Papers by Matthias Hamburger
Planta Medica, Sep 26, 2013
Bryophyllum pinnatum is a succulent perennial plant native to Madagascar which is used in anthrop... more Bryophyllum pinnatum is a succulent perennial plant native to Madagascar which is used in anthroposophical medicine to treat psychiatric disorders and as a tocolytic agent to prevent premature labour. We performed a metabolite profiling study in order to obtain a comprehensive picture of the constituents in B. pinnatum leaves and to identify chromatographic markers for quality control and safety assessment of medicinal preparations. Preliminary HPLC-PDA-ESIMS analyses revealed that flavonoid glycosides were the main UV-absorbing constituents in the MeOH extract of B. pinnatum. Two phenolic glucosides, syringic acid-D-glucopyranosyl ester (1) and 4'-O-D-glucopyranosyl-cis-p-coumaric acid (2), as well as nine flavonoids (3-11) including kaempferol, quercetin, myricetin, acacetin, and diosmetin glycosides were unambiguously identified by 1H and 2D NMR analysis after isolation from a MeOH extract. The flavonol glycosides quercetin 3-O-L-arabinopyranosyl-(1 → 2)-L-rhamnopyranoside 7-O-D-glucopyranoside (3) and myricetin 3-O-L-arabinopyranosyl-(1 → 2)-L-rhamnopyranoside (4) were new natural products. With the aid of HPLC-PDA-APCIMS and authentic references isolated from the related species B. daigremontianum, the presence of four bufadienolides, bersaldegenin-1-acetate (12), bryophyllin A (13), bersaldegenin-3-acetate (14), and bersaldegenin-1,3,5-orthoacetate (15) was detected in B. pinnatum.
Biomedicine & Pharmacotherapy
Increased activation and proliferation of T lymphocytes plays an essential role in the developmen... more Increased activation and proliferation of T lymphocytes plays an essential role in the development of chronic inflammation and autoimmune diseases. Currently used immunosuppressive drugs often do not provide longlasting relief of symptoms and show a gradual loss of efficacy over time, and are accompanied by various side effects. Therefore, novel immunosuppressive lead substances are needed. For this purpose, an in-house library consisting of 600 extracts of plants from Panama was screened for inhibition of human T lymphocyte proliferation. As one of the hits, an ethyl acetate extract from the aerial parts of Hyptis brachiata (Lamiaceae) exhibited strong inhibitory effects. Subsequent investigation resulted in the isolation of seven aryltetralin lignans, five arylnaphthalene lignans, two flavonoids, three triterpenes, and cinnamyl cinnamate. Aryltetralin lignans inhibited T lymphocyte proliferation in a concentration-dependent manner without induction of apoptosis. No relevant inhibition was observed for the arylnaphthalene lignans, flavonoids, and triterpenes. Additional cell cycle arrest investigations revealed that isolated aryltetralin lignans potently inhibited cell division in G2/M phase similarly to podophyllotoxin. Multifluorescence panel analyses of the extract also showed weak suppressive effects on the production of IL-2 and TNF-α. Therefore, preparations made out of H. brachiata could be further explored as an interesting herbal alternative in the treatment of autoimmune diseases.
Organic Letters, 2020
The (polyenoyl)tetramic acid militarinone C (1) heads a family of seven members. Before our work,... more The (polyenoyl)tetramic acid militarinone C (1) heads a family of seven members. Before our work, the configuration of C-5 was unknown whereas the configurations of C-8′ and C-10′ were either (R,R) or (S,S). We synthesized the four stereoisomers of constitution 1, which conform with these insights. This included cross-coupling both enantiomers of the western building block (8) with both enantiomers of the eastern building block (9). The specific rotations of the resulting 1 isomers suggested that natural 1 is configured like the coupling partners (S)-8 and (R,R)-9. This conclusion was corroborated by degrading natural 1 to alcohol 35 and by proving its configurational identity with synthetic (R,R)-35.
