• Journal of Nutrition and Health
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• 제36권4호
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• pp.382-388
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• 2003

(-)-Epigallocatechin-3-gallate (EGCG) is a polyphenolic compound found in peen tea leaves, and has been known to be one of the most potent catechin species which inhibits cell growth most possibly through an apoptotic cell death. We investigated the apoptotic activity of (-)-EGCG on the human myeloid leukemia cell line, HL-60. Our results of MTT test indicated that (-)-EGCG had a significant antiproliferation effect in HL-60 cells with $IC_{50}$/ (50% inhibition concentration) value of 65 $\mu$M. Giemsa statining of HL-60 cells treated with (-)-EGCG (100 $\mu$M) for 6hrs showed a typical apoptosis-specific morphological change including shrinkage of the cytoplasm, membrane blobbing and compaction of the nuclear chromatin. The DNA fragmentation was observed from the agarose gel electrophoresis of cells treated with (-)-EGCG for 3hrs or longer, and was progressed to a greater degree as treatment time increases. Treatment of the cells with (-)-EGCG (100 $\mu$M) resulted in a rapid release of mitochondrial cytochrome c into the cytosol, and a subsequent cleavage of caspase-3 to an active form in a treatment-time dependent manner. (-)-EGCG (100 $\mu$M) also stimulated proteolytic cleavage of poly-(ADP-ribose) polymerase (PARP) to an active form in HL-60 cells. Tlken together, (-)-EGCG appears to induce the apoptosis in human myeloid leukemia cells via a caspase-dependent pathway. These results suggest the possible application of (-)-EGCG, the major active compound in green tea, as an antiproliferative agent for cancer prevention.

• Environmental Analysis Health and Toxicology
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• 제19권3호
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• pp.261-269
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• 2004

Although the biological functions of metallothioneins (MTs) are still being investigated, they have been suggested to be involved in detoxification of heavy metals, scavenging of free radicals, and protection against alkylating agents. MTs have been reported to be induced in most of animal tissues by heavy metals such as zinc, copper, mercury and cadmium, and the proteins have binding affinities to the metals. However, the presence or induction of MTs was reported not to be clear in leydig cells, which produce testosterone for the maturation of spermatozoa in male testes. In this study, we investigated the inducibility of metallothionein isomers by cadmium in cultured mouse leydig cells. Total RNA was extracted from the near confluent grown leydig cells and RT-PCR was Performed using the Primers which were synthesized on the basis of MT-1, 2, 3 and 4 cDNA from GenBank database. As results, MT-1 and MT-2 mRNA were found to be expressed in cadmium non-treated control cells and MT 1 mRNA expression was dose-dependent when leydig cells were treated with cadmium chloride. But MT-3 which is known to be brain specific and MT-4 which is another isoform of metallothionein, were not expressed. Other genes induced or depressed in cadmium treated leydig cells were also identified by microarray techniques.

• 대한수의학회지
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• 제60권2호
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• pp.79-83
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• 2020

Fenbendazole (FBZ) is a benzimidazole anthelmintic that has been widely used in treatments for gastrointestinal parasites including pinworms and roundworms in animals. Recently, some studies demonstrated that FBZ has anti-cancer effects related to disruption of microtubule polymerization. In this study, we investigated whether FBZ has anti-cancer activity in HL-60 cells, a human leukemia cell line, and assessed its relationship with the production of reactive oxygen species (ROS). FBZ treatment at 0.25-1 μM significantly decreased the metabolic activity of HL-60 cells. The mitochondrial membrane potential of FBZ-treated HL-60 cells decreased in a concentration-dependent manner. Apoptosis analysis using annexin V-FITC/propidium iodide staining demonstrated that 1 μM FBZ increased the percentages of cells in apoptosis and necrosis. In addition, Hoechst 33342 staining showed the presence of broken nuclei in HL-60 cells treated with 0.5 and 1 μM FBZ. To investigate the anti-cancer mechanism of FBZ, HL-60 cells were treated with FBZ in the absence or presence of N-acetyl cysteine (NAC), an inhibitor of ROS production. NAC significantly recovered the decreased metabolic activity of HL-60 induced by 0.5 and 1 μM FBZ treatments. This study provides evidence that FBZ has anti-cancer activity in HL-60 cells provided, in part, via ROS production.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 2002년도 학술대회지
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• pp.545-555
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• 2002

