검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 9

        2.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Selenium was initially considered toxic to humans, but it was then discovered that selenium is essential for normal life processes. Selenium plays important roles in antioxidants. It is expected that chitosan microcapsules containing nano-selenium will be able to be used as a key material in bio-medical and cosmetic applications. The high concentration of chitosan derivatives guaranteesincreased antioxidative activity. Both inorganic and organic forms of selenium can be nutritional sources. The antioxidant properties of selenoproteins help prevent cellular damage from free radicals. The objective of this experiment was to study the antioxidative activity of chitosan nano-selenium. Our experiments were divided into five groups, in the presence of various concentrations(0.1%, 0.3%, 0.5%, 0.7%, and 0.9%) of chitosan. We performed an assessment of the antioxidant properties and cytotoxicity of respective concentrations of chitosan nano-selenium. The antioxidant activity was examined by the free radical scavenging activity on 1, 1-diphenyl-2-picrylhydrazyl(DPPH) assay. The cytotoxicity effect was measured by means of 3-(4, 5-dimethylthiazole-2-yl)-2, 5-diphenyltetrazolium bromide(MTT) assay. As a result, the electron donating abilities of 0.1%, 0.3%, 0.5%, 0.7%, and 0.9% of chitosan nano-selenium exhibited effective andioxidant scavenging activity at 12.5 ㎍/㎖ against DPPH radicals. 0.3% chitosan nano-selenium did not show cytotoxicity on human keratinocytes. In general, the cytotoxicity of 0.1% and 0.9% chitosan nano-selenium showed the lowest effects. Though low cytotoxicity of 0.5% and 0.7% chitosan nano-selenium exhibited 29.67% and 38.4% against human keratinocytes on adding 100 ㎍/㎖ and 50 ㎍/㎖, respectively, cell vitality was recovered with 200 ㎍/㎖. These findings support the notion that chitosan nano-selenium may be useful as a new active ingredient source for bioactive compounds.
        4,000원
        3.
        2006.12 구독 인증기관 무료, 개인회원 유료
        To study on antioxidant effects in the liver of 40-week-old mouse, the sample were orally pretreated 5mg/kg/day for 5 days with red ginseng saponin components(total saponin, protopanaxadiol saponin, protopanaxatriol saponin, ginsenoside-Rd, ginsenoside-Re, compound-K) for 5 days. The ability of saponin to protect the mouse liver from oxidative damage was examined by determining the activity of superoxide dismutase(SOD), glutathione peroxidase(GPx) and the contents of glutathione, the level of malondialdehyde, The only protopanaxadiol among the ginseng saponin fractions was significantly increased the hepatic SOD activity(p<0.01). The red ginseng saponin induced a slight increase of GPx activity, especially ginsenoside Rd, compound K and protopanaxatriol treatments significantly increased its activity. The content of glutathione was significantly increased by total saponin, protopanaxadiol and ginsenoside Rd(p<0.01), but the oxidized glutathione level was lowered in all the red ginseng saponin. Finally, the level of malondialdehyde was significantly decreased by ginsenoside Rd and protopanaxadiol. In conclusion, protopanaxadiol and ginsenoside Rd among the saponin fraction were especially increased in the activity of hepatic antioxidative enzyme and decreased the lipid peroxidation that was expressed in term of MDA formation. This comprehensive antioxidant effects of red ginseng saponin seems to be by a certain action of saponin other than a direct antioxidant action.
        4,000원
        4.
        2006.12 구독 인증기관 무료, 개인회원 유료
        Lavandula vera is indispensable member of the herb family, used for perfumes and potpourri. Androgens have profound effects on the physiology of the sebaceous gland. Sebum is secreted due to the effect of androgen, which starts to be secreted at puberty. Using the human sebocyte cell line SZ95. the author investigated the inhibitory effect of Lavandula vera on the lipid production. Light microscopic finding were examined numerous cytoplasmic lipid droplets SZ95 cells by Oil red staining and lipid droplets were increased markedly by testosterone. On the other hand, combined treatment with Lavandula vera and testosterone resulted in a lower lipid droplets than with testosterone alone in a dose-dependent manner. These findings indicate that Lavandula vera acts antagonistically to testosterone and inhibits the lipid synthesis of SZ95 cells at the cellular level.
        4,000원
        5.
        2006.12 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to investigate the effect of ethanol extract of Fagopyrum escuentum(FE) on the melanogenesis. To determine whether ethanol extract of FE suppress melanin synthesis in cellular level, B16F10 melanoma cells were cultured in the presence of different concentrations of FE ethanol extract. In the present study, the author examined the effects of FE ethanol extract on cell proliferation, melanin contents, tyrosinase activity. Cell proliferation was slightly increased by treatment with ethanol extract of FE (25-200 μg/ml). The ethanol extract of FE effectively suppressed melanin contents at a dose of 100 μg/ml. It was observed that the color of cell pellets was totally whitened compared with the control. The ethanol extract of FE inhibited tyrosinase activity, regulate melanin biosynthesis as the key enzyme in melanogenesis. These results suggest that the ethanol extract of FE exerts its depigmenting effects through the suppression of tyrosinase activity. And it may be a potent depigmetation agent in hyperpigmentation condition.
        4,000원
        6.
        2000.08 구독 인증기관 무료, 개인회원 유료
        Recently many efforts were focused to understand the mechanical insights of melanogenesis to develop the agents for hyper-pigmentation and hypo-pigmentation. In the melanin biosynthetic pathway, tyrosinase is the rate limiting enzyme, and α-melanocyte stimulating hormone(MSH) stimulate melanogenesis and enhance the melanin synthesis and the tyrosinase activity. This study the effects of Radix Trichosanthis on the basal melanogenic activities of B16/F10 mouse melanoma cells, and on the α-MSH induced melanogenesis. Radix Trichosanthis alone markedly suppressed melanin content and tyrosinase activity in a dose-dependent manner. Pretreatment of the cells with Radix Trichosanthis also suppressed the increase of α-MSH (10 nM) induced melanin content and tyrosinase activity. These results suggest that Radix Trichosanthis inhibits melanogenesis and abrogates α-MSH induced melanogenesis in B16 melanoma cells.
        4,200원
        7.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 온천 배수의 유입이 소형 하천의 부착조류군집에 미치는 영향을 조사하기 위하여, 전북 고창군 석정온천에 발원하는 하천과 그 주변의 소형 하천을 대상으로 1996년 2월부터 1998년 9월까지 계절별로 조사하였다. 온천 배수의 유입이 직접 일어나는 지점에서는 저온기에 남조의 Oscillatoria와 Phormidium이 중심이 된 독특한 남조피막이 형성되었다. 특히, 부착조류의 출현 및 군집구조는 온천 배수의 영향 하천과 비영향 하천간에 뚜렷한
        4,600원