• Food Science and Preservation
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• v.20 no.3
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• pp.342-347
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• 2013

In recent years, polyphenol-rich herbs, fruits and processed foods, which are made of plant origin, have attracted much attention due to their potential health benefits. Pomegranate (Punica granatum L.) is an important source of bioactive compounds and has been used to treat diseases because of its medicinal properties. This research was focused on characterizing Korea's national cultivar and a similar product from California, USA. To evaluate their bioactive compounds and pharmacological activities, their anti-oxidation and cancer inhibition properties, as well as their organic acid and free sugar contents, were investigated. The national cultivar had low total sugar and high organic acid contents, contrary to the imported product. The results showed that the peel of national cultivar had high polyphenol and ellagic acid contents compared to imported product. The free radical scavenging capacity was evaluated via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and its positive correlation with the total polyphenol contents was found. The anti-cancer activity of methanol extracts revealed growth inhibition against the prostate cancer cell. These results signify that while pomegranate, national cultivar, is more sour than the imported product, its health benefits could be excellent. Also, the polyphenol compound content of the non-edible part (such as the peel and the seed) was higher than that of the juice. Thus, it is suggested that the byproduct of the juice extraction could be potentially used in other fields such as medicine or dietary agents.

• The Korean Journal of Mycology
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• v.42 no.3
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• pp.219-224
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• 2014

A gram-negative bacterium was isolated from spent substrate of Agaricus bisporus and showed marked antagonistic activity against Pseudomonas tolaasii. The bacterium was identified as Pseudomonas azotoformans by based on the cultural, biochemical and physiological characteristics, and 16S rRNA gene sequence. The isolated bacterium was saprophytic but not parasitic nor pathogenic to cultivation mushroom. The isolated bacterium for P. tolaasii cell was not sufficient for inhibition in vitro. Control efficacy of Pseudomonas azotoformans HC5 to brown blotch of P. tolaasii was 73, 78, and 71% on A. bisporus, Flammulina velutipes, and Pleurotus ostreatus, respectively. In the future, the suppressive bacterium may be useful for development of a biocontrol system.

• Animal cells and systems
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• v.12 no.4
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• pp.313-319
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• 2008

The ultrastructure of oocytes during oogenesis and oocyte degeneration associated with follicle cells in female Sinonovacula constricta(Lamarck, 1818) were investigated by electron microscope observations. Ovarian follicles are surrounded by a matrix of vesicular connective tissue cells(VCT cells). VCT cells contain large quantities of glycogen particles and several lipid droplets in their cytoplasm. It is suggested that VCT cells act as a source of nutrients for vitellogenesis during oogenesis. In early vitellogenic oocytes, several coated vesicles, which appear at the basal region of the oocyte, lead to the formation of membrane-bound vesicles via endocytosis. The uptake of nutritive materials in coated vesicles formed by endocytosis appears through the formation of coated pits on the oolemma during vitellogenesis. During the late stage of oogenesis, yolk precursors(yolk granules), mitochondria and lipid droplets are present in the cytoplasm of late vitellogenic oocytes. In particular, proteinaceous yolk granules containing several different components are intermingles and form immature yolk granules. In the mature oocyte, small immature yolk granules are intermingled and form large mature yolk granules. Vitellogenesis occurs through a process of autosynthesis, involving combined activity of the Golgi complex, mitochondria and rough endoplasmic reticulum in the cytoplasm of vitellogenic oocytes. The process of heterosynthesis is where extraovarian precursors are incorporated into oocytes by endocytosis at the basal region of early vitellogenic oocytes before the formation of the vitelline coat. Follicle cells appear to play an important role in vitellogenesis and oocyte degeneration. The functions of attached follicle cells to the oocyte during oocyte degeneration are phagocytosis and digestion of phagosomes originating from oocyte degeneration. After digestion of phagosomes, it is assumed that the function of follicle cells can permit a transfer of yolk precursors necessary for vitellogenesis and allows for the accumulation of glycogen and lipid during oocyte degeneration, which can be employed by vitellogenic oocytes. Follicle cells of S. constricta may possess a lysosomal system for induction of oocyte breakdown and might resorb phagosomes in the cytoplasm for nutrient accumulation during oocyte degeneration.

