• Molecules and Cells
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• v.26 no.1
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• pp.93-99
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• 2008

Transcriptional silencing is regulated by promoter methylation and histone modifications such as methylation and acetylation. We constructed a Schizosaccaromyces pombe reporter strain, KCT120a, to identify modifiers of transcriptional silencing, by inserting the $ura4^+$ gene into a heterochromatic telomere region. Two compounds inhibited the activity of histone deacetylases, induced acetylation of histone H3 and caused apoptotic cell death in HeLa cells. Expression of gelsolin and $p21^{waf1/cip1}$ also increased, as it does in response to HDAC inhibitors such as TSA. Therefore, these compounds appear to be potent inhibitors of HDACs, and hence potential anti-cancer drugs. Our observations suggest that a yeast cell-based assay system for transcriptional silencing may be useful for identifying histone deacetylase inhibitors and other agents affecting chromatin remodeling.

• Journal of Microbiology and Biotechnology
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• v.33 no.1
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• pp.61-74
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• 2023

The global increase in multidrug-resistant (MDR) bacteria has inspired researchers to develop new strategies to overcome this problem. In this study, 23 morphologically different, soil-isolated actinomycete cultures were screened for their antibacterial ability against MDR isolates of ESKAPE pathogens. Among them, isolate BOGE18 exhibited a broad antibacterial spectrum, so it was selected and identified based on cultural, morphological, physiological, and biochemical characteristics. Chemotaxonomic analysis was also performed together with nucleotide sequencing of the 16S rRNA gene, which showed this strain to have identity with Streptomyces lienomycini. The ethyl acetate extract of the cell-free filtrate (CFF) of strain BOGE18 was evaluated for its antibacterial spectrum, and the minimum inhibitory concentration (MIC) ranged from 62.5 to 250 ㎍/ml. The recorded results from the in vitro anti-biofilm microtiter assay and confocal laser scanning microscopy (CLSM) of sub-MIC concentrations revealed a significant reduction in biofilm formation in a concentration-dependent manner. The extract also displayed significant scavenging activity, reaching 91.61 ± 4.1% and 85.06 ± 3.14% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), respectively. A promising cytotoxic ability against breast (MCF-7) and hepatocellular (HePG2) cancer cell lines was obtained from the extract with IC₅₀ values of 47.15 ± 13.10 and 122.69 ± 9.12 ㎍/ml, respectively. Moreover, based on gas chromatography-mass spectrometry (GC-MS) analysis, nine known compounds were detected in the BOGE18 extract, suggesting their contribution to the multitude of biological activities recorded in this study. Overall, Streptomyces lienomycini BOGE18-derived extract is a good candidate for use in a natural combating strategy to prevent bacterial infection, especially by MDR pathogens.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.54-54
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• 2023

Nypa fruticans Wurmb (N. fruticans) is a plant that belongs to Araceae and N. fruticans is mainly found in tropical mangrove systems. The parts (leaves, stems, and roots) of N. fruticans are traditionally used for asthma, sore throat, and liver disease. N. fruticans contains flavonoids and polyphenols, which are substances that have inhibitory effects on cancer and oxidant. In previous studies, some pharmaceutical effects of N. fruticans on melanogenesis and inflammation have been reported. The present study is conducted to investigate the effect of the ethyl acetate fraction of N. fruticans (ENF) on oxidative DNA damage and UVB-induced DNA damage. DNA damage response (DDR) pathway is important in research on cancer, apoptosis, and so on. DDR pathways are considered a crucial factor affecting the alleviation of cellular damage. ENF could reduce oxidative DNA damage derived from reactive oxygen species by the Fenton reaction. Also, ENF reduced the intensity of intracellular ROS in the live cell image by DCFDA assay. UVB is known to cause skin and cellular damage, then finally contribute to causing the formation of tumors. As for the strategies of reducing DNA damage by UVB, inhibition of p53, H2AX, and Chk2 can be important indexes to protect the human body from DNA damage. As a result of confirming the protective effect of ENF for UVB damage, MMPs significantly decreased, and the expression of apoptosis-related factors tended to decrease. In conclusion, ENF can provide protective effects against double-stranded DNA break (DSB) caused by oxidative DNA damage and UVB-induced DNA damage. These results are considered to be closely related to the protective effect against radicals based on catechin, epicatechin, and isoquercitrin contained in ENF. Based on these results, it is thought that additional mechanism studies for inhibiting cell damage are needed.

