• 제목/요약/키워드: $IC_50$

검색결과 3,255건 처리시간 0.027초

Miltefosine-Induced Apoptotic Cell Death on Leishmania major and L. tropica Strains

  • Khademvatan, Shahram;Gharavi, Mohammad Javad;Rahim, Fakher;Saki, Jasem
    • Parasites, Hosts and Diseases
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    • 제49권1호
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    • pp.17-23
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    • 2011
  • The aim of this study was to assess the cytotoxic effects of various concentrations of miltefosine on Leishmania major (MRHO/IR/75/ER) and L. tropica (MHOM/IR/02/Mash10) promastigotes and to observe the programmed cell death features. The colorimetric MTT assay was used to find L. major and L. tropica viability and the obtained results were expressed as 50% inhibitory concentration (IC50). Also, 50% effective doses (ED50) for L. major and L. tropica amastigotes were also determined, Annexin-V FLUOS staining was performed to study the cell death properties of miltefosine using FAGS analysis. Qualitative analysis of the total genomic DNA fragmentation was performed by agarose gel electrophoresis. Furthermore, to observe changes in cell morphology, promastigotes were examined using light microscopy. In both strains of L. major and L. tropica, miltefosine induced dose-dependent death with features of apoptosis, including cell shrinkage, DNA laddering, and externalization of phosphatidylserine. The IC50 was achieved at 22 ${\mu}M$ and 11 ${\mu}M$ for L. major and L. tropica after 48 hr of incubation, respectively. ED50 of L. major and L. tropica amastigotes were 5.7 ${\mu}M$ and 4.2 ${\mu}M$, respectively. Our results indicate that miltefosine induces apoptosis of the causative agent of cutaneous leishmaniasis in a dose-dependent manner. Interestingly, L. major did not display any apoptotic changes when it was exposed to miltefosine in concentrations sufficient to kill L. tropica.

감태나무(Lindera glauca Blume) 에탄올 추출물의 항산화 및 인체 대장암세포 증식 억제 효과에 대한 연구 (Antioxidative and Antiproliferative Effects of Lindera glauca Blume on Human Colorectal Cancer Cells)

  • 김예언;윤정미
    • 한국식품영양과학회지
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    • 제44권4호
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    • pp.635-640
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    • 2015
  • 본 연구에서는 감태나무 추출물의 항산화 활성을 측정하기 위하여 총 폴리페놀 함량, DPPH 라디칼 소거능, 아질산염 소거능, 환원력 방법을 사용하였으며 HT-29와 HCT116 암세포를 이용하여 세포 증식 억제 효과를 측정하였다. 그 결과 본 연구에서 사용된 식물 중 감태나무 뿌리와 감태나무 줄기가 가장 높은 총 폴리페놀 함량을 보였으며 또한 DPPH 라디칼 소거능, 아질산염 소거 활성, 환원력도 가장 높게 나타났다. 암세포 증식 억제 효능평가에서도 감태나무 줄기와 뿌리는 대장암세포 HT-29, HCT116 세포주의 증식 억제에 대한 높은 활성을 나타냈다. 이러한 연구 결과는 감태나무의 기능성 소재로써의 기초적 데이터베이스로 활용할 수 있을 것으로 생각되며, 앞으로 더욱 더 감태나무의 질병에 대한 효능 및 기전연구가 지속되어야 할 것으로 생각된다.

Synthesis and Biological Evaluation of Heterocyclic Ring-substituted Chalcone Derivatives as Novel Inhibitors of Protein Tyrosine Phosphatase 1B

  • Chen, Zhen-Hua;Sun, Liang-Peng;Zhang, Wei;Shen, Qiang;Gao, Li-Xin;Li, Jia;Piao, Hu-Ri
    • Bulletin of the Korean Chemical Society
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    • 제33권5호
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    • pp.1505-1508
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    • 2012
  • Protein tyrosine phosphatase 1B (PTP1B) is a key factor in negative regulation of the insulin pathway, and is a promising target for the treatment of type-II diabetes, obesity and cancer. Herein, compound ($\mathbf{4}$) was first observed to have moderate inhibitory activity against PTP1B with an $IC_{50}$ value of $13.72{\pm}1.53{\mu}M$. To obtain more potent PTP1B inhibitors, we synthesized a series of chalcone derivatives using compound ($\mathbf{4}$) as the lead compound. Compound $\mathbf{4l}$ ($IC_{50}=3.12{\pm}0.18{\mu}M$) was 4.4-fold more potent than the lead compound $\mathbf{4}$ ($IC_{50}=13.72{\pm}1.53{\mu}M$), and more potent than the positive control, ursolic acid ($IC_{50}=3.40{\pm}0.21{\mu}M$). These results may help to provide suitable drug-like lead compounds for the design of inhibitors of PTP1B as well as other PTPs.

