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Uwe Pfüller

Bio: Uwe Pfüller is an academic researcher. The author has contributed to research in topics: Oleanolic acid. The author has an hindex of 1, co-authored 1 publications receiving 106 citations.

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TL;DR: The triterpene acid content of neutral plant extracts above the solubility limit could be due to interactions with biocolloids, and different mechanisms of the dissolution at pH 7.3 and pH 10.2 are discussed.
Abstract: Mistletoe (Viscum album L.) contains the triterpene acids oleanolic acid (OA) and betulinic acid (BA), which were found to have anti-tumour properties. In this study, the solubilities of OA and BA were studied in water (up to 0.02 microg/mL in each case) and in alkaline solutions of 10 mM trisodium phosphate (pH 11.5; OA: 77.2 microg/mL; BA: 40.1 microg/mL). Furthermore, triterpene acids were quantified in aqueous mistletoe extracts (pH 7.3; drug to extract ratio 1:25). OA (1.1 microg/mL) and BA (0.9 microg/mL) were extracted with a yield of less than 5%. Preparing plant extracts with basic pH values resulted in a triterpene acid content of 9.3 microg/mL OA and 5.2 microg/mL BA (pH 12.1), reaching neither the solubility limits nor a complete extraction of the plant material. The triterpene acid content of neutral plant extracts above the solubility limit could be due to interactions with biocolloids. Interaction studies were performed by gel permeation chromatography. Different mechanisms of the dissolution at pH 7.3 and pH 10.2 are discussed.

115 citations


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TL;DR: Pentacyclic triterpenes are secondary plant metabolites widespread in fruit peel, leaves and stem bark display various pharmacological effects while being devoid of prominent toxicity and are promising leading compounds for the development of new multi-targeting bioactive agents.
Abstract: Pentacyclic triterpenes are secondary plant metabolites widespread in fruit peel, leaves and stem bark. In particular the lupane-, oleanane-, and ursane triterpenes display various pharmacological effects while being devoid of prominent toxicity. Therefore, these triterpenes are promising leading compounds for the development of new multi-targeting bioactive agents. Screening of 39 plant materials identified triterpene rich (> 0.1% dry matter) plant parts. Plant materials with high triterpene concentrations were then used to obtain dry extracts by accelerated solvent extraction resulting in a triterpene content of 50 - 90%. Depending on the plant material, betulin (birch bark), betulinic acid (plane bark), oleanolic acid (olive leaves, olive pomace, mistletoe sprouts, clove flowers), ursolic acid (apple pomace) or an equal mixture of the three triterpene acids (rosemary leaves) are the main components of these dry extracts. They are quantitatively characterised plant extracts supplying a high concentration of actives and therefore can be used for development of phytopharmaceutical formulations.

531 citations

Journal ArticleDOI
TL;DR: This review summarizes the potential of triterpenes belonging to the lupane, oleanane or ursane group, to treat cancer by different modes of action and utilisation of different plants as their sources is of interest.
Abstract: Today cancer treatment is not only a question of eliminating cancer cells by induction of cell death. New therapeutic strategies also include targeting the tumour microenvironment, avoiding angiogenesis, modulating the immune response or the chronic inflammation that is often associated with cancer. Furthermore, the induction of redifferentiation of dedifferentiated cancer cells is an interesting aspect in developing new therapy strategies. Plants provide a broad spectrum of potential drug substances for cancer therapy with multifaceted effects and targets. Pentacyclic triterpenes are one group of promising secondary plant metabolites. This review summarizes the potential of triterpenes belonging to the lupane, oleanane or ursane group, to treat cancer by different modes of action. Since Pisha et al. reported in 1995 that betulinic acid is a highly promising anticancer drug after inducing apoptosis in melanoma cell lines in vitro and in vivo, experimental work focused on the apoptosis inducing mechanisms of betulinic acid and other triterpenes. The antitumour effects were subsequently confirmed in a series of cancer cell lines from other origins, for example breast, colon, lung and neuroblastoma. In addition, in the last decade many studies have shown further effects that justify the expectation that triterpenes are useful to treat cancer by several modes of action. Thus, triterpene acids are known mainly for their antiangiogenic effects as well as their differentiation inducing effects. In particular, lupane-type triterpenes, such as betulin, betulinic acid and lupeol, display anti-inflammatory activities which often accompany immune modulation. Triterpene acids as well as triterpene monoalcohols and diols also show an antioxidative potential. The pharmacological potential of triterpenes of the lupane, oleanane or ursane type for cancer treatment seems high; although up to now no clinical trial has been published using these triterpenes in cancer therapy. They provide a multitarget potential for coping with new cancer strategies. Whether this is an effective approach for cancer treatment has to be proven. Because various triterpenes are an increasingly promising group of plant metabolites, the utilisation of different plants as their sources is of interest. Parts of plants, for example birch bark, rosemary leaves, apple peel and mistletoe shoots are rich in triterpenes and provide different triterpene compositions.

