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        검색결과 169

        22.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Antioxidants have been added to cryoprotectant or in vitro culture medium for sperm to reduce the detrimental damage, such as reactive oxygen species. However, curcumin, an antioxidant, shows dual effect on the viability and progressive motility of bovine sperm exposed to hydrogen peroxide. Low concentration of curcumin increases sperm viability and progressive motility, whereas high concentration of curcumin reduces them. This study was performed to identify whether TREK-1 channel is related to low sperm viability and motility induced by high concentration of curcumin. Curcumin reduced TREK-1 channel activity in a dose-dependent manner. TREK-1 channel was expressed in sperm obtained from Korean native bull. Treatment with TREK-1 channel blockers, such as curcumin, fluoxetine, GdCl3, and spadin, significantly reduced sperm viability and motility (p < 0.05). However, TREK-1 channel activators showed different effect; linoleic acid showed an increase in sperm viability and motility, and wogonin did not affect them. These results show that TREK-1 channel is involved in the regulation of sperm viability and motility. In particular, high concentration of curcumin might reduce sperm viability and progressive motility of Korean native bull through blockage of TREK-1 channel.
        4,000원
        23.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        청국장추출물과 청국장의 주요한 플라보노이드의 하나인 genistein의 HepG2 세포에서 Trp-P-1 유도 세포독성과 DNA손상에 대한 보호효과를 평가하였다. 청국장추출물과 주요 플라보노이드성분 genistein은 Trp-P-1 유도 세포독성에 대하여 세포독성보호효과를 나타내었다. 청국장추출물 은 Trp-P-1 유도 DNA single strand breaks를 억제하였다. 한편, 청국장추출물은 HepG2 세포에서 Trp-P-1 유도에 의한 CYP1A1와 CYP1A2 발현의 억제를 나타내었다. 청국 장추출물과 genistein은 Trp-P-1에 의한 유도 세포독성과 DNA손상에 대하여 CYP1A1, CYP1A2 발현억제에 의하 여 보호효과가 나타나는 것으로 판단된다. 한국의 전통 콩 발효식품인 청국장은 게놈 불안정성(genomic instability)을 일으키는 heterocyclic amines (HCAs)과 같은 식품의 가열 조리로부터 올 수 있는 발암물질에 대한 유전독성을 예방할 수 있는 유망한 기능성물질로서 활용가능성이 있을 것으로 판단된다.
        4,000원
        24.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        곤충의 혈액순환은 심장 박동에 의해 도움을 받는다. 다양한 생리적 변화는 심장 박동 조절을 수반하게 된다. 심장박동에 대한 교란은 곤충 의 생존을 위협하게 된다. 본 연구는 활성산소를 유발하여 살충력을 발휘하는 이산화염소가 혈액순환계에 미치는 영향을 심장박동을 통해 분석하 였다. 화랑곡나방(Plodia interpunctella) 유충의 등핏줄은 몸의 윗면 중앙에 위치하고 후방으로 복부 10번째 마디에서 시작하여 전방으로 첫 번째 가슴 마디까지 연결된 관 구조를 나타냈다. 등핏줄의 수축과 이완은 주로 복부 3-10번째 마디에 위치한 등핏줄에서 일어났으며 이 부위에 5개의 심실이 관찰되었다. 심장박동빈도는 25°C에서 분당 평균 118.6회의 수축 리듬을 보였다. 그러나 온도에 따라 심장박동빈도는 현격한 변화를 보 였다. 혈강에 이산화염소를 다양한 농도로 투여한 경우 심장박동빈도는 약제 농도 증가에 따라 감소하였다. 이산화염소(100 ppm)을 훈증 처리할 경우 노출 시간의 경과에 따라 심장박동리듬이 현격하게 감소하였다. 이러한 이산화염소의 심장박동 억제효과는 활성산소 저해제인 비타민 E와 함께 주입할 경우 회복되는 현상을 나타냈다. 이상의 결과는 이산화염소가 화랑곡나방의 심장박동에 억제효과를 주었으며 이러한 억제효과는 이 물질이 유발하는 활성산소에 기인된 것으로 해석된다.
