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Die Resistenz von kommensalen Bakterien gegenüber Standard- und Reserveantibiotika hat in vielen Teilen der Welt ein beängstigendes Ausmaß erreicht und stellt zunehmend eine Gefahr für den Erfolg antibiotischer Behandlungen dar. Insbesondere Infektionen mit den Bakterienarten Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterococcus faecium (VRE) und Staphylococcus aureus (MRSA), welche zu den Erregern von Wundinfektionen zählen und eine Vielzahl von Antibiotikaresistenzen aufweisen können, führen im klinischen Umfeld zunehmend zu Problemen. In Anbetracht des Mangels an verfügbaren neuen Antibiotika, eröffnet die Entwicklung von Resistenz modifizierenden Substanzen eine Perspektive um die Verbreitung von Antibiotikaresistenzen einzudämmen und die Verwendung zugelassener Antibiotika, gegen die Resistenzen auftreten, weiterhin zu ermöglichen. In dieser Arbeit wurde der Einfluss von pflanzlichen Extrakten und Einzelsubstanzen auf die Resistenz von klinischen Isolaten der oben erwähnten Bakterienarten gegenüber den Antibiotika Ampicillin, Piperacillin, Imipenem, Gentamicin, Vancomycin und Aztreonam untersucht. Die methanolischen und wässrigen Extrakte sowie die Einzelsubstanzen stammen unter anderem von Achillea millefolium, Arctostaphylos uva-ursi, Cetraria islandica, Glycyrrhiza glabra, Lythrum salicaria, Plantago lanceolata, Salvia officinalis, Solidago virgaurea und Thymus vulgaris. Für alle diese Pflanzen ist eine historische Verwendung zur Wundbehandlung belegt. Um mögliche synergistische Wechselwirkungen zwischen den Antibiotika und den Naturstoffen zu identifizieren wurden die Kombinationen mit der checkerboard-Methode analysiert. Von den 160 Kombinationen von Antibiotika und Extrakten aus acht verschiedenen Pflanzen, zeigten 30 Kombinationen Werte für den fraktionierten inhibitorischen Konzentrationsindex (FICI) von ≤0,5, was ein Nachweis für eine synergistische Wechselwirkung ist. Die meisten Synergien traten bei den gram positiven Erregern VRE und MRSA auf, hauptsächlich in Kombination mit Ampicillin und Gentamicin. Bei Klebsiella pneumoniae erwies sich keine Kombination als synergistisch und bei Pseudomonas aeruginosa traten Synergien nur mit Ampicillin, Piperacillin und Vancomycin auf. Die stärksten synergistischen Wechselwirkungen zeigten sich an den Enterokokken mit den Kombinationen von Urolithin A mit Ampicillin (FICI: ≤0,0002), Glycyrrhizinsäure mit Gentamicin (FICI: 0,018) sowie dem methanolischen Extrakt von Cetraria islandica mit Gentamicin (FICI: 0,05). Die Ergebnisse dieser Arbeit deuten auf ein therapeutisches Potential von Naturstoffen als Kombinationspartner von Antibiotika bei der Behandlung von Wundinfektionen mit multiresistenten Bakterien hin., The resistance of commensal bacteria to first- and second-line antibiotics has reached an alarming level in many parts of the world and endangers the effective treatment of infectious diseases. Particularly Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterococcus faecium (VRE) and Staphylococcus aureus (MRSA), which may exhibit a broad resistance to various antibiotics and be involved in wound infections, represent an increasing clinical problem in the treatment of infectious diseases and hinder adequate antibiotic stewardship. Considering the lack of novel antibiotic compounds, the development of resistance-modifying agents, however, can mitigate the spread of bacterial drug resistance and might possibly extend the useful application indices of an existing licensed antibiotic. In this thesis, the influence of herbal extracts and pure substances on the susceptibility of clinical isolates of the bacteria mentioned above against the antibiotics ampicillin, piperacillin, imipenem, gentamicin, vancomycin and aztreonam was investigated. Furthermore, the antibacterial properties of the natural substances under study were determined in vitro. The plants from which the methanolic and aqueous extracts and pure substances originated were among others Achillea millefolium, Arctostaphylos uva-ursi, Cetraria islandica, Glycyrrhiza glabra, Lythrum salicaria, Plantago lanceolata, Salvia officinalis, Solidago virgaurea and Thymus vulgaris. For all these plants the historical use in wound infections has been proven. The combined effects of antibiotics and natural substances were determined with the checkerboard method to estimate a possible synergy. Out of 160 investigated combinations with eight plant extracts, 30 showed a synergistic interaction, with FICI values of ≤0. 5, which indicates synergy. Most synergistic interactions occurred with the gram-positive pathogens VRE and MRSA, mostly with ampicillin and gentamicin. Klebsiella pneumoniae showed no synergy with any combination and Pseudomonas aeruginosa only with ampicillin, piperacillin and vancomycin. The strongest synergistic interactions were observed in enterococci with the combination of urolithin A with ampicillin (FICI: ≤0.0002), of glycyrrhizic acid with gentamicin (FICI: 0.018) and of the methanolic extract of Cetraria islandica with gentamicin (FICI: 0.05). In conclusion, this thesis points towards a therapeutic potential of natural substances in co-application with antibiotics for defined local bacterial infections caused by antibiotic resistant bacteria.

