• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.39-44
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• 2014

Glass discs functionalized with alkynyl (GDA) terminated monolayers were prepared and incubated in $AgNO_3$ solution (GDA-Ag). The modified functional glass surfaces were characterized by X-ray photoelectron microscopy (XPS). The potential of GDA and GDA-Ag as antimicrobial surfaces was investigated. Anti-microbial efficacies of GDA against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, and Candida albicans was relatively low ranging from 4.67 to 17.00%. However, the GDA-Ag was very effective and its antimicrobial efficacy ranged from 99.90 to 99.99% against the same set of microbial strains except for C. albicans where it was 95.50%. The durability of the Ag bonded to the terminal alkynyl groups was studied by placing the GDA-Ag in PBS buffer solution (pH 7.4) for two weeks. Initially, the silver release was relatively fast, with 40.05 ppb of silver released in first 24 h followed by a very slow and constant release. To study the potential of GDA-Ag for medical applications, in vitro cytotoxicity of GDA-Ag against Human Embryonic Kidney 293 (HEK293) cell lines was studied using WST-assay. The cytotoxicity of the GDA-Ag was very low (5%) and was almost comparable to the control (blank glass disc) indicating that GDA-Ag has a promising potential for medical applications.

• Toxicological Research
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• v.30 no.4
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• pp.261-266
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• 2014

Environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs) have been implicated in cancer development and progression. However, the effects of PAHs on carcinogenesis are still poorly understood. Here, we characterized a mouse cancer cell line BNL 1ME A. 7R.1 (1MEA) derived by transformation of non-tumorigenic liver cell line BNL CL.2 (BNL) using 3-methylcholanthrene (3MC), a carcinogenic PAH. RT-PCR and immunoblot analysis were used to determine the expression level of mRNA and proteins, respectively. To determine functionality, cell motility was assessed in vitro using a transwell migration assay. Both mRNA and protein levels of E-cadherin were significantly decreased in 1MEA cells in comparison with BNL cells. While the expression levels of mesenchymal markers and related transcription factors were enhanced in 1MEA cells, which could lead to increase in cell motility. Indeed, we found that 7-day exposure of BNL cells to 3-MC reduced the level of the adhesion molecule and epithelial marker E-cadherin and increased reciprocally the level of the mesenchymal marker vimentin in a dose-dependent manner. Taken together, these results indicate that the process of epithelial-mesenchymal transition (EMT) may be activated during premalignant transformation induced by 3-MC. A mechanism study to elucidate the relation between 3-MC exposure and EMT is underway in our laboratory.

• Toxicological Research
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• v.21 no.4
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• pp.355-360
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• 2005

Epidemiological and laboratory studies provide insight into the anti-carcinogenic potential of garlic and its constituent compounds. Garlic is appealing as an anti-carcinogenic agent due to its ability to induce apoptosis in vitro. Diallyl disulfide (DADS) is one of the major components of garlic that used to determine inhibition of cell proliferation and induced apoptosis in human colon cell lines. In this study, human colorectal cancer cell lines (LOVO, HCT-116, SW-480) were exposed to DADS. The inhibitory effects of DADS dose level more than $50\;{\mu}M$ in the cell viability of all cell lines. Cell growth activity inhibits of human colon cancer cell lines. The inhibitory effects of DADS dose level more than $25\~50\;{\mu}M$ in the cell growth using MTT assay. We found that DADS may have the apoptosis action (chromatin condensation, DNA fragmentation) using DAPI staining and increased the expression of caspase-3 at the dose level more than $100\;{\mu}M$, decreased the expression level of $\beta-catenin$ at dose dependent in the western blotting. We suggest that DADS may have a potential candidate as cancer chemopreventive agents.

• Toxicological Research
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• v.28 no.3
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• pp.165-172
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• 2012

Raphanus sativus (Cruciferaceae), commonly known as radish is widely available throughout the world. From antiquity it has been used in folk medicine as a natural drug against many toxicants. The present study was designed to evaluate the hepatoprotective activity of radish (Raphanus sativus) enzyme extract (REE) in vitro and in vivo test. The $IC_{50}$ values of REE in human liver derived HepG2 cells was over 5,000 ${\mu}g/ml$ in tested maximum concentration. The effect of REE to protect tacrine-induced cytotoxicity in HepG2 cells was evaluated by MTT assay. REE showed their hepatoprotective activities on tacrine-induced cytotoxicity and the $EC_{50}$ value was 1,250 ${\mu}g/ml$. Silymarin, an antihepatotoxic agent used as a positive control exhibited 59.7% hepatoprotective activity at 100 ${\mu}g/ml$. Moreover, we tested the effect of REE on carbon tetrachloride ($CCl_4$)-induced liver toxicity in rats. REE at dose of 50 and 100 mg/kg and silymarin at dose of 50 mg/kg were orally administered to $CCl_4$-treated rats. The results showed that REE and silymarin significantly reduced the elevated levels of serum enzyme markers induced by $CCl_4$. The biochemical data were supported by evaluation with liver histopathology. These findings suggest that REE, can significantly diminish hepatic damage by toxic agent such as tacrine or $CCl_4$.

