• Title/Summary/Keyword: LC$_50$

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Veterinary antibiotic oxytetracycline's effect on the soil microbial community

  • Danilova, Natalia;Galitskaya, Polina;Selivanovskaya, Svetlana
    • Journal of Ecology and Environment
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    • v.44 no.2
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    • pp.72-80
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    • 2020
  • Background: Antibiotics are widely used to treat animals from infections. After fertilizing, antibacterials can remain in the soil while adversely affecting the soil microorganisms. The concentration of oxytetracycline (OTC) in the soil and its effect on the soil microbial community was assessed. To assess the impact of OTC on the soil microbial community, it was added to the soil at concentrations of 50, 150, and 300 mg kg-1 and incubated for 35 days. Results: The concentration of OTC added to the soil decreased from 150 to 7.6 mg kg-1 during 30 days of incubation, as revealed by LC-MS. The deviations from the control values in the level of substrate-induced respiration on the 5th day of the experiment were, on average, 26, 68, and 90%, with OTC concentrations at 50, 150, and 300 mg kg-1, respectively. In samples with 150 and 300 mg kg-1 of OTC, the number of bacteria from the 3rd to 14th day was 2-3 orders of magnitude lower than in the control. The addition of OTC did not affect the fungal counts in samples except on the 7th and 14th days for the 150 and 300 mg kg-1 contaminated samples. Genes tet(M) and tet(X) were found in samples containing 50, 150, and 300 mg kg-1 OTC, with no significant differences in the number of copies of tet(M) and tet(X) genes from the OTC concentration. Conclusions: Our results showed that even after a decrease in antibiotic availability, its influence on the soil microbial community remains.

Hematological constituents and ultrastructural changes in dark-banded rockfish, Sebastes inermis, under nitrite stress

  • Park, In-Seok;Goo, In Bon;Kim, Young Ju;Choi, Jae Wook;Oh, Ji Su
    • Journal of fish pathology
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    • v.26 no.1
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    • pp.1-9
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    • 2013
  • The acute toxicity and sublethal effects of nitrite on the dark-banded rockfish, Sebastes inermis (mean body weight: $83.3{\pm}7.2$ g), were studied under static conditions for a period of 96 h. The acute toxicity of nitrite was at the 50% lethal concentration ($LC_{50}$) of 700 mg/L. The sublethal effects on selected hematological parameters of the dark-banded rockfish, such as its osmolality, hematocrit, cortisol, alanine aminotransferase (ALT), and aspartate aminotransferase (AST), were measured after 0, 6, 12, 24, 48, 72, and 96 h of exposure to 0, 50, 100, 200, 400, or 700 mg/L nitrite. Sublethal nitrite caused a progressive reduction in the hematocrit of the fish, depending on the nitrite concentration and the exposure period. Exposure to 100-700 mg/L nitrite for 96 h caused a reduction in the hematocrit and an increase in cortisol, ALT, and AST compared with the control levels. Abnormal ultrastructural changes in the gills and liver tissues were observed in fish exposed to 700 mg/L nitrite for up to 96 h compared with the control tissues. Ultrastructural changes included atrophic gill mitochondria and hepatocytes that developed smooth endoplasmic reticulum and atrophic mitochondria. Although no rockfish mortality occurred at 500 mg/L nitrite, all the hematological parameters examined responded adversely to a nitrite dose of 200 mg/L for 96 h. These results show that although the acute toxic concentration of nitrite for the dark-banded rockfish is > 700 mg/L, sublethal concentrations of nitrite also negatively affect its hematological parameters.

Novel Mononuclear Ruthenium(II) Compounds in Cancer Therapy

  • Anchuri, Shyam Sunder;Thota, Sreekanth;Yerra, Rajeshwar;Devarakonda, Krishna Prasad;Dhulipala, Satyavati
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.7
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    • pp.3293-3298
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    • 2012
  • The present study was conducted to evaluate in vivo anticancer activity of two novel mononuclear ruthenium(II) compounds, namely Ru(1,10-phenanthroline)$_2$(2-nitro phenyl thiosemicarbazone)$Cl_2$(Compound $R_1$) and Ru (1,10-phenanthroline)$_2$(2-hydroxy phenyl thiosemicarbazone)$Cl_2$(Compound $R_2$) against Ehrlich ascites carcinoma (EAC) mice and in vitro cytotoxic activity against IEC-6 (small intestine) cell lines and Artemia salina nauplii using MTT [(3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide)] and BLT [brine shrimp lethality] assays respectively. The tested ruthenium compounds at the doses 2 and 4 mg/kg body weight showed promising biological activity especially in decreasing the tumor volume, viable ascites cell counts and body weights. These compounds prolonged the life span (% ILS), mean survival time (MST) of mice bearing-EAC tumor. The results for in vitro cytotoxicity against IEC-6 cells showed the ruthenium compound $R_2$ to have significant cytotoxic activity with a $IC_{50}$ value of $20.0{\mu}g/mL$ than $R_1$ ($IC_{50}=78.8{\mu}g/mL$) in the MTT assay and the $LC_{50}$ values of $R_1$ and $R_2$ compounds were found to be 38.3 and $43.8{\mu}g/mL$ respectively in the BLT assay. The biochemical and histopathological results revealed that there was no significant hepatotoxicity and nephrotoxicity associated with the ruthenium administration to mice.