We investigated the virulence of three European isolates of the entomopathogenic fungus (EPF) Metarhizium anisopliae against three wireworm species which are important pests of arable crops and vegetables in Europe: Agriotes lineatus, A. obscurus and A. sputator. In laboratory experiments, up to 90 % of the wireworms were killed by the fungus, depending on the fungal isolate and the wireworm species. Speed of kill was generally low with first wireworms showing unambiguous signs of fungal disease after two to three weeks. Maximum mortality rates were reached after six to eight weeks post inoculation. The next steps of this investigation will be to determine the most suitable fungal isolate and the validation of the laboratory results under greenhouse and field conditions. The aim of the study is to develop an easily applicable formulation with the most effective EPF isolate as the main active ingredient. In addition, applications of the EPF will be combined with entomoparasitic nematodes (EPNs) and repellent semiochemicals. Possible synergistic interactions between EPFs and EPNs or repellents may contribute significantly to improved biological control of wireworms.

In der vorliegenden Arbeit wurde ein onkolytisches Vaccinia-Virus unter Ausnutzung seiner Eigenschaft als Vektorsystem mit dem Designer-Zytokin Hyper-IL-6 ausgestattet (GLV 1h90). Bei Hyper IL 6 handelt es sich um ein Fusionsprotein bestehend aus humanem Interleukin-6 und der Liganden-Bindungsdomäne des löslichen Interleukin-6-Rezeptors, welche kovalent über einen flexiblen Linker miteinander verbunden sind. Dieses chimäre Designer-Zytokin erlaubt die Untersuchung von IL-6-Effekten, welche über das IL-6-Trans-Signaling vermittelt werden. Daraus ergibt sich einerseits eine beträchtliche Erweiterung des Wirkspektrums und darüber hinaus weist Hyper-IL-6 sowohl in vitro als auch in vivo eine 100-1000fach verstärkte biologische Aktivität auf. Aufgrund der Tatsache, dass Hyper-IL-6, neben seiner Tumor-inhibierenden Wirkung, eine Vielzahl weiterer Effekte zugeschrieben wird, wurde in dieser Arbeit durch die Kombination des Designer-Zytokins mit einem onkolytischen Vaccinia-Virus nicht nur additive Effekte auf die Tumorregression, sondern darüber hinaus auch mögliche systemisch-vermittelte Hyper-IL-6-Effekte untersucht. Nach intravenöser Injektion von GLV-1h90 in DU-145-Tumor-tragende Mäuse konnte neben der intratumoralen Replikation des Virus und der Expression des Markerproteins Ruc-GFP zusätzlich die Expression des integrierten Designer-Zytokins Hyper-IL-6 im Tumor nachgewiesen werden. Von entscheidender Bedeutung war der zusätzliche Nachweis des Designer-Zytokins in Serum-Proben von GLV-1h90-injizierten Mäusen. Nach einer aktiven Hyper-IL-6-Sekretion von infizierten Tumorzellen, bildet der Transport in die Blutbahn die Voraussetzung für systemisch-vermittelte Hyper-IL-6-Effekte. In dieser Arbeit wurde untersucht, ob sich durch die Überexpression von Hyper-IL-6 im Tumor, zusätzlich zu den onkolytischen Eigenschaften des Vaccinia-Virus, additive anti-Tumor-Effekte ergeben. Eine systemische Injektion von GLV 1h90 bzw. GLV 1h68 in DU-145-Tumor-tragende Mäuse führte zu einer signifikanten Reduktion des Tumorvolumens im Vergleich zu PBS-injizierten Mäusen. Neben Effekten, welche mit Entzündungsprozessen assoziiert sind, wie eine Rotfärbung der Haut, eine signifikanten Vergrößerung der Leber sowie eine massive Stimulation der Akute-Phase-Antwort in der Leber, konnte in GLV-1h90-injizierten Mäusen ein verbesserter Gesundheitszustand auf der Basis einer signifikanten Gewichtszunahme, verbunden mit einer beschleunigten Wundheilung Virus-induzierter Schwanzläsionen, beobachtet werden. Darüber hinaus konnte für Hyper-IL-6 eine Stimulierung der Megakaryopoese im Knochenmark nachgewiesen werden, welche zu einer signifikanten Erhöhung der Thrombozyten-Zahl im Blutkreislauf von GLV-1h90-injizierten Mäusen führte. Es ist von entscheidender Bedeutung anzumerken, dass alle beobachteten systemischen Hyper-IL-6-Effekte eine zeitliche Limitierung aufwiesen, welche sich höchstwahrscheinlich auf die Virus-bedingte Zerstörung Hyper IL 6-produzierender Tumorzellen zurückführen lässt. Dies impliziert zudem, dass eventuelle Komplikationen, welche durch die Überexpression des Designer-Zytokins hervorgerufen werden können, ebenfalls selbstlimitierend sind. Es konnte bereits mehrfach gezeigt werden, dass eine Kombinationstherapie aus onkolytischen Viren und Chemotherapie über synergistische Effekte zu einer signifikant verbesserten Tumorregression führt. Allerdings kommt es in Folge einer Chemotherapie oft zu einer Vielzahl von gefährlichen Nebenwirkungen, da alle schnell proliferierenden Zellen des Körpers betroffen sind. Thrombozytopenie ist eine der am häufigsten vorkommenden Nebenwirkung und beschreibt eine massive Reduktion der Thrombozyten-Zahl im Blut. Im Hinblick auf eine mögliche klinische Anwendung von GLV 1h90 wurde deshalb untersucht, ob in einer Kombinationstherapie mit Mitomycin C, neben einer Verstärkung der therapeutischen Effekte des Virus, basierend auf den beobachteten Hyper-IL-6-Effekten, zusätzlich der Gesundheitszustand der behandelten Mäuse verbessert werden kann. Die Experimente belegen, dass eine Kombination onkolytischer Vaccinia-Virus-Konstrukte mit Mitomycin C zu einer signifikant verbesserten Tumorregression im Vergleich zu den jeweiligen Monotherapien führt. Von bedeutender Relevanz