• Title/Summary/Keyword: Low-dose

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The Effect of Ginkgo Biloba Extract on the Fractionsted Radiation Therapy in C3H Mouse Fibrosarcoma (Ginkgo Biloba Extract가 C3H 마우스 섬유육종의 분할 방사선치료에 미치는 영향)

  • Kim, Jong-Hoon;Ha, Sung-Whan;Park, Charn-Il
    • Radiation Oncology Journal
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    • v.20 no.2
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    • pp.155-164
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    • 2002
  • Purpose : A ginkgo biloba extract (GBE) has been known as a hypoxic cell radiosensitizer. Its mechanisms of action are increase of the red blood cell deformability, decrease the blood viscosity, and decrease the hypoxic cell fraction in the tumor. The aims of this study were to estimate the effect of GBE on fractionated radiotherapy and to clarify the mechanism of action of the GBE by estimating the blood flow in tumor and normal muscle. Materials and Methods : Fibrosarcoma (FSall) growing in a C3H mouse leg muscle was used as the tumor model. When the tumor size reached 7 mm in diameter, the GBE was given intraperitoneally at 1 and 25 hours prior to irradiation. The tumor growth delay was measured according to the various doses of radiation (3, 6, 9, 12 Gy and 15 Gy) and to the fractionation (single and fractionated irradiation) with and without the GBE injection. The radiation dose to the tumor the response relationships and the enhancement ratio of the GBE were measured. In addition, the blood flow of a normal muscle and a tumor was compared by laser Doppler flowmetry according to the GBE treatment. Results : When the GBE was used with single fraction irradiation with doses ranging from 3 to 12 Gy, GBE increased the tumor growth delay significantly (p<0.05) and the enhancement ratio of the GBE was 1.16. In fractionated irradiation with 3 Gy per day, the relationships between the radiation dose (D) and the tumor growth delay (TGD) were TGD $(days)=0.26{\times}D$ (Gy)+0.13 in the radiation alone group, and the TGD $(days)=0.30{\times}D$ (Gy)+0.13 in the radiation with GBE group. As a result, the enhancement ratio was 1.19 ($95\%$ confidence interval; $1.13\~1.27$). Laser Doppler flowmetry was used to measure the blood flow. The mean blood flow was higher in the muscle (7.78 mL/100 g/min in tumor and the 10.15 mL/100 g/min in muscle, p=0.005) and the low blood flow fraction (less than 2 mL/100 g/min) was higher in the tumor $(0.5\%\;vs.\;5.2\%,\;p=0.005)$. The blood flow was not changed with the GBE in normal muscle, but was increased by $23.5\%$ ( p=0.0004) in the tumor. Conclusion : Based on these results, it can be concluded that the GBE enhanced the radiation effect significantly when used with fractionated radiotherapy as well as with single fraction irradiation. Furthermore, the GBE increased the blood flow of the tumor selectively.

The Effect of the Histidine-Tryptophan-Ketoglutarate (HTK) Solution on Myocardial Protection in Isolated Rat Heart (흰쥐의 적출심장에서 HTK 용액의 심근보호 효과)

