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        검색결과 122

        41.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        t-BHP는 대표적인 산화스트레스에 의한 간 손상 모델이며, 본 연구자는 랫드에 기능성이 강화된 기능성 들깻잎 추출물(P. frutescens leaf extract, PLE)을 250, 500 또는 1000 mg/kg body weight (b.w.)으로 6일간 경구 투여하고 t-BHP의 복강 주사로 간 손상을 일으킨 후 기능성 들깻잎 추출물이 간에서 산화스트레스를 얼마나 억제하여 주는지를 혈액의 간 손상 지표인 lactate dehydrogenase (LDH), aspartate aminotransferase (AST) 그리고 alanine aminotransferase (ALT)를 측정하였으며, 간 조직에서 항산화 바이오 마커인 reduced glutathione (GSH), 지질과산화물의 척도인 malondialdehyde (MDA)를 통해서 측정하였다. 산화스트레스에 의한 간 손상시 GSH는 아무것도 처리하지 않은 정상 대조군(146.0 ± 5.4 mM GSH/g protein)에 비해 t-BHP로 산화스트레스를 유발한 그룹에서 128.6 ± 6.8 mM GSH/g protein로 감소하였다. 반면 기능성 들깻잎 추출물을 250, 500 그리고 1000 mg/kg b.w. 을 투여한 그룹에서는 129.3 ± 2.6 mM GSH/g protein, 151.9 ± 6.8 mM GSH/ g protein, 171.9 ± 5.2 mM GSH/g protein로 농도 의존적으 로 GSH 함량이 회복되는 경향을 나타내며, 500 mg/kg b.w. 투여군부터 정상 대조군의 GSH 함량과 비슷한 수준을 나타내었다. 또한, 간 조직에서 산화스트레스에 의하여 발생된 지질 과산화물을 측정하였을 때 t-BHP에 의하여 산화스트레스만 유발한 그룹은 834.0 ± 154.7 μM/g protein 로 정상 대 조군의 385.6 ± 39.7 μM/g protein 보다 2.17배 높은 MDA 를 생성한 것으로 지질과산화가 많이 일어난 것을 확인하였으나, 기능성 들깻잎 추출물을 투여한 그룹의 MDA의 생성량은 669.2 ± 145.0, 595.1 ± 142.6, 415.9 ± 133.8 μM/g protein 로 농도에 따라 감소하는 경향을 확인하였다. 랫드의 간 조직에서, 독성을 유발하는 t-BHP를 복강 투여 후 기능성 들깻잎 추출물을 경구 투여하였을 때 지질과산화의 지표인 MDA의 감소와 항산화의 지표인 GSH 함량이 증 가하였다. 조직병리학적 확인을 위하여 간 조직을 H&E 염색 후 광학현미경으로 관찰하였을 때, t-BHP만 처리한 음성 대조군의 경우 간 세포의 괴사와 조직의 변형을 확인할 수 있었지만 기능성 들깻잎 추출물을 처리하였을 경우 모두 정상 상태의 조직을 관찰할 수 있었다. 위의 결과들을 종합하였을 때, t-BHP가 간에서 산화스 트레스를 유발하여 간 손상을 야기시키고, 간 조직의 인지질 막 손상을 줄 수 있으며, 기능성 들깻잎 추출물은 간 손상에 대한 보호 효과가 있음을 확인하였다.
        4,000원
        43.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Selenium (Se) is known to prevent from several cancers, while iron (Fe) is known to be associated with high risk of cancers. The role of Se on colon carcinogenesis was investigated in an animal model induced by azoxymethane (AOM) and dextran sodium sulfate (DSS) in low Fe mice. Six-week old ICR mice fed on a low Fe diet (4.5 ppm Fe; generally 10 times lower than normal Fe) with three different Se (0.02, 0.1 or 0.5 ppm) levels for 24weeks. The animals received weekly three (0~2nd weeks) i.p. injections of AOM (10 mg/kg B.W), followed by 2%DSS with drinking water for 1 week to induce the colon cancer. There were five experimental groups including vehicle,positive control (normal Fe level, AOM/DSS), Low Fe (LFe) + AOM/DSS+Low Se (LSe), LFe + AOM/DSS + medium Se (MSe) and LFe + AOM/DSS + high Se (HSe) groups. HSe group showed a 66.7% colonic tumor incidence, MSe group showed a 69.2% tumor incidence, and LSe group showed a 80.0% tumor incidence. The tumor incidence was negatively associated with Se levels of diets. Tumor multiplicity in Hse group was significantly low compared to the other groups (p < 0.05). With increasing Se levels of diets, the primary anti-proliferating cell nuclear antigen (PCNA)-positive cells were decreased and apoptotic bodies were increased in a dose-dependent manner. Sedependent glutathione peroxidase activity and its protein level were dependent on the levels of Se of diets. Malondialdehyde level in liver was lowest in Hse group among experimental groups. These findings indicate that dietary Se is chemopreventive for colon cancer by increasing antioxidant activity and decreasing cell proliferation in Fe-deficient mice.
