• Biomolecules & Therapeutics
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• v.21 no.4
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• pp.270-276
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• 2013

Fucoxanthin is an important carotenoid derived from edible brown seaweeds and is used in indigenous herbal medicines. The aim of the present study was to examine the cytoprotective effects of fucoxanthin against hydrogen peroxide-induced cell damage. Fucoxanthin decreased the level of intracellular reactive oxygen species, as assessed by fluorescence spectrometry performed after staining cultured human HaCaT keratinocytes with 2',7'-dichlorodihydrofluorescein diacetate. In addition, electron spin resonance spectrometry showed that fucoxanthin scavenged hydroxyl radical generated by the Fenton reaction in a cell-free system. Fucoxanthin also inhibited comet tail formation and phospho-histone H2A.X expression, suggesting that it prevents hydrogen peroxide-induced cellular DNA damage. Furthermore, the compound reduced the number of apoptotic bodies stained with Hoechst 33342, indicating that it protected keratinocytes against hydrogen peroxide-induced apoptotic cell death. Finally, fucoxanthin prevented the loss of mitochondrial membrane potential. These protective actions were accompanied by the down-regulation of apoptosis-promoting mediators (i.e., B-cell lymphoma-2-associated ${\times}$ protein, caspase-9, and caspase-3) and the up-regulation of an apoptosis inhibitor (B-cell lymphoma-2). Taken together, the results of this study suggest that fucoxanthin defends keratinocytes against oxidative damage by scavenging ROS and inhibiting apoptosis.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.3
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• pp.112-116
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• 2015

Nitric Oxide (NO) has been known to play important physiological and pathological roles. In this study, Sodium nitroprusside (SNP), NO donor, induced the apoptosis of HaCaT cell, human spontaneous immortal keratinocyte, which was investigated through DAPI staining and cleavage of PARP and caspase-3 protein. However, the expression level of Bip and CHOP, involved in ER stress, was not significantly changed as compared to the control cell group. Recent studies have showed that SIRT1, $NAD^+$-dependent deacetylase, is the key protein that controls cell survival and death. SNP treatment suppressed the SIRT1 gene expression, which indicated that apoptosis induced by SNP could be implicated in SIRT1 down-regulation.

• 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.

• The Korea Journal of Herbology
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• v.38 no.5
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• pp.61-67
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• 2023

Objective : Mori Fructus has been used to relieve thirst, and treat dizziness, tinnitus, and insomnia caused by poor constitution. This study was performed to investigate the protective effect of the ethanol extract of Mori Fructus (MF) in ultraviolet B (UVB)-induced apoptotic cell death in human keratinocyte cells. Methods : MF was prepared by extracting 100 g of Mori Fructus in 1 L of 100% ethanol for 48 h. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to measure cell viability. Apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, and the expression of apoptosis-related proteins was observed by Western blot. Tyrosinase activity was measured with a colorimetric commercial kit. Results : MF promoted cell vitality and inhibited apoptosis of UVB-induced HaCaT cells. MF pretreatment reduced TUNEL-positive cells and increased the expression of caspase-3 and -9. MF also displayed antioxidant effect with high radical scavenging ability. At 2 ㎎/㎖ concentration, the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical inhibition rates were 55.3 ± 4.6% and 48.5 ± 1.3%, respectively. Furthermore, MF showed a concentration-dependent inhibitory effect on tyrosinase. Conclusion : These results suggest that MF functions as a protective regulator in UVB-induced HaCaT cells by regulating apoptosis and partially exerting antioxidant effects. In addition, the tyrosinase inhibitory effect of MF shows the potential for MF to be used for skin pigmentation.

• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.56-64
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• 2010

Pentoxifylline (PTX) has been used for the local reduction of fat tissue in the clinical setting. However, its safety and efficacy have not been proven. The aim of this study was to evaluate the effects of PTX on cell lines established from fat tissue. Newly cultured human preadipocytes and adipocytes from subcutaneous abdominal fat in addition to purchased human lung fibroblasts and keratinocytes were treated with PTX at different concentrations. Cell viability was determined using the Cell counting kit (CCK)-8 assay and lipolysis was evaluated using an Elisa kit. DNA fragmentation, Western blot analysis, Hoechst and Propidium Iodide (PI) staining and fluorescence activated cell scanning analysis were performed to confirm apoptosis. The viability of adipocytes, preadipocytes, keratinocytes and fibroblasts was markedly decreased at concentrations of PTX above 20 mM. Apoptosis was induced at concentrations of PTX over 40 mM in all cell lines. Lipolysis was increased by 60% at concentrations of PTX of 20 mM compared to the control. In conclusion, the results of this study showed that 20 mM of PTX induced lipolysis. At concentrations over 20 mM, PTX reduced the viability of all cells studied including: adipocytes, preadipocytes, fibroblasts and keratinocytes, in a non-specific manner.

• Biomolecules & Therapeutics
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• v.24 no.6
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• pp.616-622
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• 2016

Baicalein (5,6,7-trihydroxy-2-phenyl-chromen-4-one) is a flavone, a type of flavonoid, originally isolated from the roots of Scutellaria baicalensis. This study evaluated the protective effects of baicalein against oxidative damage-mediated apoptosis induced by ultraviolet B (UVB) radiation in a human keratinocyte cell line (HaCaT). Baicalein absorbed light within the wavelength range of UVB. In addition, baicalein decreased the level of intracellular reactive oxygen species (ROS) in response to UVB radiation. Baicalein protected cells against UVB radiation-induced DNA breaks, 8-isoprostane generation and protein modification in HaCaT cells. Furthermore, baicalein suppressed the apoptotic cell death by UVB radiation. These findings suggest that baicalein protected HaCaT cells against UVB radiation-induced cell damage and apoptosis by absorbing UVB radiation and scavenging ROS.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.6
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• pp.483-490
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• 2001

There were many controversies in the cause and progress of tumorigenesis. Recently, studies on the mutation of genes related to the tumor have extensively been performed due to development of molecular biology. Structural and morphological changes of chromosomes, which are related to the abnormal activation of oncogenes or inactivation of tumor suppression genes, transform the normal cells into the tumor cells. p53 and Rb are well known tumor suppressor genes, while oncogenes include c-myc, bcl-2 and ras, etc. When exposed to cell damaging agents, p53 inhibits cell growth by inducing transcription of p21. Especially p73, which is homo-logy of p53, frequently deleted in melanoma, neuroblastoma, colon cancer, and breast cancer, when over produced, p73 activates the transcription of p21, bax-1 and inhibits cell growth by inducing apoptosis. For study on mRNA expression of p21 and p73, normal oral keratinocytes, and cell lines of primary and metastatic oral squamous cell carcinoma were cultured and then electrophoresis and RT-PCR(reverse transcription-polymerase chain reaction) were performed. 1. The mRNA of p21 and p73 in normal oral keratinocyte expressed lower than that of primary squamous cell carcinoma. 2. The mRNA of p21 in metastatic oral squamous carcinoma cell lines was expressed as various patterns compared with that of normal oral keratinocyte. 3. In the metastatic oral squamous cell lines, the mRNA of HN8 expressed higher than that of HN12 or HN19. 4. The mRNA of p73 in primary oral squamous cell lines expressed 4-5 times higher than that of normal keratinocyte. 5. In metastatic oral squamous cell lines, there was no significant expression of p73 mRNA compared with that of normal oral keratinocyte. From the results obtained in this study, mRNA expression of p73 in primary oral squamous cell lines was remarkable, while mRNA expression of p21 and p73 in metastatic oral squamous cell lines were statistically insignificant.

