113 research outputs found

    Enhanced cytostatic activity of the sesquiterpene lactone eupatoriopicrin by glutathione depletion.

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    Eupatoriopicrin (EUP), a sesquiterpene lactone from Eupatorium cannabinum L., possesses cytostatic activity. This was demonstrated for FIO 26 cells in vitro with the aid of a clonogenic assay and in vivo by tumour growth delay in FIO 26 and Lewis lung tumour-bearing mice. In vitro the IC50 for 1 h exposure to EUP was 1.5 microgram ml-1 (4.1 nmol ml-1). This concentration depleted about 25% of its cellular GSH concentration. Pretreatment of FIO 26 cells with BSO, resulting in greater than 99%. GSH depletion, enhanced the cytotoxic effect of EUP. The dose-enhancement factor at the level of 10% cell survival was 2.3. Growth inhibition of the Lewis lung carcinoma and the FIO 26 fibrosarcoma, solidly growing in C57Bl mice, was found after i.v. injection of 20 or 40 mg kg-1 EUP, at a tumour volume of about 500 microliters. Pretreatment with BSO at a dose of 4 mmol kg-1 i.p., 6 h before EUP administration, resulted in a significantly stronger growth delay of both tumours compared with EUP only. At the time of EUP treatment, cellular GSH in the tumours was reduced by BSO treatment to about 60%. It is concluded that EUP possesses antitumour activity in vivo and that chemosensitisation of EUP may be accomplished by pretreatment with BSO, indicating that endogenous GSH protects against the cytostatic action of EUP

    pH-dependent ileocolonic drug delivery, part I:in vitro and clinical evaluation of novel systems

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    After the pH dependency of novel pH-dependent ileocolonic drug delivery systems is confirmed in vitro, their performance should be evaluated in human volunteers

    A Retrospective Surveillance of the Antibiotics Prophylactic Use of Surgical Procedures in Private Hospitals in Indonesia

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    Background: According to international guidelines, prophylactic antibiotics in elective surgery should be given as a single dose 30 to 60 minutes before the operation is conducted. Postoperative administration of antibiotics should be discontinued 24 hours after surgery to minimize bacterial resistance and to keep control over hospitalization costs. There is a lack of data on the actual antibiotic use around surgical procedures in Indonesia. Objective: This retrospective surveillance study aimed to obtain defined daily doses (DDD) and DDDs per 100 bed days (DDD-100BD) for prophylactically used antibiotics in two private hospitals in Surabaya, East Java. These hospitals are considered to be representative for the current situation in Indonesia. Method: Data from a total of 693 patients over a nearly 1-year period (2016) were collected and evaluated. Results: The overall DDD per patient was 1.5 for hospital A and 1.7 for hospital B. The overall DDD-100BD was 30 for hospital B. Of the 24 antibiotics given prophylactically, ceftriaxone was the most commonly used in both hospitals. Conclusion: There was a clear discrepancy between daily practice in both hospitals and the recommendations in the guidelines. This study shows that better adherence to antibiotic stewardship is needed in Indonesia. Substantial improvements need to be made toward guided precision therapy regarding quantity (dose and frequency), route of administration (prolonged intravenous), and choice of the type of antibiotic

    Anti-plasmodial polyvalent interactions in Artemisia annua L. aqueous extract – possible synergistic and resistance mechanisms

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    Artemisia annua hot water infusion (tea) has been used in in vitro experiments against P. falciparum malaria parasites to test potency relative to equivalent pure artemisinin. High performance liquid chromatography (HPLC) and mass spectrometric analyses were employed to determine the metabolite profile of tea including the concentrations of artemisinin (47.5±0.8 mg L-1), dihydroartemisinic acid (70.0±0.3 mg L-1), arteannuin B (1.3±0.0 mg L-1), isovitexin (105.0±7.2 mg L-1) and a range of polyphenolic acids. The tea extract, purified compounds from the extract, and the combination of artemisinin with the purified compounds were tested against chloroquine sensitive and chloroquine resistant strains of P. falciparum using the DNA-intercalative SYBR Green I assay. The results of these in vitro tests and of isobologram analyses of combination effects showed mild to strong antagonistic interactions between artemisinin and the compounds (9-epi-artemisinin and artemisitene) extracted from A. annua with significant (IC50 <1 μM) anti-plasmodial activities for the combination range evaluated. Mono-caffeoylquinic acids, tri-caffeoylquinic acid, artemisinic acid and arteannuin B showed additive interaction while rosmarinic acid showed synergistic interaction with artemisinin in the chloroquine sensitive strain at a combination ratio of 1:3 (artemisinin to purified compound). In the chloroquine resistant parasite, using the same ratio, these compounds strongly antagonised artemisinin anti-plasmodial activity with the exception of arteannuin B, which was synergistic. This result would suggest a mechanism targeting parasite resistance defenses for arteannuin B’s potentiation of artemisinin

