• Biomolecules & Therapeutics
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• v.18 no.2
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• pp.152-158
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• 2010

Melanin concentrating hormone is a neuropeptide highly expressed in the brain that regulates several physiological functions mediated by receptors in the G-protein coupled receptor family, especially plays an important role in the complex regulation of energy balance and body weight mediated by the melanin concentrating hormone receptor subtype 1 (MCH1). Compelling pharmacological evidence implicating MCH1 signaling in the regulation of food intake and energy expenditure has generated a great deal of interest by pharmaceutical companies as MCH1 antagonists may have potential therapeutic benefit in the treatment of obesity and metabolic syndrome. Although fluorescence-based calcium mobilization assay platform has been one of the most widely accepted tools for receptor research and drug discovery, fluorescence interference and shallow assay window limit their application in high throughput screening and have led to a growing interest in alternative, luminescence-based technologies. Herein, a luminescence-based functional assay system for the MCH1 receptor was developed and validated with the mitochondrial targeted aequorin. Aequorin based functional assay system for MCH1 presented excellent Z' factor (0.8983) and high signal-to-noise ratio (141.9). The nonpeptide MCH1 receptor antagonist, SNAP 7941 and GSK 803430, exhibited $IC_{50}$ values of 0.62 ${\pm}$ 0.11 and 12.29 ${\pm}$ 2.31 nM with excellent correlation coefficient. These results suggest that the aequorin based assay system for MCH1 is a strong alternative to the traditional GPCR related tools such as radioligand binding experiments and fluorescence functional determinations for the compound screening and receptor research.

• Animal cells and systems
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• v.13 no.2
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• pp.97-103
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• 2009

Recently, great advance is achieved in the field of genome-wide functional screening using cell-based assay. Here, we briefly introduce well-established and typical cell-based assays of GPCR and some parameters which should be considered for genome-wide functional screening. Because of characters and importance of GPCR as drug targets, several ways of assay systems were devised. Among them, high-content screening (HCS) that is based on the analysis of image by confocal microscope is becoming favorite choice. The advances in this technology have been driven exclusively by industry for their convenience. Now, it is turn for academy to define more detail signaling networks via HCS using cDNA or siRNA libraries at genome-wide level. By isolating novel signaling mediators using cDNA or siRNA library, and postulating them as new candidates for therapeutic target, more understanding about life science and more increased chances to develop therapeutics against human disease will be achieved.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.747-754
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• 2000

DNA damages in post-mortem bovine muscle samples caused by gamma irradiation at doses of 1 to 10 kGy were determined by Comet assay. When the cell extract was prepared in a physical method and followed by neutral lysis and neutral electrophoresis, the optimal comet images could be obtained. DNA damages were evaluated from the mean tail length, the distributions of comet images in 4 groups divided by tail length and the relative damage index (RDI) values calculated from the distribution pattern. The mean tail length and RDI value were increased by increasing the irradiation dose, and the RDI value was found to be useful as an index for discriminating of irradiation and measuring the irradiated dose. Blind tests using Korean domestic (Hanwoo) and imported beef samples showed a higher RDI value for the latter. However, the value was lower than those of irradiated samples indicating that the cause of DNA damages in the imported beef samples might be not irradiation but low-temperature treatments. It was concluded from the results of this study that the irradiated beef and its irradiated dose could be detected and predicted by Comet assay.

• The Plant Pathology Journal
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• v.35 no.4
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• pp.372-380
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• 2019

Pseudomonas syringae pv. actinidiae (Psa) is by far the most important pathogen of kiwifruit. Sustainable expansion of the kiwifruit industry requires the use of Psa-tolerant or resistant genotypes for the breeding of tolerant cultivars. However, the resistance of most existing kiwifruit cultivars and wild genotypes is poorly understood, and suitable evaluation methods of Psa resistance in Actinidia have not been established. A unique in vitro method to evaluate Psa resistance has been developed with 18 selected Actinidia genotypes. The assay involved debarking and measuring the lesions of cane pieces inoculated with the bacterium in combination with the observation of symptoms such as callus formation, sprouting of buds, and the extent to which Psa invaded xylem. Relative Psa resistance or tolerance was divided into four categories. The division results were consistent with field observations. This is the first report of an in vitro assay capable of large-scale screening of Psa-resistance in Actinidia germplasm with high accuracy and reproducibility. The assay would considerably facilitate the breeding of Psa-resistant cultivars and provide a valuable reference and inspiration for the resistance evaluation of other plants to different pathogens.

