Drug Discoveries & Therapeutics
Online ISSN : 1881-784X
Print ISSN : 1881-7831
Volume 10 , Issue 3
Showing 1-9 articles out of 9 articles from the selected issue
Reviews
  • Atmika Paudel, Hiroshi Hamamoto, Suresh Panthee, Kazuhisa Sekimizu
    2016 Volume 10 Issue 3 Pages 123-128
    Published: 2016
    Released: July 19, 2016
    JOURNALS FREE ACCESS

    The current trend of increasing infections by multidrug-resistant pathogens requires the discovery of novel antimicrobial agents with new target and selective toxicity towards pathogens. Menaquinone is a component of electron transport chains in a majority of anaerobic bacteria and Gram-positive bacteria. Due to its exclusivity in bacteria, menaquinone is thought to be a potential target for development of therapeutically effective antibacterial agents without side effects. In this review, we summarize inhibitors of menaquinone biosynthesis and antibiotics directly targeting menaquinone in bacteria.

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  • Junichiro Yamamoto, Yoshinobu Ijiri, Yukinori Tamura, Masahiro Iwasaki ...
    2016 Volume 10 Issue 3 Pages 129-140
    Published: 2016
    Released: July 19, 2016
    JOURNALS FREE ACCESS

    In the quest for prevention of atherothrombotic diseases, an antithrombotic diet may offer a promising approach. The major stumbling block in finding an effective diet is the lack of pathophysiological relevant techniques to detect potential antithrombotic effects of various diet components. Platelet function and coagulation/fibrinolysis tests currently in use do not allow assessment of global thrombotic status and their value in screening diet-components for antithrombotic effects. Recently, we combined the point-of-care shear-induced ex vivo thrombosis test (Global Thrombosis Test-GTT) with the Flow-mediated Vasodilation (FMV) in vivo test and found that the combination improved the assessment of thrombotic status in humans and could be used for screening diet-components for antithrombotic effects. In the present experiments, a combination of GTT, hemostatometry, laser-induced thrombosis tests and FMV were employed for screening. The results show that the overall antithrombotic effect is determined by the effect on thrombus formation and endogenous thrombolytic activities. This study showed a great variation in the observed antithrombotic effect between the tested varieties. Antithrombotic activities were independent from polyphenolic content or antioxidant activities. The presented experimental techniques seem to be suitable for establishing an antithrombotic diet, which may be effective in the prevention of atherothrombotic cardiovascular diseases in humans.

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Original Articles
  • Florence Déclaire Mabou, Jean-de-Dieu Tamokou, David Ngnokam, Laurence ...
    2016 Volume 10 Issue 3 Pages 141-149
    Published: 2016
    Released: July 19, 2016
    JOURNALS FREE ACCESS

    Diarrhea continues to be one of the most common causes of morbidity and mortality among infants and children in developing countries. The aim of the present study was to evaluate the antibacterial and antioxidant activities of extracts and compounds from Ludwigia leptocarpa, a plant traditionally used for its vermifugal, anti-dysenteric, and antimicrobial properties. A methanol extract was prepared by maceration of the dried plant and this was successively extracted with ethyl acetate to obtain an EtOAc extract and with n-butanol to obtain an n-BuOH extract. Column chromatography of the EtOAc and n-BuOH extracts was followed by purification of different fractions, leading to the isolation of 10 known compounds. Structures of isolated compounds were assigned on the basis of spectral analysis and by comparison to structures of compounds described in the literature. Antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and gallic acid equivalent antioxidant capacity (GAEAC) assays. Antibacterial activity was assessed with the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) with respect to strains of a Gram-positive bacterium, Staphylococcus aureus (a major cause of community and hospital-associated infection), and Gram-negative multi-drug-resistant bacteria, Vibrio cholerae (a cause of cholera) and Shigella flexneri (a cause of shigellosis). All of the extracts showed different degrees of antioxidant and antibacterial activities. 2β-hydroxyoleanolic acid, (2R,3S,2''S)-3''',4',4''',5,5'',7,7''-heptahydroxy-3,8"-biflavanone, and luteolin-8-C-glucoside displayed the most potent antibacterial and antioxidant properties, and these properties were in some cases equal to or more potent than those of reference drugs. Overall, the present results show that L. leptocarpa has the potential to be a natural source of anti-diarrheal and antioxidant products, so further investigation is warranted.