war die Beobachtung, dass in einer Kombinationstherapie von Mitomycin C und GLV-1h90, im Gegensatz zu GLV-1h68, eine signifikante zeitliche Verkürzung der auftretenden Thrombozytopenie erreicht wird. Zusammenfassend konnte in dieser Arbeit gezeigt werden, dass eine systemische Injektion von GLV-1h90 zu einer funktionellen Expression des Designer-Zytokins Hyper-IL-6 führte, welches in der Lage ist eine erfolgreiche Kombinationstherapie aus einem onkolytischen Vaccinia-Virus und dem Chemotherapeutikum Mitomycin C durch eine Reduktion der Nebenwirkungen zusätzlich zu optimieren., In this thesis, an oncolytic vaccinia virus was armed with the designer cytokine Hyper-IL-6 by recombinant integration (GLV-1h90), exploiting its features as a vector system. Hyper IL-6 is composed of human interleukin-6 (IL-6) and the cytokine-binding domain of its soluble receptor sIL-6R which are bond covalently by a flexible peptide linker. Hyper-IL-6 is a multifunctional cytokine which exhibits not only anti-tumor activity, but also a variety of other effects. For this reason, the combination of the designer cytokine and an oncolytic vaccinia virus was used to study possible improvements regarding tumor regression and more importantly additional systemically mediated Hyper IL-6 effects. In addition to intratumoral replication and visualization of the marker gene ruc-gfp, intratumoral expression of the inserted designer cytokine Hyper-IL-6 could be detected after systemic administration of GLV-1h90 into DU-145-tumor-bearing mice. Of special interest was the presence of hyper-IL-6 in blood serum samples of GLV-1h90-injected mice. Following active hyper-IL-6 secretion of infected tumor cells, the transport into the blood circulation is essential for its ability to induce signal transduction pathways outside the tumor. IL-6 is a pro-inflammatory cytokine which is postulated to exhibit both, tumor promoting as well as tumor inhibiting effects. However, growth or proliferation inhibition of tumors could only be observed after addition of soluble IL-6 receptor and is consequently associated with the IL 6-trans-signaling pathway. Therefore, the thesis deals with the question of whether overexpression of hyper-IL-6 can further enhance the pre-existing oncolytic effects of vaccinia virus. Systemic administration of either GLV-1h90 or GLV-1h68 led to significant tumor regression compared to PBS-treated mice. Comparison of the two viral constructs demonstrated a slightly increased oncolytic activity of GLV-1h90. However, further studies have to clarify to which extend this improvement is resulting from an intratumoral overexpression of hyper IL 6. Following the detection of hyper-IL-6 in the blood circulation as a consequence of GLV 1h90-mediated overexpression in the tumor, functionality of the designer cytokine was analyzed regarding systemically mediated effects. Besides effects which can be associated with inflammatory processes, such as red skin, significant enlargement of the liver as well as enormous stimulation of the acute-phase-response, GLV-1h90-injected mice showed improved healthiness. Health status was assessed by significant gain in body weight associated with accelerated epithelial barrier repair of virus-induced tail lesions. Moreover, it could be demonstrated that Hyper-IL-6 stimulates megakaryopoiesis in the bone marrow, which in turn leads to significantly elevated levels of blood platelets in GLV-1h90-injected mice. It is particularly important to note that all observed systemic Hyper-IL-6 effects occurred only temporarily, which could be explained by virus-mediated oncolysis, reducing the amount of viable Hyper-IL-6 producing tumor cells. The results also implicate that potential complications associated with the overexpression of the designer cytokine can be self-limiting due to the destruction of the virus replication site. Recently, we and others demonstrated that the combination of oncolytic virotherapy and chemotherapy could lead to synergistic interactions that ultimately result in enhanced tumor regression. On the other hand, chemotherapy is often associated with serious side effects, since all fast proliferating cells are affected. Among the most frequently observed adverse effects is thrombocytopenia, which is characterized by a massive reduction of blood platelets. With regard to a possible clinical application of GLV 1h90, combination therapy of the hyper IL 6 encoding vaccinia-virus strain and the chemotherapeutic agent mitomycin C was investigated. Besides therapeutic effects of the virus, the issue was addressed, whether the health status of mice can be improved based on the observed hyper-IL-6 effects. Experimental results clearly demonstrated that combination therapy of mitomycin C and oncolytic vaccinia viruses led to a significantly improved DU-145 tumor regression compared to the respective monotherapies. Of particular importance was the finding that as compared to GLV-1h68, a combination of GLV-1h90 and mitomycin C reduced the time interval during which treated mice suffered from thrombocytopenia significantly. Taken together, this thesis revealed that systemic injection of GLV-1h90 leads to functional expression of the designer cytokine hyper-IL-6, which is able to further optimize the already effective combination therapy of the oncolytic virus GLV-1h90 and the chemotherapeutic agent mitomycin C by reducing of serious adverse effects.