• Clinical and Experimental Vaccine Research
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• v.12 no.1
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• pp.47-59
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• 2023

Purpose: The development and study of hepatitis C virus (HCV) vaccine candidates' individualized responses are of great importance. Here we report on an HCV DNA vaccine candidate based on selected envelope (E1/E2) epitopes. Besides, we assessed its expression and processing in human peripheral blood mononuclear cells (PBMCs) and in vivo cellular response in mice. Materials and Methods: HCV E1/E2 DNA construct (EC) was designed. The antigen expression of EC was assayed in PBMCs of five HCV-uninfected donors via a real-time quantitative polymerase chain reaction. Serum samples from 20 HCV antibody-positive patients were used to detect each individual PBMCs expressed antigens via enzyme-linked immunosorbent assay. Two groups, five Swiss albino mice each, were immunized with the EC or a control construct. The absolute count of lymph nodes' CD4⁺ and CD8⁺ T-lymphocytes was assessed. Results: Donors' PBMCs showed different levels of EC expression, ranging between 0.83-2.61-fold in four donors, while donor-3 showed 34.53-fold expression. The antigens expressed in PBMCs were significantly reactive to the 20 HCV antibody repertoire (all p=0.0001). All showed comparable reactivity except for donor-3 showing the lowest reactivity level. The absolute count % of the CD4⁺ T-cell significantly increased in four of the five EC-immunized mice compared to the control group (p=0.03). No significant difference in CD8⁺ T-cells % was observed (p=0.89). Conclusion: The inter-individual variation in antigen expression and processing dominance was evident, showing independence in individuals' antigen expression and reactivity levels to antibodies. The described vaccine candidate might result in a promising natural immune response with a possibility of CD4⁺ T-cell early priming.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.136-141
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• 2009

Biological activities of enzymatic hydrolysate of spirulina (EHS) were investigated. EHS showed no significant effects on the growth-stimulating activity for lactic-acid bacteria and antioxidant activity. EHS showed slight in vitro growth-inhibitory effects (15% at 1.42 mg/L) on a human cervical cancer cell line (HeLa). In addition, the anticoagulant activities of EHS were measured based on three different pathways: common, intrinsic and extrinsic pathways. As an indication of anticoagulant activity on common pathway, thrombin time (TT) of EHS (100 mg/L) was measured as 155.6 sec. Activated partial thromboplastin time (aPTT) for intrinsic pathway of EHS (1,000 mg/L) was measured as 95.8 sec. Prothrombin time (PT) based on extrinsic pathway of EHS (1,000 mg/L) was measured as 10.6 sec. These data showed that EHS have influences on anticoagulant factors of common pathway and intrinsic pathway. Consequently it was found that EHS could be used as a functional food for blood circulation.

• Korean Journal of Agricultural Science
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• v.21 no.2
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• pp.142-147
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• 1994

Characteristics of TNP-cellulose which prepared from carboxymethyl cellulose powder, CM32, as substrate for cellulase activity assay were investigated. Enzymatic hydrolysis of TNP-cellulose occured on the cellulose moiety but not on amide bonds, following Michaelis-Menten kinetics. Three cellulase preparations from Trichoderma viride, Aspergillus niger, and Cellulomonas sp. were tested for their pH and temperature dependences and compared with the method determining the increase in reducing power. The enzyme activity was found to have the same temperature range in both methods, however the pH range was broadened in the case of using TNP-cellulose as substrate. The colorimetric method for cellulase assay using TNP-cellulose as substrate was compared with the other methods: one based on determination of the increase in reducing power; and the other based on determining the decrease in viscosity of Na-CM-cellulose solution. The activities measured by the colorimetric method showed a linear correlation with the enzyme concentration of certain range in all three enzymes tested, and the activity values were proportional to those obtained from the other methods. Depending on the enzyme, however, the activity values from this method were not always in proportion to those from the viscometric method. suggesting that this method was not specific for determination of the endo-type cellulase.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.3
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• pp.169-175
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• 2016