• Korean Journal of Plant Resources
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• v.22 no.4
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• pp.323-329
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• 2009

In order to find out superior corn line which has a strong antioxidant activity in the corn silk, antioxidant compounds and antioxidant activity were measured from various inbred and F1 lines. As a result, the contents of phenolic and flavonoid compounds range from 532 mg/100 g to 3,274 mg/100 g and from 980 mg/100 g to 2,420 mg/100 g respectively. Absorbance at 517 nm for contents of anthocyanins ranges from 0.05 to 0.76. Correlation coefficients between antioxidant compounds and various antioxidant assays such as DPPH, ABTS and FRAP were analyzed. Correlation coefficients between antioxidant activity and phenolic compounds and anthocyanin were significantly high in ABTS and FRAP assays. Considering acidic extraction condition and intervention between anthocyanins and DPPH solution, ABTS assay and FRAP assay are more suitable methods to evaluate antioxidant activity of corn silks. Especially, ABTS assay is thought to be the best method among three assays because the antioxidant activity in ABTS assay showed high correlation with phenol, flavonoid and anthocyanin compounds respectively. Among the samples, S15 which showed the highest contents of total phenolic compounds and the most potent antioxidant activity in ABTS and FRAP assay will be a good source for functional material.

• Journal of Korean Medical Science
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• v.33 no.51
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• pp.340.1-340.14
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• 2018

Background: Various pneumococcal vaccines have been evaluated for immunogenicity by opsonophagocytic assay (OPA). A multiplexed OPA (MOPA) for 13 pneumococcal serotypes was developed by Nahm and Burton, and expanded to 26 serotypes in 2012. The development of new conjugate vaccines with increased valence has necessitated expanded MOPAs to include these additional serotypes. In this study, we validated this expanded MOPA platform and applied to measure antibodies against 11 additional serotypes (2, 8, 9N, 10A, 11A, 12F, 15B, 17F, 20B, 22F, and 33F) in human sera. Methods: All materials, including serum, complement, bacterial master stocks, and HL-60 cells, were evaluated for assay optimization. Following optimization, the assay was validated for accuracy, specificity, and intra- and inter-assay precision with sera from adult donors following standard protocols. The assay was applied to evaluate functional antibodies of 42 sera immunized with 23-valent pneumococcal polysaccharide vaccine (PPV23). Results: The expanded MOPA platform was specific for all serotypes, with the exception of serotype 20. The assay results were highly correlated with those obtained from single-serotype OPA, indicating acceptable accuracy. The coefficients of variation were 7%-24% and 13%-39% in tests of intra- and inter-assay precision, respectively, using three quality-control samples. A MOPA that included 11 additional serotypes in the PPV23 was established and validated with respect to accuracy, specificity, and precision. The opsonic indices of immune sera were obtained using this validated assay. Conclusion: The expanded MOPA will be useful for evaluation of the immunogenicity of PPV23 and future conjugate vaccine formulations.

• Preventive Nutrition and Food Science
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• v.8 no.1
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• pp.54-60
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• 2003

To develop a functional chungkookjang; the anticancer effects of chungkookjangs prepared with different varieties of soybeans, starters, fermentation periods and seasoning additive ratios; were studied against AGS human gastric adenocarcinoma cells using the MTT assay, at different stages chungkookjang processing. The chungkookjang samples exerted different antiproliferative effects according to the variety of soybeans used. The chungkookjangs manufactured with soybean var. manrikong exhibited the highest cytotoxicity against AGS human cancer cells. The chungkookjangs fermented with rice straw and B. licheniformis strongly inhibited the growth of the AGS human cancer cells. All fermented chungkookjangs had a strong inhibitory effect on the growth of the cancer cells; however, the non-fermented soybean (chungkookjang) showed a low inhibition rate. The fermented chungkookjangs mixed with red pepper powder (RPP) and garlic exhibited strong antiproliferative effect against the cancer cells, and chungkookjang prepaved with 1.1 % RPP and 1.1 % garlic showed the highest cytotoxicity against the cancer cells. The functional chungkookjang fermented with soybean variety of manrikong and B. licheniformis for 3 days at 4$0^{\circ}C$ and then mixed with 7.9% salt, 1.l% RPP and 1.1% garlic, exhibited a higher antiproliferative effect than the chungkookjangs prepared by traditional or modified methods, according to the MTT assay. The functional chungkookjang exhibited a similar anticancer effect to the traditional doenjang. These results indicate that the fermentation period and the ratio of seasoning additives, as well as the variety of soybeans and starter cultures may affect the degree of the anticancer effect of chungkookjang.