        4,000원
        25.
        2016.12 구독 인증기관 무료, 개인회원 유료
        Chlorhexidine has long been used in mouth washes for the control of dental caries, gingivitis and dental plaque. Minimal inhibitory concentration (MIC) is the lowest concentration of an antimicrobial substance to inhibit the growth of bacteria. Concentrations lower than the MIC are called sub minimal inhibitory concentrations (sub-MICs). Many studies have reported that sub-MICs of antimicrobial substances can affect the virulence of bacteria. The aim of this study was to investigate the effect of sub-MIC chlorhexidine on biofilm formation and coaggregation of oral early colonizers, such as Streptococcus gordonii, Actinomyces naeslundii and Actinomyces odontolyticus. The biofilm formation of S. gordonii, A. naeslundii and A. odontolyticus was not affected by sub-MIC chlorhexidine. However, the biofilm formation of S. mutans increased after incubation with sub-MIC chlorhexidine. In addition, cell surface hydrophobicity of S. mutans treated with sub-MIC of chlorhexidine, decreased when compared with the group not treated with chlorhexidine. However, significant differences were seen with other bacteria. Coaggregation of A. naeslundii with A. odontolyticus reduced by sub-MIC chlorhexidine, whereas the coaggreagation of A. naeslundii with S. gordonii remained unaffected. These results indicate that sub-MIC chlorhexidine could influence the binding properties, such as biofilm formation, hydrophobicity and coaggregation, in early colonizing streptococci and actinomycetes.
        4,000원
        26.
        2016.12 구독 인증기관 무료, 개인회원 유료
        Flavonoid myricetin, usually found in tea and medicinal plants, has antioxidant and anti-inflammatory effects. Our objectives in this study were to verify the effects of myricetin on periodontal ligament fibroblasts (PDLFs) under inflammatory conditions and to observe its effects on osteoclast generation and on cytokine expression in RAW264.7 cells. To determine the effects of myricetin on PDLFs, we examined the expression and activity of proteolytic enzymes, including MMP-1, MMP-2, and MMP-8, which all play an important role in chronic periodontitis. We observed the effects of myricetin on intracellular signal transduction to verify the molecular mechanism involved. By measuring the formation of TRAP–positive multinucleated cells and the expression and activity of MMP-8, we were able to assess the effects of myricetin on osteoclast generation. In addition, by measuring the secretion of IL-6 and NO, we could evaluate the effects of myricetin on inflammatory mediators. We found that Myricetin had no effect on the viability of the PDLFs in the presence of inflammation, but it did decrease both the expression of MMP-1 and MMP-8 and the enzyme activity of MMP-2 and MMP-8 in these fibroblasts. Myricetin also decreased the lipopolysaccharide-stimulated phosphorylation of JNK, p38 signaling, IKKB, AKT, and p65RelA in the PDLFs. In the RAW264.7 cells, myricetin inhibited both the expression and the activity of MMP-8. Furthermore, Myricetin not only suppressed the generation of LPS-stimulated osteoclasts, but it also slightly inhibited LPS-stimulated degradation of IkB and decreased the release of LPS-induced IL-6 and NO. These findings suggest that myricetin alleviates the tissue-destructive processes that occur during periodontal inflammation.