Toxic Effects of Heavy Metals on the Growth and Phosphorus Removal Efficiency of Phosphorus Accumulating Microorganisms (PAOs)

  • Sin, Da Hee;Kim, Deok Hyeon;Kim, Jong In;Lee, Moon-Soon;Chung, Keun-Yook
    • 한국토양비료학회지
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    • 제46권6호
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    • pp.673-680
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    • 2013
  • Phosphorus accumulating microorganisms (PAOs) are influenced by various environmental factors and heavy metals. This study was performed to evaluate the effects of the selected heavy metals on the growth and phosphorus removal capacity of Bacillus sp. 3434 BRRJ, Pseudomonas aerunogisa, and Bacillus Subtilis, well known as PAOs. The heavy metals used in this study included Cu, Cd, As, and Zn. The $IC_{50}$ (median inhibition concentration) values of Bacillus sp. 3434 BRRJ for the Cu, Cd, As, and Zn were 8.07 mg $L^{-1}$, 0.18 mg $L^{-1}$, 73.62 mg $L^{-1}$ and 0.25 mg $L^{-1}$, respectively. The $IC_{50}$ values of Pseudomonas aerunogisa for the Cu, Cd, As, and Zn were 4.45 mg $L^{-1}$, 0.16 mg $L^{-1}$, 18.51 mg $L^{-1}$ and 2.34 mg $L^{-1}$, respectively. The $IC_{50}$ values of Bacillus Subtilis for the Cu, Cd, As, and Zn were 3.81 mg $L^{-1}$, 0.18 mg $L^{-1}$, 11.31 mg $L^{-1}$ and 0.47 mg $L^{-1}$, respectively. The phosphorus removal efficiencies of the three bacteria, Bacillus sp. 3434 BRRJ, Pseudomonas aerunogisa, and Bacillus subtilis were 93.12%, 71.81%, and 65.31%, respectively. Based on the results of the three PAOs obtained from the study, it appears that Bacillus sp. 3434BRRJ may have the best results in terms of their growth rate and P removal efficiencies.

갈근에서 분리한 화합물의 $\alpha$-glucosidase와 $\alpha$-amylase 활성 저해 효과 ($\alpha$-Glucosidase and $\alpha$-Amylase Inhibitory Activity of Compounds from Roots Extract of Pueraria thunbergiana)

  • 박지희;백목련;이병회;연규환;유시용;김영섭;박상언;홍경식
    • 한국약용작물학회지
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    • 제17권5호
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    • pp.357-362
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    • 2009
  • Compounds of isolated from roots extract of Pueraria thunbergiana were tested their inhibitory effects on $\alpha$-glucosidase and $\alpha$-amylase. Inhibitory activity of methylene chloride (MC) fraction and ethyl acetate (EA) fraction against $\alpha$-glucosidase showed more than 60% at a concentration of $500{\mu}g/m{\ell}$. Among the nine compounds tested on $\alpha$-glucosidase, biochanin A, (-)-tuberosin and calycosin from MC fraction and daidzein from EA fraction were stronger inhibitors than acarbose ($IC_{50}=530{\mu}g/m{\ell}$), and their $IC_{50}$ were 9, 144, 328 and $20{\mu}g/m{\ell}$, respectively. Biochanin A and (-)-tuberosin also inhibited $\alpha$-amylase activity as like as acarbose $IC_{50}=20.5{\mu}g/m{\ell}$), and their $IC_{50}$ were 22 and $348{\mu}g/m{\ell}$, respectively. Although daidzein was already known $\alpha$-glucosidase inhibitory effects, it was newly evaluated that biochanin A and (-)-tuberosin inhibited $\alpha$-glucosidase as well as $\alpha$-amylase, and that calycosin did $\alpha$-glucosidase.