Saccharin (o-benzoic sulfimide) is the first artificial and non-caloric sweetener that was first synthesized in 1879. In this study, we examined the biological activity of saccharin against various human cancer cell lines and human bone marrow-derived mesenchymal stem cells. A viability assay based on the conversion of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was performed to test for the cytotoxicity of saccharin about the four human cancer cell lines (H460, H157, A549 and SKOV3), one murine cancer cellline (Raw264.7), and MSCs. In order to find the differentially expressed gene in saccharin-treated MSCs against untreated MSCs, we performed annealing control primer (ACP)-based differential display reverse transcriptionp-olymerase chain reaction (DDRT-PCR). All tested cells were treated with saccharin at various concentrations (0.0, 4.8, 7.2, 9.6, 12.0, 14.4 mg/mL) for 48 hr. The number of metabolically active cancer cells decreased when treated with the saccharin at various concentrations for 48 hr as compared with the untreated cells. The decrease in cell survival was more evident with increasing concentrations of saccharin. Moreover, novel candidate genes, which were differentially expressed in MSCs in response to saccharin, were identified in 16 bands on 2% agarose gel. This revealed 16-7 up-regulated and 9 down-regulated-differentially expressed genes indicated by arrows. One of these candidate genes was a FK506-binding protein gene. The functional roles of FK506 binding proteins, with respect to the activities of stem cell proliferation, were not characterized. Further studies are required to get a better understanding of FK506-binding proteins in its roles in increasing stem cell proliferative activities from using saccharin.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3581-3586
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• 2014

Aim: To investigate the effects of tetramethypyrazine (TMP) on proliferation and apoptosis of the human gastric carcinoma cell line 7901 and its possible mechanism of action. Methods: The viability of TMP-treated 7901 cells was measured with a 3-(4, 5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT) and cell apoptosis was analyzed by flow cytometry. The distribution of cells in different phases of cell cycle after exposure of TMPs was analyzed with flow cytometry. To investigate the molecular mechanisms of TMP-mediated apoptosis, the expression of NF-${\kappa}Bp65$, cyclinD1 and p16 in SGC-7901 cells was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. Results: TMP inhibited the proliferation of human gastric carcinoma cell line 7901 in dose and time dependent manners. Cell growth was suppressed by TMP at different concentrations (0.25, 0.5, 1.0, 2.0 mg/ml), the inhibition rate is 0.46%, 4.36%, 14.8%, 76.1% (48h) and 15.5%, 18.5%, 41.2%, 89.8% (72h) respectively. When the concentration of TMPs was 2.0mg/ml, G1-phase arrest in the SGC-7901 cells was significant based on the data for cell cycle distribution. RT-PCR demonstrated that NF-${\kappa}Bp65$ and cyclin D1 mRNA expression was significantly down-regulated in 7901 cells treated with 2.0 mg/ml TMP for 72h (p<0.05), while the p16 mRNA level was up-regulated (p<0.05). The protein expression of NF-${\kappa}Bp65$ and cyclin D1 decreased gradually with the increase in TMP concentration, compared with control cells (p<0.05), while expression of protein p16 was up-regulated (p<0.01). Conclusion: TMP exhibits significant anti-proliferative and pro-apoptotic effects on the human gastric carcinoma cell line SGC-7901. NF-${\kappa}Bp65$, cyclinD1 and p16 may also play important roles in the regulation mechanisms.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.6115-6120
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• 2013