Ginsenosides of 20(S)-protopanaxadiol and 20(S)-protopanaxatriol classification including the aglycones, PD, PI and ginsenosides Rh2, Rhl were shown to posses characteristic effects on proliferation of THP-l human leukaemia cells. A similar result was not apparent for ginsenoside Rg3 or dexamathasone. The concentration to inhibit $50\%$ of cells $(LC_{50})$ for PD, Rh2, PI and Rhl were 13 ${\mu}g/mL,\;15{\mu}g/mL,\;19{\mu}g/mL\;and\;210\;{\mu}g/mL$ respectively. Cell cycle analysis showed apoptosis with PD and PI treatment of THP-1 cells resulting in a build up of sub-G1 cells after 24, 48 and 72 hours of treatment. Rh2, and dexamathasone treatments also increased apoptotic cells after 24 hours, where as Rhl did not. After 48 and 72 hours Rh2, Rhl and dexamathasone similarly increased apoptosis, but these effects were significantly (P<0.05) lower than observed for both PD and PI treatments. Furthermore, treatments that produced the largest build up of apoptotic cells were also found to have the largest release of lactate dehydrogenase (LDH). It can be concluded from these studies that the presence of sugars to PD and PI aglycone structure reduces the potency to induce apoptosis, and alternately alter membrane integrity. These cytotoxic effects to THP-l cells were different from dexamethasone.

• Journal of Plant Biotechnology
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• 제50권
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• pp.76-81
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• 2023

As cultured plant cells can grow in high oxidative stress conditions, they form an excellent system to study antioxidant mechanisms and the mass production of antioxidants. Oxidative stress is a major cause of damage in plants exposed to various types of environmental stress, including heavy metals, such as cadmium (Cd). Heavy metal accumulation can interfere with many cell functions and plant growth. To evaluate the contribution of oxidative stress to Cd-induced toxicity, cultured sweetpotato (Ipomoea batatas) cells were treated with increasing concentrations of Cd (0, 10, 25, and 50 μM) and cultured further. Cell growth was significantly inhibited by 25 and 50 μM of Cd, and the total protein content increased with 50 μM of Cd. Additionally, the activity of peroxidase (POD) and ascorbate peroxidase (APX), antioxidant enzymes that remove hydrogen peroxide (a reactive oxygen species), increased in the cells after treatment with 50 μM of Cd. The expression analysis of POD, APX, and peroxiredoxin (PRX) isolated from sweetpotato cultured cells in a previous study revealed the differential expression of POD in response to Cd. In this study, the expression levels of several acidic POD (swpa2, swpa3, and swpa4) and basal POD (swpb1, swpb2, and swpb3) genes were increased in Cd-treated cultured cells. These results indicate that Cd-mediated oxidative stress is closely linked to improved POD-mediated antioxidant defense capacity in sweetpotato suspension-cultured cells.

• Journal of Periodontal and Implant Science
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• 제36권2호
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• pp.335-344
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• 2006

