• 제목/요약/키워드: Lethal concentration

검색결과 252건 처리시간 0.031초

무화과 잎의 용매분획 및 항미생물 활성 (Solvent Fractionation of Fig Leaves and its Antimicrobial Activity)

  • 강성국;정희종
    • Applied Biological Chemistry
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    • 제38권4호
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    • pp.289-292
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    • 1995
  • 무화과잎으로부터 천연 항미생물 물질의 개발을 검토할 목적으로 무화과잎을 메탄올로 추출하고 ethyl acetate와 buffer용액을 이용하여 용매분획하였고 각 분획에 대한 항미생물 활성을 측정하였으며 활성이 강한 분획에 대한 최소저해농도(MIC)와 최소치사농도(MLC)를 측정하였다. 무화과 잎중의 항미생물 활성은 산성 분획과 페놀성 분획에서 강하게 나타났으며 미생물의 종류에 관계없이 활성범위가 넓었다. 페놀성 분획이 산성 분획에 비하여 MIC와 MLC값이 상대적으로 낮았고 MIC값의 경우 두 분획이 공통적으로 세균보다는 진균류에 대하여 낮았으며 특히 저온세균인 Pseudomonas aeruginosa에 대한 MIC와 MLC값이 대단히 낮음을 알 수 있었다.

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감성돔, Acanthopagrus schlegeli 배의 생존과 부화에 미치는 동해방지제의 영향 (Effects of Cryoprotectants on Survival and Hatching of Black Seabream, Acanthopagrus schlegeli Embryos)

  • 임한규;장영진;조필규
    • 한국양식학회지
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    • 제16권4호
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    • pp.262-266
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    • 2003
  • 어류 배의 냉동보존 방법을 개발하기 위한 연구의 일환으로 감섬돔, Acanthopagrus schlegeli의 초기 배를 대상으로 동해방지제인 DMSO, ethylene glycol 및 glycerol의 최적 농도와 처리시간을 파악하기 위한 연구가 수행되었다. 동해방지제의 적정 농도를 평가하기 위하여 배의 사망률, 부화율 및 반수치사 농도를 조사하였다. 동해방지제로 처리된 감성돔 배의 사망률은 침지농도나 시간과 밀접히 연관되었으며, 감성돔 배에 대한 독성은 DMSO, ethylene glycol, glycerol의 순서로 낮았다. 배의 사망률, 부화율 및 반수치사농도에 대한 결과로부터 감성돔 배를 냉동보존하기 위한 가장 적합한 동해방지제는 DMSO였으며, 다음이 ethylene glycol이었다. 20분의 처리시간에서 효과적인 DMSO의 침지 농도는 2.0∼2.25 M이었으며, ethylene glycol의 경우 1.0∼1.78 M이었다.

지렁이를 이용한 바이오디젤 유래 펜타에리쓰리톨계 윤활유 베이스의 환경 독성 테스트 (Biodiesel - derive d Pentaerythritol Lubricant Oil Bases Earthworm Using Toxicity Test)

  • 정해영;박완선;김의용;채희정
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2004년도 춘계학술대회
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    • pp.311-314
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    • 2004
  • 바이오디젤 (지방산 메틸에스테르)을 기반으로 하여 생산된 합성윤활유 베이스에 대한 독성을 분석 평가하였다. OECD 207의 방법에 의거하여 인공토양(artifical soil)에서 300$\~$600 mg의 지렁이를 선별하였다. 0.01, 0.1, 1, 10, 100과 1,000 mg/kg의 각 농도별로 선별된 지렁이를 10마리씩 넣고 수분 $31\~37\%$, 온도 $20{\pm}2^{\circ}C$와 PH 6.0 $\pm$ 0.5를 조절하여 14일간 지렁이의 반수치사농도(lethal concentration when $50\%$ of the population were killed, $LC_{50}$)를 측정하였다. 합성윤활유의 측정 된 반수치사농도($LC_{50}$)는 1,555 mg/kg로 측정되었으며, 유의 확률이 < 0.02로서 유의수준 $5\%$에서 유의함을 알 수 있었다.