        4,000원
        44.
        2011.12 구독 인증기관 무료, 개인회원 유료
        Periodontitis is an inflammatory disorder of the periodontium, characterized by destruction of the tooth supporting tissues including alveolar bone and mediated by various pro-inflammatory mediators. Here, we demonstrated that HP08-0106, composed of four crude drugs-Gardenia jasminoides Grandiflora, Angelica gigas Nakai, Rehmannia glutinosa, and Schizonepeta tenuifolia in a weight ratio of 2:2:1:2, perturbs inflammatory responses, osteoclast formation in LPS-induced RAW 264.7 cells and alveolar bone resorption in ligature-induced periodontitis. HP08-0106 decreased the protein level of iNOS and COX2 as well as the secreted level of IL-1β, indicating that HP08-0106 has antiinflammatory effects. HP08-0106 also inhibited the expression of genes associated with osteoclastogenesis including c-Fos, MMP-9 and TRAP. Moreover, HP08-0106 exhibited a protective effect from alveolar bone loss in ligature-induced periodontitis animal models. Our results strongly suggest that HP08-0106 represent an important therapeutic tool to treat inflammatory disorders associated with bone loss such as periodontitis.
        4,000원
        45.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Plantago asiatica L. (P. asiatica) has been used as one of the popular folk medicines in Asia for human health care practices. Various activities of P. asiatica have been reported, such as anti-oxidant, anti-glycation,anti-inflammatory and hepatoprotective activity. Therefore, the potential of P. asiatica to reduce oxidative stress has been studied in several ways for over 20 years, especially at liver and kidney. However no investigation has been reported revealing its protective effect on prostate. Method : Treatment of P. asiatica leaf ethanolic extract (PLE) (1 g/kg body weight (b.w.), 2 g/kg b.w., or 4 g/kg b.w.) were given separately to animals for pretreatment once per day for 7days, and on the seventh day ferric nitrilotriacetate (Fe-NTA; 0.24 mmol Fe/kg b.w.), which is known as an oxidative stress-inducer at prostate, was administrated by i.p to negative control group. At the end of the study period, dissection was carried out for detecting the prostate protective effect of PLE. Result : Fe-NTA-treated animals produced reactive oxygen species (ROS) resulting in depletion of antioxidant biomaker, such as glutathione (GSH), glutathione reductase (GR), and glutathione s-transferase (GST) and increase of lipid peroxidation in prostate. However, PLE pretreatment resulted in an increase in the GSH, GST and GR levels concentration dependent manner and in an significant decrease in the levels of lipid peroxidation. Conclusion : Our data suggest that PLE may be effective in protecting oxidative stress-induced damage of prostate, and PLE may be an chemopreventive agent against Fe-NTA-mediated prostate oxidative damage.
        4,000원
        46.
        2011.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Plantago asiatica L. (PA), which is widely distributed in Korea, Japan and China, has traditionally been used as a popular folk medicine for the treatment of liver diseases. A variety of activities of PA was reported, that is hepatoprotective, anti-inflammatory, anti-glycation and anti-oxidant effect. Ferric nitrilotriacetate (Fe-NTA) is a potent nephrotoxic agent and has been reported to induce renal proximal tubular necrosis. In the present study, pretreatment with PA extract (PAE) in Wistar rat followed by Fe-NTA i.p. treatment (13.5 mg Fe/kg body weight) was performed to detect the renal protective effect of PAE. Only Fe-NTA treated group showed increases in the level of serum blood urea nitrogen (BUN) and serum creatinine (Cr), and renal tissue malondialdehyde (MDA), product of lipid peroxidation. Moreover, the level of biomarkers indicate the antioxidants status, reduced glutathione (GSH), glutathione-S-transferase (GST) and glutathione reductase (GR) were decreased. However, PAE pre-treated group showed decreases in the levels of serum BUN, serum Cr and renal tissue MDA in concentration dependent manner and increases in the level of GSH, GST and GR. These results are significantly different (p < 0.05) to the other groups. Our data suggest that PAE may be used as an chemopreventive material against Fe-NTA-mediated renal oxidative stress.
