• 한국수산과학회지
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• 제51권4호
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• pp.369-375
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• 2018

This study investigated the effects of selected seaweeds on rice koji preparation (rice inoculated with Aspergillus luchuensis) and enzyme activity. Four types of rice koji were prepared using one of three seaweeds (0.5% laver, 0.5% kelp and 0.5% green laver) or a control for 72 h. The changes in the moisture content, water activity, pH, total mold cell count, amylase and protease activities were measured. During preparation, there was no significant difference in the moisture content among the four kojis, whereas the pH in the kojis made with either laver or green laver decreased rapidly compared with the control (P<0.05). This seemed to result from the seaweeds promoting the growth of mold cells. In terms of the activities of both amylase and protease, the koji with laver was superior. Subsequently, the amylase and protease activities of the koji made with laver were evaluated at various pHs (3 to 9), temperatures ($15-55^{\circ}C$) and NaCl concentrations (0-10%). The activities of both enzymes decreased notably at pH 9 and the protease activity decreased at temperatures above $45^{\circ}C$. Although the activities of both enzymes decreased at greater than 2.5% NaCl, activity was present at 10% NaCl.

• Asian-Australasian Journal of Animal Sciences
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• 제27권2호
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• pp.290-301
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• 2014

The first purpose of this review is to outline some of the background information necessary to understand the mechanisms of action of fibre-degrading enzymes in non-ruminants. Secondly, the well-known and understood mechanisms are described, i) eliminating the nutrient encapsulating effect of the cell wall and ii) ameliorating viscosity problems associated with certain Non Starch Polysaccharides, particularly arabinoxylans and ${\beta}$-glucans. A third, indirect mechanism is then discussed: the activity of such enzymes in producing prebiotic oligosaccharides and promoting beneficial cecal fermentation. The literature contains a wealth of information on various non starch polysaccharide degrading enzyme (NSPase) preparations and this review aims to conclude by discussing this body of work, with reference to the above mechanisms. It is suggested that the way in which multi- versus single-component products are compared is often flawed and that some continuity should be employed in methods and terminology.

• BMB Reports
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• 제42권3호
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• pp.131-135
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• 2009

MicroRNAs control gene expression by inhibiting translation or promoting degradation of their target mRNAs. Since the discovery of the first microRNAs, lin-4 and let-7, in C. elegans, hundreds of microRNAs have been identified as key regulators of cell fate determination, lifespan, and cancer in species ranging from plants to humans. However, while microRNAs have been shown to be particularly abundant in the brain, their role in the development and activity of the nervous system is still largely unknown. In this review, we describe recent advances in our understanding of microRNA function at synapses, the specialized structures required for communication between neurons and their targets. We also propose how these advances might inform the molecular model of memory.

• Molecules and Cells
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• 제24권3호
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• pp.445-451
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• 2007

Translation initiation factor 4E (eIF4E) is a key regulator of protein synthesis. Abnormal regulation of eIF4E is closely linked to oncogenic transformation. Several regulatory mechanisms affecting eIF4E are discussed, including transcriptional regulation, phosphorylation and binding of an inhibitor protein. However it is not clear how the level of eIF4E protein is regulated under basal conditions. Here we demonstrate that Diap1 (Drosophila Inhibitor of Apoptosis Protein), a cell death inhibitor, binds directly to eIF4E and poly-ubiquitinates it via its E3 ligase activity, promoting its proteasome-dependent degradation. Expression of Diap1 caused a reduction of Cyclin D1 protein level and inhibited the growth stimulation induced by overexpression of eIF4E. Taken together, our results suggest that the level of eIF4E protein is regulated by Diap1, and that IAPs may play a role in cap-dependent translation by regulating the level of eIF4E protein.

• 한국환경성돌연변이발암원학회지
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• 제22권4호
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• pp.312-318
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• 2002

Dioxin represents a group of halogenated aromatic hydrocarbons of which 2,3,7,8-tetrachlorod-ibenzo-p-dioxin (TCDD) is well known for its extremely toxic properties as well as ubiquitous presence in our environment and ecosystems. In order to better assess the carcinogenic mechanism of dioxin, we should utilize the reliable biomarkers that can precisely and correctly reflect multi-stage carcinogenesis. When MCF10A cells were exposed to TCDD (10 nM), expression of both CYP1A1 and CYP1B1 was induced in a time-related manner. The expression as well as activity of ornithine decarboxylase was transiently induced by TCDD treatment. In contrast, the induction of COX-2 that is implicated in carcinogenesis as well as inflammation, was not induced by TCDD. In another study, gap-junctional intercellular communication (GJIC) was attenuated by TCDD treatment as revealed by the dye-transfer assay. Based on these findings, TCDD has both tumor initiating and promoting potential in human breast epithelial cells in culture. Also, treatment of MCF10A cells with the carcinogen 7,12-dimethylbenz[a]anthracene plus TCDD resulted in malignant cell transformation as revealed by increased anchorage-independent growth of exposed cells. Additional studies may be necessary to assess the effects of TCDD on multi-stage carcinogenesis in vivo.

