• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.677-680
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• 2007

To analyze a cotG-based Bacillus subtilis spore display system directly, $GFP_{UV}$ was expressed on the surface of Bacillus subtilis spores. When $GFP_{UV}$ was fused to the C-terminal of the cotG structural gene and expressed, the existence of a $CotG-GFP_{UV}$ fusion protein on the B. subtilis spore was confirmed by flow cytometry confocal microscopic analysis. When the cotG anchoring motif was deleted, no fluorescence emission was observed under flow cytometry and confocal microscopic analysis from the purified spore, confirming the essential role of CotG as an anchoring motif. This $GFP_{UV}$ displaying spore might be used for another signaling application triggered by intracellular or extracellular stimuli.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1257-1265
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• 2017

The present study was carried out to investigate the antioxidative and neuroprotective effects of sea buckthorn (Hippophae rhamnoides L.) leaves (SBL) harvested at different times. Reversed-phase high-performance liquid chromatography analysis revealed five major phenolic compounds: ellagic acid, gallic acid, isorhamnetin, kaempferol, and quercetin. SBL harvested in August had the highest total phenolic and flavonoid contents and antioxidant capacity. Treatment of neuronal PC-12 cells with the ethyl acetate fraction of SBL harvested in August increased their viability and membrane integrity and reduced intracellular oxidative stress in a dose-dependent manner. The relative populations of both early and late apoptotic PC-12 cells were decreased by treatment with the SBL ethyl acetate fraction, based on flow cytometry analysis using annexin V-FITC/PI staining. These findings suggest that SBL can serve as a good source of antioxidants and medicinal agents that attenuate oxidative stress.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.2
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• pp.87-92
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• 2022

Objective: The aim of this study was to determine the effects of melatonin and selenium in freezing extenders on frozen-thawed rat sperm. Methods: Semen samples were collected from 20 adult male Wistar albino rats. Following dilution, the samples were divided into six groups: four cryopreserved groups with 1 mM and 0.5 mM melatonin and selenium supplements, and two fresh and cryopreserved control groups. The rapid freezing technique was used to freeze the samples. Flow cytometry was used to assess plasma membrane integrity, mitochondrial membrane potential, and DNA damage, while computer-assisted sperm analysis was used to assess motility. Results: Total motility was higher in the 1 mM melatonin supplementation group than in the cryopreserved control group (mean±standard error of the mean, 69.89±3.05 vs. 59.21±1.31; p≤0.05). The group with 1 mM selenium had the highest plasma membrane integrity (42.35%±1.01%). The cryopreserved group with 0.5 mM selenium had the highest mitochondrial membrane potential, whereas the cryopreserved control group had the lowest (45.92%±4.53% and 39.45%±3.52%, respectively). Conclusion: Cryopreservation of rat semen supplemented with 1 mM melatonin increased sperm motility after freeze-thawing, while supplementation with 0.5 mM selenium increased mitochondrial activity.

• Biomolecules & Therapeutics
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• v.31 no.1
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• pp.68-72
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• 2023

Pancreatic cancer is one of the most fatal cancers with a poor prognosis. Standard chemotherapies have proven largely ineffective because of their toxicity and the development of resistance. Therefore, there is an urgent need to develop novel therapies. In this study, we investigated the antitumor activity of MS-5, a naphthalene derivative, on BxPC-3, a human pancreatic cancer cell line. We observed that MS-5 was cytotoxic to BxPC-3 cells, as well as inhibited the growth of cells in a concentration- and time- dependent manner. Flow cytometry analysis revealed that the percentage of annexin V-positive cells increased after MS-5 treatment. We also observed cleavage of caspases and poly (ADP-ribose) polymerase, and downregulation of Bcl-xL protein. Flow cytometry analysis of intracellular levels of reactive oxygen species (ROS) and mitochondrial superoxide suggested that MS-5 induced the generation of mitochondrial superoxide while lowering the overall intracellular ROS levels. Thus, MS-5 may be potential candidate for pancreatic cancer treatment.

