• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.174-183
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• 2003

To obtain effective and safe topical depigmenting agents, we synthesized hydroxybenzoates, alkoxybenzoates, and 3,4,5-trimethoxycinnamate containing a thymol moiety and screened then for high-level inhibitory activity against melanin synthesis. Among them, 5-methyl-2-(methylethyl)phenyl (2Ε)-3-(3,4,5-trimethoxyphenyl)prop-2-enoate (Melasolv)$^{TM}$ 4h, showed the most potent depigmenting effect ($IC_{50}$/ = 10$\mu$M) with low cytotoxicity ($IC_{50}$/ = 200$\mu$M). To find the inhibition mechanism of our candidate, various in vitro tests were performed such as DPPH assay, tyrosinase activity in mushroom or in culture cell and expression of tyrosinase, TRP-l and TRP-2. The result of this study suggested that 4h inhibited melanin synthesis by reducing the expression of tyrosinase and TRP-l at the transcriptional level in melan-a melanocytes.s.

• The Journal of Korean Obstetrics and Gynecology
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• v.20 no.3
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• pp.65-80
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• 2007

Purpose: This study is to examine anti-obesity effect and cytotoxicity of the long-term oral administration of Ephedra Sinica(Ma-hwang, ES) Methods: Using diet-induced obesity C57BL/6 mouse model, anti-obesity effect and DNA chip expression and cytotoxicity of the long-term oral administration of this herbal extract were investigated. Results: The herbal extract treated groups were arrested in weight increment only when they were lodged together. Such effects were abolished when they kept individually. ES fed mice behaved very rudely and violently. On the basis of histological studies of liver tissues and also in vitro cytotoxicity tests of the liver and kidney cell lines, no significant toxicity was found by 14 weeks of ES treatments. However, we found significant changes in gene expression profile in ES treated group by micro-array analysis. In case of ES group, up-regulated genes were 113 and down-regulated were 120. Some of lipid metabolism related genes also significantly changed in treatment groups. Conclusion: ES had effects of increasing the basal metabolic rate by stimulating the sympathetic nervous systems.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.23 no.3
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• pp.33-41
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• 2010

Background & Objective : This study was performed to find a new anti-aging, anti-wrinkle agent. Ten kinds of hers were evaluated by proliferation, cytotoxicity, collagen synthesis tests in cultured human dermal fibroblast. Methods : MTT assay was carried out to check cell proliferation, cytotoxic effect of each herbal medicine. Collagen synthesis was investigated by the amount of propeptide using procollagen type-Ⅰ C peptide(PIP) ELISA kit(Takara). Results and Conclusions : There are no cytotoxicity in all group herbs by MTT assay. Collagen synthetic ability was greatest in LYCII FRUCTUS(LF) and was excellent in order of Rehmanniae Radix Preparat(RRP) > Nelumbinis Semen(NS) > Asparai Radix(AR) > Schizandrae Frucus(SF).

• Archives of Pharmacal Research
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• v.25 no.4
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• pp.457-462
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• 2002

Oregonin, a diarylheptanoid derivative from Alnus hirsuta Turcz, Betulaceae, was evaluated for its antitumor activity. Oregonin, known to have an antitumor function, and is a novel immunomodulator, which may augment macrophage activity. MTT assays and NO production tests were performed in order to investigate the cytotoxicity of oregonin in tumor cells and to examine its influence on macrophage in detail. In this study, the tumoricidal activity was also evaluated by a MTT assay. The cytotoxicity measurements in the oregon in-treated group both in vitro and in vivo showed a significant difference from that of the control group. In vivo, oregonin significantly increased NO production in a dose-dependent manner, and in vitro, the thioglycolate-induced inflammatory macrophages increased NO production in a dose-dependent manner after incubation. These results suggest that oregonin reacts with both the inflammatory and non-inflammatory macrophages in a similar way.

• YAKHAK HOEJI
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• v.41 no.5
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• pp.629-637
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• 1997

