• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.10-10
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• 2011

Graphene and graphene derivatives have attracted enormous attention from various research fields for applications in electronic devices, transparent electrodes, biosensors, drug delivery system and surface coatings. In the viewpoint of chemist, the chemical structure of graphene derivatives seems intriguing but detailed structures are being revealed only recently while engineering approaches for various applications are being executed very actively. Recently, several reports are available on interactions of graphene with biomolecules including proteins and nucleic acids. In this talk, I'll introduce recent studies which harness graphene derivatives for developing bioanalytical platforms to quantitatively analyze various enzyme activities. The systems rely on attractive interaction between graphene oxide and nucleic acids or phospholipids.

• KSBB Journal
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• 제16권2호
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• pp.99-106
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• 2001

Proteomics research includes identification and quantitation of single protein and/or protein complex, profiling of protein expression changes in response to biological perturbations, characterization of protein functions and interactions, and elucidation the linkage between proteins and diseases. In this review paper, recent developments in the basic technologies involved in the proteomics research such as 2-dimensional PAGE and mass spectrometry are discussed. Also, the application areas of proteomics technology such as protein expression mapping and cell map proteomics are introduced with the focus on new drug development.

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.2907-2909
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• 2012

A disintegrin and metalloprotease with thrombospondin domains (ADAMTS) are a member of peptidase and involved in processing of von Willebrand factor as well as cleavage of aggrecan, versican, brevican and neurocan. Among 19 subfamilies of human ADAMTS, ADAMTS-4 is a zinc-binding metalloprotease and is a famous therapeutic target for arthritis. It has been reported that a flavonoid luteolin shows inhibitory activity against ADMATS-4. In this study, we verified that luteolin is a potent inhibitor of ADAMTS-4 and probed the molecular basis of its action. On the basis of a docking study, we proposed a binding model between luteolin and ADAMTS-4 in which 3',4'-dihydroxyl groups in luteolin formed hydrogen bonding with ADMATS-4 and these interactions are important for its inhibitory activity against ADAMTS-4.

• 동의생리병리학회지
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• 제18권4호
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• pp.957-964
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• 2004

Herbal medicines are increasingly used to treat various diseases and lots of studies have been reported that they had benefits in treating and preventing of diseases. But organic toxicity is increasingly recognized as herbal medicines become more popular in industrialized countries. Some herbal products potentially benefit people with lots of diseases, however these benefits remain generally unproved in humans, and a greater awareness for potential adverse effects is required. A herb containing a wide variety of, mostly unknown, substances may well include some with unwanted effects. This review focuses on emerging organic toxicities that have been observed associated with various herbal preparations involving the liver, kidney, and heart, and patterns of organ injury, potential risk factors for organic toxicities. In addition to the potential for organic toxicities, drug drug interactions between herbal medicines and conventional agents may affect the efficacy and safety of concurrent medical therapy. Appropriate reporting and regulatory system to monitor herbal toxicity are required, in conjunction with ongoing scientific evaluation of the potential benefits of phytotherapy.

• 대한약침학회지
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• 제25권2호
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• pp.79-87
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• 2022

Since ancient times, plants have been a major source of novel drug molecules and have been used in the treatment of different infectious diseases. Secondary plant metabolites have miraculous healing properties and show potent therapeutic responses when used in combination drug therapy. The prime objective of this review is to summarize the concept of drug combination with special emphasis on the synergistic interactions between plant-derived bioactive phytochemicals with commercially available antimicrobial agents. The study also assesses the roles, importance, and applicability of phytochemicals in the management of different diseases. The review focuses on different aspects of combined antimicrobial activities, the possible mechanisms involved, and the current status of research in the field. The study was conducted based on an extensive literature survey that resulted in the following hypothesis: secondary metabolites derived from plants possess remarkable therapeutic activities. The study was designed as a systematic review that ensures unbiased and accurate representations of the relevant data and information. Jadad scale selection criteria were used for qualitative analysis of the articles to assess them based on the relevant secure score (minimum and maximum scores range between 1 and 5, respectively). Articles with secure scores > 3 were considered for the study. A comprehensive literature survey was conducted using resource databases including PubMed, Google Scholar, Bielefeld Academic Search Engine, Research Gate, Scopus, Medline, and Science Direct up to June 2019. This article contains concise information about the most commonly used bioactive phytochemicals with potent antifungal and antibacterial effects.

• Journal of Pharmaceutical Investigation
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• 제38권3호
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• pp.183-189
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• 2008

The present study compared the feasibility of Caco-2 and MDCK cells as an efficient in-vitro model for the drug classification based on Biopharmaceutics Classification System (BCS) as well as an in-vitro model for drug interactions mediated by P-gp inhibition or P-gp induction. Thirteen model drugs were selected to cover BCS Class I{\sim}IV$ and their membrane permeability values were evaluated in both Caco-2 and MDCK cells. P-gp inhibition studies were conducted by using vinblastine and verapamil in MDCK cells. P-gp induction studies were also performed in MDCK cells using rifampin and the P-gp expression level was determined by western blot analysis. Compared to Caco-2 cells, MDCK cells required shorter period of time to culture cells before running the transport study. Both Caco-2 and MDCK cells exhibited the same rank order relationship between in-vitro permeability values and human permeability values of all tested model compounds, implying that those in-vitro models may be useful in the prediction of human permeability (rank order) of new chemical entities at the early drug discovery stage. However, in the case of BCS drug classification, Caco-2 cells appeared to be more suitable than MDCK cells. P-gp induction by rifampin was negligible in MDCK-cells while MDCK cells appeared to be feasible for P-gp inhibition studies. Taken all together, the present study suggests that Caco-2 cells might be more applicable to the BCS drug classification than MDCK-cells, although MDCK cells may provide some advantage in terms of capacity and speed in early ADME screening process.