• 혜화의학회지
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• 제10권2호
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• pp.1-10
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• 2002

In review of "invigorating spleen and supplementing qi" of clinical and experimental studies on malignant tumor, we obtained the conclusions as follows 1. Asthenic splenic qi is an important factor in mutation, occurrence and development of tumor. 2. The anti-tumor mechanism of "invigorating spleen and supplementing qi" is improvement of immune suveillance, controling cell proliferating period and enhancing body metabolism. 3. "Invigorating spleen and supplementing qi" is often used with "nourishing kidney" or "expelling pathogen" for treating cnacer. 4. In experimental studies, "invigorating spleen and supplementing qi" has effects on inhibiting occurrence and development of tumor, protecting mutation, inhibiting recurrence and metastasis, immune activity, enhancing metabolism, promoting bone marrow hemopoietic cell proliferation, increasing anti-tumor effect and protecting normal cells. 5. In clinical studies, "invigorating spleen and supplementing qi" has effects on prolonging the survival period of cancer patients, improving clinical symptoms and quality of life of cancer patients, degrading the side effects of western therapie(operation, chemotherapy and radiotherapy). 6. "Invigorating spleen and supplementing qi" is an extensive discipline of syndrome differentiation used to inhibit occurence, development, recurrence and metastasis.

• Journal of Microbiology and Biotechnology
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• 제32권8호
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• pp.982-988
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• 2022

Licorice (Glycyrrhiza) has been used as preventive and therapeutic material for hyperpigmentation disorders. Previously, we isolated noble compounds including dehydroglyasperin C (DGC), dehydroglyasperin D (DGD) and isoangustone A (IAA) from licorice hexane/ethanol extracts. However, their anti-melanogenic effects and underlying molecular mechanisms are unknown. The present study compared effects of DGC, DGD and IAA on pigmentation in melan-a melanocytes and human epidermal melanocytes (HEMn). DGD exerted the most excellent anti-melanogenic effect, followed by DGC and IAA at non-cytotoxic concentrations. In addition, DGD significantly inhibited tyrosinase activity in vitro cell-free system and cell system. Western blot result showed that DGD decreased expression of microphthalmia-associated transcription factor (MITF), tyrosinase and tyrosinase-related protein-1 (TRP-1) in melan-a cells and HEMn cells. DGD induced phosphorylation of MITF, ERK and Akt signal pathway promoting MITF degradation system. However, DGD did not influence p38 and cAMP-dependent protein kinase (PKA)/CREB signal pathway in melan-a cells. These result indicated that DGD inhibited melanogenesis not only direct regulation of tyrosinase but also modulating intracellular signaling related with MITF level. Collectively, these results suggested a protective role for DGD against melanogenesis.

• 한국식품영양학회지
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• 제35권3호
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• pp.204-212
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• 2022

The purpose of this study was to investigate the biological activity of fucoidan, a sulfur-containing polysaccharide, on cytotoxicity and apoptosis in the human HT-29 colorectal cancer cell line using cell viability, Flow cytometry, Western blot, and RT-PCR analyses. Fucoidan inhibited the proliferation of HT-29 cells by 39.6% at a concentration of 100 ㎍/mL for 72 h. The inhibition was dose-dependent and accompanied by apoptosis. Flow cytometric analysis showed that fucoidan increased early apoptosis and late apoptosis by 65.84% and 72.09% at concentrations of 25 and 100 ㎍/mL, respectively. Analysis of the mechanism of these events indicated that fucoidan-treated cells exhibited increases in the activation of caspase-3, caspase-8, and PARP in a dose-dependent manner. These results suggest that fucoidan may inhibit the growth of human colorectal cancer cells by various apoptosis-promoting effects, as well as by apoptosis itself.

• The Korean Journal of Physiology and Pharmacology
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• 제27권6호
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• pp.533-540
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• 2023

Sweroside is a natural monoterpene derived from Swertia pseudochinensis Hara. Recently, studies have shown that sweroside exhibits a variety of biological activities, such as anti-inflammatory, antioxidant, and hypoglycemic effects. However, its role and mechanisms in high glucose (HG)-induced renal injury remain unclear. Herein, we established a renal injury model in vitro by inducing human renal tubular epithelial cell (HK-2 cells) injury by HG. Then, the effects of sweroside on HK-2 cell activity, inflammation, reactive oxygen species (ROS) production, and epithelial mesenchymal transition (EMT) were observed. As a result, sweroside treatment ameliorated the viability, inhibited the secretion of inflammatory cytokines (TNF-α, IL-1β, and VCAM-1), reduced the generation of ROS, and inhibited EMT in HK-2 cells. Moreover, the protein expression of SIRT1 was increased and the acetylation of p65 NF-kB was decreased in HK-2 cells with sweroside treatment. More importantly, EX527, an inhibitor of SIRT1, that inactivated SIRT1, abolished the improvement effects of sweroside on HK-2 cells. Our findings suggested that sweroside may mitigate HG-caused injury in HK-2 cells by promoting SIRT1-mediated deacetylation of p65 NF-kB.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1235-1239
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• 2008

To study the health promoting effects of medicinal plants, 30 medicinal plants commonly available in Korea have been evaluated for their antioxidant compounds and antioxidant and antiproliferative activities. Total polyphenolics and flavonoids in the methanolic extracts were measured by spectrophotometric methods and 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activities and chelating effects have been determined for antioxidant activities. Moreover, the effects of medicinal plants on cell proliferation of intestinal (Caco-2) and pituitary (GH3) tumor cells were investigated using thiazolyl blue terazolium bromide (MIT) assay. The methanolic extracts of Pueraria thunbergiana and Artemisiae asiatria contained the highest total polyphenolic and flavonoid contents, respectively. P. thunbergiana exhibited the highest antioxidant activities. A. asiatria showed the strongest antiproliferative activity against Caco-2 and Ponciruc trifoliata Rafin and Lophathrum gracile Bronghiart exhibited the highest activities against GH3. Although there was positive correlation between ABTS radical scavenging activity and polyphenolic contents ($R^2=8189$), no relationship was found between antiproliferative and antioxidant activities.