        4,200원
        27.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A recent study reported that Pleurotus ostreatus has the potential to be used as a β-glucan-based cream for supportive complementary therapy of atopic dermatitis. KH054 is a new herbal prescription consisting of P. ostreatus and Panax ginseng. The effects of atopic dermatitis-induced materials on the expression of cytokine genes in human monocytes (THP-1, EoL- 1) have been examined. Some reports demonstrated that P. ginseng augments the activity of natural killer cells, which plays an important role in innate immunity against infection and tumor development. Monocyte chemotactic protein 1 (MCP-1), interleukin (IL)-6, and IL-8 have important roles in mediating the infiltration of various cells into the skin of atopic dermatitis and psoriasis. The present study investigated whether KH054 on induced IL-6, IL-8, and MCP-1 secretion by house dust mite (Dermatophagoides pteronissinus) in THP-1 (human acute monocytic leukemia) and EoL-1(Human eosinophilic leukemia) cell. D. pteronissinus functions in the pathogenesis of allergic diseases, including atopic dermatitis and asthma. The inhibitory effect of KH054 on the induction of IL-6, IL-8, and MCP-1 secretion by D. pteronissinus extract in THP-1 and EoL-1 cells was examined. KH054 potently suppressed the elevated production of IL-6 and IL-8 induced by D. pteronissinus treatment in THP-1 and EoL-1 cells. Based on the present results, KH054 may be useful for developing functional foods to treat atopic dermatitis.
        4,000원
        29.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Allergic diseases have rapidly increased in recent years. Mast cells play a critical role in IgE-mediated allergy responses and, therefore, closely associated with rhinitis, asthma, and atopic dermatitis. We studied antiallergic effect of Penthorum chinense extract (PCE) in vitro and in vivo. PCE inhibited the degranulation of mast cells by antigen stimulation and its effect was dose-dependent and reversible in mast cells. PCE also suppressed the production of inflammatory cytokines such as TNF-α and IL-4 by antigen in mast cells. Mechanistically, PCE inhibited the activation of Syk/LAT pathway which is a key signaling pathway for the activation of mast cells by antigen. Notably, PCE suppressed IgE-mediated allergic responses by antigen in mice. These results strongly suggest that PCE is a potential candidate for anti-allergic treatment.
        4,000원
        30.
        2015.12 구독 인증기관 무료, 개인회원 유료
        Minimal inhibitory concentration (MIC) is the lowest antibiotic concentration that inhibits the visible growth of bacteria. Sub-minimal inhibitory concentration (Sub-MIC) is defined as the concentration of an antimicrobial agent that does not have an effect on bacterial growth but can alter bacterial biochemistry, thus reducing bacterial virulence. Many studies have confirmed that sub-MICs of antibiotics can inhibit bacterial virulence factors. However, most studies were focused on Gram-negative bacteria, while few studies on the effect of sub-MICs of antibiotics on Gram-positive bacteria. In this study, we examined the influence of sub-MICs of doxycycline, tetracycline, penicillin and amoxicillin on biofilm formation and coaggregation of Streptococcus gordonii, Streptococcus mutans, Actinomyces naeslundii, and Actinomyces odontolyticus. In this study, incubation with sub-MIC of antibiotics had no effect on the biofilm formation of S. gordonii and A. naeslundii. However, S. mutans showed increased biofilm formation after incubation with sub-MIC amoxicillin and penicillin. Also, the biofilm formation of A. odontolyticus was increased after incubating with sub-MIC penicillin. Coaggregation of A. naeslundii with S. gordonii and A. odontolyticus was diminished by sub-MIC amoxicillin. These observations indicated that sub-MICs of antibiotics could affect variable virulence properties such as biofilm formation and coaggregation in Gram-positive oral bacteria.
        4,000원
        35.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Mushroom is known for anti-inflammatory and anti-oxidative potential. This study provides evidence that theinhibitory effect of mushroom on the expression of pro-inflammatory cytokines in human keratinocytes, HaCaT cells. To definethe underlying mechanisms of action, tumor necrosis factorα/IFNγ-activated human keratinocytes model was used. Mushroomsignificantly inhibited the expression of cytokines in HaCaT cells. Taken together, the results demonstrate that mushroom inhibitedinflammtion, suggesting that mushroom (DW extract: Grifola frondosa Cordyceps militaris), (Ethanol extract: Ganoderma lucidum,Lentinus edodes, Cordyceps militaris, Flammulina velutipes) might be a candidate for the treatment of skin inflammation.