In this work molecules with catalytic and magnetic properties were used to structure and to functionalize surfaces. For this we used the simple but powerful technique of molecular self organisation which is employed since the beginning of organic life to produce highly complicated units. Even 2D crystals can be obtained applying this method. For this reason novel functional surfaces with catalytic and magnetic properties become accessable which are attactive materials for molecular electronics. Especially multi nuclear compounds are of great interest because of synergistic interactions between the metal centers. In the last years such complexes were in the focus of actual research due to their magnetic properties. The occurring spin coupling phenonema of the metal ions in multinuclear complexes are of great importance in the development of new information storage devices. In this work especially the design and the two dimensional self organisation of ligands and particularly metal complexes with interesting catalytic and magnetic properties were in the main focus of investigation. Highly ordered monolayers were created by exposing a drop of a solution of the designed functionalized organic and corresponding metal organic compounds in proper solvents like 1,2,4 trichlorobenzene or 1-octanol on the surface of a freshly cleaved highly oriented pyrolytic graphite (HOPG). The self organized arrangements of the molecules were visualised by scanning tunneling microscopy (STM) at the liquid/solid interface. The metal complexes were investigated in respect to their catalytic and magnetic properties. Furthermore in a synthetical approach derivatives of 2,4-dihydroxybenzaldehyde with polymerizable groups were prepared in order to stabilize the resulting physisorbed monolayers by intermolecular connection.

Apfeltrester fallen in großen Mengen als Reststoffe bei der industriellen Fruchtsaftproduktion an. Neben der Pektinherstellung können Apfeltrester u. a. für die Alkoholerzeugung genutzt werden. Im Gegensatz zur Produktion von technischem Alkohol werden bei der Trinkalkoholherstellung jedoch höhere Anforderungen an die chemische Zusammensetzung und die sensorischen Eigenschaften der erzeugten Destillate gestellt. Apfeltrester besitzen eine Trockensubstanz von ca. 25 %, die sich zum größten Teil aus löslichen Restzuckern sowie unlöslichen Polysacchariden, darunter Cellulose, Hemicellulosen und Pektin, zusammensetzt. Die zusätzliche Nutzung von Glucose als Grundbaustein der Cellulose und potentiell vergärbarer Zucker kann zu einer signifikanten Erhöhung der Alkoholausbeute führen, wenn geeignete Aufschlussverfahren zum Abbau der Zellwandpolysaccharide zur Anwendung kommen. Im Rahmen der vorliegenden Arbeit wurden physikalische und enzymatische Verfahrensschritte im Laborverfahren kombiniert, um ein Maximum an Zellwandaufschluss zu erreichen und damit die Basis für eine signifikante Alkoholausbeutesteigerung zu schaffen. Für den enzymatischen Aufschluss wurden zellwandabbauende Enzyme, darunter Pektinasen, Cellulasen und Cellobiasen eingesetzt. Die Enzyme wurden anhand der Freisetzung verschiedener Zuckerbausteine hinsichtlich ihrer Haupt- und Nebenaktivitäten gegenüber Modellsubstraten, Apfeltresterfaserpräparaten und nativen sowie säurehydrolysierten Apfelnasstrestern charakterisiert. Die Freisetzung reduzierender Zucker und Glucose aus Apfeltresterfasern durch Cellulasen wurde durch die partielle Degradation des Pektin-Hemicellulose-Netzwerkes stark begünstigt. Durch die geeignete Kombination von Pektinase und Cellulase wurden in Abhängigkeit von der Faserart überadditive Wechselwirkungseffekte erzielt. Aus nativen Apfelnasstrestern konnten mit Hilfe eines Enzym-Mixes aus Pektinase, Cellulase und Cellobiase nach mechanischem Standardaufschluss und 48-stündiger Enzymeinwirkung bis zu 90 % der gesamten im Material verfügbaren Glucose freigesetzt werden, was einem Hydrolysegrad (Freisetzung unlöslicher Glucose) von 79 % entsprach. Die Anwendung zusätzlicher physikalischer Vorbehandlungen hatte einen signifikanten Einfluss auf die Freiset-zung reduzierender Zucker und Glucose. Die Erhöhung des Tresteranteils in den Versuchsansätzen führte zu einer verzögerten Viskositätsabnahme und bezogen auf die Trockensubstanz zu einer reduzierten Glucosefreisetzung. Durch die simultane Verflüssigung, Verzuckerung und Vergärung nativer Apfelnasstrester wurden Alkoholausbeuten von über 81 % erzielt, was einem Hydrolysegrad von über 55 % entsprach. Die erzeugten Destillate wiesen typische Gärungsnebenproduktprofile auf, enthielten jedoch große Mengen an Methanol. Die Verwendung säurehydrolysierter Trester führte zu einer weiteren Erhöhung der Hydrolysegrade. Die Methanolgehalte in den resultierenden Destillaten waren jedoch stark erhöht. In vergorenen und abdestillierten Trestern reichern sich lösliche und unlösliche Ballaststoffe sowie Polyphenole an, die als funktionelle Lebensmittelkomponenten genutzt werden könnten. Apple pomace