Toxicological Efects of Aroclor 1254 on the Embryonic Development of the Olive Flounder Paralichthys olivaceus

  • Min, Eun Young;Kang, Ju Chan
    • Fisheries and Aquatic Sciences
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    • v.16 no.4
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    • pp.253-260
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    • 2013
  • We investigated the toxicological effects of Aroclor 1254 on the fertilized eggs, embryos and larvae of the olive flounder Paralichthys olivaceus. The survival rate and hatching success of the embryos decreased significantly in treated groups in an Aroclor 1254-dose-dependent manner. Significant differences were found at ${\geq}5{\mu}g/L$ Aroclor 1254 compared to the control group. Hatching success occurred at ${{\leq}}10{\mu}g/L$ Aroclor 1254, which was not significantly different to the control. Embryo malformation increased significantly at ${\geq}1{\mu}g/L$, and included yolk-sac and tail-flexure abnormalities. There was a significant decrease in the survival rate of the larvae at ${\geq}5{\mu}g/L$, which was accompanied by the malformations described above. Notably, concentrations as low as $1{\mu}g/L$ caused a significant increase in abnormalities in the larvae, including incidences of multi-focal hemorrhages, pericardial and yolk-sac edema, inhibition of swim bladder inflation and severe developmental delay. The responses to Aroclor 1254-induced toxicity were generally similar among fertilized eggs, embryos and larvae from three separate flounder hatcheries: Cheju Island, Yeosu and Chungnam, South Korea. These results indicate the high acute toxicity of Arolcor 1254 concentrations of which as low as $1{\mu}g/L$ in olive flounder larvae can affect unhatched embryos. To conclude, the average $LC_{50}$ values for Aroclor 1254 in the embryos and larvae were 50.92 and $3.08{\mu}g/L$, respectively. Additionally, the average $EC_{50}$ values, based on the rate of damage were 14.72 and 5.6$1{\mu}g/L$, respectively.

Ecotoxicological Evaluation of Synthetic Surfactant (합성세제의 생태독성 평가)

  • 최병기;홍사욱;한상욱
    • Environmental Analysis Health and Toxicology
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    • v.9 no.3_4
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    • pp.91-101
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    • 1994
  • In order to evaluate the ecotoxicological harzardousness of synthetic surfactants on Han river, Jung-ryang and Jin-Wi stream, we used the Ecotoxicological Risk Quotient (ERQ). The chemical harzardousness is evaluated by the balance of the toxicity and concentration in the environment.. Then, ERQ is defined as follows; ERQ = - log ( Concentration in the environment / Effective concentration in the test ) ERQ of chemical is a logtrighmic value of ratio of a chemical concentration and the toxicity in the laboratory. In case of small ERQ, tie chemical harzardousness is high. If ERQ equals O, the same biological effect as in the laboratory test will be observed in the enviromment by the chemicals. ERQ values of the chemicals were calculated using the maximum concentration in water environment which were cited from the annual report by our ministry of environment, and EC$_{50}$ of Daphnia magna (water flea; acute immobilization test) LC$_{50}$ of Oryzias latipes (fish; acue toxicity test) and EC$_{50}$ of chlorella vulgaris (alga; growth inhibition test), which were taken from the annual report of "Chemical in environment" by Japan EA. Liner alkylbenzene sulfonate (determined to MBAS) showed the high average values with more than 2.0 to three species in Han river and Jin-wi stream, and these results mean to be favorable to environmental safety. The areas of Jung-ryang stream were polluted, as the average values of ERQ were less than 2.0 with equal to three species, and attention should be paid. Therefore, they must be inspected again because their concentration in the environment may have changed during that period. The chemical harzardousness can be numerated with ERQ, and it can be a help to find the chemicals that should be kept under observation and to see whether the chemical pollution is improved or worsened. The determination of the chemical concentration in the environment and toxicity are essential for the effective use of ERQ.se of ERQ.