  • 송원영;장봉현;김규태
    • Journal of Chest Surgery
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    • v.37 no.8
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    • pp.632-643
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    • 2004
  • Background: The Histidine-Tryptophan-Ketoglutarate (HTK) solution has been shown to provide the excellent myocardial protection as a cardioplegia. The HTK solution has relatively low potassium as an arresting agent of myocardium, and low sodium content, and high. concentration of histidine biological buffer which confer a buffering capacity superior to that of blood.. Since HTK solution has an excellent myocardial protective ability, it is reported to protect myocardium from ischemia for a considerable time (120 minutes) with the single infusion of HTK solution as a cardioplegia. The purpose of this study is to evaluate the cardioprotective effect of HTK solution on myocardium when the ischemia is. exceeding 120 minutes at two different temperature (10 to 12$^{\circ}C$, 22 to 24$^{\circ}C$) using the Langendorff apparatus, Material and Method: Hearts from Sprague-Dawley rat, weighing 300 to 340 g, were perfused with Krebs-Henseleit solution at a perfusion pressure of 100 cm $H_2O$. After the stabilization, the heart rate, left ventricular developed pressure (LVDP), and coronary flow were measured. Single dose of HTK solution was infused into the ascending aorta of isolated rat heart and hearts were preserved at four different conditions. In group 1 (n=10), hearts were preserved at deep hypothermia (10∼12$^{\circ}C$) for 2 hours, in group 2 (n=10), hearts were preserved at moderate hypothermia (22∼24$^{\circ}C$) for 2 hours, in group 3 (n=10), hearts were preserved at deep hypothermia for 3 hours, and in group 4 (n=10), hearts were preserved at moderate hypothermia for 3 hours. After the completion of the preservation, the heart rate, left ventricular developed pressure, and coronary flow were measured at 15 minutes, 30 minutes, and 45 minutes after the initiation of reperfusion to assess the cardiac function. Biopsies were also done and mitochondrial scores were counted in two cases of each group for ultrastructural assessment. Result: The present study showed that the change of heart rate was not different between group 1 and group 2, and group 1 and group 3. The heart rate was significantly decreased at 15 minutes in group 4 compared to that of group 1 (p<0.05 by ANCOVA). The heart rate was recovered at 30 minutes and 45 minutes in group 4 with no significant difference compared to that of group 1. The decrease of LVDP was significant at 15 minutes, 30 minutes and 45 minutes in group 4 compared to that of group 1 (p < 0.001 by ANCOVA). Coronary flow was significantly decreased at 15 minutes, 30 minutes, and 45 minutes in group 4 compared to that of group 1 (p < 0.001 by ANCOVA). In ultrastructural assessment, the mean myocardial mitochondrial scores in group 1, group 2, group 3, and group 4 were 1.02$\pm$0.29, 1.52$\pm$0.26, 1.56$\pm$0.45, 2.22$\pm$0.44 respectively. Conclusion: The HTK solution provided excellent myocardial protection regardless of myocardial temperature for 2 hours. But, when ischemic time exceeded 2 hours, the myocardial hemodynamic function and ultrastructural changes were significantly deteriorated at moderate hypotherma (22∼ 24$^{\circ}C$). This indicates that it is recommended to decrease myocardial temperature when myocardial ischemic time exceeds 2 hours with single infusion of HTK solution as a cardioplegia.

The Efficacy of Interferon(IFN)-${\gamma}$ in Idiopathic Pulmonary Fibrosis (특발성 폐섬유화증에서 Interferon-${\gamma}$의 효과)

  • Park, Joo Hun;Oh, Yeon Mok;Shim, Tae Sun;Lim, Chae-Man;Koh, Younsuck;Lee, Sang-Do;Kim, Woo Sung;Kim, Won Dong;Kim, Dong Soon
    • Tuberculosis and Respiratory Diseases
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    • v.56 no.6
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    • pp.611-618
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    • 2004
  • Background : Idiopathic pulmonary fibrosis(IPF), a subtype of IIP(idiopathic interstitial pneumonia), is a fatal disease with a 3-5 year median survival. Many attempts at treating this condition have failed to demonstrate a survival benefit in IPF. Recently Ziesche et $al^{12}$ reported the efficacy of IFN-${\gamma}$ for treating IPF but there is still some controversy. The aim of this study was to determine the efficacy of IFN-${\gamma}$ in patients with advanced IPF who had not been responsive to steroid and cytotoxic agents. Method : Nine patients with advanced IPF(age: $55.4{\pm}15.3$ years, Male: Female=8:1) were enrolled. One year treatment regime with 2 million IU of IFN-${\gamma}$ administered subcutaneously three times a week, and low dose prednisolone(10-30 mg/d) was also used. In the case of a definite aggravation and serious side effects, the IFN-${\gamma}$ was discontinued. During the IFN-${\gamma}$ trial, a pulmonary function test and chest radiography were checked every three month throughout the study. Result : 1) Among 9 patients, only 4 patients were able to complete the 12 month treatment with IFN-${\gamma}$, and 5 patients died during the treatment period. 2) No improvement either in the respiratory symptoms or pulmonary functions were observed any of the patients, even in those who completed the 12 months trial of IFN-${\gamma}$, 3) At the time of IFN-${\gamma}$ trial, the survivors who finished the IFN-${\gamma}$ treatment for 12 months had a higher oxygen level($81.3{\pm}2.8$ vs. $67.4{\pm}8.4$, P=0.024) and a better pulmonary function(FVC: $61.3{\pm}5.1$ % predicted vs. $45.7{\pm}12.3%$, P=0.048, and $D_Lco$: $45.0{\pm}5.0%$ predicted vs. $30.8{\pm}11.2%$, P=0.048) than the non-survivors. Conclusion : Our data suggested that IFN-${\gamma}$ therapy was not effective in the patients with advanced IPF refractory compared with other therapeutic agents. Furthermore, these results suggest that severe impairment of the pulmonary function and hypoxemia during the IFN-${\gamma}$ therapy requires special attention.