• Applied Biological Chemistry
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• v.42 no.1
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• pp.68-72
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• 1999

The cytotoxicity of 1,3-diphenylpropenone derivatives known to inhibit the farnesyl protein transferase (FPTase) was examined against various established tumor cell line, A549 (lung cancer), SKMEL-2 (uterine cancer), HCT-15 (skin cancer), SKOV-3 (brain cancer) and XF-498 (colon cancer) of the 1,3-diphenylpropenone derivatives showing farnesyl protein transferase (FPTase) inhibition activity. And the structure-activity relationship (SAR) between structure of 1,3-diphenylpropenone derivatives as substrate and cytotoxicity was investigated by Free-Wilson analysis as well as Hansch method with tumor cell lines. From the result of Free-Wilson analyses, X-substituents on the benzoyl group have a more important role than Y-substituents on the styryl group. The 2,4-dichloro substituent, 15 and 2,4-dimethyl substituent, 16 showed the highest cytotoxicity (average pI_(50)=5.0). Particulary, the cytotoxicity of X-substituents increased with electronic effect $({\sigma})$ due to weak electron withdrawing group with optimum value $({\sigma}_{opt}=0.22{\sim}0.29})$ whereas that of Y-substituent resulted from various factors such as logP, $B_1$ and R constant.

• Toxicological Research
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• v.18 no.1
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• pp.59-64
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• 2002

Substantial evidences have been accumulated about the hormone-like effects of exogenous substances such as pesticides and industrial chemicals during past years. The effects of these substances on the endocrine system are believed to be either enhancing or reducing of various endocrine action. It is necessary to identify putative causal agents by the batter system and to assess their ability to disrupt the endocrine system. A variety of in vitro and In vivo approaches have been used to determine the androgenic effects of environmental chemicals. To establish the method for assessment of the putative endocrine disruptors with androgenic activity, we carried out the cell proliferation assay by MTS method after treatment with the various concentration of testosterone in LNCaP cells (human prostatic cancer cell line) and also observed the expression of androgen-related genes by quantitative RT-PCR. In the cell proliferation assay, the results showed that the grouth of LNCaP cells increased within level of at least 10pM testosterone. We measured by quantitative RT-PCR method on the effects of testosterone on mRNA expression of androgen receptor (AR), prostate-specific antigen (PSA), bone morphogenetic protein (BMP) and BMP receptor (BMPR) In LNCaP cells. The results demonstrated that mRNA expression of PSA and BMPR-IB was observed differently within level of at least 0.01 pM testosterone compared with non-treated control. These observations suggest that the detection of PSA and BMPR-IB mRNA by the quantitative RT-PCR in LNCaP cells is very sensitive method to identify the endocrine disruptors to have the androgenic effects.

• Toxicological Research
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• v.32 no.3
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• pp.225-230
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• 2016

Zingiber officinale Roscoe has been widely used as a folk medicine to treat various diseases, including cancer. This study aims to re-examine the therapeutic potential of co-administration of natural products and cancer chemotherapeutics. Candidate material for this project, ${\alpha}$-zingiberene, was extracted from Zingiber officinale Roscoe, and ${\alpha}$-zingiberene makes up $35.02{\pm}0.30%$ of its total essential oil. ${\alpha}$-Zingiberene showed low $IC_{50}$ values, $60.6{\pm}3.6$, $46.2{\pm}0.6$, $172.0{\pm}6.6$, $80.3{\pm}6.6$ (${\mu}g/mL$) in HeLa, SiHa, MCF-7 and HL-60 cells each. These values are a little bit higher than $IC_{50}$ values of general essential oil in those cells. The treatment of ${\alpha}$-zingiberene produced nucleosomal DNA fragmentation in SiHa cells, and the percentage of sub-diploid cells increased in a concentration-dependent manner in SiHa cells, hallmark features of apoptosis. Mitochondrial cytochrome c activation and an in vitro caspase-3 activity assay demonstrated that the activation of caspases accompanies the apoptotic effect of ${\alpha}$-zingiberene, which mediates cell death. These results suggest that the apoptotic effect of ${\alpha}$-zingiberene on SiHa cells may converge caspase-3 activation through the release of mitochondrial cytochrome c into cytoplasm. It is considered that anti-proliferative effect of ${\alpha}$-zingiberene is a result of apoptotic effects, and ${\alpha}$-zingiberene is worth furthermore study to develop it as cancer chemotherapeutics.

