• Title/Summary/Keyword: $IC_{50}$ values

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Antioxidant potential of aerial part of Asclepias curassavica. Linn (Family-Asclepiadaceae)

  • Raja, S;Ahamed, KFH Nazeer;Kumar, V;Mukherjee, Kakali;Bandyopadhyay, Arun;Mukherjee, Pulok K
    • Advances in Traditional Medicine
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    • v.5 no.2
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    • pp.92-99
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    • 2005
  • Asclepias curassavica. Linn, an erect, simple (or) much branched perennial herb with a somewhat woody base, belonging to the family Asclepiadaceae. It has been reported to have multiple pharmacological effect of anti-inflammatory, cardiotonic, anticancer, anthelmintic and to treat piles and gonorrhoea. It is to be expected that several activities might be related to a possible antioxidant action from this plant. The hydro alcoholic extract of Asclepias curassavica was tested in vitro for its antioxidant activities, such as DPPH radical, nitric oxide radical, superoxide anion radical, lipid peroxidation assay, hydroxyl radical, reducing power, and total phenol content. The extract exhibited scavenging potential with $IC_{50}$ value of $8.7\;{\mu}g/ml,\;198.4\;{\mu}g/ml\;and\;21.7\;{\mu}g/ml$ for DPPH, nitric oxide and superoxide anion radicals. The values were found to higher than those of Vitamin-C, rutin, and curcumin, as standards. The extract showed 50% protection at the dose of $134.2\;{\mu}g/ml\;and\;41.4\;{\mu}g/ml$ in lipid peroxidation as well as deoxyribose degradation, those values more to that of standard, vitamin E $(IC50\;values,\;119.2\;{\mu}g/ml\;and\;32.5\;{\mu}g/ml,\;respectively)$. The reducing power of the extract depends on the concentration and amount of extract. Since a significant amount of polyphenol could be detected by the equivalent to $0.0495\;{\mu}g$ of pyrocatechol from 1 mg of extract. It can be concluded that hydro alcoholic extract of aerial part of Asclepias curassavica could be considered as potent antioxidant, which makes it suitable for the prevention of human disease.

Inhibitory Effects of Medicinal Herbs on Cytochrome P450 Drug Metabolizing Enzymes (생약추출물의 Cytochrome P450 약물대사 효소계 저해활성)

  • Jeong, Hye-Gwang;You, Ho-Jin;Chang, Young-Su;Park, Sung-Jun;Moon, Young-Hee;Woo, Eun-Rhan
    • Korean Journal of Pharmacognosy
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    • v.33 no.1 s.128
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    • pp.35-41
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    • 2002
  • The MeOH ext., $CH_2Cl_2$ Frac., EtOAc Frac., n-BuOH Frac., and $H_2O$ Frac. of 23 Korean medicinal herbs were prepared and were tested the inhibitory effects on Cytochrome P450 (Cyp) 1A1/2, 2B1/2, 2E1. Among the tested samples, the extracts of Selaginella tamariscina, Euonymus alatus, Salvia miltiorhiza, Angelica acutiloba, Rheum palmatum, Paeonia moutan, Scutellaria barbata, Tribulus terrestris, Hedyotis diffusa, Curcuma zedoaria, Rehmania glutinosa, Trogopterus xanthipes, Melandryum firmum, Achyranthes bidentata, Leonurus sibricus, Panax ginseng, Paeonia lactiflora, Poncirus trifoliata, Cnidium officinale, Cyperus rotundus, Corydalis ternata showed significant inhibitory effects on Cyp 1A1/2, 2B1/2, 2E1. The $IC_{50}$ values of those extracts were found to be below $50\;{\mu}g/ml$.

Cytotoxic Polyene Antibiotics from Myxococcus stipitatus JW111 (Myxococcus stipitatus JW111이 생산하는 Polyene계 항암활성물질)

  • Ahn, Jong-Woong
    • Applied Biological Chemistry
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    • v.45 no.2
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    • pp.114-118
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    • 2002
  • Phenalamides $A_1{\sim}A_3$ were reisolated as cytotoxic substances from culture broth of Myxococcus stipitatus JW111. The producing strain was isolated from the marine sediment collected off the shore of Geomun Island, Korea. The active principles were extracted from cell mass with acetone and successively purified by silica gel column chromatography, Sephadex LH-20 column chromatography, and finally recycling prep. HPLC. These compounds demonstrated significant cytotoxicity against certain human cancer cells, having $IC_50$ values ranging from 0.23 to 0.50 ${\mu}g/ml$. Moreover, they also inhibited the growth of adriamycin-resistant HCT/ADM human cancer cell line as well as its parent sensitive cell line.