A Basic Study on the Radiological Characteristics and Disposal Methods of NORM Wastes (공정부산물의 방사선적 특성과 처분방안에 관한 기본 연구)

  • Jeong, Jongtae;Baik, Min-Hoon;Park, Chung-Kyun;Park, Tae-Jin;Ko, Nak-Youl;Yoon, Ki Hoon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.3
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    • pp.217-233
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    • 2014
  • Securing the radiological safety is a prerequisite for the safe management of the naturally occurring radioactive materials (NORM) which cannot be reused. This becomes a crucial focus of our R&D efforts upon the implementation of the Act on Protective Action Guidelines against Radiation in the Natural Environment. To secure the safety, the establishment of technical bases and procedures for securing radiological safety related to the disposal of NORM is required. Thus, it is necessary to analyze the characteristics, to collect the data, to have the radiological safety assessment methodologies and tools, to investigate disposal methods and facilities, and to study the effects of the input data on the safety for the NORM wastes. Here, we assess the environmental impact of the NORM waste disposal with respect to the major domestic and foreign NORM characteristics. The data associated with major industries are collected/analyzed and the status of disposal facilities and methodologies relevant to the NORM wastes is investigated. We also suggest the conceptual design concept of a landfill disposal facility and the management plan with respect to the major NORM wastes characteristics. The radionuclide pathways are identified for the atmospheric transport and leachate release and the environmental impact assessment methodology for the NORM waste disposal is established using a relevant code. The assessment and analysis on the exposure doses and excessive cancer risks for the NORM waste disposal are performed using the characteristics of the representative domestic NORM wastes including flying ash, phosphor gypsum, and redmud. The results show that the exposure dose and the excessive cancer risks are very low to consider any radiation effects. This study will contribute to development in the areas of the regulatory technology for securing radiological safety relevant to NORM waste disposal and to the implementation technology for the Act.

A Study on the Environmental Condition and Safety in Dental Radiographic Room (치과 방사선 촬영실의 촬영실태와 방사선 안전관리 실태에 관한 조사 연구)

  • Kang, Eun-Ju;Lee, Kyung-Hee;Ju, On-Ju
    • Journal of dental hygiene science
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    • v.5 no.2
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    • pp.83-88
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    • 2005
  • In spite of relatively low level of radiation dose used at dental clinics, long term exposure may be harmful, so radiation workers at dental clinics must be well aware of its danger. This study was radiation safety management by dental hygienists in order to take preventive measures for dental hygienists and suggest ideas to develop radiation safety training programs. For this, we contacted dental hygienists working at the local dental clinics for 4 months from December of 2003 to march of 2004 and obtained the following findings. 1. Regarding the intraoral radiographic method, the average daily photographing frequency of standard films stood at one to five pieces (47.5%), and the average weekly photographing frequency of digital radiation medicine stood at less than one piece (69.8%), and the average weekly photographing frequency of bitewing films stood at less than one piece (67.7%), and and the average weekly photographing frequency of occlusal films stood at less than one piece (95.5%), and the dentistries whose average weekly photographing frequency of pediatric films stood at one to five pieces accounted for 47.1 percent. 2. Regarding the extraoral radiographic method, the average weekly photographing frequency of panorama film stood at one to five pieces (63.7%), and less than one piece (20.9%), the average weekly photographing frequency of cephalometric film stood at less than one piece (72.3%), and one to five pieces (20.1%). 3. Concerning the radiation safety management training program, only 18.7% of total 278 surveyed attended the training progra., Attendance tendency of the training program by general characteristics showed statistically significant difference according to age (p<0.01), working experience (p<0.001), and marital status (p<0.01). 4. When asked about the protective equipments against radiation exposure, 40.6% of them said "modest", and 71.1% appeared equipped with led apron as a protective tool.