• Molecules and Cells
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• 제43권7호
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• pp.662-670
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• 2020

We have investigated the involvement of the pre-mRNA processing factor 4B (PRP4) kinase domain in mediating drug resistance. HCT116 cells were treated with curcumin, and apoptosis was assessed based on flow cytometry and the generation of reactive oxygen species (ROS). Cells were then transfected with PRP4 or pre-mRNA-processing-splicing factor 8 (PRP8), and drug resistance was analyzed both in vitro and in vivo. Furthermore, we deleted the kinase domain in PRP4 using Gateway™ technology. Curcumin induced cell death through the production of ROS and decreased the activation of survival signals, but PRP4 overexpression reversed the curcumin-induced oxidative stress and apoptosis. PRP8 failed to reverse the curcumin-induced apoptosis in the HCT116 colon cancer cell line. In xenograft mouse model experiments, curcumin effectively reduced tumour size whereas PRP4 conferred resistance to curcumin, which was evident from increasing tumour size, while PRP8 failed to regulate the curcumin action. PRP4 overexpression altered the morphology, rearranged the actin cytoskeleton, triggered epithelial-mesenchymal transition (EMT), and decreased the invasiveness of HCT116 cells. The loss of E-cadherin, a hallmark of EMT, was observed in HCT116 cells overexpressing PRP4. Moreover, we observed that the EMT-inducing potential of PRP4 was aborted after the deletion of its kinase domain. Collectively, our investigations suggest that the PRP4 kinase domain is responsible for promoting drug resistance to curcumin by inducing EMT. Further evaluation of PRP4-induced inhibition of cell death and PRP4 kinase domain interactions with various other proteins might lead to the development of novel approaches for overcoming drug resistance in patients with colon cancer.

• BMB Reports
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• 제46권5호
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• pp.282-287
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• 2013

Cecropin A and papiliocin are novel 37-residue cecropin-like antimicrobial peptides isolated from insect. We have confirmed that papiliocin possess high bacterial cell selectivity and has an ${\alpha}$-helical structure from $Lys^3$ to $Lys^{21}$ and from $Ala^{25}$ to $Val^{35}$, linked by a hinge region. In this study, we demonstrated that both peptides showed high antimicrobial activities against multi-drug resistant Gram negative bacteria as well as fungi. Interactions between these cecropin-like peptides and phospholipid membrane were studied using CD, dye leakage experiments, and NMR experiments, showing that both peptides have strong permeabilizing activities against bacterial cell membranes and fungal membranes as well as $Trp^2$ and $Phe^5$ at the N-terminal helix play an important role in attracting cecropin-like peptides to the negatively charged bacterial cell membrane. Cecropin-like peptides can be potent peptide antibiotics against multi-drug resistant Gram negative bacteria and fungi.

• 한국임상약학회지
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• 제23권4호
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• pp.322-326
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• 2013

Purpose: Telmisartan, an angiotensin receptor blocker has been known to be a potent blocker of both CYP2J2 and P-glycoprotein (P-gp) in vitro. This study aims to investigate the drug-drug interactions between telmisartan and ebastine, a CYP2J2 and P-gp substrate in rats. Method: Ebastine (10 mg/kg) was orally given in the presence and absence of telmisartan (4 mg/kg, p.o.). Heparinized blood was serially taken and the plasma concentrations of ebastine and its three metabolites (hydroxyebastine, carebastine and desalkylebastine) were determined using LC-MS/MS, and their pharmacokinetic parameters were compared. Results: Peak concentrations ($C_{max}$) and AUC of ebastine were significantly (p<0.05) increased in the presence of telmisartan by 2.1 and 1.9 times, respectively. While $C_{max}$ of hydroxyebastine was significantly increased by 1.9 times, the half-life of hydroxyebasteine was decreased significantly with telmisartan (p<0.05). There was no change in the pharmacokinetic parameters of carebastine, the active metabolite of ebastine, and desalkylebastine was not detected in plasma. The systemic exposure of ebastine was significantly augmented by telmisartan, indicating that telmisartan may enhance the absorption of ebastine by blocking P-gp. Conclusion: Although telmisartan may also partially contribute to inhibit the biotransformation to hydroxyebastine, the inhibitory action seemed to be overridden by the enhancement of absorption, because the generation of hydroxyebastine was not diminished. In spite of such interactions between telmisartan and ebastine, no clinical consequence could be expected due to no significant change of the active metabolite, carebastine.

• 대한한방내과학회지
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• 제33권2호
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• pp.160-171
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• 2012

Background and Objective : Warfarin is the standard anticoagulation treatment for atrial fibrillation, venous thromboembolism (VTE), and mechanical heart valves. Close monitoring of the International Normalized Ratio (INR) is required due to the drug's very narrow therapeutic window. Many factors can affect INR levels. Drug and food interactions are frequently cited as causes of adverse events with warfarin. We discussed interactions between herbs and warfarin studied in this research. Methods : In this review, PubMed was used to search medical journals. Keywords "warfarin AND interaction" were applied. Results : 55 articles were included. The possibility of correlation between warfarin and single herbal medicines such as Salviae Miltiorrhizae Radix, Angelicae Gigantis Radix, Ginseng Radix Alba, Lycii Fructus, Ginkgo Folium, Menthae Herba, Trigonellae semen was suggested. Furthermore, some herbal compounds interacting with warfarin were reported. The conclusion of studies reporting the effect of herbal medicine on warfarin were controversial due to small size or quality of research. Conculsions : We suggest that we should prescribe therapeutic herbal medicines to patients using warfarin more carefully and do INR follow-up regularly.