is generated to a great extend as a waste material in industrial fruit juice production and can be utilised as a potential recyclable. Amongst others, e. g. pectin recovery, apple pomace can be used for alcohol production. Unlike technical alcohol, the production of potable spirits needs to consider requirements regarding chemical composition and sensory parameters of the distillates. Apple pomace averages about 25 % of dry substance, which is mainly composed of residual soluble sugars and insoluble polysaccharides, like cellulose, hemicelluloses and pectin. The additional utilisation of glucose as the cellulosic basic module and a potential fermentable sugar can lead to a significant increase of alcohol yield if suitable disintegration steps are used for decomposing cell wall polymers. In this context, physical and enzymatical procedures were combined in laboratory scale to reach a maximum in cell wall decomposition, and with that significantly increase alcohol yield. Commercial cell wall degrading enzymes, like cellulases, cellobiases and pectinases were used for enzymatic degradation. Enzymes were characterised regarding their main and side activities towards model substrates, complex apple pomace fibre preparations as well as towards native and acid-hydrolysed apple pomace. The release of total reducing sugars and glucose from fibre preparations by cellulases was favoured by the partial degradation of the pectin-hemicellulose network. The combination of pectinases and cellulases led to synergistic interactions regarding sugar release depending on type of fibre preparation and type of pectinase applied. A mixture of pectinase, cellulase and cellobiase was able to reach a release of up to 90 % of total glucose from native apple pomace which corresponded to a degree of hydrolysis of 79 % after mechanical pretreatment and 48 h of enzyme treatment. The application of additional physical treatments significantly affected the release of total reducing sugars and glucose. Increasing the amount of apple pomace in the test batches led to a delayed decrease in pomace viscosity and reduced glucose release, based on the batch dry substance. Simultaneous liquefaction, saccharification and fermentation of native apple pomace led to more than 81 % of alcohol yield after mechanical pretreatment which came up to a degree of hydrolysis of more than 55 %. The resulting distillates exhibited typical aroma profiles but methanol contents were rather high. Utilising acid-hydrolysed apple pomace yielded in even increased degrees of hydrolysis but also even higher methanol contents were found in the resulting distillates compared with those from native pomace. Different amounts of soluble and insoluble dietary fibre as well as total polyphenolics were enriched in fermented and distilled apple pomace which could be potentially finished to functional food constituents.

The introduction of thienopyridines, specifically of clopidogrel, offered for the first time an orally active therapeutic alternative to acetylsalicylic acid (ASA) as an antiplatelet agent. Despite of established clinical efficacy, it became also evident with increasing clinical use that the antiplatelet actions of clopidogrel are subject of considerable interindividual variations of its antiplatelet efficacy (clopidogrel resistance) in laboratory tests which might also be clinically relevant. Prasugrel is a new, orally active thienopyridine with an expected spectrum of biological activities similar to clopidogrel. Prasugrel, like clopidogrel, is also an inactive prodrug that has to be transformed into the active metabolite by the liver cytochrome P450 system. However, different cytochromes appear to be involved for different extent in the generation of the active metabolite. The active metabolite of prasugrel, R-138727, inhibits irreversibly the platelet P2Y(12) ADP receptor. In contrast to ASA, neither clopidogrel nor prasugrel inhibit the arachidonic acid metabolism. This allows synergistic interactions with ASA as thromboxane inhibitor and PGI(2) as stimulator of cAMP-formation in platelets. Prasugrel is orally more potent and acts more rapidly than clopidogrel, allowing lower oral dosing despite of similar in vitro activity of the active metabolites. These pharmacological advantages of prasugrel are probably due to its improved pharmacokinetics, i.e. the higher conversion rate of the prodrug into the active metabolite. In case of clopidogrel, only about 10-15% of the prodrug is converted into the active metabolite. This higher conversion rate possibly also explains the more rapid onset of platelet inhibition, the lower interindividual variability and higher oral potency with apparently less "resistance" than clopidogrel. Clinically, this might result in an improved efficacy. Whether this is associated with an increased risk of bleeding will be seen from the first phase III clinical trial in PCI-patients. The first results are expected at the end of the year.