• Weed & Turfgrass Science
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• v.4 no.4
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• pp.308-314
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• 2015

This study was conducted to establish a fluorescence assay system for high efficient mass screening of the herbicides causing rapid membrane peroxidation, based on the fact that peroxide in cellular leakage could be fluorometrically determined through the fuorescent compounds formed after reacting with homovanillic acid (HVA) and peroxidase (HRP). The assay procesure established in this study was as follows. Only single disc (4 mm diameter) excised from cucumber cotyledon is placed on the well containing test solution ($200{\mu}L$) with 96-well microplate. The plate is shaking-incubated for 8 h under light condition. Then after removing the cucumber disc, HVA and HRP are supplied in the medium buffer and incubated for 5 min at room temperature. Fluorescence values are determined at Ex 320 nm/Ex 425 nm. The higher fluorescence values are obtained in the treatment of chemical having higher herbicidal activity. Using this assay with 96-well microplates, a large number of herbicides inducing rapid membrane peroxidation seemed to be screened more efficiently than spectrophotometric microtiter assay reported previously.

• Journal of Life Science
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• v.18 no.1
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• pp.52-57
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• 2008

Xylan is a major hemicellulose component of the cell walls of monocots and hardwood, representing up to 30% of the dry weight of these plants. To efficiently hydrolyze xylan, the endoxylanase gene from Bacillus sp. was expressed in B. subtilis DB431 by introducing the plasmid pJHKJ4. The total activity of the recombinant endoxylanase reached about 857 unit/ml by batch fermentation of B. subtilis DB431/pJHKJ4 in LB maltose medium. The majority (>92%) of endoxylanase was efficiently secreted into the culture medium. The recombinant endoxylanase hydrolyzed more the birchwood xylan efficiently than the other xylans. When 4 % concentration of xylan was used, the highest production of xylooligosaccharide was observed, and xylobiose and xylotriose were the major products. Optimal amount of enzyme and reaction time for producing xylooligosaccharide were found to be 10 unit and 1 hr, respectively. In addition, the temperature of $40^{\circ}C{\sim}50^{\circ}C$ gave the highest production of xylooligosaccharide. Consequently, the optimized conditions for the production of xylooligosaccharide through the hydrolysis of xylan were determined as follows: 10 unit endoxylanase, $50^{\circ}C$, 4% birchwood xylan, 1 hr reaction.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.905-909
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• 2007

The dual-function protein redox factor-1 (Ref-1) is essential for base excision repair of oxidatively damaged DNA and also governs the activation of many redox-sensitive transcription factors. We examined the role of Ref-1 in regulation of nitric oxide (NO) synthesis employing adenoviral-mediatedoverexpression of Ref-1 in bradykinin-stimulated endothelial cells. Intracellular NO was detected with the NO-sensitive fluorophore DAF-2. Overexpression of Ref-1 potentiates bradykinin-stimulated NO production in endothelial cells. And, cells ifected with AdRef-1 showed higher fluorescence intensity compared with uninfected or AdD1312-infected cells. In parallel with this, over expression of Ref-1 also stimulated endothelial NO synthase (eNOS) enzyme activity, compared with unifected or AdD1312-infected cells, in bradykinin-stimulated cells as well as in unstimulated cells. These results suggest that Ref-1 implicates in endothelium-dependent vasorelaxation resulting from NO production in vascular system.

• Journal of Life Science
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• v.19 no.11
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• pp.1672-1678
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• 2009

The purified antifungal substances produced by Bacillus amyloliquefaciens IUB158-03 was positive to ninhydrin but negative to aniline, suggesting that the antifungal substance could be a peptide. FAB-MS, UV adsorption spectrum, and amino acid composition analysis revealed that the molecular weight of the antifungal substance was 1042 and that maximal adsorption was at 220 nm and 277 nm. The antifungal substance was composed of $Asn_3$, $Gln_2$, $Ser_1$, $Gly_1$, and $Tyr_1$. The composition and structural characteristics of antifungal substance were analysed by $^1H$-NMR spectrum, $^1H$-COSY, HMQC, which revealed that the compound belongs to the iturin A family. Temperature and pH had little effect on the stability of the antifungal substance in the ranges of $-70{\sim}121^{\circ}C$ and pH 6.0~10.0, respectively. It showed strong antibiotic activity against fungi. An in vitro cytotoxicity test using NIH3T3 cell showed that the antifungal substance does not have cytotoxicity. The number of circulating leukocytes and the hematobiological analysis of the mice administered with the antifungal substances was similar to those of the control group, indicating no cytotoxicity in vivo. Therefore, the antifungal substances extracted from culture broth of Bacillus amyloliquefaciens IUB158-03 have future potential as biocontrol agents against plant diseases caused by fungi.