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A Study on Effectiveness of Conventional Phenylalanine Loading before BH4 Loading Test in Children with Hyperphenylalaninemia (고페닐알라닌혈증 환아들에게 BH4 부하검사 이전에 시행되는 페닐알라닌 부하의 효과에 대한 고찰)

  • Park, Youngcheon;Kim, Kang-in;Lee, Jeongho;Lee, Dong Hwan
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.16 no.2
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    • pp.86-92
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    • 2016
  • Purpose: The $BH_4$ loading test is an important test that distinguishes PKU from $BH_4$ deficiency and identifies the $BH_4$ reactivity of PKU patients. Phenylalanine and $BH_4$ loading tests are useful methods that can shorten the length of hospital stay while improving patients' convenience. However, sufficient research on the dose of phenylalanine loading and $BH_4$ administration time after the loading has not been carried out. The present study investigates the effectiveness of the existing phenylalanine loading method by analyzing the medical records of six patients who underwent the $BH_4$ loading test after taking 100 mg/kg of phenylalanine patients. Methods: The medical records of six patients who underwent the $BH_4$ load test after taking 100 mg/kg of phenylalanine were examined out of 207 patients who were followed up in the Genetic Metabolic Clinic in Soonchunhyang University Hospital. All of the six patients had a low phenylalanine diet. First, they were taking 100 mg/kg of phenylalanine. 3 hours later, 20 mg/kg of $BH_4$ were loaded. The phenylalanine levels in the blood were continuously measured at 1, 2, 4, 6, 8, 12, and 24 hours by setting the time the $BH_4$ was loaded as the basal. Results: The average of the highest phenylalanine concentrations of six patients was $20.0{\pm}11.70mg/dL$. One reached the highest concentration seven hours after taking phenylalanine; another reached it five hours after that, and the remaining three reached it four hours after that. Only one patient reached the highest concentration within three hours. The phenylalanine levels of four out of six patients (66%) rose above $400{\mu}mol/L$ after being loaded with phenylalanine. The phenylalanine levels of the remaining two were 6.1 mg/dL ($366{\mu}mol/L$) and 5 mg/dL ($300{\mu}mol/L$), respectively. Conclusion: One of six patients (16%) reached the highest concentration three hours after taking 100 mg/kg of phenylalanine and four patients (66%) reached $400{\mu}mol/L$ or higher phenylalanine levels. There were patients whose phenylalanine levels did not rise above $400{\mu}mol/L$ using a commonly known test method; moreover, this method had the disadvantage of reaching the highest concentration after more than three hours. Therefore, it is considered that taking 200 mg/kg or more of phenylalanine and performing $BH_4$ loading four to six hours after taking phenylalanine are helpful in proper diagnosis.

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Effects of Administration of Oxytocin Antagonist on Implantation and Pregnancy Rates in Patients with Repeated Failure of IVF/ICSI Treatment (체외수정시술의 반복적인 실패 환자에서 옥시토신 길항제 주입이 착상 및 임신에 미치는 영향)