저분자량 키토산 올리고당의 항종양성 (Antineoplastic Effect of Low Molecular Weight Chitooligosaccharide on Various Tumor Cell Lines)

  • 박헌국
    • 한국식품영양학회지
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    • 제22권2호
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    • pp.308-312
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    • 2009
  • 저분자량 키토산 올리고당의 세포 독성을 실험하였다. 저분자량 키토산 올리고당은 정상세포주인 Vero E6(Africa green monkey kidney cell)에 대한 세포 독성을 거의 나타내지 않았다. 정상세포주에 대한 저분자량 키토산 올리고당의 $IC_{50}$값은 $1,060.28{\mu}g/m{\ell}$이었다. 저분자량 키토산 올리고당은 폐암 세포주인 A549, 방광암 세포주인 J82, 대장암 세포주인 SNU-C4, 위암 세포주인 SNU-1, 유방암 세포주인 ZR75-1 등과 같은 사람의 종양세포주에 대한 in vitro 항종양성을 나타내었다. 종양세포주에 대한 저분자량 키토산 올리고당의 $IC_{50}$값은 A549, J82, SNU-C4, SNU-1, ZR75-1 세포주의 경우에 각각 $477.42{\mu}/m{\ell}$, $480.40{\mu}g/m{\ell}$, $436.84{\mu}g/m{\ell}$, $373.55{\mu}g/m{\ell}$, and $539.95{\mu}/m{\ell}$이었다.

키토산 가수분해물의 In Vitro 항종양성 (In Vitro Antineoplastic Effects of Chitosan Hydrolysates on Various Tumor Cell Lines)

  • 박헌국
    • 한국식품영양학회지
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    • 제22권4호
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    • pp.639-643
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    • 2009
  • 키토산 가수분해물의 세포 독성 및 항종양성 실험에서 키토산 가수분해물은 정상세포주인 Vero E6(Africa green monkey kidney cell)에 대한 세포 독성을 거의 나타내지 않았다. 정상세포주에 대한 키토산 가수분해물의 $IC_{50}$값은 1,107.95 ${\mu}g/m{\ell}$이었다. 키토산 가수분해물은 폐암 세포주인 A549, 방광암 세포주인 J82, 대장암 세포주인 SNU-C4, 위암 세포주인 SNU-1, 유방암 세포주인 ZR75-1 등과 같은 사람의 종양세포주에 대한 in vitro 항종양성을 나타내었다. 종양세포주에 대한 키토산 가수분해물의 $IC_{50}$값은 A549, J82, SNU-C4, SNU-1, ZR75-1 세포주의 경우에 각각 421.06 ${\mu}g/m{\ell}$, 417.99 ${\mu}g/m{\ell}$, 445.54 ${\mu}g/m{\ell}$, 380.65 ${\mu}g/m{\ell}$, and 460.49 ${\mu}g/m{\ell}$이었다.

오징어 간 액젓으로부터 분리된 Angiotensin Converting Enzyme 저해 Peptide의 특성 (Characteristics of Angiotensin Converting Enzyme Inhibitory Peptides from Salt-fermented Squid Liver Sauce)

  • 박영범
    • 한국식품영양과학회지
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    • 제39권11호
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    • pp.1654-1659
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    • 2010
  • 오징어 가공 부산물인 오징어 간의 효율적 이용을 위하여 오징어 간을 이용하여 액젓을 제조하고 이들 액젓의 ACE 저해효과를 살펴보았다. 액젓의 ACE 저해활성은 12개월까지는 점차적으로 증가하였으나 그 이후에는 저해활성이 둔화되어 거의 일정한 저해활성을 유지하였다. 숙성 액젓 중 15개월째 액젓($IC_{50}=29.66\;{\mu}g$)을 한외여과막으로 통과시켜 회수한 분자량 10,000 Da 이하의 저분자물질을 Bio-gel P-2 gel chromatography를 행하여 ACE 저해효과를 가지는 3개획분을 분취하였다. 이들 획분 중에서 ACE 저해효과가 가장 높은 B 획분을 SuperQ-Toyopearl 650S column을 이용한 음이온 교환크로마토그래피에 의해 B-1의 활성획분을 분리하였다. 획분 B-1의 아미노산 조성은 lysine, glycine 및 proline의 함량이 가장 많아 전체의 약 85%를 차지하였으며 $IC_{50}$$5.46\;{\mu}g$으로 나타났다.