In dem ersten Teil der vorliegenden Arbeit (Studie 1) wurde der Einfluss von alpha-Tocopherol, Ascorbinsäure, Kaffeesäure und ausgewählten Flavonoiden (einzeln oder in unterschiedlichen Kombinationen) auf die kupfer-induzierte LDL-Oxidation untersucht. Die Kinetik der Lipidperoxidation wurde durch die Bildung konjugierter Diene verfolgt. Die Fragmentierung des Apolipoprotein B während LDL-Oxidation wurde durch den Verlauf der Tryptophanfluoreszenz und die Bildung von Carbonylgruppen gemessen. Es konnte beobachtet werden, dass die Phenolsäuren eine höhere antioxidative Aktivität als alpha-Tocopherol oder Ascorbinsäure besitzen. Die wirksamsten Antioxidantien waren Quercetin gefolgt von Epicatechin und Kaffeesäure. Bei Kombination von zwei verschiedenen Antioxidantien zeigten Quercetin und Kaffeesäure den stärksten Effekt auf die Verlängerung der lag-phase (244 %). In Studie 2 wurde der Konzentrationsverlauf von alpha-Tocopherol, Quercetin und Kaffeesäure in verschiedenen LDL-Präparationen untersucht. Dazu wurden die LDL zunächst mit den Substanzen inkubiert (allein oder in Kombination), die Oxidationsreaktion durch Zugabe von Kupferionen gestartet und die Konzentration der Antioxidantien zu unterschiedlichen Zeitpunkten mittels HPLC bestimmt. Quercetin wurde dabei am schnellsten verbraucht (3-16 % nach fünf Minuten). alpha-Tocopherol wurde etwas langsamer verbraucht als Quercetin, nach fünf Minuten konnte noch ein Tocopherolgehalt von 26-44 % gemessen werden. Kaffeesäure wurde deutlich langsamer verbraucht, nach fünf Minuten waren noch zwischen 90 und 100 % der Kaffeesäure vorhanden. In Studie 3 sollte der in Studie 1 beobachtete Synergieeffekt von Quercetin und Kaffeesäure bei kupfer-induzierter LDL-Oxidation näher untersucht werden. Dazu wurde die antioxidative Wirkung von Quercetin und Kaffeesäure auf die kupfer-induzierte LDL-Oxidation mit den strukturverwandten Substanzen Kaempferol, p-Cumarsäure und Dopamin verglichen. Es konnte festgestellt werden, dass Kaempferol (Verlängerung der lag-phase von 286%), p Cumarsäure (2 %) oder Dopamin (606 %) in dem hier verwendeten Versuchsansatz eine niedrigere antioxidative Aktivität besitzen als Quercetin (1053 %) und Kaffeesäure (730 %). Außerdem konnte gezeigt werden, dass nur die Kombination von Quercetin und Kaffeesäure eine antioxidative Aktivität aufwies, die über der Summe der Einzeleffekte lag. In Studie 4 sollten verschiedene Kaffeesäurederivate, die nach Kaffeekonsum im Urin von Testpersonen identifiziert wurden, auf ihre antioxidative Aktivität getestet werden.. Ferulasäure hatte in dem hier verwendeten Versuchsansatz sowohl prooxidative als auch antioxidative Wirkung, abhängig von der eingesetzten Konzentration. Liegt die Konzentration von Ferulasäure unter der Kupferkonzentration scheinen verstärkt prooxidative Reaktionen aufzutreten. Ist die Konzentration von Ferulasäure höher als die der Kupferionen scheint die antioxidative Wirkung verstärkt einzusetzen. Isoferulasäure und Dihydroferulasäure hatten eine prooxidative Aktivität und o Hydroxyhippursäure wirkte antioxidativ. In Studie 5 wurde die Wirkung von Zinkhistidin, Histidin und Zinksulfat auf die kupfer-induzierte LDL-Oxidation untersucht. Dazu wurde LDL mit Zinkhistidin, Histidin oder Zinksulfat inkubiert und anschließend der Verlauf der Dienkonjugation verfolgt. Zinksulfat hatte in dem hier verwendeten Versuchsansatz keine antioxidative Aktivität. Zinkhistidin und Histidin dagegen wiesen eine antioxidative Aktivität auf. In der Ernährung und im Organismus liegen Antioxidantien als komplexe Gemische vor. Die Ergebnisse der vorliegenden Arbeit zeigten eine kombinatorische Wirkung verschiedener Antioxidantien in vitro und können dazu beitragen die Bedeutung von Interaktionen zwischen einzelnen Antioxidantien auch in vivo besser zu verstehen. In the first part of this work the influence of alpha-tocopherol, ascorbic acid, caffeic acid, and different flavonoids on the copper-mediated LDL-Oxidation was tested. The kinetics of lipidperoxiation were assessed by conjugated diene formation. The fragmentation of the apolipoprotein B during LDL-Oxidation was measured by tryptophan loss and protein carbonyl content. The phenolic acids showed higher antioxidant activity than alpha-tocopherol or ascorbic acid. Quercetin had the highest antioxidant activity followed by epicatechin and caffeic acid. When combinations of two antioxidants were tested, the combination of quercetin and caffeic acid was most effective by prolonging the lag-phase of LDL by 244 %. In the second part of this work, the content of alpha -tocopherol, quercetin, and caffeic acid in different LDL-preparations was measured. Therefore LDL was incubated with the different compounds (single compounds or combinations) and the oxidation was started by adding copper ions. Then concentrations of the antioxidants were measured at different times by HPLC. Quercetin was consumed at first (3-16 % after five minutes). alpha-tocopherol was consumed slower than quercetin, after five minutes 26-44 % were remaining. After five minutes 90-100 % of caffeic acid could still be measured. In the third part, the synergistic antioxidant activity of quercetin and caffeic acid, observed in the first part, was investigated more closely. Therefore the antioxidant activity of quercetin, caffeic acid, and structurally related compounds (dopamine, p-cumaric acid, kaempferol) was evaluated by measuring the inhibition of copper-mediated LDL-oxidation. The incubation of LDL with kaempferol (prolonging the lag-phase by 286 %), p-cumaric acid (2 %), or dopamine (606 %) showed lower antioxidant activities than incubation with quercetin (1053 %) or caffeic acid (730 %). Synergistic interactions were only found, when LDL was incubated with quercetin and caffeic acid. This effect was higher than the sum of the individual effects. In part four the antioxidant activity of different caffeic acid derivatives, that