Tumor necrosis factor-${alpha}$ (TNF) induced a cytotoxic response in ME-180 cervical carcinoma cells in vitro. This cytotoxic response was accompanied by a temporal series of mitogenic stimuli : increased c-fos, c-jun and jun-B expression. Depletion of protein kinase C (PKC) by exposure of ME-180 cells to 100ng/ml phorbol myristate acetate (PMA) for 24hours almost completely abolished TNF-mediated increase in these signals, indicating that a PKC-dependent pathway is involved in TNF-mediated increases in the expression of c-fos, c-jun and jun-B. Characteristics of TNF receptors after exposure to 100ng/ml PMA or 24hours were not altered, suggesting that diminished induction of these oncogenes by TNF after PMA treatment is not due to any changes at the receptor level. To examine whether a PKC-dependent pathway is involved in TNF-mediated cytotoxicity in ME-180 cells, cytotoxicity was measured after depletion of PKC. No apparent changes in cytototoxicity after PKC depletion suggest that a PKC-dependent pathway is not involved in TNF-mediated cytotoxicity. Furthermore, results from cytotoxicity tests after exposure to staurosporine (PKC inhibitor) did not show any changes in the TNF-mediated cytotoxicity, confirming that a PKC-dependent pathway is not involved in this process. These data indicate that 1) TNF induces expression of c-fos, c-jun and jun-B oncogenes via a PKC-dependent pathway and 2) PKC-dependent expression of these three oncogenes by TNF may not be involved in TNF-mediated cytotoxicity in ME-180 cells.

• Restorative Dentistry and Endodontics
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• v.41 no.3
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• pp.167-175
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• 2016

Objectives: Endodontically treated teeth with insufficient tooth structure are often restored with esthetic restorations. This study evaluated the cytotoxicity and biological effects of yttria partially stabilized zirconia (Y-TZP) blocks in combination with several dental cements. Materials and Methods: Pairs of zirconia cylinders with medium alone or cemented with three types of dental cement including RelyX U200 (3M ESPE), FujiCEM 2 (GC), and Panavia F 2.0 (Kuraray) were incubated in medium for 14 days. The cytotoxicity of each supernatant was determined using 3-(4,5-dimethylthiazole- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays on L929 fibroblasts and MC3T3-E1 osteoblasts. The levels of interleukin-6 (IL-6) mRNA were evaluated by reverse transcription polymerase chain reaction (RT-PCR), and IL-6 protein was evaluated by enzyme-linked immunosorbent assays (ELISA). The data were analyzed using one-way ANOVA and Tukey post-hoc tests. A p < 0.05 was considered statistically significant. Results: The MTT assays showed that MC3T3-E1 osteoblasts were more susceptible to dental cements than L929 fibroblasts. The resin based dental cements increased IL-6 expression in L929 cells, but reduced IL-6 expression in MC3T3-E1 cells. Conclusions: Zirconia alone or blocks cemented with dental cement showed acceptable biocompatibilities. The results showed resin-modified glass-ionomer based cement less produced inflammatory cytokines than other self-adhesive resin-based cements. Furthermore, osteoblasts were more susceptible than fibroblasts to the biological effects of dental cement.

• Journal of Preventive Medicine and Public Health
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• v.30 no.3 s.58
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• pp.555-566
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• 1997

This study was carried out to evaluate the cytotoxicity of rock wool fibers(RWFs) such as cell division disturbance, chromosomal and DNA damage, and mutagenicity using cultured cells. RWFs were the man made mineral fibers. In order to find the correlation between the cytotoxicity of RWFs and the phagocytic capacity of cells, the phagocytic processes were observed using scanning electron microscope. Cell division disturbance by RWFs was evaluated by the formation of multinucleated giant cells. The chromosomal damage was evaluated by the micronucleus formation. For the evaluation of oxidative DNA damage, 8-hydroxy-2'-deoxyguanosine (8-OH-dG) formation was measured utilizing calf thymus DNA. Mutagenicity was determined by the point mutation of HGPRT and the effect of RWFs on cell transformation was also observed. 1. Compared with the results of chrysotile, RWFs were no or little effect on the cell growth according to the results done by the tests of cell proliferation inhibition and relative plating efficiency. 2. The frequency of multinucleated giant cell formation was increased by the treatment of RWFs and it was dose-dependent. However, the effect of RWFs was weaker than that of chrysotile. 3. The number of micronuclei formed in the RWFs treated cells was between those of cells treated with chrysotile and those of untreated cells. 4. The 2 fold increase in the formation of 8-OH-dG in calf thymus DNA was observed in the cells treated with RWFs in the presence of $H_2O_2$. On the other hand, chrysotile had no effect on the 8-OH-dG formation. 5. RWFs had no effect on the HGPRT point mutation and cell transformation. These results showed that RWFs could induce chromosomal damage, cell division disturbance and oxidative DNA damage in the RWFs treated cells.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.3
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• pp.237-242
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• 2009