Introduction: Some non-small cell lung cancer (NSCLC) tumor cells are insensitive to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) -based therapy. This study was conducted to examine the effect of embelin on the sensitivity of the A549 NSCLC cell line to TRAIL receptor2 (TRAILR2) monoclonal antibodies and to investigate the potential mechanisms. Materials and Methods: A549 cells were treated with embelin, TRAILR2 mAb or a combination of both. Cell viability was measured using ATPlite assay and apoptosis rates were determined by flow cytometry with AnnexinV-FITC and propidium iodide staining, with the expression levels of proteins analyzed by Western blotting. Results: The cell survival rate of separate treatments with 100 ng/ml TRAILR2 antibody or 25 uM embelin were $81.5{\pm}1.57%$ and $61.7{\pm}2.84%$, respectively. Their combined use markedly decreased cell viability in A549 cells to $28.1{\pm}1.97%$ (P<0.05). The general caspase inhibitor Z-VAD-FMK could inhibit the embelin-enhanced sensitivity of A549 cells to TRAILR2 mAb ($75.97{\pm}3.17%$)(P<0.05). Both flow cytometry and cell morphological analysis showed that embelin was able to increase TRAIL-induced apoptosis in A549 cells. Combined treatment with embelin and TRAILR2 mAb augmented the activation of initiator caspases and effector caspase. In addition, A549 cells showed increasing levels of TRAILR2 protein and decreasing levels of Bcl-2, survivin and c-FLIP following the treatment with embelin+TRAILR2 mAb. Conclusions: Embelin could enhance TRAIL-induced apoptosis in A549 cells. The synergistic effect of the combination treatment might be due to modulation of multiple components in the TRAIL receptor-mediated apoptotic signaling pathway, including TRAILR2, XIAP, survivin, Bcl-2 and c-FLIP.

• The Journal of Advanced Prosthodontics
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• v.8 no.3
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• pp.172-180
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• 2016

PURPOSE. The purpose of this study was to analyze the antimicrobial, antioxidant activity and cytotoxicity of Dendropanax morbifera $L{\acute{e}}veille$ extract for assessing whether Dendropanax morbifera $L{\acute{e}}veille$ can be used for the development of natural mouthwash and denture cleaning solution. MATERIALS AND METHODS. The extract was obtained from branches of Dendropanax morbifera $L{\acute{e}}veille$. The solvent fractions were acquired by fractionating Dendropanax morbifera $L{\acute{e}}veille$ extract using n-hexane, ethyl acetate, chloroform and butanol solvent. Paper disc test was used to evaluate the antimicrobial and antifungal activity of Dendropanax morbifera $L{\acute{e}}veille$ extract and solvent fractions against Streptococcus mutans and Candida albicans. The analysis of antioxidant activity was carried out through DPPH radical scavenging assay. The cytotoxicity of Dendropanax morbifera $L{\acute{e}}veille$ extract was analyzed through MTT assay using normal human oral keratinocytes. RESULTS. Dendropanax morbifera $L{\acute{e}}veille$ extract showed antimicrobial activity against Streptococcus mutans and especially Candida albicans. The solvent fractions of Dendropanax morbifera $L{\acute{e}}veille$ showed strong antimicrobial activity against Streptococcus mutans and Candida albicans in n-hexane and butanol solvent fraction, respectively. Dendropanax morbifera $L{\acute{e}}veille$ extract also showed outstanding antioxidant activity. Butanol, ethyl acetate, and chloroform solvent fraction of Dendropanax morbifera $L{\acute{e}}veille$ tended to have increased antioxidant activity as the concentration increased. Dendropanax morbifera $L{\acute{e}}veille$ extract showed high cell survival rate in cytotoxicity test. CONCLUSION. Dendropanax morbifera $L{\acute{e}}veille$ extract turned out to have antimicrobial, antioxidant activity and cytophilicity. Based on these results, it is expected that Dendropanax morbifera $L{\acute{e}}veille$ is applicable as an ingredient for natural mouthwash and denture cleanser.