• Korean Journal of Clinical Laboratory Science
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• v.43 no.4
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• pp.161-170
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• 2011

Quercetin is one of the most distributed flavonoids in the plant kingdom and occurs naturally in a wide range of fruits and vegetables. This study was undertaken to determine whether quercetin exerts beneficial effect against necrotic and apoptotic cell death induced by hydrogen peroxide ($H_2O2$) in intestinal cells using the human-derived cultured T84 colonic epithelial cell line. Necrotic cell death was induced by exposing cells to 0.5 mM $H_2O_2$ for 2 h and apoptosis was induced by incubating cells in normal culture medium for 18 h following exposure of cells to 0.5 mM $H_2O2$ for 2 h. Cell viability was evaluated by the trypan blue exclusion assay and apoptosis was assessed by Hoechst 33258 staining and flow cytometry. $H_2O_2$ induced necrotic cell death in a time and dose-dependent fashion. Both necrotic and apoptotic cell deaths were not prevented by the antioxidants N,N'-diphenyl-p-phenylenediamine(DPPD) and Trolox, whereas both cell deaths induced by the organic hydroperoxide t-butylhydroperoxide (tBHP) were prevented by DPPD, suggesting that $H_2O_2$ induces cell death through a lipid peroxidation-independent mechanism. $H_2O2$-induced necrotic death was prevented by deferoxamine and 3-aminobenzamide, while the apoptotic cell death was not affected by these agents. Quercetin prevented both necrotic and apoptotic cell deaths induced by $H_2O_2$ in a dose-dependent manner. $H_2O_2$ caused activation of poly (ADP-ribose) polmerase (PARP), which was inhibited by deferoxamine, 3-aminobenzamide, and quercetin, but not DPPD. These results indicate that quercetin inhibits both necroticand apoptotic deaths of T84 cells. The anti-necrotic effect of quercetin may be attributed to its iron chelator activity rather than a direct $H_2O_2$ scavenging capacity and antioxidant. The present study suggests that quercetin may play a therapeutic role in the treatment of human gastrointestinal diseases mediated by oxidants.

• Preventive Nutrition and Food Science
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• v.4 no.4
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• pp.255-259
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• 1999

The anticarcinogenic effects of the methanol extracts from leek (buchu in Korean) kimchi and Korean cabbage kimchi were evaluated using cytotoxicity and transformation tests in C3H/10T1/2 cells. Various fractions of the 6-day fermented leek kimchi at 15$^{\circ}C$, hexane, methanol soluble, dichloromethane, ethyl acetate, butanol and aqueous fraction, were also studied in the same system. The inhibitory effect of the leek kimchi(6-day fermented at 15$^{\circ}C$, pH 4.29) was higher than that of the Korean cabbage kimchi(4-day fermented at 15$^{\circ}C$, pH 4.21) on the cytotoxicity induced by 3-methylcholanthrane (MCA) in the C3H/10T1/2 cell system. While the MCA-treated culture(control) formed 21.0 foci of type II plus III in C3H/10T1/2 cells, 100$\mu\textrm{g}$/ml of the methanol extract of the leek kimchi and that of the 4-day fermented Korean cabbage kimchi treated cultures reduced the formation of type II plus III foci to 7.4 and 11.3, respectively. Among the fractions of the leek kimchi, the dichloromethane fraction showed the highest inhibitory effect on MCA-induced cytotoxicity in C3H/10T1/2 cells. Fifty $\mu\textrm{g}$/ml of dichloromethane fraction from the leek kimchi suppressed the MCA-induced cytotoxicity by 77%. On the transformation test using MCA, the dichloromethane fraction considerably reduced the formation of type II plus III foci, especially thpe III foci. When 50$\mu\textrm{g}$/ml of dichloromethane fraction from the leek kimchi was treated, the numbers of type III foci mediated by MCA were decreased to 1.7 compared to 10 for the control. These results indicate that leek kimchi has stronger anticarcinogenic effects than Korean cabbage kimchi and that the dichloromethane fraction of the leek kimchi may contain the major compound(s) that suppress the carcinogenesis in the eukaryotic cells.

• The Korea Journal of Herbology
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• v.36 no.5
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• pp.93-99
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• 2021

Objective : Caryophylli Flos has been used in Korean medicine to relieve vomiting and pains caused by chills that make fluid circulation difficult. This study was designed to investigate the protective effect of ethanol extract of Caryophylli Flos (CF) in hydrogen peroxide (H₂O₂)-induced apoptotic cell death in human keratinocyte HaCaT cells. Methods : CF was prepared by extracting 200 g of Caryophylli Flos in 2 L of ethanol for 48 h. Cell viability was measured by MTT assay, and the protein expression was monitored by Western blot analysis. Apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Reactive oxygen species (ROS) was measured using fluorescent dye, and reduced glutathione (GSH) was determined with a colorimetric commercial kit. Results : CF protected HaCaT cells from cell death caused by oxidative stress after H₂O₂ treatment. H₂O₂ amplified generation of ROS and induced depletion of GSH, whereas these changes in ROS and GSH were inhibited by GF treatment. In addition, H₂O₂ resulted in apoptosis as assessed by TUNEL assay and the expression of apoptosis regulator proteins. However, cells treated with CF showed a decrease in TUNEL-positive cells and restored the reduced expression of procaspase-9, -3 and PARP. Conclusion : This study showed cytoprotective effects of CF by anti-apoptotic activity while exerting antioxidative activity in H₂O₂-treated HaCaT cells. These results suggest that CF could be beneficial in skin damage caused by oxidative stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.235-240
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• 2000