Naphthazarin Derivatives: Synthesis, Inhibition of DNA Topoisomerase-I and Antitumor Activity

  • Ahn, B-Z;Kim, Y;You, Y-J;Chung, S-K;Kim, K-S;Song, G-Y;Sok, D-E
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1997년도 춘계학술대회
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    • pp.109-109
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    • 1997
  • Inhibitory effect on DNA topoisomerase-I, rate of glutathione conjugation and cytotoxicity of naphthoquinone derivatives were correlated. During 5 min exposure of the derivatives to glutathione (GSH), it was found that 14% of 5,8-dimethoxy-1,4-naphthoquinone(DMNQ) was converted into a GSH-conjugate, whereas 5,8-dihydroxy-1,4-naphthoquinone(DHNQ) did not interact with GSH, implying that DMNQ exerted higher electrophilicity than DHNQ. However, DHNQ (IC$\_$50/, 0.15 ${\mu}$M) showed stronger cytotoxicity in L1210 cells than DMNQ(IC$\_$50/, 0.45 ${\mu}$M). The stronger cytotoxicity of DHNQ, compared to DMNQ, could be ascribed to more rapid redox cycling. Both naphthoquinones (IC$\_$50/, 60-65 ${\mu}$M) exhibiting about the same inhibitory effect on DNA topoisomerase-I were more potent than 1,4-naphthoquinone(1,4-NQ, IC$\_$50/, 134 ${\mu}$M). Thus, 5,8-oxy groups in the structure seem to be important for the inhibition of the enzyme. DMNQ showed a broader dose range while maintaining a good antitumor activity against S-180 fluid tumor. For these reasons, DMNQ was taken as useful pharmacophore for structural modification. Introduction of 1-hydroxyalkyl groups at C-2 of DMNQ lowered all of the activities mentioned above, while acetylation of 1-hydroxyalkyl moiety enhanced the activities by 4-5 times. Introduction of the same side chains at C-6 exhibited stronger activities than 2-substituted ones. Based on these results it was suggested that the quinonoid moiety in 6-substituted DMNQ was more exposed to cellular nucleophiles such as DNA, thiols of enzymes and so on. The synthesis of DHNQ or DMNQ derivatives are going on, and the corelationship between structure-activity will be discussed.

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Discovery of Cyclin-dependent Kinase Inhibitor, CR229, Using Structure-based Drug Screening

  • Kim, Min-Kyoung;Min, Jae-Ki;Choi, Bu-Young;Lim, Hae-Young;Cho, Youl-Hee;Lee, Chul-Hoon
    • Journal of Microbiology and Biotechnology
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    • 제17권10호
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    • pp.1712-1716
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    • 2007
  • To generate new scaffold candidates as highly selective and potent cyelin-dependent kinase (CDK) inhibitors, structure-based drug screening was performed utilizing 3D pharmacophore conformations of known potent inhibitors. As a result, CR229 (6-bromo-2,3,4,9-tetrahydro-carbolin-1-one) was generated as the hit-compound. A computational docking study using the X-ray crystallographic structure of CDK2 in complex with CR229 was evaluated. This predicted binding mode study of CR229 with CDK2 demonstrated that CR229 interacted effectively with the Leu83 and Glu81 residues in the ATP-binding pocket of CDK2 for the possible hydrogen bond formation. Furthermore, biochemical studies on inhibitory effects of CR229 on various kinases in the human cervical cancer HeLa cells demonstrated that CR229 was a potent inhibitor of CDK2 ($IC_{50}:\;3\;{\mu}M$), CDKI ($IC_{50}:\;4.9\;{\mu}M$), and CDK4 ($IC_{50}:\;3\;{\mu}M$), yet had much less inhibitory effect ($IC_{50}:>20\;{\mu}M$) on other kinases, such as casein kinase 2-${\alpha}1$ (CK2-${\alpha}1$), protein kinase A (PKA), and protein kinase C (PKC). Accordingly, these data demonstrate that CR229 is a potent CDK inhibitor with anticancer efficacy.