426 citations

Journal ArticleDOI
TL;DR: This review summarizes the diverse molecular targets of OA and its derivatives and also provides clear evidence on their promising potential in preclinical and clinical situations.

220 citations

Journal ArticleDOI
TL;DR: VAEs seem to have an impact on QoL and reduction of side effects of conventional therapies (chemotherapy, radiation) in experimental trials as well as in routine daily application.
Abstract: Objective. To evaluate controlled clinical studies on the efficacy and effectiveness of Viscum album for quality of life (QoL) in cancer. Materials and methods. The authors conducted a search of 7 electronic databases and reference lists and had extensive consultations with experts. They carried out a criteria-based assessment of methodological study quality. Results. The authors identified 26 randomized controlled trials (RCTs) and 10 non-RCTs that investigated the influence of V album extracts (VAEs) on QoL in malignant diseases; 26 studies assessed patient-reported QoL. Questionnaires were mostly well established and validated. Half of the studies investigated VAEs concomitant with chemotherapy, radiotherapy, or surgery. Some studies were well designed, whereas others had minor or major methodological weaknesses. Among the 26 RCTs, 22 reported a QoL benefit, 3 indicated no difference, and 1 did not report any result. All the non-RCTs reported a QoL benefit. Of the studies with higher methodological quality, most reported a benefit, whereas 1 found no difference. Improvements were mainly in regard to coping, fatigue, sleep, exhaustion, energy, nausea, vomiting, appetite, depression, anxiety, ability to work, and emotional and functional well-being in general and, less consistently, in regard to pain, diarrhea, general performance, and side effects of conventional treatments. VAEs were well tolerated. Conclusions. VAEs seem to have an impact on QoL and reduction of side effects of conventional therapies (chemotherapy, radiation) in experimental trials as well as in routine daily application. The influence on fatigue especially should be investigated further.

190 citations

Journal ArticleDOI
01 Nov 2013
TL;DR: Anthroposophic medicine is an integrative multimodal treatment system based on a holistic understanding of man and nature and of disease and treatment that is integrated with conventional medicine in large hospitals and medical practices.
Abstract: Anthroposophic medicine is an integrative multimodal treatment system based on a holistic understanding of man and nature and of disease and treatment. It builds on a concept of four levels of formative forces and on the model of a three-fold human constitution. Anthroposophic medicine is integrated with conventional medicine in large hospitals and medical practices. It applies medicines derived from plants, minerals, and animals; art therapy, eurythmy therapy, and rhythmical massage; counseling; psychotherapy; and specific nursing techniques such as external embrocation. Anthroposophic healthcare is provided by medical doctors, therapists, and nurses. A Health-Technology Assessment Report and its recent update identified 265 clinical studies on the efficacy and effectiveness of anthroposophic medicine. The outcomes were described as predominantly positive. These studies as well as a variety of specific safety studies found no major risk but good tolerability. Economic analyses found a favorable cost stru...

139 citations