Inhibitory effects of cockle extracts on carcinogen-induced cytotoxicity in C3H/10T1/2 cells were studied. Soup (62$\mu\textrm{g}$/mL), solubility (28$\mu\textrm{g}$/mL) and liposolubility (9 $\mu\textrm{g}$/mL) of the cockle inhibited 3-methyl-cholanthrene(MCA)-induced cytotoxicity in C3H/10T1/2 cells by 53 and 94%, respectively. These results suggest that the extracts cockle might have anticarcinogen-induced cytotoxicity of C3H/10T1/2 cells. The effects of cockle extracts on the immune response related to its antitumor activity in vitro and in vivo were investigated. The cockle extracts showed a direct cytotoxic effect on sarcoma-180 cells, tumor cells in vitro. Soup (0.49 mg/mL), solubility (0.11 mg/mL) and liposolubiliy (0.05 mg/mL) of the cockle markedly decreased the total numbers of sarcoma-180 cells, but not their viability. The phagocytic acitivity of peritoneal macrophage of mice was significantly augmented by these extracts of the cockle compared with that of control in vivo. These extracts also raised the phagocuytic index, indicating that the number of phagocytize dmicrobes per macrophage increased. Thus, cockle extracts might show a antitumor activity by enhancing the phagocytic cell activities.

• Korean Journal of Microbiology
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• v.29 no.4
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• pp.263-266
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• 1991

The growth of T. novellus in auto trophic and geterotrophic media was studied to determine the time required for cells to enter stationary phase and relative percentage of ribosomal proteins. When T. novellus was grown autotrophically, growth proceeded at a slow rate characteristic of autotrophs and did not enter log phase until the end of the first day. Logarithmic growth proceeded for 3-4 days at which time the cells entered the stationary phase. In particular, logarithmic growth was accompanied by decreasing pH of culture media and in the stationary phase the pH levelled off at 6.0, a decrease of 1.6 pH value compared to original pH of media. The pH decrease was greatest during log phase when cells oxidized thiosulfate to $H_{2}$$SO_{4}$. The doubling time was about 26h. In heterotrophic media growth proceeded at a much faster rate and cells entered stationary phase 20-22h after inoculation. The doubling time was 3h. The protein content of the ribosomes in T. novellus grown heterotrophically was 4.2% greater than those from the organism grown autotrophically.

• Parasites, Hosts and Diseases
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• v.31 no.3
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• pp.215-222
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• 1993

In order to establish a useful cell culture system for T gondii we compared the degree of proliferation of T gondii tachyzoites among 8 different cell lines: 2 kinds of normal animal cells (MDCK-canine kidney cells; Vero-monkey kidney cells) and 6 kinds of human tumor cells (A 549, PC 14-lung cancer cells; SNU 1, SNU 16. Mlm 45-stomach cancer cells; HL-60-promyelocytic leukemia cells), through morphological observation and 3H-uracil uptake assay. The degree of susceptibility to infection with T gondii tachyzoites was highest in A 549 and PC 14 cells, medium in Vero, HL-60, MDCK and SNU 1, and lowest in SNU 16 and MBm 45 cells. The kinetics of T gondii multiplication during the post-Infection 60 hours were higllly dependent upon the dose of tachyzoites administered and the duration among the 8 tested fur the growth and multiplication of T gondii in vitro.

• International Journal of Oral Biology
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• v.39 no.2
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• pp.97-105
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• 2014

The aim of this study was to determine the beneficial effect of propofol on human keratinocytes that have undergone hypoxia reoxygenation (H/R) injury and to investigate whether autophagy is associated with the protective mechanism. Thus, we evaluated how propofol influences the intracellular autophagy and apoptosis during the H/R process in the HaCaT cells. The cultured human keratinocyte cells were exposed to 24 h of hypoxia (5% $CO_2$, 1% $O_2$, 94% $N_2$) followed by 12 h of reoxygenation (5% $CO_2$, 21% $O_2$, 74% $N_2$). The experiment was divided into 4 groups: (1) Control=Normoxia ; (2) H/R=Hypoxia Reoxygenation ; (3) PPC+H/R=Propofol Preconditioning+Hypoxia Reoxygenation; (4) 3-MA+PPC+ H/R=3-MA-Methyladenine+Propofol Preconditioning+ Hypoxia Reoxygenation. In addition, Western blot analysis was performed to identify the expression of apoptotic pathway parameters, including Bcl-2, Bax, and caspase 3 involved in mitochondrial-dependent pathway. Autophagy was determined by fluorescence microscopy, MDC staining, AO staining, and western blot. The H/R produced dramatic injuries in keratinocyte cells. In our study, the viability of Propofol in H/R induced HaCaT cells was first studied by MTT assay. The treatment with 25, 50, and $100{\mu}M$ Propofol in H/R induced HaCaT cells enhanced cell viability in a dose-dependent manner and $100{\mu}M$ was the most effective dose. The Atg5, Becline-1, LC3-II, and p62 were elevated in PPC group cells, but H/R-induced group showed significant reduction in HaCaT cells. The Atg5 were increased when autophagy was induced by Propofol, and they were decreased when autophagy was suppressed by 3-MA. These data provided evidence that propofol preconditioning induced autophagy and reduced apoptotic cell death in an H/R model of HaCaT cells, which was in agreement with autophagy playing a very important role in cell protection.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.55-58
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• 2004