• Journal of Ginseng Research
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• v.41 no.2
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• pp.169-179
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• 2017

Background: Ginsenosides are the main pharmacological components of Panax ginseng root, which are thought to be primarily responsible for the suppressing effect on oxidative stress. Methods: 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and oxygen radical absorption capacity were applied to evaluate the antioxidant activities of the ginsenosides. Human embryonic kidney 293 (HEK-293) cells were incubated with ginsenosides extracted by pulsed electric field (PEF) and solvent cold soak extraction (SCSE) for 24 h and then the injury was induced by $40{\mu}M$ $H_2O_2$. The cell viability and surface morphology of HEK-293 cells were studied using MTS assay and scanning electron microscopy, respectively. Dichloro-dihydro-fluorescein diacetate fluorescent probe assay was used to measure the level of intracellular reactive oxygen species. The intracellular antioxidant activities of ginsenosides were evaluated by cellular antioxidant activity assay in HepG2 cells. Results: The PEF extracts displayed the higher 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and stronger oxygen radical absorption capacity (with an oxygen radical absorption capacity value of $14.48{\pm}4.04{\mu}M\;TE\;per\;{\mu}g/mL$). The HEK-293 cell model also suggested that the protective effect of PEF extracts was dose-dependently greater than SCSE extracts. Dichloro-dihydro-fluorescein diacetate assay further proved that PEF extracts are more active (8% higher than SCSE extracts) in reducing intracellular reactive oxygen species accumulation. In addition, scanning electron microscopy images showed that the HEK-293 cells, which were treated with PEF extracts, maintained more intact surface morphology. Cellular antioxidant activity values indicated that ginsenosides extracted by PEF had stronger cellular antioxidant activity than SCSE ginsenosides extracts. Conclusion: The present study demonstrated the antioxidative effect of ginsenosides extracted by PEF in vitro. Furthermore, rather than SCSE, PEF may be more useful as an alternative extraction technique for the extraction of ginsenosides with enhanced antioxidant activity.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1071-1076
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• 1999

This study was carried out to isolate the colonies of dominant fermented bacteria from Kimchi (Korean native fermented foodstuffs) and investigate their inhibitory potentials on mutagenesis and carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) as direct carcinogen. For this purpose, single cell gel electrophoresis technique (SCGE assay, or comet assay) which is a sensitive and rapid technique for detecting the presence of DNA strand breaks in individual cells was used. DNA damages of Kimchi isolates were compared with that of the positive control, MNNG. Among 3 isolates from Tongbaechu Kimchi, two isolates B-1 and B-2 showed antigenotoxicities (p<0.01). All 4 isolates from Yulmu Kimchi had antigenotoxicities (p<0.05). Also, 3 of 5 isolates from Chonggak Kimchi and 2 of 9 isolates from Kaktugi were antigenotoxic (p<0.05 and p<0.01, respectively).

• Korean Journal of Plant Resources
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• v.29 no.5
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• pp.588-597
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• 2016

Little attention has been paid to the functional aspect of the flower petal of Paeonia lactiflora, compared to that of its root. To determine the components of flower petal of Paeonia lactiflora, we conducted the Fourier transform ion cyclotron resonance (FT-ICR) MASS spectrophotometric analysis. We detected the 24 different types of ingredients from the 70% ethanol extracts of flower petal of peonia lactiflora cv. ‘Red Charm’. The main compounds were quercetin glucopyranosides, methyl gallate, paonioflolol and kaemperol glucopyranosides. We further tested its functional activity. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the extracts was 87.9-90.4% at 0.1mg/ml. This result showed that these flower extracts have approximately 5-fold stronger antioxidant potential than a previous report with root extracts (Bang et al. 1999). The result of tyrosinase inhibition assay of Paeonia lactflora extract was almost similar to that of arbutin except significantly higher effect in the coral sunset extract at 0.1% concentration. Hyaluronidase inhibition assay showed 76.5% inhibition at 5% concentration of this flower extract, indicating that Peaonia lactiflora flower extracts have the major anti-inflammatory, anti-oxidant and brightening effects. Taken together, these results suggest these three Paeonia lactiflora species extracts might provide the basis to develop a new natural brightening agent.