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급격한 저염분 노출에 따른 참돔 Pagrus major 치어의 단기 행동반응 및 내성 한계에 관한 연구 (Short-term behavioral responses and tolerance limits of red seabream Pagrus major fingerlings following sudden low salinity exposure)

  • 윤성진
    • 환경생물
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    • 제39권4호
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    • pp.495-506
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    • 2021
  • In this study, using a continuous behavior measurement technique, the short-term behavioral responses and tolerance limits of red seabream Pagrus major fingerlings to sudden exposure to low salinity in a controlled environment were observed. The activity of the fingerlings suddenly exposed to 21.4, 17.3, and 9.8 psu increased temporarily at the initial exposure to show irregular swimming behavior, but then recovered a stable activity pattern through rapid salinity adaptation. However, the organisms suddenly exposed to 7.3 and 4.3 psu could not withstand the salinity stress, and their swimming behavior was severely disturbed and all individuals died within 48 hours. The findings suggest that red seabream underwent a temporary salinity stress process at the beginning of the exposure to concentrations of 10.0 psu or higher. At these concentrations, osmotic control was possible within at least 11 hours, so stable metabolic activity was also possible. However, organisms suddenly exposed to concentrations below 5.0 psu exceeded the tolerance to low salinity and the sublethal limit. In red seabream exposed to this concentration range, severe behavioral and metabolic disturbances were observed, and death was observed due to osmotic control failure. In conclusion, a salinity range of 5.0 to 10.0 psu can be predicted to correspond to a concentration range in which the osmotic control ability of the red seabream fingerlings is lost, and sub-lethal reactions occur.

Assessment of acute inhalation toxicity of citric acid and sodium hypochlorite in rats

  • Jinhee Kim;Chul-Min Park;Su Hyun Choi;Mi Jin Yang;Ju-Yeon Lee;Byung-Suk Jeon;Hyun-Ok Ku;Min-Seok Kim
    • Journal of Veterinary Science
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    • 제24권2호
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    • pp.22.1-22.12
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    • 2023
  • Background: Citric acid (CA) and sodium hypochlorite (NaOCl) have been used to disinfect animals to protect them against avian influenza and foot-and-mouth disease. Objectives: We performed a good laboratory practice (GLP)-compliant animal toxicity study to assess the acute toxic effects of CA and NaOCl aerosol exposure in Sprague-Dawley rats. Methods: Groups of five rats per sex were exposed for 4 h to four concentrations of the two chemicals, i.e., 0.00, 0.22, 0.67, and 2.00 mg/L, using a nose-only exposure. After a single exposure to the chemicals, clinical signs, body weight, and mortality was observed during the observation period. On day 15, an autopsy, and then gross findings, and histopathological analysis were performed. Results: After exposure to CA and NaOCl, body weight loss was observed but recovered. Two males died in the CA 2.00 mg/L group and, two males and one female died in the 2.00 mg/L NaOCl group. In the gross findings and histopathological analysis, discoloration of the lungs was observed in the CA exposed group and inflammatory lesions with discoloration of the lungs were observed in the NaOCl exposed group. These results suggest that the lethal concentration 50 (LC50) of CA is 1.73390 mg/L for males and > 1.70 mg/L for females. For NaOCl, the LC50 was 2.22222 mg/L for males and 2.39456 mg/L for females. Conclusions: The Globally Harmonized System is category 4 for both CA and NaOCl. In this study, the LC50 results were obtained through a GLP-based acute inhalation toxicity assessment. These results provide useful data to reset safety standards for CA and NaOCl use.

질산납이 한국산 무미양서류의 배아발달에 미치는 영향 (The Effects of Lead(II) Nitrate on the Embryo Development in Native Amphibians)

  • 이해범;고선근
    • 환경생물
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    • 제35권4호
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    • pp.706-714
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    • 2017
  • 국내에 서식하는 대표적인 무미양서류 중 두꺼비 (Bufo gargarizans), 청개구리 (Hyla japonica), 참개구리 (Rana nigromaculata) 및 무당개구리 (Bombina orientalis)를 대상으로 각 종의 배아 발달에 미치는 Pb의 효과를 FETAX를 활용하여 분석한 결과 4종의 배아 모두 Pb의 농도가 증가함에 따라 사망률, 기형율이 증가하고 다양한 기형 양상이 나타났으며 성장률은 감소하였다. 두꺼비, 청개구리, 참개구리, 무당개구리의 반수치사농도(half maximal lethal concentration; $LC_{50}$)는 각각 0.58, 0.49, 0.52, $0.54mg\;L^{-1}$를 나타내었고 반수영향농도 (half maximal effective concentration; $EC_{50}$)은 각각 0.35, 0.27, 0.30, $0.29mg\;L^{-1}$을 나타냈다. 기형성지수(teratogenic index; $TI=LC_{50}/EC_{50}$)는 두꺼비, 청개구리, 참개구리 및 무당개구리에서 각각 1.66, 1.81, 1.73, 1.86로 나타나 무당개구리가 가장 민감한 영향을 나타냈으며 다음으로 청개구리, 참개구리, 두꺼비 순으로 나타났다. 이는 서로 다른 종이 같은 농도의 오염물질에 노출되었다 하더라도 종에 따라 차이가 나타날 수 있음을 의미한다. 이상의 결과를 통해 Pb가 무미양서류 4종의 배아 발달에 기형성 물질로 작용함을 알 수 있었다.