can be found in urine after consumption of coffee, was tested. Ferulic acid showed prooxidant as well as antioxidant activity, depending on the Concentration used. Concentrations lower than the copper concentration seem to enhance prooxidative reactions; is the concentration of ferulic acid higher than the copper concentration, antioxidant activity can be observed. Isoferulic acid and dihydroferulic acid showed prooxidant activity, and o-hydroxyhippuric acid had antioxidant activity. In part five of the study the effect of zinc histidine, histidine, and zinc sulphate on copper-mediated LDL-oxidation was tested. Therefore LDL was incubated with zinc histidine, histidine, and zinc sulphate and the increase of conjugated diene was was measured. Zinc sulphate showed no activity, whereas zinc histidine and histidine exerted antioxidant activity. In the diet and the organism, antioxidants can be found in complexe mixtures. The results showed combinative effects of different antioxidants in vitro and could provide a better understanding of the antioxidant interactions in vivo.

Blight-MOP Late blight (caused by Phytophthora infestans) is the most devastating fungal disease affecting organic (and conventional) potato production in the EU. It kills the foliage and usually results in losses of yield which can be very large when infection is severe and occurs early in the season. The disease may be transmitted to the tubers which become unmarketable and these can lead to complete deterioration of the stored crop if put into storage with healthy tubers. To a great extent, conventional production systems rely upon frequent applications of synthetic fungicides with different modes of action for late blight control, but this is seldom completely successful. However, in organic systems, the availability of chemical fungicides is currently restricted to those which are ‘considered to be traditional organic farming practices’: these include copper hydroxide, copper oxychloride (tribasic), copper sulphate and cuprous oxide that have a protectant action and are reasonably effective. Their use is restricted by national legislation and organic certifying authorities and pressure has been mounting to withdraw them not only because of possible adverse effects on wildlife, the environment and human health but also their incompatibility with organic production principles. This led to a proposed ban on the use of copper fungicides for control of late blight in organic farming in the EU from March 2002 which had potentially serious implications for the potato crop. The resultant losses of yield and hence income in the absence of copper-based fungicide sprays were expected to threaten the economic viability of both organic potato enterprises and/or whole organic farming businesses in many areas of the EU in the medium to long term until effective, alternative methods are developed. In the meantime, two major approaches were adopted. One was to set a limit to the amount of copperbased fungicides permitted for application: until 31 December 2005, the maximum application was restricted to 8kg of elemental copper/ha/year for annual crops, declining to 6kg/ha/year from 1 January 2006 (but this could be changed at any time in the light of developments in viable alternatives or should there be proposals for withdrawal under the EC Review programme for existing active substances). Another was to promote further research to identify and develop effective alternative late blight control methods and strategies without the undesirable effects associated with copper-based fungicides. The Blight-MOP project – ‘Development of a systems approach for late Blight (caused by Phytophthora infestans) Management in EU Organic Production systems’ was initiated in March 2001 to achieve this aim and maintain yield and quality and hence commercial viability of organic potato crops without the use of copper fungicides. Such an approach involves integrated use of (i) resistant varieties (ii) existing agronomic strategies (iii) alternative treatments that can replace synthetic and copper-based fungicides (iv) use of existing blight forecasting systems to optimise control treatments and to maximise synergistic interactions between (i), (ii), (iii) and (iv). The specific objectives were to: 1. Assess the socio-economic impact of late blight and ‘state-of-the-art’ blight management practices in EU organic potato production systems 2. Assess varietal performance in organic production systems in different EU regions and interactions with local blight populations 3. Develop within field diversification strategies to prevent/delay blight epidemics 4. Optimise agronomic strategies for the management of late blight 5. Develop alternative control treatments to copper-based fungicides that comply with organic farming standards 6. Evaluate novel application and formulation strategies for copper- free/alternative and copper-based late blight treatments 7. Integrate optimised resistance management, diversification, agronomic and alternative control treatment strategies into existing organic potato management systems. To pursue these objectives, experiments were conducted over 4 seasons from 2001 to 2004 under organic cropping system conditions in seven countries (Denmark, France, Germany, Netherlands, Norway, Switzerland and United Kingdom) spanning a wide range of aerial, soil, production and marketing environments. The rate and severity of the late blight epidemics in 2001, 2002 and 2004 gave a rigorous test of the different components of the integrated management system which gave broadly similar effects in the three years. In 2003, the very hot, dry summer (and August in particular) severely restricted the disease making it difficult to evaluate the efficacy of treatments in some regions, but in others where infection did occur the general trends were similar to those observed in other years.