Cell separation from peripheral blood was investigated using surface-modified polyurethane (PU) membranes with different functional groups. Both red blood cells and platelets could pass through unmodified PU and PU-SO$_3$H membranes, while the red blood cells preferentially passed through PU-N(C$_2$H$_{5}$ )$_2$ and PU-NHC$_2$H$_4$OH membranes. The permeation ratio of T and B cells was less than 25% for the surface-modified and unmodified PU membranes. CD34$^{+}$ cells have been recognized as various kinds of stem cells including hematopoietic and mesenchymal stem cells. The adhesiveness of CD34$^{+}$ cells on the PU membranes was found to be higher than that of red blood cells, platelets, T cells or B cells. Overall, the adhesiveness of blood cells on the PU membranes increased in the following order: red blood cells $\leq$ platelets ＜ T cells $\leq$ B cells ＜ CD34$^{+}$ cells. Treatment of PU-COOH membranes with a human albumin solution to detach adhered blood cells, allowed recovery of mainly CD34$^{+}$ cells in the permeate, while both red blood cells and platelets could be isolated in the permeate using unmodified PU membranes. The PU membranes showed different permeation and recovery ratios of specific cells depending on the functional groups attached to the membranes.mbranes.

• Food Science and Preservation
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• v.31 no.2
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• pp.307-314
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• 2024

Broussonetia kazinoki twig extract (BKT) is recognized for its antioxidant and anti-cancer effects and natural whitening properties. So, it is used as a raw material for cosmetics. B. kazinoki twig is also an edible raw material. B. kazinoki has been used in Asia for paper production and oriental medicine, has anti-diabetic effects, and contains various flavonoids and alkaloids. In this study, to evaluate the efficacy of BKT on allergic skin inflammatory responses, we investigated its effects on factors related to skin inflammation in HaCaT keratinocytes and allergic responses in RBL-2H3 cells. There was no cytotoxicity of the 70% ethanol extract against HaCaT and RBL-2H3 cells. In HaCaT cells, stimulation with tumor necrosis factor-alpha (TNF-𝛼) and interferon-gamma (IFN-𝛾) increased the production of several chemokines, including thymus and activation-regulated chemokine (TARC), macrophage-derived chemokine (MDC), and regulated on activation, normal T cell expressed and secreted (RANTES). However, it was observed that this elevation was notably mitigated in a concentration-dependent manner upon treatment with BKT. Furthermore, BKT treatment demonstrated a significant reduction of 𝛽-hexosaminidase and inflammatory cytokines TNF-𝛼 and IL-4 in IgE-sensitized RBL-2H3 cells. Thus, it is expected that BKT can be used as a natural cosmetic and food ingredient that effectively suppresses allergic inflammatory reactions.

• Biomolecules & Therapeutics
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• v.16 no.3
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• pp.219-225
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• 2008

Taurine is the most abundant amino acid in many tissues and is found to be enhancing the bone tissue formation or inhibits the bone loss. Although it is reported that taurine reduces the alveolar bone loss through inhibiting the bone resorption, its functions of taurine and expression of taurine transporter (TauT) in bone have not been identified yet. The purpose of this study is to clarify the uptake mechanism of taurine in osteoblast using mouse osteoblast cell lines. In this study, mouse stromal ST2 cells and mouse osteoblast-like MC3T3-E1 cells as osteoblast cell lines were used. The activity of taurine uptake was assessed by measuring the uptake of [$^3H$]taurine in the presence or absence of inhibitors. TauT mRNA was detected in ST2 and MC3T3-E1 cells. [$^3H$]Taurine uptake by these cells was dependent on the presence of extracellular calcium ion. The [$^3H$]taurine uptake in ST2 cells treated with 4 mM calcium was increased by 1.7-fold of the control which was a significant change. In contrast, in $Ca^{++}$-free condition and L-type calcium channel blockers (CCBs), taurine transport to osteocyte was significantly inhibited. In oxidative stress conditions, [$^3H$]taurine uptake was decreased by TNF-$\alpha$ and $H_2O_2$. Under the hyperosmotic conditions, taurine uptake was increased, but inhibited by CCBs in hyperosmotic condition. These results suggest that, in mouse osteoblast cell lines, taurine uptake by TauT was increased by the presence of extracellular calcium, whereas decreased by CCBs and oxidative stresses, such as TNF-$\alpha$ and $H_2O_2$.