Helicobactericidal Activity of Cissus quadrangularis L. Variant I

  • Austin, Anoop;M, Jegadeesan;R., Gowrishankar
    • Natural Product Sciences
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    • 제10권5호
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    • pp.217-219
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    • 2004
  • Cissus quadrangularis L. variant I (Family: Vitaceae), the common variant with square stem is widely used for peptic ulcer disorders (PUD) in traditional medicine. Aerial parts were collected during flowering and vegetative seasons and analysed. Aqueous (hot and cold) and solvent extracts (acetone, chloroform and ethanol) were screened for their anti-Helicobacter pylori (Hp) activities. Among them chloroform extract was observed to recover bioactive principles markedly with low minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC). MIC was $30\;{\mu}g$ in both samples and MLC was $35\;{\mu}g$ for vegetative and $30\;{\mu}g$ for flowering seasons, respectively. Extracts from samples collected during flowering season were better than thse of vegetative season.

Antiprotozoal Activity of Deacetylated Chitosan Oligosaccharide (dp 2-8) on Trichomonas vaginalis

  • Shin, Woon-Seob;Kil, Jun-Cheul;Park, Gab-Man
    • Journal of Microbiology and Biotechnology
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    • 제16권12호
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    • pp.1984-1989
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    • 2006
  • Deacetylated chitosan oligosaccharide (COS) had effective antiprotozoal activity against Trichomonas vaginalis (Minimal Inhibitory Concentration, MIC 0.25%), whereas 80% acetylated cas showed no antiprotozoal activity (MIC > 1 %). an the other hand, 80% acetylated cas showed growth stimulatory activity against the protozoa. When T. vaginalis was treated with 98% deacetylated COS at 0.25% concentration, the viability of the protozoa was rapidly decreased within 15 min, and the protozoa completely died within 40 min. Ultrastructural changes of trichomonads treated with COS included a loss of defined nuclear membrane and endoplasmic reticulum membranes, an increase in the number of free ribosome, vacuolation, and ultimately lysis of the cell membrane. These results indicate that deacetylated COS can be used as an antitrichomonal agent, although its lethal mechanism is not known.

수중에서 카이토산에 의한 수은 제거 (Chitosan for the Removal of Mercury, Hg)

  • 석규진
    • 한국양식학회지
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    • 제5권2호
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    • pp.177-182
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    • 1992
  • 카이토산이 수중의 수은 제거에 미치는 영향을 알아보기 위하여, 금붕어를 사용하여 염화수은을 사용한 군 (대조군, n=75, 농도=0.6 $mg/{\ell}1.0mg/{\ell}$)과 염화수은에 카이토산을 첨가한 군(실험군, n=75, 농도=1.2 $mg/{\ell}\~2.0mg/{\ell}$)의 폐사율을 비교 분석하여 다음과 같은 결과를 얻었다. 염화수은에 대한 금붕어의 48 시간 동안의 반수치사 농도 ($LC_{50}$)는 0.6$mg/{\ell}$ 와 0.7 $mg/{\ell}$ 사이였다. 대조군에 있어서 수은의 농도가 증가함에 따라 폐사율이 현저하게 증가되었다 (P<0.05). 그러나, 카이토산이 첨가된 실험군에 있어서는 폐사율이 감소되었으며 수은 농도가 높은 경우 $100{\%}$ 폐사에 이르는 시간이 연장되었다(P<0.05). 상기 결과로서 카이토산이 수중의 수은 제거와 금붕어에 수은의 독성을 완화시키는 효과가 있는 것으로 사료된다.

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가감투농산(加減透膿散)의 항염작용에 대한 실험적 연구 (Anti-inflammatory Effects of Gagamtunong-san)

  • 김상진;유동열
    • 동의생리병리학회지
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    • 제22권1호
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    • pp.100-107
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    • 2008
  • The purpose of this research was to investigate the anti-inflammatory effects of Gagamtunong-san(GTNS) which has been medicated the patient such as mastitis. The results were as follows. The cytotoxicity on mouse lung fibroblast Cells(mLFC) was not served at all concentration of GTNS. GTNS in RAW264.7 cell inhibited $IL-1{\beta}$, IL-6, $TNF-{\alpha}$, COX-2 and NOS-II mRNA genes expression in a concentration-dependent manner. Specially GTNS inhibited NOS-II production very significantly at 100 ${\mu}g/ml$. GTNS inhibited NO production significantly in a concentration-dependent manner. GTNS inhibited ROS production in a concentration-dependent manner. GTNS inhibited $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ production significantly in serum of acute anti-inflammation-induced mice. GTNS increased the survival rate from the 3rd day on LPS-induced lethal endotoxemia. These results suggest that Gagamtunong-san(GTNS) can be useful in treating a lot of women mammary diseases caused by inflammation such as acute and chronic mastitis.