        4,000원
        47.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Selenium is an essential micronutrient which functions as an essential constituent of selenoproteins. The selenoproteins play an important role in the body’s defense from free radicals associated with chronic diseases such as cancer. The effect of selenium on colon carcinogenesis was investigated using an experimental animal model. Five-week old ICR mice were acclimated for one week, and fed on the Fe-overloaded diet (450 ppm) with different Se diets (0.02, 0.1 or 0.5 ppm) for 12 weeks. Animals were injected intraperitoneally with azoxymethane (AOM, 10 mg/㎏ B.W. weekly for 3 weeks), followed by 2% dextran sodium sulfate (DSS) in the drinking water for a week. There were three experimental groups including low Se group (Lse), medium (normal standard diet for mice) Se (MSe), and high Se (HSe). The numbers of aberrant crypt foci (ACF) and aberrant crypt (AC) were measured in the colonic mucosa. The iron and selenium concentrations in liver was measured using ICP-AES. Glutathione peroxidase (GPx) activity was determined in the liver and colon. TUNEL assay for cell apoptosis and proliferating cell nuclear antigen (PCNA) staining for cell proliferation were performed. Immunohistochemical staining of β-catenin was also performed in mucous tissue of colon. The dietary Se decreased the numbers of ACF/㎠ and AC/㎠ in a dose-dependent manner. HSe diet significantly decreased the numbers of AC/㎠, compared with LSe diet (p<0.05). The tumor incidence rate in low Se diet group was 5% higher than medium Se diet group and 20% higher than high Se diet group. The activities of GPx in the liver and colon were dependent on the content of dietary selenium. Apoptosis-positive cells were also increased by dietary Se in a dose-dependent manner. PCNA-positive staining was weak in high Se group. β-catenin stained area was increased in low Se group while it was decreased in high Se group. These findings indicate that dietary selenium exert a protecting effect on colon cancer by inhibiting the development of ACF/AC, increasing GPX and apoptosis, and decreasing cell proliferation and expression of β-catenin in mice.
        4,000원
        48.
        2010.12 구독 인증기관 무료, 개인회원 유료
        Periodontitis is an inflammatory disorder of the periodontium and is characterized by destruction of the tooth supporting tissues, mediated by the upregulation of synthesis and release of a variety of pro-inflammatory factors. Inflammatory cytokines and prostaglandins upregulate RANKL and its subsequent binding to RANK stimulates osteoclast formation, resorption activity, and survival. In our present study, we investigated the effects of HP08-0111, composed of Coptis japonica (Thunb.) Makino, vitamin C and vitamin E, upon inflammatory responses, osteoclastogenesis and alveolar bone loss. HP08-0111 decreased the expression of IL-1β and COX2 on LPS-induced RAW 264.7 cells and inhibited osteoclast-specific genes such as c-Fos, MMP-9, and TRAP. HP08-0111 also exhibited protective effects against alveolar bone loss in rats with ligature-induced periodontitis. Our results suggest that HP08-0111 is potentially an important therapeutic tool for the treatment of disorders associated with bone loss such as periodontitis.
        4,000원
        49.
        2010.09 구독 인증기관 무료, 개인회원 유료
        Wrinkles are an outward sign of cutaneous aging appearing preferentially on ultraviolet B (UVB)-exposed areas. The anti-wrinkle effects of herbal extracts were investigated in an animal model. Female albino hairless mice (HR/ICR) were randomly allocated to the control group (non-irradiated vehicle), positive control group (UVB irradiated-vehicle), and two herbal extract mixture groups (HE-1 and HE-2). HE-1 included Glycyrrhizae radix, Rhei Rhizoma, Cornus officinalis, and Sesami semeni, and HE-2 included Swertia pseudo-chinensis, Sophora flavescens, Scutellaria baicalensis, and Salvia miltiorrhiza. The herbal extract mixtures were pre-treated dorsally with 0.2 ml per individual five times per week for four weeks prior to the start of UVB irradiation. At the fifth week, the animals were exposed to UVB irradiation for a subsequent eight weeks, three times per week. The intensity of irradiation showed a gradual increase, from 30 mJ/cm 2 to 240 mJ/cm2 (1 MED: 60 mJ/cm2 ). Dorsal skin samples were stained with H&E in order to examine the epidermal thickness. In addition, Masson-Trichrome staining was performed for determination of the amount of collagen fiber. Treatments with HE-1&2 resulted in an increase in the amount of collagen fiber, a better appearance, and fewer wrinkles, compared with the positive control. As determined by hydroxyproline assay, treatments with HE-1&2 led to a significant increase in the amount of collagen, compared with the positive control group (p<0.05). Chronic UVB irradiation to skin of hairless mice resulted in an increase in expression of matrix metalloproteinase-1 (MMP-1), however, treatments with HE-1&2 tended to decrease the expression of MMP-1. These results indicate that the herbal extracts used in this study have a preventive effect on UVB-induced wrinkle formation in a hairless mouse model, due in part to inhibition of MMP-1 expression and increment of collagen amount.