  • Ahn, Jun-Woo;Kim, Chung-Hoon;Kim, So-Ra;Jeon, Gyun-Ho;Kim, Sung-Hoon;Chae, Hee-Dong;Kang, Byung-Moon
    • Clinical and Experimental Reproductive Medicine
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    • v.36 no.4
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    • pp.275-281
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    • 2009
  • Objective: This study was performed to evaluate the effect of oxytocin antagonist on the outcome of IVF/ICSI cycles in infertile patients with repeated failure of IVF/ICSI treatment. Method: Forty patients who had experienced two or more failures of IVF/ICSI treatment without low ovarian reserve, were recruited for this prospective randomized study. All patients received controlled ovarian stimulation (COS) using GnRH antagonist multidose protocol (MDP). For the intervention group, intravenous administration of atosiban (mixed vasopressin $V_{1A}$/oxytocin antagonist) started with a bolus dose 6.75 mg one hour before embryo transfer (ET) and continued at an infusion rate of 18 mg/hour. After ET, administered atosiban was reduced to 6 mg/hour and continued for 2 hours. The main efficacy endpoints were clinical pregnancy rate and implantation rate. Results: Patients' characteristics were comparable in the intervention and control groups. COS parameters and IVF results were also similar. The number of uterine contractions for 3 minutes measured just before ET was significantly lower in the intervention group than control group ($3.5{\pm}1.4$ vs $8.7{\pm}2.2$, p<0.001). While there was no statistically significant difference in the clinical pregnancy rate between control group and intervention group (20.0% and 40.0%, p=0.168), the implantation rate was significantly higher in the intervention group, with 16.9% (11/65) compared with 6.0% (4/67) in the control group (p=0.047). There were no differences in ectopic pregnancy rate and miscarriage rate between the two groups. Conclusion: This study demonstrates that administration of oxytocin antagonist during ET can improve the implantation rate probably by decreasing the frequency of uterine contractions in infertile patients undergoing IVF/ICSI treatment.

Action Mechanism of Antiestrogens on Uterine Growth in Immature Rats (자궁세포 성장에 미치는 항에스트로젠제의 작용기전)

  • Lee, Jung-Bin;Yoon, Mi-Chung;Kim, Chang-Mee;Hong, Sa-Suk;Ryu, Kyung-Za
    • The Korean Journal of Pharmacology
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    • v.26 no.2
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    • pp.167-176
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    • 1990
  • In the present study, we examined the effects of tamoxifen and LY117018 on various parameters for the estrogenic actions in order to understand the mechanism by which tamoxifen and LY117018 act on the uterine cells in 21-23 day old immature rats. Tamoxifen and LY117018 stimulated uterine weight and uterine contents of DNA, protein, and peroxidase activity in the absence of estradiol while inhibited above parameters in the presence of estradiol. Both cytosolic and nuclear progesterone receptors were increased by the treatment of tamoxifen and LY117018 as well as estradiol, but estradiol-induced increase in the progesterone receptors were reduced by the treatment of antiestrogens. These effects were enhanced by the multiple injections of antiestrogens. It seemed that tamoxifen was more agonistic than LY117018 but less antagonistic than LY117018, judged by their effects on various parameters for the estrogenic action. The affinities of estradiol, tamoxifen, and LY117018 for the estrogen receptor were $0.17{\pm}0.01nM(100%)$, $1.10{\pm}0.01nM(6.3%)$, and $0.23{\pm}0.01nM(77%)$, respectively. Furthermore, LY117018 was the competitive ligand for the estrogen receptor in dose-related manner but tamoxifen was not. Following estradiol treatment, nuclear estrogen receptor was sharply increased by 1 h, reaching the maximum by 16 h, while tamoxifen and LY117018 slightly increased nuclear estrogen receptor by 1 h and then decreased thereafter. It is therefore concluded that LY117018 is a competitive antagonist for the estrogen receptor with less estrogenic activity, compared to tamoxifen with low affinity to the estrogen receptor, and tamoxifen may act through other binding site than the estrogen receptor.