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Effect of 2.5 hr-interval single oral combination treatment of Gamisoyo-san with Tamoxifen on the pharmacokinetics profiles of Tamoxifen in rats

  • Kim, Joo-Ik;Ku, Sae-Kwang;Lee, Young-Joon
    • The Journal of Korean Medicine
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    • v.41 no.4
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    • pp.1-11
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    • 2020
  • Objectives: Objectives: The object of this study was to elucidate the possible effects on the pharmacokinetics of tamoxifen after single oral co-administration of Gamisoyo-san (GMSYS) with 2.5 hr-intervals combination therapy of tamoxifen with GMSYS. Methods: After 2.5 hr of 50 mg/kg of tamoxifen treatment, GMSYS 100 mg/kg was administered. The plasma was collected at 30 min before administration, 30 min, 1, 2, 3, 4, 6, 8 and 24 hrs after end of GMSYS treatment, and plasma concentrations of tamoxifen were analyzed using LC-MS/MS methods. PK parameters of tamoxifen were analysis as compared with tamoxifen single administered rats. Results: Although single co-administration with GMSYS with 2.5 hr-interval induced increased trends of plasma tamoxifen concentrations, there are no significant changes on the plasma concentrations of tamoxifen were demonstrated in tamoxifen and GMSYS 100 mg/kg co-administrated rats with 2.5 hr-intervals as compared to those of tamoxifen single 50 mg/kg treated rats, and also GMSYS co-administrated rats did not showed any significant changes on the all pharmacokinetic parameters as compared to those of tamoxifen single formula treated rats. Conclusions: According to the this study, single co-administration of GMSYS with 2.5 hr-intervals did not critically influenced on the oral bioavailability of tamoxifen, suggesting GMSYS did not critically influenced on the absorption and excretion of tamoxifen, the oral bioavailability, when they were co-administered with 2.5 hr-intervals, at the dose levels of tamoxifen 50 mg/kg and GMSYS 100 mg/kg.

HPLC, NMR Based Characterization, Antioxidant and Anticancer Activities of Chemical Constituents from Therapeutically Active Fungal Endophytes

  • Waqas Hussain Shah;Wajiha Khan;Sobia Nisa;Michael H.J. Barfuss;Johann Schinnerl;Markus Bacher;Karin Valant-Vetschera;Ashraf Ali;Hiba-Allah Nafidi;Yousef A. Bin Jardan;John P. Giesy
    • Journal of Microbiology and Biotechnology
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    • v.34 no.7
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    • pp.1452-1463
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    • 2024
  • Fungi generate different metabolites some of which are intrinsically bioactive and could therefore serve as templates for drug development. In the current study, six endophytic fungi namely Aspergillus flavus, Aspergillus tubigenesis, Aspergillus oryzae, Penicillium oxalicum, Aspergillus niger, and Aspergillus brasiliensis were isolated and identified from the medicinal plant, Silybum marianum. These endophytic fungi were identified through intra transcribed sequence (ITS) gene sequencing. The bioactive potentials of fungal extracts were investigated using several bioassays such as antibacterial activity by well-diffusion, MIC, MBC, anti-biofilm, antioxidant, and haemolysis. The Pseudomonas aeruginosa PAO1 was used to determine the antibiofilm activity. The ethyl acetate extract of Aspergillus flavus showed strong to moderate efficacy against Staphylococcus aureus, Escherichia coli, P. aeruginosa, and Bacillus spizizenii. Aspergillus flavus and Aspergillus brasiliensis exhibited significant antibiofilm activity with IC50 at 4.02 and 3.63 mg/ml, while A. flavus exhibited maximum antioxidant activity of 50.8%. Based on HPLC, LC-MS, and NMR experiments kojic acid (1) and carbamic acid (methylene-4, 1-phenylene) bis-dimethyl ester (2) were identified from A. flavus. Kojic acid exhibited DPPH free radical scavenging activity with an IC50 value of 99.3 ㎍/ml and moderate activity against ovarian teratocarcinoma (CH1), colon carcinoma (SW480), and non-small cell lung cancer (A549) cell lines. These findings suggest that endophytic fungi are able to produce promising bioactive compounds which deserve further investigation.

Screening of Potential Anticancer Compounds from Marketed Drugs: Aripiprazole, Haloperidol, Miconazole, and Terfenadine Inhibit Cytochrome P450 2J2 (시판 약물의 시토크롬 2J2 약물대사효소 저해능 탐색)