Implant-supported fixed and removable prostheses provide a proper treatment modality with reliable success. The SS $II^{(R)}$ Implants is a one-stage nonsubmerged threaded titanium implants with Resorbable Blasting Media (RBM) surface developed by Osstem company (Busan, Korea) in October of 2002. This study is to evaluate the survival rate of the SS $II^{(R)}$ Implants for 4 years using radiographic parameters and to review the retrieved implants by the cytotoxicity tests. Since September 2003, 439 SS $II^{(R)}$ implants had been used for 173 patients at Ewha Womans University Medical Center in Korea. Patients consisted of 91 females (52.6 %) and 82 males (47.4 %). The patients' mean age was $42\;{\pm}16$ years, ranging from 21 to 83 years. The follow-up period ranged from 9 to 46 months (mean F/U $24.2\;{\pm}\;10.2$ months). The results are as follows; 1. Of 439 implants, 17 implants were removed and 4-year cumulative survival rate was 96.1%. 2. 82.3% of 17 failed implants were founded during healing phase, and 94.1% of failed fixtures were removed within 5 months after implantation. 3. Crestal bone around the implants was resorbed to 1 mm in 89.0%, to 1 - 2 mm loss of the marginal bone in 8.3%, and the bone loss over 2 mm was occurred in 2.7%. 4. Microscopic examination of the retrieved implants disclosed Grade 0 cytotoxicity in 4 and Grade 1 cytotoxicity in 2 of 6 groups divided according to LOT numbers. Inhibition rate with optical density was acceptable as low as ISO standard.

• Restorative Dentistry and Endodontics
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• v.39 no.2
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• pp.89-94
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• 2014

Objectives: The aim of this study was to evaluate the cytotoxicity, setting time and compressive strength of MTA and two novel tricalcium silicate-based endodontic materials, Bioaggregate (BA) and Biodentine (BD). Materials and Methods: Cytotoxicity was evaluated by using a 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-((phenylamino)carbonyl)-2H-tetrazolium hydroxide (XTT) assay. Measurements of 9 heavy metals (arsenic, cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc) were performed by inductively coupled plasma-mass spectrometry (ICP-MS) of leachates obtained by soaking the materials in distilled water. Setting time and compressive strength tests were performed following ISO requirements. Results: BA had comparable cell viability to MTA, whereas the cell viability of BD was significantly lower than that of MTA. The ICP-MS analysis revealed that BD released significantly higher amount of 5 heavy metals (arsenic, copper, iron, manganese, and zinc) than MTA and BA. The setting time of BD was significantly shorter than that of MTA and BA, and the compressive strength of BA was significantly lower than that of MTA and BD. Conclusions: BA and BD were biocompatible, and they did not show any cytotoxic effects on human periodontal ligament fibroblasts. BA showed comparable cytotoxicity to MTA but inferior physical properties. BD had somewhat higher cytotoxicity but superior physical properties than MTA.

• Restorative Dentistry and Endodontics
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• v.28 no.5
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• pp.425-430
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• 2003

The purpose of this study was to evaluate the clinical applications of the Sodium Dichloroisocyanurate effervescent tablet as a routine root canal irrigant by performing several in vitro tests such as $Cl^{-}$ content. cytotoxicity. antimicrobial effect as well as its pH level compared to the equivalent concentration of sodium hypochlorite solution. 1. Sodium Dichloroisocyanurate demonstrated lower level of $Cl^{-}$ concentration than each dilution of sodium hypochlorite solution. Both solution has increased level of $Cl^{-}$ as the concentration of each solution increased. There was no significant change of $Cl^{-}$ concentration in sodium hypochlorite as time goes by. However. $Cl^{-}$ concentration in Sodium Dichloroisocyanurate was increased. 2. The antimicrobial effects of both solutions were increased when their concentrations were increased. One day after dilution. antimicrobial effect of Sodium Dichloroisocyanurate was slightly higher than sodium hypochlorite. however. there was no difference in 1 week dilution solution. One month dilution solution of sodium hypochlorite still retain its activity. but antimicrobial effect of Sodium Dichloroisocyanurate was drastically decreased 1 month after dilution. 3. The cytotoxicity of Sodium Dichloroisocyanurate was rather higher than same concentration of sodium hypochlorite solution until 1 week after dilution. Then in 1 month. cytotoxicity of Sodium Dichloroisocyanurate was decreased than that of 1 week dilution solution. especially 4% Sodium Dichloroisocyanurate solution has almost no toxicity. However. 1% and 2% sodium hypochlorite solution has unchanged moderate degree of cytotoxicity after the dilution. Furthermore. 4% sodium hypochlorite solution showed high level of toxicity. 4. The pH level of Sodium Dichloroisocyanurate showed that the solution was weak acid (pH5). On the other hand. sodium hypochlorite was revealed as a strong alkaline solution (pH12). There was no change in pH following the dilution of each solution. As results. Sodium Dichloroisocyanurate solution fully satisfy the basic requirements as a root canal irrigation solution. However. we strongly recommend to use this solution clinically in low concentration and try to apply into the root canal within 1 week after dilution.