        4,000원
        50.
        2010.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polyvinyl acetate (PVAc) prepared by emulsion polymerization has broad applications for additive such as paint binder, adhesive for wood and paper due to its low glass transition temperature which help to plasticize substrate resins. Since emulsion polymerization has a disadvantage that surfactant and ionic initiator degrade properties of the product polymer, poly (vinyl acetate-eo-ethyl acrylate) (VAc-EA) was synthesized using potassium persulfate as catalyst and polyvinylalcohol (PVA) as protective colloid to prevent the degradation. The copolymer latex product was internally plasticized and has enhanced adhesion, water resistance during VAc-EA emulsion polymerization. No coagulation and complete conversion occur with the reactant mixture of 10 mmol/L potassium persulfate, 10 mmol/L poly ( vinyl alcohol) (PVA 17). As the concentrations of PVA increase, the viscosity becomes increase.
        4,000원
        51.
        2010.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        자색고구마 추출물의 항산화 효과와 산화적 스트레스로 유도된 PC12 신경세포에 대한 보호효과에 대하여 연구하 였다. 자색고구마 추출물의 총 페놀함량은 44.25 mg/g, monomeric anthocyanin 함량은 2,394 mg/L로 나타났 다. 자색고구마 추출물의 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylben-zthiazoline- 6-sulfonic acid) (ABTS) radical 소거활성, ferric reducing/antioxidant power (FRAP) 및 환원력은 농도 의존 적으로 항산화 활성이 증가하였다. MTT {3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl-tetrazoliumbromide} reduction assay를 이용하여 자색고구마 추출물의 신경세포 보호효과를 측정한 결과, 세포 생존율이 두드러지게 증가하는 것으로 나타났다. 산화적 스트레스는 신경세포막 손상 정도를 증가시키기 때문에 lactate dehydrogenase (LDH) release assay와 neutral red uptake assay를 이용하여 세포막 손상 보호효과를 조사한 결과 자색고구마 추출물 처리구는 대조구에 비하여 산화적 스트레스로 유도된 세포막 손상 보호효과가 농도 의존적으로 나타났다. 따라서 자색고구마 추출물은 천연 항산화 소재 및 알츠하이머성 치매와 같은 신경퇴행성 질환의 예방 소재로서의 활용 가능성이 기대된다.
        4,000원
        53.
        2009.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Metal thin film patterns on a LTCC substrate, which was connected through inner via and metal paste for electrical signals, were formed by a screen printing process that used electric paste, such as silver and copper, in a conventional method. This method brought about many problems, such as non uniform thickness in printing, large line spaces, and non-clearance. As a result of these problems, it was very difficult to perform fine and high resolution for high frequency signals. In this study, the electric signal patterns were formed with the sputtered metal thin films (Ti, Cu) on an LTCC substrate that was coated with protective oxide layers, such as TiO2 and SiO2. These electric signal patterns' morphology, surface bonding strength, and effect on electro plating were also investigated. After putting a sold ball on the sputtered metal thin films, their adhesion strength on the LTCC substrate was also evaluated. The protective oxide layers were found to play important roles in creating a strong design for electric components and integrating circuit modules in high frequency ranges.
        4,000원
        54.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An extract of Allomyrina dichotoma larva (ADL), one of the insects used most frequently in traditional Chinese medicine for the treatment of liver diseases such as hepatocirrhosis and hepatofibrosis, was assessed for antioxidant bioactivity in this study.
        4,000원
        55.