  • Liu, Kwang-Hyeon
    • Journal of Life Science
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    • v.21 no.11
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    • pp.1558-1564
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    • 2011
  • Cytochrome P450 2J2 (CYP2J2) plays important roles in the metabolism of endogenous metabolites such as arachidonic acid as well as therapeutic drugs. CYP2J2 is overexpressed in human cancer tissues and cancer cell lines, as well as in epoxyeicosatrienoic acids (EETs) and CYP2J2-mediated metabolites, and prevent apoptosis of cancer cells. This study aimed to screen marketed drugs for inhibitory potential on CYP2J2 isoforms using human liver microsomes. The initial screen isolated 4 compounds, from 120 marketed drugs, that inhibited the CYP2J2-mediated astemizole O-demethylation more than 50% in the following the order: haloperidol (75%) > terfenadine (56%) > aripiprazole (55%) > miconazole (52%). Miconazole strongly inhibited CYP2J2-mediated ebastine hydroxylation ($IC_{50}$=11.2 ${\mu}M$) and terfenadine hydroxylation ($IC_{50}$=2.2 ${\mu}M$), and terfenadine also inhibited CYP2J2-mediated ebastine hydroxylation ($IC_{50}$=13.6 ${\mu}M$) in a dose dependent manner. The present data suggest that these drugs are potential candidates for further evaluation for their anti-cancer activities.

Fish Safety and Antimicrobial Activity of Natural Sulfur Solution on Aquatic Microorganisms (Saprolegnia parasitica) Isolated from Misgurnus mizolepis (미꾸라지(Misgurnus mizolepis)에서 분리된 수생균 (Saprolegnia parasitica)에 대한 천연유황수의 항균 활성 및 처리에 대한 어류 안전성)

  • Yi, Seung-Won;Lee, Seung-Hyeop;Lee, Sang-Jong;Kim, Mi-Hee;Lee, Hye-Hyun;Chu, Saet-Byul;Kim, Kyung-Hee;Lee, Hee Jung
    • Korean Journal of Environmental Biology
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    • v.35 no.2
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    • pp.116-122
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    • 2017
  • Basic dyes such as malachite green and methylene blue have been used as disinfectants to control water fungal infections since the 1930s. However, after succeeding reports of carcinogenicity and bioaccumulation of the dye, their use was forbidden in lieu of public health. This study undertook to evaluate the therapeutic effect of sulfur solution processed by effective microorganisms (EM-PSS) against Saprolegnia parasitica infection, and its safety in fish. In vitro antifungal evaluation of EM-PSS inhibited the growth of S. parasitica mycelia at concentrations of 50 ppm or higher. The acute toxicity test of EM-PSS to the mud fish (Misgurnus mizolepis) measured a no effect concentration (NOEC) at 100 ppm, the lowest effect concentration (LOEC) at 125 ppm, and the half-lethal concentration ($LC_{50}$) at 125 ppm in juvenile and 250 ppm in the immature stage. In addition, the ecotoxicity test of EM-PSS using Daphnia magna inhibited swimming of D. magna at concentrations of 100 ppm or less. Lastly, the EM-PSS prevented infection of S. parasitica to mud fish, at concentrations of 50 ppm. Furthermore, at 100 ppm concentration, the EM-PSS showed no acute toxicity on mud fish, nor any eco-toxic effects on D. magnano. Therefore, we conclude that carcinogenic disinfectants such as malachite green and methylene blue could be replaced by EM-PSS to remove S. parasitica in mud fish farming, and might be a potential eco-friendly disinfectant in aquaculture.

The Effect of TBT Toxicity on Survival and Growth of Olive Flounder, Paralichthys olivaceus (넙치 생존과 성장에 미치는 TBT의 독성)

  • TAK Keon-Tae;KIM Joong Kun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.2
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    • pp.103-108
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    • 2001
  • Toxic effect of TBTO on larva flounder was studied by the use of a food-chain system in which indirect toxicity from seawater or/and plankton can be measured, Under the treatment of 0.5 ng/L TBTO, the combined effect of diets ( Chlorella and rotifer) and seawater was significant by synergism, although the sole effect from TBTO treated diets or seawater was equally not, The values of $LT_{50}$ from results of acute-toxicity experiments for juvenile flounder were estimated to be 230.0, 48.0, 24.0, 14.6, 9.3 5.5 3.0 and 1.7 hr at 1, 10, 25, 50, 100, 250, 500 and 1000 ng/L of TBTO, respectively, and $96hr-LC_{50}$ was 3.5 ng/L. From the above results, the experiments for chronic toxicity of TBTO was executed at the concentration range of $1\sim10 ng/L$. In long-term experiments for four months, the weight and the total length of the juvenile flounder in all TBTO treated experiments slowly increased when compared to control. No significant differences in the growth and survival of the juvenile flounder were found in the treatment of 1 ng/L TBTO(P>0.05), But, $90\%$ of the juvenile flounder died in 20 days under TBTO treated seawater at both concentrations of 5 and 10 ng/L, The TBTO treated on seawater was more effective and significantly different in the growth and survival of the juvenile flounder when compare with that on artificial diets (P<0.05). From the all results, TBTO should be regulated below 5 ng/L in a coast.

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