    Oromucosal films: from patient centricity to production by printing techniques

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    INTRODUCTION: Oromucosal films, comprising mucoadhesive buccal films (MBFs) and orodispersible films (ODFs), are considered patient-centric dosage forms. Target groups are patients with special needs. Various active pharmaceutical ingredients have been shown to be suitable for oromucosal film production. A shift is seen in the production techniques, from conventional solvent casting to printing techniques. AREAS COVERED: In this review, the patient acceptability of oromucosal films is discussed. An overview is given of the small molecule drugs, biopharmaceuticals and herbal extracts that have been incorporated so far. Finally, the current state of 2D and 3D printing techniques for production purposes is discussed. EXPERT OPINION: The patient-centric features are important for the further development and acceptance of this oral solid dosage form. Oromucosal films perfectly fit in the current attention for personalized medicine. Both MBFs and ODFs are intended for either a local or a systemic effect. For buccal absorption, sufficient mucoadhesion is one of the most important criteria an oromucosal film must comply with. For the preparation, the solvent casting technique is still predominately used. Some limitations of this production method can be tackled by printing techniques. However, these novel techniques introduce new requirements, yet to be set, for oromucosal film preparation

    Functional analysis of genes involved in the biosynthesis of isoprene in Bacillus subtilis

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    In comparison to other bacteria Bacillus subtilis emits the volatile compound isoprene in high concentrations. Isoprene is the smallest representative of the natural product group of terpenoids. A search in the genome of B. subtilis resulted in a set of genes with yet unknown function, but putatively involved in the methylerythritol phosphate (MEP) pathway to isoprene. Further identification of these genes would give the possibility to engineer B. subtilis as a host cell for the production of terpenoids like the valuable plant-produced drugs artemisinin and paclitaxel. Conditional knock-out strains of putative genes were analyzed for the amount of isoprene emitted. Differences in isoprene emission were used to identify the function of the enzymes and of the corresponding selected genes in the MEP pathway. We give proof on a biochemical level that several of these selected genes from this species are involved in isoprene biosynthesis. This opens the possibilities to investigate the physiological function of isoprene emission and to increase the endogenous flux to the terpenoid precursors, isopentenyl diphosphate and dimethylallyl diphosphate, for the heterologous production of more complex terpenoids in B. subtilis

    Dihydroartemisinin Enhances Apo2L/TRAIL-Mediated Apoptosis in Pancreatic Cancer Cells via ROS-Mediated Up-Regulation of Death Receptor 5

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    BACKGROUND: Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, has recently shown antitumor activity in various cancer cells. Apo2 ligand or tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) is regarded as a promising anticancer agent, but chemoresistance affects its efficacy as a treatment strategy. Apoptosis induced by the combination of DHA and Apo2L/TRAIL has not been well documented, and the mechanisms involved remain unclear. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that DHA enhances the efficacy of Apo2L/TRAIL for the treatment of pancreatic cancer. We found that combined therapy using DHA and Apo2L/TRAIL significantly enhanced apoptosis in BxPC-3 and PANC-1 cells compared with single-agent treatment in vitro. The effect of DHA was mediated through the generation of reactive oxygen species, the induction of death receptor 5 (DR5) and the modulation of apoptosis-related proteins. However, N-acetyl cysteine significantly reduced the enhanced apoptosis observed with the combination of DHA and Apo2L/TRAIL. In addition, knockdown of DR5 by small interfering RNA also significantly reduced the amount of apoptosis induced by DHA and Apo2L/TRAIL. CONCLUSIONS/SIGNIFICANCE: These results suggest that DHA enhances Apo2L/TRAIL-mediated apoptosis in human pancreatic cancer cells through reactive oxygen species-mediated up-regulation of DR5
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