• Toxicological Research
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• v.32 no.3
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• pp.215-223
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• 2016

This study is to investigate the biological, biochemical and cytotoxic effects of puffer fish (Arothron stellatus) toxin extracts under in-vitro condition. Extracted toxins from various organs of puffer fish were purified by using active charcoal column, and Bio-gel-P2 column chromatography. The lethality of toxin was tested in crabs, which consists of neurotoxic compounds. The degree of the brine shrimp lethality assay was found directly proportional to the concentration of the toxin extracts, which was well supported by hemolytic assay. The experimental results suggested that the gonad was found higher toxins than the liver and muscles. The mortality rate of brine shrimp nauplii was increased with the raise of concentrations of toxin level. Among the different doses and time dependent cytotoxic effect of human cervical carcinoma (HeLa) cells were showed $4.0{\mu}g/mL$ of toxin, which was effectively inhibited cancer cell proliferation. HPLC and TLC analysis was revealed that the A. stellatus toxin contains tetrodotoxin (TTX), related compounds 4-epi TTX and anhydro-TTX. The present results suggested that the A. stellatus contain TTX as a major and anh-TTX as a minor toxin. It could be the potential candidate in the field of anticancer drug discovery against human cervical cancer cells. The present data is confirming that the puffer fish toxin as an interesting source of novel bioactive natural compounds with potent applications in pharmacology.

• Toxicological Research
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• v.27 no.3
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• pp.173-180
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• 2011

Atopic dermatitis (AD) is a chronic, recurrent inflammatory skin disease that is associated with Th2 cell-mediated allergy. The process that leads to infiltration of inflammatory cells into an AD lesion is remarkably dependent on various chemokines, especially TARC (thymus and activation-regulated chemokine/CCL17) and MDC (macrophage-derived chemokine/CCL22). Serum levels of these chemokines are over-expressed in AD patients. Citrus unshiu, which is known as Satsuma mandarin, has anti-oxidative, anti-inflammation, and anti-microviral activity. Therefore, we investigated the effect of EtOH extract of premature C. unshiu on AD. We did this using a DNCB-induced AD mouse model. We also tried to confirm an inhibitory effect for premature C. unshiu on the expression of inflammatory chemokines in IFN-${\gamma}$ and TNF-${\alpha}$ stimulated HaCaT human keratinocytes. We found that extract of premature C. unshiu reduced DNCB-induced symptoms such as hyperkeratosis, increased skin thickness, and infiltrated mast cells, in our AD-like animal model. The extract decreased levels of IFN-${\gamma}$ and IL-4 in ConA-stimulated splenocytes isolated from DNCB-treated mice. Also, extract of premature C. unshiu inhibited mRNA expression and protein production of TARC and MDC through the inhibition of STAT1 phosphorylation. These results suggest that C. unshiu has anti-atopic activity by regulating inflammatory chemokines such as TARC and MDC.

• Journal of Pharmacopuncture
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• v.22 no.1
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• pp.49-54
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• 2019

Objective: Antibiotic resistance is a global health problem and threatens health of societies. These problems have led to a search for alternative approaches such as combination therapy. The aim of the present study was to investigate the effect of caffeine and omeprazole in combination with gentamicin or ciprofloxacin against standard and clinically resistant isolates of Staphylococcus aureus and Escherichia coli. Methods: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of different agents against bacterial strains were determined. The interaction of non- antibiotic drugs with gentamicin and ciprofloxacin was studied in vitro using a checkerboard method and calculating fraction inhibitory concentration index (FICI). Verapamil as efflux pump inhibitor was used to evaluate the possible mechanism of bacterial resistance to antibiotics. Results: The MIC and MBC values of gentamicin against bacterial strains were in the range of $20-80{\mu}g/ml$ and $40-200{\mu}g/ml$, respectively. Caffeine and omeprazole had no intrinsic inhibitory activity against tested microorganisms. However, upon combination of caffeine with antibiotics, the synergistic effects were observed. Verapamil was able to reduce the MIC values of gentamicin (4 folds) only in some bacterial strains. Conclusion: These findings indicated that caffeine was effective in removing bacterial infection caused by S. aureus and E. coli. The relevant mechanisms of antibiotic resistance were not related to the drug efflux.