        2008.09 구독 인증기관 무료, 개인회원 유료
        Somatic cells such as oviduct epithelial cell, uterine epithelial cell, cumulus-granulosa cell and buffalo rat river cell has been used to establish an effective culture system for bovine embryos produced in in vitro. But nitric oxide (NO) metabolites secreted from somatic cells were largely arrested the development of bovine in vitro matured/ in vitro fertilized (IVM/IVF) embryos, suggesting that NO was induced the embryonic toxic substance into culture medium. The objective of this study was to investigate whether BOEC co-culture system can ameliorate the NO-mediated oxidative stress in the culture of bovine IVM/IVF embryos. Therefore, we evaluated the developmental rate of bovine IVM/IVF embryos under BOEC co-culture system in the presence or absence of sodium nitroprusside (SNP), as a NO donor, and also detected the expression of growth factor (TGF-p , EGF and IGFBP) and apoptosis (Caspase-3, Bax and Bcl-2) genes. The supplement of SNP over 5 uM was strongly inhibited blastocyst development of bovine IVM/IVF embryos than in control and 1 uM SNP group (Table 2). The developmental rates beyond morulae stages of bovine IVM/IVF embryos co-cultured with BOEC regardless of SNP supplement (40.4% in 5 uM SNP+ BOEC group and 65.1% in BOEC group) were significantly increased than those of control (35.0%) and SNP single treatment group (23.3%, p<0.05: Table 3). The transcripts of Bax and Caspase-3 genes were detected in all experiment groups (1:Isolated fresh cell (IFC), 2:Primary culture cell (PCC), 3:PCC after using the embryo culture, 4: PCC containing 5 uM SNP and 5: PCC containing 5 uM SNP after using the embryo culture), but Bcl-2 gene was not detected in IFC and PCC (Fig. 1). In the expression of growth factor genes, TGF-p gene was found in all experimental groups, and EGF and IGFBP genes were not found in IFC and PCC (Fig. 2). These results indicate that BOEC co-culture system can increase the development beyond morula stages of bovine IVM/IVF embryos, possibly suggesting the alleviation of embryonic toxic substance like nitric oxide.
        4,000원
        56.
        2008.06 구독 인증기관 무료, 개인회원 유료
        Phytic acid (PA) is a naturallu occurring polyphosphorylated carbohydrate that is present in substantial amounts in almost all plants and mammalian cells. Recently PA has received much attention for its role in anticancer activity. We investigated the preventive effect of PA on the formation of colonic aberrant crypt foci (ACF), a preneoplastic lesion, induced by azoxymethane (AOM). After acclimation for one week, six-week old male ICR mice were fed on the AIN-93G purified diet and PA (0.5% or 2% PA in water) for 8 weeks. The animals were treated with azoxymethane (AOM, 10 mg/kg b.w.) three times (0, 1, and 2 weeks) to induce colonic aberrant crypt foci (ACF). After sacrifice, the total numbers of aberrant crypts (AC) and ACF in colonic mucosa were counted after staining with methylene blue. Blood and serum were analyzed with a blood cell differential counter and an automatic serum analyzer. AOM treatment without PA induced the total numbers of 85.7 ± 12.9 and 115.2 ± 19.9, respectively. PA at the dose of 2% AC/colon by PA at the dose of 0.5% were 73.4 ± 12.9 and 115.2 ± 19.9, respectively. PA at the dose of 2% significantly decreased the ACF and AC numbers to 56.5 ± 14.6 and 95.4 ± 17.2, respectively (p<0.01). PA at the doses of 0.5 and 2% decreased the numbers of ACF and AC/colon in a dose-dependent manner. Although some parameters in blood counts and serum chemistry were changed compared with the control, no specific toxicity was found. Theses findings suggest that phytic acid can be a chemopreventive agent for colon carcinogenesis resulting from inhibition of the development of ACF in ICR mice.
        4,000원
        58.
        2005.09 구독 인증기관 무료, 개인회원 유료
        EGCG [(-)-epigallocatechin gallate], is a major component of green tea has been considered as a major antioxidant constituent. It has been considered as potential chemopreventive and chemotherapeutic agents. However, very little is known about the cellular actions by which EGCG mediates its therapeutic effects. Various aspects of antioxidant activity of EGCG were evaluated in this study. EGCG itself did not show significant cytotoxicity. Significant 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was observed in all ranges of concentration (0.8-100μ/mℓ used in this study. Protective effect of EGCG against hydrogen peroxide induced cell death was observed. Relatively high lipid peroxidation inhibitory activity were detected ( IC50was about 20μg/mℓ). EGCG also dose-dependently enhanced the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in V79-4 cells. In concentrations of 100μ/mℓ of EGCG, activities of SOD, CAT and GPX were measured as 36.9 U/mg of protein, 22.9 U/mg of protein and 17.8 U/mg of protein, respectively. When these values were compared with those of the control groups (24.9 U/mg of protein, 14.9 U/mg of protein and 11.7 U/mg of protein), the relative increases were calculated as 48, 54 and 52%, respectively. Taken together, our findings suggest that EGCG can act as an antioxidant by scavenging radicals and enhancing antioxidant enzyme activities.
        4,000원
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