Investigation of Antitumor Effects of Sorafenib and Lapatinib Alone and in Combination on MCF-7 Breast Cancer Cells

  • Kacan, Turgut;Altun, Ahmet;Altun, Gulsah Gultekin;Kacan, Selen Baloglu;Sarac, Bulent;Seker, Mehmet Metin;Bahceci, Aykut;Babacan, Nalan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.7
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    • pp.3185-3189
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    • 2014
  • Background: Breast cancer evolution and tumor progression are controlled by complex interactions between steroid receptors and growth factor receptor signaling. Aberrant growth factor receptor signaling can augment or suppress estrogen receptor function in hormone-dependent breast cancer cells. Thus, we aimed to investigate antitumor effects of sorafenib and lapatinib alone and in combination on MCF-7 breast cancer cells. Materials and Methods: Cytotoxicity of the sorafenib and lapatinib was tested in MCF-7 cells by XTT assays. 50, 25, 12.5 and $6.25{\mu}M$ concentrations of sorafenib and 200, 100, 50 and $25{\mu}M$ concentrations of lapatinib were administered alone and in combination. Results were evaluated as absorbance at 450nM and $IC_{50}$ values are calculated according to the absorbance data Results: Both sorafenib and lapatinib showed concentration dependent cytotoxic effects on MCF-7 cells. Sorafenib exerted cytotoxic effects with an $IC_{50}$ value of $32.0{\mu}M$; in contrast with lapatinib the $IC_{50}$ was $136.6{\mu}M$. When sorafenib and lapatinib combined, lapatinib increased cytotoxic effects of sorafenib at its ineffective concentrations. Also at the concentrations where both drugs had cytotoxic effects, combination show strong anticancer effects and killed approximately 70 percent of breast cancer cells. Conclusions: Combinations of tyrosine kinase inhibitors and cytotoxic agents or molecular targeted therapy has been successful for many types of cancer. The present study shows that both sorafenib and lapatinib alone are effective in the treatment of breast cancer. Also a combination of these two agents may be a promising therapeutic option in treatment of breast cancer.

Optimal Extraction Conditions to Produce Rosemary Extracts with Higher Phenolic Content and Antioxidant Activity (폴리페놀 함량과 항산화력에 따른 로즈마리의 최적 추출조건 확립)

  • Lee, Chang-Yong;Kim, Ki-Myeong;Son, Hong-Seok
    • Korean Journal of Food Science and Technology
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    • v.45 no.4
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    • pp.501-507
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    • 2013
  • We evaluated the effects of temperature, time, solvent type, and solvent concentration on the phenolic content and antioxidant activity of rosemary extracts. The antioxidant capacity of rosemary extracts was demonstrated by their ability to scavenge stable free radicals, and the phenolic content of the extracts was determined using the Folin Ciocalteu method. The highest values were obtained by water-based extraction at $90^{\circ}C$ for 30 min, a 75% methanol solution at $60^{\circ}C$ for 30 min, and a 50% ethanol solution at $70^{\circ}C$ for 10 min. The aqueous solution of 75% methanol, extraction temperature of $60^{\circ}C$, and extraction time of 30 min were the most efficient parameters for the extraction of polyphenols from dry rosemary.

Antioxidative Activities and Whitening Effects of Solvent Fraction from Prunus davidiana (Carriere) Franch. Fruit (산복사나무(Prunus davidiana (Carriere) Franch.) 열매 분획 추출물의 항산화 및 미백 효능)

  • Kim, Won Baek;Park, So Hae;Hwang, Hye Sun;Woo, Jung Yoon;Lee, Hye Ryun;Hwang, Dae Youn;Choi, Ji Hye;Lee, Heeseob
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.10
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    • pp.1363-1370
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    • 2012
  • In this study, methanol extract and its organic solvent fractions were prepared from Prunus davidiana (Carriere) Franch. fruit. Antioxidative activities, polyphenolic and flavonoid contents, and tyrosinase inhibitory activities were evaluated. Among the fractions, ethyl acetate fraction showed the highest antioxidative activity with $IC_{50}$ values of 5.8 ${\mu}g/mL$ and 88.1 ${\mu}g/mL$ for DPPH radical and nitrite scavenging, respectively, which were comparable to those of ascorbic acid. Further, total flavonoid and polyphenolic contents were highest in the ethyl acetate fraction with $IC_{50}$ values of 244.5 mg/g and 210.2 mg/g, respectively. $IC_{50}$ values for tyrosinase inhibitory activity were 0.310 mg/mL and 0.329 mg/mL for the ethyl acetate and n-butanol fractions, respectively. Based on these results, it is suggested that the ethyl acetate fraction of Prunus davidiana (Carriere) Franch. fruit could be used as a functional material in the food and pharmaceutical industries.

LB30057 Inhibits Platelet Aggregation and Vascular Relaxation Induced by Thrombin

  • Jung, Byoung-In;Kang, a-Kyu-Tae;Bae, Ok-Nam;Lee, Moo-Yeol;Chung, Seung-Min;Lee, Sang-Koo;Kim, In-Chul;Chung, Jin-Ho
    • Archives of Pharmacal Research
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    • v.25 no.6
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    • pp.879-884
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    • 2002
  • Previous study showed that an amidrazonophenylalanine derivative, LB30057, which has high water solubility, inhibited the catalytic activity of thrombin potently by interaction with the active site of thrombin. In the current investigation, we examined whether LB30057 inhibited platelet aggregation and vascular relaxation induced by thrombin. Treatment with LB30057 to plateletrich plasma (PRP) isolated from human blood resulted in a concentration-dependent inhibition of thrombin-induced aggregation. Values for $IC_{50}$ and $IC_{100}$ were $54{\pm}4$ nM and $96{\pm}3$ nM, respectively. This inhibition was agonist (thrombin) specific, since $IC_{50}$ values for collagen and ADP were \much greater than those for thrombin. In addition, concentration-dependent inhibitory effects were observed on the serotonin secretion induced by thrombin in PRP. Consistent with these findings, thrombin-induced increase in cytosolic calcium levels was inhibited in a concentration-dependent manner. When LB30057 was treated with aortic rings isolated from rats, LB30057 resulted in a concentration-dependent inhibition of thrombin-induced vascular relaxation. All these results suggest that LB30057 is a potent inhibitor of platelet aggregation and blood vessel relaxation induced by thrombin.