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Metabolic Responses of Activated Sludge to Pentachlorophenol in SBR Systems

  • ;Larry D. Benefield
    • Journal of Environmental Science International
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    • v.3 no.3
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    • pp.273-284
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    • 1994
  • The primary objective of this study was to examine the toxic effects of PCP on activated sludge and to analyze its metabolic responses while treating wastewater containing pentachlorophenol (PCP) in a sequencing batch reactor (SBR) system operating under different control strategies. This study was conducted in two phases 1 and 2 (8-hr and 12-hr cycles). Each phase was operated with two control strategies I and II. Strategy I (reactor 1) involved rapid addition (5 minutes to complete) of substrate to the reactor with continuous mixing but no aeration for 2 hours. Strategy ll (reactor 2) involved adding the feed continuously during the first 2 hours of the cycle when the system was mixed but not aerated. During both phases each reactor was operated at a sludge age of 15 days. The synthetic wastewater was used as a feed. The COD of the feed solution was about 380 mg/l. After the reference response for both reactors was established, the steady state response of each system was established for PCP feed concentrations of 0.1 mg/l, 1.0 mg/l, and 5.0 mg/l in SBR systems operating on both 8-hr and 12-hr cycles. Soluble COD removal was not inhibited at any feed PCP concentrations used. At 5.0 mg/l fined PCP concentration and in SBR systems operating on phase 2, the concentrations of MLVSS were decreased; selective pressure on the mixed biomass might be increased, narrowing the range of possible ecological responses; the settleability of activated sludge was poor; the SOURS were increased, showing that the systems were shocked. Nitrification was made to some extent at all concentrations of feed PCP in SBR systems operating on phase 2 whereas in SBR systems operating on phase 1 little nitrification was observed. Then, nitrification will be delayed as much as soluble COD removal is retarded due to PCP inhibition effects. Enhanced biological phosphorus removal occurring in the system operating with control strategy I during phase 1 of this work and in the presence of low concentrations of PCP was unreliable and might cease at anytime, whereas enhanced biological phosphorus removal occurring in the system operating with either control strategy I or II during phase 2 of this work and in the Presence of feed PCP concentrations up to 1.0 mg/l was reliable. When, however, such processes were exposed to 5.0 mg/l PCP dose, enhanced phosphorus removal ceased and never returned.

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Antioxidant and Antigenotoxic Effects of Sansuyu Fruit (Corni fructus) Extracted with Water at Different Temperatures (추출 온도에 따른 산수유의 항산화 활성 및 항유전독성 효과 비교)

  • Lee, Min-Hee;Kim, Jung-Mi;Park, Eun-Ju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.2
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    • pp.149-155
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    • 2011
  • The objective of this study was to evaluate the antioxidant and antigenotoxic activities of sansuyu fruit (Corni fructus, CF) at temperatures of $25^{\circ}C$, $50^{\circ}C$, and $90^{\circ}C$ using a water extraction method. Total phenolic content (TPC), DPPH radical-scavenging activity (RSA), and superoxide dismutase (SOD)-like activity, and ORAC (Oxygen radical absorbance capacity) values were determined. Also the antigenotoxicity of CF was determined by measuring inhibitory effects of $H_2O_2$ induced DNA damage in human leukocytes using the comet assay. The TPC in the CF extracts was 4.2, 4.6, and 5.5 g/100 g GAE in $25^{\circ}C$, $50^{\circ}C$, and $90^{\circ}C$, respectively. The DPPH RSA of the CF extracts increased in a dose-dependent manner over the range of $50\sim1000\;{\mu}g$/mL in all temperatures and the $SC_{50}$ of DPPH RSA of the CF extracts were not significantly different at different extraction temperatures. The $SC_{50}$ of SOD-like was the highest in CF extracted at $25^{\circ}C$ (1.1 mg/mL) followed by $90^{\circ}C$ (1.2 mg/mL) and $50^{\circ}C$ (1.3 mg/mL). The ORAC values of the CF extracts were not significantly different in low concentration ($10\;{\mu}M$/mL) and was in order of $25^{\circ}C$ ($5.7\;{\mu}M$ TE)< $90^{\circ}C$ ($6.2\;{\mu}M$ TE)< $50^{\circ}C$ ($8.5\;{\mu}M$ TE) in high concentration ($50\;{\mu}M$/mL). $200\;{\mu}M$ $H_2O_2$ induced DNA damages in human leukocytes were significantly reduced by the pretreatment with the CF extracts. These results suggest that sansuyu fruit (Corni fructus) can be used as a natural source for antioxidant activities and as antigenotoxic agents regardless of the water extraction temperature.