        4,000원
        37.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The carcinogenesis mechanism of human salivary gland adenocarcinoma NOS is poorly understood. MicroRNA155(miRNA155) has been involved in the carcinogenesis of many malignant tumors. The purpose of this study was to examine the role of miRNA155 in tumor growth and invasion of adenocarcinoma NOS. Using SGT cells as a model for adenocarcinoma NOS, cell proliferation was examined by MTT assay after knocking down miRNA155 expression, and cell cycle analysis was performed. Invasive capacity by a Transwell culture assay, and miRNA155 expression in SGT cell line by RT-PCR were examined. In MTT assay, proliferation of SGT-miRNA155 cells was decreased prominently after 96 hrs. Proliferation of SGT cells was markedly inhibited by knocking down miRNA155, resulting from a blockade of cell cycle in the G1 phase, but apoptosis was increased about 4 folds. In adhesion assay, SGT-miRNA155 cells decreased about 60% compared to SGT cells. In invasion assay, inhibition of miRNA155 significantly suppressed the invasive capacity of about 34% SGT cells. mRNA expression of SGT-miRNA155 cells prominently were decreased compared to SGT cells by RT-PCR. It suggested that miRNA155 could play an role in cell cycle progression and invasion in SGT cells, including antitumor effect. These results have provided insights into the carcinogenic mechanisms and new intervention method of salivary gland adenocarcinoma NOS.
        4,000원
        38.
        2014.06 구독 인증기관 무료, 개인회원 유료
        Minimal inhibitory concentration (MIC) is the lowest concentration of antibiotics that inhibits the visible growth of a microorganism. It has been reported that sub-MIC of antibiotics may result in morphological alterations along with biochemical and physiological changes in bacteria. The purpose of this study was to examine morphological changes of periodontal pathogens after treatment with sub-MIC antibiotics. Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis were used in this study. The MIC for amoxicillin, doxycycline, metronidazole, penicillin, and tetracycline were determined by broth dilution method. The bacterial morphology was observed with bright field microscope after incubating with sub-MIC antibiotics. The length of A. actinomycetemcomitans and F. nucleatum were increased after incubation with metronidazole; penicillin and amoxicillin. P. gingivalis were increased after incubating with metronidazole and penicillin. However, F. nucleatum showed decreased length after incubation with doxycycline and tetracycline. In this study, we observed that sub-MIC antibiotics can affect the morphology of periodontal pathogens.
        4,000원
        40.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to evaluate antimicrobial effects of organic acid and some natural occurring antimicrobials against Staphylococcus aureus isolated from various origins (vegetables, peanut, pea leaf, kim- bab, person, perilla leaf, and animal) and to calculate their MIC and MBC values. Five organic acids (acetic, lactic, citric, malic, and propionic acid), three essential oils (carvacrol, thymol, and eugenol), and two other natural antimicrobials (nisin and cinnamic acid) were evaluated for their antimicrobial effects against 113 strains of S. aureus using combination treatments. Propionic acid (7%), nisin (1%), thymol (1%), carvacrol (1%) showed antimicrobial activities against S. aureus strains in agar disc diffusion test. And, carvacrol, thymol, and nisin were found to be the most effective with the lowest MIC values of 0.0313%, 0.0625%, and 0.0625% against S.aureus, respectively. Propionic acid (0.2313%) and citric acid (0.6000%) were the most effective among organic acids tested. Therefore, these five antimicrobials were selected for next combination treatments. Combination of propionic acid and citric acid were showed the strongest inhibitory effectiveness against S. aureus among combination treatments. These results suggest that organic acid such as propionic and citric acid, and natural occurring antimicrobial such as nisin, carvacrol, and thymol might be possibly used as preservatives for inhibiting S. aureus in foods.
        4,000원
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