The Physiological Activities of Bark Extract of Albizia julibrissin (자귀나무(A. julibrissin) 수피 추출물의 생리활성)

  • Lee, Yang-Suk;Kim, Kwang-Kon;Kim, Nam-Woo
    • Food Science and Preservation
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    • v.18 no.1
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    • pp.79-86
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    • 2011
  • Three bark extracts of Albizia julibrissin were prepared using water (AW), 70% (v/v) ethanol (AE), and hot water (AHW). Organic solvent fractions were analyzed for total flavonoids and polyphenols, antioxidant activities, and inhibitory activities against xanthine oxidase. Total flavonoid and polyphenol contents of the AHW extract were 8.57 mg/g and 108.67 mg/g, respectively. The SOD-like activities of all extracts, assayed at 1.0 mg/mL, were 10.46-16.73%. The nitrite-scavenging ability of the AHW extract, assayed at pH 1.2, was 60.82%, and the $IC_{50}$ value was $770.18\;{\mu}g$/mL. The electron-donating ability of the AHW extract, at 0.3 mg/mL, was 92.30%; the $IC_{50}$ values of the AW and AHW extracts were $31.31\;{\mu}g$/mL and $36.22\;{\mu}g$/mL, respectively; thus higher than that of ascorbic acid ($39.06\;{\mu}g$/mL). Xanthine oxidase inhibition by the AHW extract, at 1.0 mg/mL, was 94.05%. These results indicate that the AHW of A. julibrissin has potential as a natural antioxidant, for addition to foods and nutraceuticals.

Phytochemical constituents of Coix lachryma-jobi var. ma-yuen roots and their tyrosinase inhibitory activity (율무근의 식물화학적 성분 연구 및 Tyrosinase 저해 활성)

  • Choi, Yun-Hyeok;Choi, Chun Whan;Lee, Jae Yeon;Ahn, Eun-Kyung;Oh, Joa Sub;Hong, Seong Su
    • Journal of Applied Biological Chemistry
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    • v.60 no.1
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    • pp.49-54
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    • 2017
  • In the course of screening tyrosinase inhibitory activity, EtOAc-soluble fraction of Coix lachryma-jobi var. mayuen Stapf. (Gramineae) roots showed significant inhibition. Further fractionation of the EtOAc-soluble fraction resulted in six compounds, which were identified as (+)-icariol $A_2$ (1), zhepiresionol (2), 4-hydroxybenzaldehyde (3), trans-${\rho}$-coumaric acid (4), N-(2-hydroxy-4-methoxyphenyl)-2-hydroxyacetamide (5), and coixol (6). The chemical structures of these compounds were identified on the basis of spectroscopic methods (MS, 1D and 2D NMR) and comparison with literature values. Compound 1 was first reported from this plant. Also, this is the first time that the isolation of compound 5 has been reported from nature source. Among the isolated compounds, compounds 4 and 6 showed enzyme inhibitory activity, with $IC_{50}$ values of 6.5 and $62.4{\mu}M$, respectively, in comparison with these of positive control, arbutin.

In vitro Studies on the Superoxide Scavenging Activities, the Cytotoxic and the Immunomodulating Effects of Thirteen Kinds of Herbal Extracts (13종 허브추출물의 수퍼옥사이드 소거능과 세포독성 및 면역증강 효과의 in vitro계 검색)

  • Chung, Ha-Yull;Kim, Hyun-Bae
    • Korean Journal of Food Science and Technology
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    • v.32 no.3
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    • pp.699-705
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    • 2000
  • The superoxide scavenging activities of thirteen kinds of herbal extracts were examined together with their cytotoxic and immunomodulating effects. The extracts of 6 kinds of herbs such as eucalyptus, mate, peppermint, sage, thyme and yarrow, so called medicinal herbs, showed above 70% of the superoxide scavenging activities. They also showed cytotoxicities against the cancer cell lines of Hepa-1c1c7 and KB-3-1 as well as the normal fibroblast cell line of mouse. The $IC_{50}$ values of above 6 herb extracts on the cancer cell lines were above or similar to the $IC_{50}$ values on the normal cell line, so it was unable to observe the herb extract which showed cytotoxicity only to the cancer cell lines. Considering the results of nitric oxide test that the sage extract was the only one having the immunomodulating effect(37% of positive control), there was no significant relationship between the superoxide scavenging activities of herbs and their immunomodulating effects.

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