• Journal of Life Science
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• v.19 no.8
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• pp.1119-1124
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• 2009

Hyperlipidemia has been reported to be associated with the development of fatty liver. Palmitic acid, a major saturated fatty acid, is involved in the development of diverse diseases. The activation of mitogen activated protein kinases (MAPKs), such as Jun N-terminal kinase (INKs) and p38 MAPK is implicated in the apoptosis in diverse cells. Thus, this study was conducted to investigate the effects of palmitic acid on apoptosis and its relationship between JNK and p38 MAPK in cultured rat hepatocytes. In the present study, palmitic acid (>50 uM) decreased cell proliferation and increased lactate dehydrogenase activity in hepatocytes, which was blocked by the treatment of SP600125 (a JNK inhibitor) and SB203580 (a p38 MAPK inhibitor). Indeed, palmitic acid decreased Bcl-2 expression but increased Bax expression in rat hepatocytes, which was blocked by the treatment of SP600125 and SB203580. In addition, palmitic acid decreased glutathione (GSH) content and increased lipid peroxide formation, which was blocked by the treatment of SP600125 and SB203580. Western immunoblotting analysis also revealed that palmitic acid increased JNK and p38 MAPK. In conclusion, palmitic acid induced apoptosis through oxidative stress via JNK and p38 MAPK activation in rat hepatocytes.

• Journal of Life Science
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• v.19 no.8
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• pp.1159-1163
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• 2009

It has been postulated that endoplasmic (ER) stress is involved in the development of several diseases. However, the detailed molecular mechanisms have not been fully understood. Therefore, we characterized a genetic network of genes induced by ER stress using cDNA microarray and gene set expression coherence analysis (GSECA), and identified gene function as well as several transcription regulators associated with ER stress. We analyzed time-dependent gene expression profiles in thapsigargin-treated Sk-Hep1 using an oligonucleotide expression chip, and then selected functional gene sets with significantly high expression coherence which was processed into functional clusters according to the expression similarities. The functions related to sugar binding, lysosome, ribosomal protein, ER lumen, and ER to golgi transport increased, whereas the functions with mRNA processing, DNA replication, DNA repair, cell cycle, electron transport chain and helicase activity decreased. Furthermore, functional clusters were investigated for the enrichment of regulatory motifs using GSECA, and several transcriptional regulators associated with regulation of ER-induced gene expression were found.

• Journal of Life Science
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• v.20 no.3
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• pp.326-335
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• 2010

The concentration of phenolics in Phellinus pini (CY001) extracts, expressed as mg of GAEs per g of P. pini fractions, and the EtOAc fraction (436.5 mg GAEs/g) of P. pini had a higher phenolic content than other fractions. Several biochemical assays were used to screen antioxidant properties such as reducing power, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, NBT/XO superoxide system and inhibition of DCF/AAPH peroxyl radicals. Among the six mushroom extracts, the EtOAc fraction from P. pini (CY001) showed the most potent DPPH radical, superoxide radical, and peroxyl radical scavenging activities, with $IC_{50}$ values of $11.49\;{\mu}g/ml$, $8.32\;{\mu}g/ml$, and $1.91\;{\mu}g/ml$, respectively. The EtOAc fraction of P. pini (CY001) significantly inhibited enzymatic lipid peroxidation and effectively attenuated LPS-induced NO production of RAW 264.7 cells without cytotoxicity. We also found that the EtOAc fraction had a significant hepato-protectant effect on tacrine-induced cytotoxicity in HepG2 cells. These findings suggest that P. pini (CY001) may have potential as a natural antioxidant, which contains compound(s) with radical scavenging activity.