Epidemiological studies have suggested synergistic interactions between chronic hepatitis B virus (HBV) infection and microcystin (MCYST) exposure in the etiology of hepatocellular carcinoma (HCC). As a potent inhibitor of protein phosphatase 1 and 2A could probably induce the hyperphosphorylation of tumorsuppressor proteins, retinoblastoma protein and p53, including their associated cell cycle proteins. The MCYST- mediated hyper-phosphorylation of pRb and p53 in HepG2 cells was confirmed by protein analytical methods and functinal transfection analysis with a luciferase reportergen system. Hyperphosphorylation of tumor suppressor proteins, mediated through inhibition of protein phosphatase 1 and 2A are involved in the deregulation of the cell cycle and a biochemical alternativly pathway of tumor promotion. In addition to prove the possibility of MCYST- associated functional inactivation of p53 we performed apoptosis assays and to consider the influence of MCYST of the subcellular localization of p53 using a p53-GFP- transfection system. The human hepatitis B virus x-protein (HBx) is suspected to play a role in the hepatocarcinogenic process by virtue of its capacity to transactivate oncogenes and serveral other cellular genes. We demonstrated confirmed by transient transfection assays with diverse specific luciferase reportergen systems that HBx is able to stimulate the cell cycle progression and influence the checkpionts controll. Finally, with cotransfection analyses in HepG2 we showed that that MCYST and HBx in combination deregulate the activity of cell cycle proteins such as p53,pRb, E2F and c-myc. Taken together, our results indicate that MCYST and HBx in an initiated human hepatoma cell culture system (HepG2) alone and in combination affected the activity of essential regulators of the G1 phase of the cell cycle.These datas suggest a molecular mechanism by which MCYST and HBx are likely to contribute to viral carcinogenesis.

Aqueous alcoholic extracts of St. John s wort are used for the treatment of mild to moderate depression. Recently, Hypericum extracts were also shown to inhibit the growth of various human malignant cells. We promote the hypothesis that the various biological activities of aqueous Hypericum extracts are based on synergistic interactions of all compounds present therein and not on the pharmacological activities of single compounds.

The danger to which man is exposed as a result of viruses contained in food differs basically from the risk to man caused by bacteria, fungi or their toxins. With respect to viral injuries it is not the specific diseases (e.g. hepatitis and polio) that are in the foreground but the much more dangerous noxious groups whose cause/effect relationships are rather complex. 1. the oncogenic risk, 2. synergistic interactions with opportunistic problem viruses, 3. slowly developing chronic diseases and persistent infections with their indirect injuries, 4. new infectious pathogens (viroids). Viral contamination of food can be exogenous or endogenous. Exogenous contamination is possible by: 1. specific human-pathogenic viruses, 2. polyphagous, human-pathogenic and animal-pathogenic viruses (zoonosis), 3. animal-pathogenic viruses only, 4. fish viruses, 6. bacteriophages, 7. fungal viruses. The viruses of group 1 and 2 are of practical importance, those of group 6 and 7 are it occasionally. Endogenous contamination is caused when an animal suffered from a viral infection at the time of slaughter or product extraction (e.g. milk, egg, fish) or when the animal has picked up a virus shortly beforhand. As far as endogenous contamination is concerned, a distinction must be made between 1. primarily biological and 2. primarily mechanical contamination. For the first, mainly the clinically inapparent especially persistent infections and viraemic stages at the end of incubation are dangerous. In both cases the animal is clinically healthy. In primarily biological contamination the zoonosis viruses predominate. In addition the bacteriophages must be taken into account. Primarily mechanical contamination is restricted to fish, molluscs, milk and eggs. The possibilities and consequences of exogenous and endogenous contamination are discussed. The risk of viral transmission by foodstuffs depends chiefly on the tenacity of the virus in the affected food, but also on its virulence and concentration. Basic considerations are discussed. Practically from any useful, healthy animal the most varied viruses can be isolated. In order to avoid destroying the confidence of the consumer, it is necessary to take stock of the following: 1. viral contamination in foodstuffs demonstrated so far 2. verified human diseases caused by the intake of virus-contaminated foodstuff and 3. speculations on imaginable consequential damage caused by the consumption of food containing virus. This is also dealt with in the paper. In a final, critical review the importance of virus contained in food is discussed comprehensively from a scientific, legal and practical point of view.