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  • Tanongsak Sassa-deepaeng, Surachai Pikulkaew, Siriporn Okonogi
    2016 Volume 10 Issue 3 Pages 150-155
    Published: 2016
    Released: July 19, 2016
    [Advance publication] Released: June 29, 2016
    JOURNALS FREE ACCESS
    Poloxamer micelles promise safety and efficacy for many water insoluble drugs. Chrysin has been reported to have anticancer, anti-inflammatory, antioxidant, and anti-aromatase activities but its water insoluble properties limit its pharmaceutical application. In the present study, chrysin loaded poloxamer micelles were developed. Two types of poloxamers, Pluronic F-68 and Pluronic F-127 were compared. It was found that chrysin loaded Pluronic F-68 micelles (CS-P68) and chrysin loaded Pluronic F-127 micelles (CS-P127) obviously increase the aqueous solubility of chrysin. The results also indicated that the type of polymer and ratio of drug to polymer affected size and desirable characteristics of the micelles. The micelle system of CS-P68 and CS-P127 formed at drug to polymer ratios of 1:4 and 1:2, respectively, was found to be the most suitable monodispersed system with a nanosize-range diameter. The in vivo study in zebrafish eggs indicates that the toxicity of CS-P68 and CS-P127 is a dose response. CS-P68 and CS-P127 at a drug dose of 10 ng/mL or less is safe for zebrafish embryo growth. The results of this study indicate enhanced water solubility of chrysin. Chrysin loaded poloxamer micelles are promising for further use in in vivo studies in mammalian animals and humans.
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  • Ikumi Ito, Akihiko Ito, Sakae Unezaki
    2016 Volume 10 Issue 3 Pages 156-162
    Published: 2016
    Released: July 19, 2016
    [Advance publication] Released: June 15, 2016
    JOURNALS FREE ACCESS
    This study investigated the effect of polyvinylpyrrolidone (PVP) on a film containing carboxymethyl cellulose sodium (CMC) as a matrix to improve surface roughness caused by drug recrystallization. Acetaminophen (AA) was used as the model drug. Recrystallization is a problem encountered during the preparation of films that contain high drug doses, making them difficult to take. A film that does not disintegrate for clinical applications requires a smooth surface, moderate strength and elasticity, and a low level of adhesiveness to facilitate taking of the medication. Addition of PVP to the film formulation made the surface significantly smoother, and it was independent of the compounding method. Smooth films were obtained when the CMC concentration was kept constant and the amount of PVP was increased, but it also increased the adhesiveness and strength, and decreased the elasticity of the films. When high polymer concentration was kept constant and the ratio of CMC and PVP was varied, the films with smaller amounts of PVP tended to have a smoother surface and less adhesiveness. However, when the amount of PVP was reduced, the film strength increased and elasticity decreased. The amount of PVP had a negligible effect on drug dissolution behavior, making it useful for preparation of the AA film. However, it is necessary to determine the compounding method and the PVP load considering the adhesiveness, strength, and elasticity of the films.
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Brief Reports
  • Jiang Bian, Yepeng luan, Chunbo Wang, Lei Zhang
    2016 Volume 10 Issue 3 Pages 163-166
    Published: 2016
    Released: July 19, 2016
    [Advance publication] Released: May 07, 2016
    JOURNALS FREE ACCESS
    The indoles plant growth hormones have exhibited potentially antitumor activities. However, the targets of these indoles have not been clearly elucidated. By introduction of hydroxamic acid group to the structure of indolebutyric acid, the derived molecule (IBHA) exhibited potent HDAC2 (IC50 value of 0.32 ± 0.02 µM) and HDAC3 (IC50 value of 0.14 ± 0.01 µM) inhibitory activities compared with SAHA (IC50 value of 1.25 ± 0.06 µM and 0.97 ± 0.04 µM against HDAC2 and HDAC3). In the antiproliferative assays, the tested hematologic cell lines (U937 and K562) are more sensitive to IBHA than the solid tumor cell lines (MDA-MB-231 and PC-3). In the docking studies, the derived molecule (IBHA) could bind to the active site of human HDAC2 and HDAC3 by strong H-bond interactions and hydrophobic interactions. Pharmacophore mapping results revealed that properties of IBHA matches the receptor (HDAC3) based pharmacophore model.
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  • Robert D Steigerwalt Jr., Antonella Pascarella, Mauro De Angelis, Fran ...
    2016 Volume 10 Issue 3 Pages 167-171
    Published: 2016
    Released: July 19, 2016
    [Advance publication] Released: June 15, 2016
    JOURNALS FREE ACCESS