• Biomolecules & Therapeutics
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• v.22 no.2
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• pp.136-142
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• 2014

We investigated the protective effects of chlorogenic acid (CGA), a polyphenol compound, on oxidative damage induced by UVB exposure on human HaCaT cells. In a cell-free system, CGA scavenged 1,1-diphenyl-2-picrylhydrazyl radicals, superoxide anions, hydroxyl radicals, and intracellular reactive oxygen species (ROS) generated by hydrogen peroxide and ultraviolet B (UVB). Furthermore, CGA absorbed electromagnetic radiation in the UVB range (280-320 nm). UVB exposure resulted in damage to cellular DNA, as demonstrated in a comet assay; pre-treatment of cells with CGA prior to UVB irradiation prevented DNA damage and increased cell viability. Furthermore, CGA pre-treatment prevented or ameliorated apoptosis-related changes in UVB-exposed cells, including the formation of apoptotic bodies, disruption of mitochondrial membrane potential, and alterations in the levels of the apoptosis-related proteins Bcl-2, Bax, and caspase-3. Our findings suggest that CGA protects cells from oxidative stress induced by UVB radiation.

• Molecular & Cellular Toxicology
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• v.1 no.2
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• pp.111-115
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• 2005

Ultraviolet (UV) radiation to mammalian skin is known to alter cellular function via generation of Reactive Oxygen Species (ROS), DNA damage and DNA lesions, such as pyrimidine dimmers and photoproducts, which could lead to DNA mutation if they are not repaired. In this study, we have investigated the reduction of DNA damage and of apoptosis with a particular attention to genetic effect of paeoniflorin in Normal Human Epidermal Keratinocytes (NHEK). After UVB irradiation from $10\;to\;500mJ/cm^{2}$ to NHEK, Mean Tail Moments (MTM) were increased with UVB dose increase. The greatest amount of strand breaks was induced at $500mJ/cm^{2}$ of UVB. Even at the lowest dose of UVB ($10mJ/cm^{2}$), change in MTM was detected (P<0.0001). Pretreated cell with 0.1% paeoniflorin maximally reduced the level of DNA damage to about 21.3%, compared to untreated cell. In the lower concentrations less than 0.01% of paeoniflorin, MTM had a small increase but paeoniflorin still had reductive effects of DNA damage. We measured the apoptosis suppression of paeoniflorin with annexin V flous staining kit. As we observed under the fluorescence microscopy to detect apoptosis in the irradiated cell, the fluorescence intensity was clearly increased in the untreated cell, but decreased in treated cells with paeoniflorin. These results suggest that paeoniflorin reduces the alteration of cell membranes and prevents DNA damage. Therefore, the use of paeoniflorin as a free radical scavenger to reduce the harmful effects of UV lights such as chronic skin damage, wrinkling and skin cancer can be useful to prevent the formation of photooxidants that result in radical damage.

• Clinical and Experimental Pediatrics
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• v.57 no.3
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• pp.153-156
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• 2014

Toxic epidermal necrolysis is an unpredictable and severe adverse drug reaction. In toxic epidermal necrolysis, epidermal damage appears to result from keratinocyte apoptosis. This condition is triggered by many factors, principally drugs such as antiepileptic medications, antibiotics (particularly sulfonamide), nonsteroidal anti-inflammatory drugs, allopurinol, and nevirapine. Lamotrigine has been reported potentially cause serious cutaneous reactions, and concomitant use of valproic acid with lamotrigine significantly increases this risk. We describe a case of an 11-year-old girl with tic and major depressive disorders who developed toxic epidermal necrolysis after treatment with lamotrigine, and who was diagnosed both clinically and pathologically. Children are more susceptible to lamotrigine-induced rash than adults, and risk of serious rash can be lessened by strict adherence to dosing guidelines. Unfortunately, in our case, the patient was administered a higher dose than the required regimen. Therefore, clinicians should strictly adhere to the dose regimen when using lamotrigine, especially in children.