• Journal of Food Hygiene and Safety
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• v.31 no.4
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• pp.286-293
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• 2016

This study is an experiment for gastric protective effects of ursolic acid. In order to identify the effects of ursolic acid on gastrointestinal disorder, acute and chronic gastritis were also observed using HCl ethanol and indomethacin-induced gastric lesion models, respectively. As for gastric acid, it was also identified through proton pump ($H^+/K^+-ATPase$) inhibiting activity. In regards to protective factor for gastric damage, prostaglandin $E_2$ ($PGE_2$) was quantitatively analyzed. Antibacterial activity experiment was done on Helicobacter pylori (H.pylori), which is known to be the causing factor of chronic gastritis, gastric ulcer and gastric cancer. By making use of AGS cell, it was confirmed that ursolic acid was involved in apoptosis of gastric cancer cell through 4',6-diamidino-2-phenylindol (DAPI) staining and flow cytometry analysis. As a result, ursolic acid reduced gastric lesions caused by HCl ethanol and indomethacin. Ursolic acid inhibited acid secretion by inhibiting proton pump ($H^+/K^+-ATPase$), which is the gastric acid secreting enzyme involved at the final phase of gastric acid secretion. And ursolic acid was identified with gastric mucosa protection effects by increasing the concentration of $PGE_2$, a protective factor of gastric mucosa preservation. The antibacterial activity on H. pylori, which is aggressive factor in gastrointestinal disorder, ursolic acid showed inhibitory effects on H. pylori colonization. In the DAPI nuclear staining, unlike the control group, shape of the nucleus has deformed, and has been observed either shrinked cell or chromatin condensation phenomenon. In the Flow cytometry assay, confirmed the growth rate of apoptosis in a concentration-dependent manner.

• Imaging Science in Dentistry
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• v.38 no.3
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• pp.133-146
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• 2008

Purpose : To observe and evaluate the effects of Simvastatin-induced osteogenesis on the wound healing of defective bone. Materials and Methods : 64 defective bones were created in the parietal bone of 32 New Zealand White rabbits. The defects were grafted with collagen matrix carriers mixed with Simvastatin solution in the experimental group of 16 rabbits and with collagen matrix carriers mixed with water in the controlled group. The rabbits were terminated at an interval of 3, 5, 7, and 9 days, 2, 4, 6, and 8 weeks after the formation of defective bone. The wound healing was evaluated by soft X-ray radiography. The tissues within defective bones were evaluated through the analysis of flow cytometry for the manifestation of Runx2 and Osteocalcin, and observed histopathologically by using H-E stain and Masson's trichrome stain. Results : 1. In the experimental group, flow cytometry revealed more manifestation of Runx2 at 5, 7, and 9 days and Osteocalcin at 2 weeks than in the controlled groups, but there was few difference in comparison with the controlled group. 2. In the experimental group, flow cytometry revealed considerably more cells and erythrocytes at 5, 7, and 9 days in comparison with the controlled group. 3. In the experimental group, soft x-ray radiography revealed the extended formation of trabeculation at 2, 4, 6, and 8 weeks. 4. Histopathological features of the experimental group showed more fibroblasts and newly formed vessels at 5 and 7 days, and the formation of osteoid tissues at 9 days, and the newly formed trabeculations at 4 and 6 weeks. Conclusion : As the induced osteogenesis by Simvastatin, there was few contrast of the manifestation between Runx2 and Osteocalcin based on the differentiation of osteoblasts. But it was considered that the more formation of cells and erythrocytes depending on newly formed vessels in the experimental group obviously had an effect on the bone regeneration.

