susceptibilities to CY. Moreover, these results suggest that multiple low doses may sesectivley inhibit suppressor T cell proliferation involving DTH, HA or contact sensitivity without effecting helper T cells, but high doses presumably inhibit helper T cells and suppressor T cells with effecting B cells.

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비타민 A 및 피리딘으로 유발된 사염화탄소 유발성 간독성에 대한 2-(알릴티오)피라진의 보호효과: ${\Phi}$x-174 DNA 손상에 미치는 효과 (Protective Effects of 2-(Allylthio)pyrazine on Retinoyl Palmitate- and Pyridine-Potentiated Carbon tetrachloride- induced Hepatotoxicity: Effect on ${\Phi}x$-174 DNA Strand Breakage)

  • 김상건;조주연;최성희;김낙두
    • 약학회지
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    • 제40권6호
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    • pp.727-733
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    • 1996
  • 2-(Allylthio)pyrazine is effective in selectively suppressing constitutive and inducible expression of cytochrome P450 2E1. The effect of 2-(allylthio)pyrazine against potentiat ed chemical injury was studied in rats. Vitamin-A pretreatment of rats substantially increased carbon tetrachloride hepatotoxicity, as supported by an ~4-fold increase in serum alanine aminotransferase (ALT) activity. Concomitant pretreatment of rats with 2-(allylthio)pyrazine at the daily dose of 200mg/kg resulted in a 76% decrease in vitamin-A-potentiated hepatotoxicity, which supported the possibility that 2-(allylthio)pyrazine protects the liver against chemical-induced hepatic injury by the mechanism associated with Kupffer cell inactivation. Pyridine pretreatment caused substantial enhancement in carbon tetrachloride hepatotoxicity. 2-(Allylthio)pyrazine treatment of rats reduced the pyridine-potentiated toxicity in a dose-dependent manner. Animals treated with both pyridine and 2-(allylthio)pyrazine prior to intoxicating dose of CCl$_4$ resulted in 85% and 47% decreases in pyridine-increased triglycerides and cholesterol levels in the liver. The protective effect of 2-(allylthio)pyrazine on the DNA strand breakage induced by benzenetriol was assessed by measuring the conversion of supercoiled ${\Phi}x$-174 DNA to the open relaxed form. 2-(Allylthio)pyrazine blocked the benzenetriol-induced conversion of supercoiled DNA to open circular form in a dose-dependent manner. The presence of 2-(allylthio)pyrazine at the doses from I to 10mM in the incubation mixture containing 5 ${\mu}$M benzenetriol completely protected benzenetriol-induced DNA strand breakage with the EC50 for the 2-(allylthio)pyrazine blocking being noted as ~220 ${\mu}$M, whereas allyl disulfide exerted protecting effect at relatively high concentrations (i.e. ~850 ${\mu}$M), suggesting that 2-(allylthio)pyrazine effectively scavenges the reactive oxygen species. These results provide evidence that 2-(allylthio)pyrazine blocks vitamin A- or pyridine-potentiated CCl$_4$ hepatotoxicity and that the agent is active in protecting DNA by scavenging the reactive oxygen species.

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Chemoprevention of chemical-induced skin cancer by Panax ginseng root extract

  • Sharma, Jyoti;Goyal, Pradeep K.
    • Journal of Ginseng Research
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    • 제39권3호
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    • pp.265-273
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    • 2015
  • Background: Cancer has emerged as a major health problem globally as a consequence to the increased longevity of the population, changing the environment and life style. Chemoprevention is a new and promising strategy for reducing cancer burden. Recently, some natural products have been identified for their chemopreventive activity to reduce the cancer incidence. Ginseng is known for its potential to treat various ailments in human beings. The present study was designed to explore the anticancer and antioxidative potential of Panax ginseng against chemical-induced skin carcinogenesis in mammals. Methods: Skin tumors were induced in Swiss albino mice by a single topical application of 7,12-dimethylbenz(a)anthracene ($100{\mu}g/100{\mu}L$ acetone) and, 2 wks later, promoted by repeated applications of croton oil (thrice in a wk in 1% acetone) till the end of the experiment (i.e., 16 wk). Hydroalcoholic ginseng root extract at a dose of 25 mg/kg body weight/d was orally administered at the periinitiation, postinitiation, and peri-post-initiation stages. Results: Ginseng root extract treatment caused a significant reduction in tumor incidence, cumulative number of tumors, tumor yield, and tumor burden, as compared to the 7,12-dimethylbenz(a)anthracene-croton oil-treated control group. Further, biochemical assays revealed a significant enhancement in the levels of reduced glutathione, superoxide dismutase, catalase, vitamin C, and total proteins but a significant reduction in lipid peroxidation levels in both the liver and skin with ginseng root extract treatment, as compared to carcinogen-treated control group. Conclusion: These results suggest that P. ginseng has the potential to become a pivotal chemopreventive agent that can reduce cancer in mammals.

Antimelanogenic effect of ginsenoside Rg3 through extracellular signal-regulated kinase-mediated inhibition of microphthalmia-associated transcription factor

  • Lee, Seung Jae;Lee, Woo Jin;Chang, Sung Eun;Lee, Ga-Young
    • Journal of Ginseng Research
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    • 제39권3호
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    • pp.238-242
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    • 2015
  • Background: Panax ginseng has been used to prolong longevity and is believed to be useful for improving skin complexion. Ginsenosides are the most active components isolated from ginseng, and ginsenoside Rg3 (G-Rg3) in particular has been demonstrated to possess antioxidative, antitumorigenic, and anti-inflammatory properties. The aim of this study was to examine the ability of G-Rg3 to inhibit melanogenesis. Methods: The effects of G-Rg3 on melanin contents and the protein levels of tyrosinase, microphthalmia-associated transcription factor (MITF), and tyrosinase-related protein 1 (TRP1) were evaluated. Melanogenesis-regulating signaling molecules such as Akt and extracellular signal-regulated kinase (ERK) were also examined to explore G-Rg3-induced antimelanogenic mechanisms. Results: G-Rg3 was found to significantly inhibit the synthesis of melanin in normal human epidermal melanocytes and B16F10 cells in a dose-dependent manner. The activity of cellular tyrosinase and the expression of MITF, tyrosinase, and TRP1 were all reduced, whereas ERK was strongly activated. PD98059 (a specific inhibitor of ERK) attenuated the G-Rg3-induced inhibition of melanin synthesis and tyrosinase activity. Conclusion: Taken together, these results showed that G-Rg3 induces the activation of ERK, which accounts for its antimelanogenic effects. G-Rg3 may be a promising safe skin-whitening agent, adding to the long list of uses of P. ginseng for the enhancement of skin beauty.