Osteoblast or bone marrow stromal cell-derived RANKL is the major effector molecule essential for osteoclastogenesis. Previous studies have shown that tetracyclines have beneficial therapeutic effects in the prevention and treatment of inflammatory bone disease including periodontal disease. Periodontal ligament cells are thought not only to play an important role in the progression of periodontal disease, but to play an important role in alveolar bone remodeling. Previous studies indicated that receptor activation of nuclear factor $\kappa\;B$ ligand (RANKL) and osteoprotegerin (OPG) are expressed in periodontal ligament cells by pro-inflammatory cytokine, such as $IL-1{\beta}$ and $TNF-{\alpha}$. This study was designed to investigate the inhibitory effect of doxycycline on RANKL and OPG mRNA in rat periodontal ligament cells induced by $IL-1{\beta}$ (1 ng/ml). The results are as follows; 1. MTT assay showed that doxycycline at the concentration of $1-50\;{\mu}g/m{\ell}$ didn't result in statistically significant cell death at day 1 and 3. 2. RANKL mRNA expression was increased to 2.6 folds by $IL-1{\beta}$. When cells were treated with doxycycline ($50{\mu}g/m{\ell}$), $IL-1{\beta}$ -induced mRANKL expression was reduced by 33%. In contrast to RANKL, OPG mRNA expression was not inhibited by pre-treatment with doxycycline. These results suggest that doxycycline decrease the expression of mRANKL resulting in regulation of osteoclastogenesisp in rat periodontal ligament cells.

• The Korean Journal of Physiology and Pharmacology
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• 제2권3호
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• pp.369-376
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• 1998

This report shows that hydroxyl radical, generated by a Fenton reaction involving adenosine $5'-diphosphate/Fe^{2+}$ complex ($5-15\;{\mu}M$) and $H_2O_2$ ($2\;{\mu}M$), induced differentiation of HL-60 cells in a dose- and time-dependent manner. This is evidenced by the increases in 12-O-tetradecanoylphorbol 13-acetate- and fMLP-stimulated superoxide production capability. The cells exposed to hydroxyl radical for defined periods (24∼96 hr) continued to differentiate even after the hydroxyl radical generating system had been removed. The differentiated cells displayed fMLP-stimulated calcium mobilization and increased expression of myeloid-specific antigen CD11b and CD14. The extent of the differentiation was markedly reduced by desferrioxamine ($100\;{\mu}M$), dimethylthiourea (5 mM), N,N'-diphenyl-1,4-phenylenediamine ($2\;{\mu}M$), and N-acetyl-L-cysteine (5 mM). The induction of differentiation by hydroxyl radical was enhanced by 3-isobutyl-1-methylxanthine ($200\;{\mu}M$) and Ro-20-1724 ($8\;{\mu}M$), and inhibited by dipyridamole (2 ${\mu}M$). These results suggest that hydroxyl radicals may induce commitment of HL-60 cells to differentiate into more mature cells of myelomonocytic lineage through specific signal-transduction pathway that is modulated by phosphodiesterase inhibitors.

• 한국미생물·생명공학회지
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• 제11권3호
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• pp.223-231
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• 1983

Bacillus thuringiensis 16개 균주에서 Beta-exotoxin 생산을 연구하였다. 균주는 Conner-Han-sen Mineral Salts 배지에 시험균을 접종하여 28$^{\circ}C$에서 진탕배양을 한 후 Micrococcus flava을 이용하여 감수성과 생산능을 조사했고, Spectrophotometer를 이용하여 260nM에서 생산량량과 생산속도 등을 조사했다. 1. Bacillus thuringiensis의 돌연변이 균주BTK2-T1, BTK2-T13, BTK2-T17, BTK2-T33과 BTK2-T40은 Conner-Hansen 배지에서 배양 6시간부터 Stationary Phase에 접어들어 가서 48시간 배양과 별 차이를 나타내지 않았으나, Bata-exotoxin의 생산은 6시간 배양에서는 O.D. 260nm에서 약 1.0미만(약 40$\mu\textrm{g}$/$m\ell$)이였고, 12시간 배양에서는 O.D.260nm에서 약 1.7미만(약 70$\mu\textrm{g}$/$m\ell$) 이었으며, 24시간배양부터 48시간 배양에 서는 거의 증가를 보이지 않고 O.D. 260nm에서 2.0내지 2.3(약 85$\mu\textrm{g}$/$m\ell$)을 계속 유지했다. 48시간 배양균주들은 BTK2는 배지 $m\ell$당 80$\mu\textrm{g}$(5.5$\times$$10^{8}$ Cells/$m\ell$), BTK2-T13은 84$\mu\textrm{g}$(4.3$\times$$10^{8}$ Cells/$m\ell$), BTK2-T17은 87$\mu\textrm{g}$(1.4$\times$$10^{8}$ Cells/$m\ell$), 그리고 BTK2-T33은 84$\mu\textrm{g}$ (4.9$\times$$10^{8}$ Cells/$m\ell$)을 분비했다. 2. 다른 혈청형 균주들도 모두 Beta-exotoxin을 생산했는데, 48시간 배양 배지 $m\ell$당 70$\mu\textrm{g}$을 분비한 균주는 BTK-1이고, BTK-37 균주는 $m\ell$당 88$\mu\textrm{g}$(6.1$\times$$10^{8}$ Cells/$m\ell$) BTK-35 균주는 $m\ell$당 81$\mu\textrm{g}$(5.2$\times$$10^{8}$ Cells/$m\ell$)을 생산했고. 그외는 모두 70$\mu\textrm{g}$미만이었다. 3. Beta-exotoxin과 B. thuringiensis 균체을 동시에 per os, interaperitoneal injection, subcuntaneous injection, nasal cavity inoculation, intracerebral injection을 120시간 처리했어도 치사효과를 나타내지 않았다.