    Retinal vein occlusions may decrease visual acuity. There is no known therapy to treat ocular thrombosis. The authors used fondaparinux, an ultra-low-molecular-weight heparin, to treat 13 consecutive cases of recent-onset retinal vein occlusions. Two patients with renal insufficiency were not included. Eight central retinal vein occlusions and 5 branch retinal vein occlusions in 13 patients were treated with subcutaneous fondaparinux 2.5 mg once a day. The patients were seen every 2 weeks. Macular edema was treated with intravitreal injections of anti-vascular endothelial growth factor or steroids. Two patients elected to discontinue treatment. Of the remaining 11, 9 occlusions resolved in 1.5 to 13.5 months with rapid resolution of retinal edema and hemorrhage as soon as the occlusions resolved. One patient had a retinal vein that was still occluded after 8 months of therapy and 1 had retinal vein occlusion that partially resolved after 15 months of treatment. Of the 9 eyes with occlusions that resolved, visual acuity improved in 7. In 2, visual acuity decreased due to macular ischemia. Occlusion recurred in 1 2.5 months after the suspension of initial treatment. This patient is again being treated with fondaparinux 2.5 mg. No hemorrhaging occurred. Fondaparinux 2.5 mg can be given subcutaneously once a day to patients with recent-onset retinal vein occlusions without renal insufficiency. An occlusion may take a number of months to resolve. Once the vein occlusion has resolved, retinal edema and hemorrhage rapidly resolve and vision improves. Macular edema should be treated while waiting for the vein occlusion to resolve.
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  • Saori Yamada, Masatoshi Jinnin, Ikkou Kajihara, Taiji Nakashima, Jun A ...
    2016 Volume 10 Issue 3 Pages 172-176
    Published: 2016
    Released: July 19, 2016
    [Advance publication] Released: May 07, 2016
    JOURNALS FREE ACCESS
    We focused on the interaction of cytokines in squamous cell carcinoma (SCC), and determined the expression profile of multiple cytokines in the serum of each patient with SCC in the present study. Serum samples were obtained from 12 SCC patients and 7 normal subjects. Four cytokines (IFN-γ, IL-6, GM-CSF, and TGF-β) were selected because they are reported to be involved in keratinocyte proliferation and SCC progression. Serum levels were measured using ELISA. We found a statistically significant increase of serum IFN-γ levels in SCC patients compared to those in normal subjects, and areas under the curve (AUC) of 0.82 for the serum levels of IFN-γ were higher than those for other cytokine levels according to ROC curve analysis. Patients with increased IFN-γ levels had a significantly more severe cancer stage. Furthermore, the combination of IFN-γ levels and TGF-β levels could improve the AUC to 0.84. We also found there was a significant correlation between IFN-γ levels and GM-CSF levels or between GM-CSF levels and TGF-β levels only in SCC patients. Our results suggest that the combination of IFN-γ levels and TGF-β levels is more effective to diagnose SCC, while serum levels of IFN-γ alone are useful to evaluate tumor progression. Furthermore, expression of these cytokines was not independent, but may be regulated by common upstream factors (e.g. cytokines or methylation) in SCC patients, and such factors may play some roles in the pathogenesis of SCC.
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Case Report
  • Robert D Steigerwalt Jr., Antonella Pascarella, Mauro De Angelis, Gabr ...
    2016 Volume 10 Issue 3 Pages 177-180
    Published: 2016
    Released: July 19, 2016
    [Advance publication] Released: June 15, 2016
    JOURNALS FREE ACCESS
    Non-arteritic posterior ischemic optic neuropathy (NA-PION) is a disorder involving reduced blood flow to the retrobulbar portion of the optic nerve. This disorder usually develops acutely, and research has suggested that high-dose steroid therapy soon after the onset of visual loss can result in significant visual improvement. This treatment, however, is not universally successful. The addition of a potent vasodilator could help to restore ocular blood flow. This case report describes the use of prostaglandin E1 (PGE1), a powerful vasodilator of the microcirculation, to treat three separate episodes of NA-PION over five years in the same patient. A 68-year-old white male was first seen in June 2009 with NA-PION in the left eye, and the condition was treated with steroids and PGE1. The patient had a subsequent episode in July 2010 that was treated with steroids and PGE1 and another in May 2014 that was treated with PGE1 alone. Visual acuity improved from 4/10 to 11/10 in 2009, from 4/10 to 11/10 in 2010, and from 5/10 to 10/10 in 2014. No complications due to the use of PGE1 were noted. PGE1 should be considered as a treatment for NA-PION to immediately restore blood flow and potentially improve vision.
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