• Korean Journal of Plant Tissue Culture
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• v.25 no.2
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• pp.81-88
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• 1998

The Southeast Asian javanica rice variety Tinawen was investigated for efficient protoplast culture and plant regeneration from cell suspension-derived protoplasts using a feeder cell culture method. Feeder cells of both Lolium multiflorum and Oryza ridleyi, either alone, or in combination, were employed and plants were regenerated from protoplast-derived colonies on several plant regeneration media. Dehydration of protoplast-derived colonies was also investigated as a means of enhancing plant regeneration. In the presence of L. multiflorum or O. ridleyi feeder cells, the protoplast plating efficiency ranged from 0.09% to 1.48%, depending on the feeder cell type and the age of the cell suspension. L. multiflorum feeder cells induced approximately 6-fold higher plating efficiency compared with those of O. ridleyi. The plant regeneration frequencies were 19.3-31.7% with L. multiflorum, 13.0-18.0% with O. ridleyi and 18.0-22.0% with a mixture of both in various plant regeneration media when protoplast-derived colonies were dehydrated, while for the non-dehydrated colonies, the values were 2.0-7.0%, 3.0-5.0% and 0-4.0%, respectively. Flow cytometric analysis of 34 protoplast-derived plants showed that the majority of plants were diploids and only 2 plants were tetraploids. The plants which were transferred to glasshouse were fertile.

• Journal of the Korean Society of Visualization
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• v.9 no.2
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• pp.21-26
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• 2011

Hydrodynamic focusing technique to generate focused flow has been used for flow cytometry in microfluidic devices. However, devices with circular capillary tubes made of glass are not suitable for flow visualization or optical signal detection because the rays of light are distorted at the curved interface. We devised a new acrylic chamber assembled with a pulled micropipette and a rectangular microchannel made of glass. This new channel geometry enabled us to visualize the three-dimensional (3D) flow characteristics with confocal imaging technique. We analyzed the 3D hydrodynamic focusing in a circular capillary tube and a rectangular microchannel over a practical range of flow rates, viscosities and pressure drops.

• Toxicological Research
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• v.25 no.3
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• pp.113-118
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• 2009

Cell death induced by menadione (vitamin K-3,2-methyl-1,4-naphthoquinone) has been investigated in human promyelocytic leukemia HL-60 cells. Menadione was found to induce both apoptosis and necrosis in HL-60 cells. Low concentration ($1{\sim}$50 ${\mu}$M) of menadione induced apoptotic cell death, which was demonstrated by typical DNA ladder patterns on agarose gel electrophoresis and flow cytometry analysis. In contrast, a high concentration of menadione (100 ${\mu}$M) induced necrotic cell death, which was demonstrated by DNA smear pattern in agarose gel electrophoresis. Necrotic cell death was accompanied with a great reduction of cell viability. Menadione activated caspase-3, as evidenced by both increased protease activity and proteolytic cleavage of 116 kDa poly(ADP-ribose) polymerase (PARP) into 85 kDa cleavage product. Caspase-3 activity was maximum at 50 ${\mu}$M of menadione, and very low at 100 ${\mu}$M of menadione. Taken together, our results showed that menadione induced mixed types of cell death, apoptosis at low concentrations and necrosis at high concentrations in HL-60 cells.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.207-212
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• 2009

Celandine (Chelidonium majus, family Papaveraceae) is an herb used extensively in traditional Korean medicine. To investigate its antioxidant and antiproliferative activities, the methanolic extract of celandine was introduced. The antioxidant properties of the extract were tested using various in vitro systems, including hydroxyl radical scavenging assay, DNA damage protection assay, 1,1-diphenyll-2-2-pricylhydrazyl (DPPH) free radical scavenging activity, metal chelating activity, and reducing power assay. The extract exhibited stronger antioxidant activity ($IC_{50}=7.92{\mu}g/mL$) against hydroxyl radicals in the Fenton system than butylated hydroxyanisole ($IC_{50}=51.46{\mu}g/mL$) and $\alpha$-tocopherol ($IC_{50}=67.48{\mu}g/mL$). Likewise, damage to the plasmid pBR 322 induced by hydroxyl radicals was found to be protected by the extract at a concentration of $400{\mu}g/mL$. Cellular proliferation and the induction of apoptosis were also examined by a cellular proliferation assay, flow cytometry, and mRNA expression analysis. Taken together, the extract significantly inhibited the growth of HT-29 cells in a concentration- and time-dependent manner, and gradually increased both the proportion of apoptotic cells and the expression of caspase-3. Overall, our research suggests that celandine possesses antioxidant and antiproliferative properties.