• Biomolecules & Therapeutics
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• 제16권2호
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• pp.106-112
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• 2008

The effects of harman and norharman on dopamine content and L-DOPA-induced cytotoxicity were investigated in PC12 cells. Harman and norharman decreased the intracellular dopamine content for 24 h. The $IC_{50}$ values of harman and norharman were 20.4 ${\mu}M$ and 95.8 ${\mu}M$, respectively. Tyrosine hydroxylase (TH) activity and TH mRNA levels were also decreased by 20 ${\mu}M$ harman and 100 ${\mu}M$ norharman. Under the same conditions, the intracellular cyclic AMP levels were decreased by harman and norharman. In addition, harman and norharman at concentrations higher than 80 ${\mu}M$ and 150 ${\mu}M$ caused cytotoxicity at 24 h in PC12 cells. Non-cytotoxic ranges of 10-30 ${\mu}M$ harman and 50-150 ${\mu}M$ norharman inhibited L-DOPA (20-50 ${\mu}M$)-induced increases of dopamine content at 24 h. Harman at 20-150 ${\mu}M$ and norharman at 100-300 ${\mu}M$ also enhanced LDOPA (20-100 ${\mu}M$)-induced cytotoxicity at 24 h. These results suggest that harman and norharman decrease dopamine content by reducing TH activity and aggravate L-DOPA-induced cytotoxicity in PC12 cells.

• Preventive Nutrition and Food Science
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• 제7권3호
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• pp.250-254
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• 2002

The anticancer effects of leek (buchu in Korean) kimchi were evaluated in the human cancer cells: AGS gastric adenocarcinoma cells, HT-29 human colon adenocarcinoma cells and HL-60 leukemia cells. The leek kimchi (fermented for 6 days at 15$^{\circ}C$) was fractionated into 7 groups: methanol extract, hexane extract, methanol soluble extract MSE), dichloromethane (DCM) fraction (fr.), ethyl acetate fr., butanol fr. and aqueous fr. Most of the leek kimchi tractions inhibited the growth of AGS and HT-29 cancer cells in a dose dependent manner. In particular, the DCM fr. showed the highest inhibitory effect among the tractions. Treatment with the DCM fr. (0.1 mg/mL) reduced the survival rates of AGS and HT-29 cancer cells to 19% and 37% of the controls, respectively. Moreover the DCM fr. of the leek kimchi arrested G2/M phase in the cell cycle and induced apoptosis in HL-60 human promyelocytic leukemia cells. These results indicate that the leek kimchi exerted an anticancer effect on those human cancer cells, and that the DCM fr. arrested G2/M phase in the cell cycle and induced apoptosis in the leukemia cells.