Planta Medica, 2016
Bryophyllum pinnatum l " Bryophyllum daigremontianum l " Bryophyllum delagoense l " Crassulaceae ... more Bryophyllum pinnatum l " Bryophyllum daigremontianum l " Bryophyllum delagoense l " Crassulaceae l " constituents l " anthroposophic medicine l " pharmacological activities l " clinical studies
Journal of Biological Chemistry, 2016
Myotonic dystrophy type I (DM1) is a disabling neuromuscular disease with no causal treatment ava... more Myotonic dystrophy type I (DM1) is a disabling neuromuscular disease with no causal treatment available. This disease is caused by expanded CTG trinucleotide repeats in the 3′ UTR of the dystrophia myotonica protein kinase gene. On the RNA level, expanded (CUG)n repeats form hairpin structures that sequester splicing factors such as muscleblind-like 1 (MBNL1). Lack of available MBNL1 leads to misregulated alternative splicing of many target pre-mRNAs, leading to the multisystemic symptoms in DM1. Many studies aiming to identify small molecules that target the (CUG)n-MBNL1 complex focused on synthetic molecules. In an effort to identify new small molecules that liberate sequestered MBNL1 from (CUG)n RNA, we focused specifically on small molecules of natural origin. Natural products remain an important source for drugs and play a significant role in providing novel leads and pharmacophores for medicinal chemistry. In a new DM1 mechanism-based biochemical assay, we screened a collectio...
A library of more than 2’500 plant extracts were screened for their activity on oncogenic signali... more A library of more than 2’500 plant extracts were screened for their activity on oncogenic signaling in melanoma cells. The ethyl acetate extract from aerial parts of Artemisia argyi displayed pronounced inhibition of the PI3K/AKT pathway. Active compounds were tracked with the aid of HPLC-based activity profiling, and a total of 21 active compounds were isolated, including one novel dimerosequiterpenoid (1), one new disesquiterpenoid (2), three new guaianolides (3-5), 12 known sesquiterpenoids (6-17), as well as four known flavonoids (19-22). A new eudesmanolide derivative (13b) was isolated as an artifact formed by methanolysis. Compound 1 is the first adduct comprising a sesquiterpene lactone and a methyl jasmonate moiety. The absolute configurations of compounds 1 and 3-18 were established by comparison of experimental and calculated ECD spectra. The absolute configuration for 2 was determined by X-ray diffraction. Guaianolide 8 was the most potent sesquiterpene lactone, inhibiti...
Planta Medica, Dec 1, 2021
Complementary Medicine Research, Dec 1, 2014
Editorials 1 4 Komplementäre, alternative und integrative Therapien in den medizinischen Leitlini... more Editorials 1 4 Komplementäre, alternative und integrative Therapien in den medizinischen Leitliniendie Leitlinie «Diagnostik und Therapie der Colitis ulcerosa» als Beispiel gelungener Integration
Planta Medica, Jun 25, 2014
Journal of Ethnopharmacology, 2021
While the interest in finding medical solutions for the worldwide antibiotics crisis is rising, t... more While the interest in finding medical solutions for the worldwide antibiotics crisis is rising, the legal possibility of simplified authorization of herbal veterinary medicinal products is dwindling. An important basis for both the preservation and development of knowledge in veterinary herbal medicine are pharmacological and clinical studies on the performance of herbal remedies, based on historical written sources on the treatment of farm animals with medicinal plants, as well as current ethnoveterinary research. Nevertheless, there is only limited systematic ethnoveterinary research in Europe, with the exceptions of the Mediterranean region, Switzerland and Austria. We conducted a survey on the ethnoveterinary knowledge of farmers in Bavaria, and analyzed two regional historical textbooks. We documented the local veterinary knowledge about livestock in Bavaria based upon local historical textbooks and upon ethnoveterinary interviews to discover opportunities for the future development of European veterinary herbal medicine. In 2018/2019 we conducted 77 semi-structured interviews with 101 farmers from different types of farms. Detailed information about homemade herbal remedies (plant species, plant part, manufacturing process, source of knowledge) and the corresponding use reports (target animal species, category of use, route of administration, dosage, source of knowledge, frequency of use, last time of use and farmers' satisfaction) were collected. To compare our data with the literature, the use reports of two local historical textbooks were analyzed and compared with the data from the interviews. 716 homemade remedy reports (HRs) for altogether 884 use reports (URs) were documented in this study. We picked the 363 HRs that consisted of a single plant species with or without other natural products (HSHRs) for a deeper analysis. These HSHRs were prepared from 108 plant species that belonged to 57 botanical families. The most URs were documented for the families of: Asteraceae, Linaceae and Urticaceae. Calendula officinalis L. (Asteraceae), Linum usitatissimum L. (Linaceae) and Urtica dioica L. (Urticaceae) were the most often documented single species. A total of 448 URs were gathered for the 363 HSHRs. The largest number of URs was for treatments of gastrointestinal disorders and metabolic dysfunctions, followed by skin alterations and sores. For nearly half of the URs the source of knowledge was family and friends. For 80 URs the source of knowledge was different from that of the corresponding HSHRs. For 68% of the URs farmers mentioned at least one use during the last 5 years. Half of the plant species that were mentioned in the historical literature were also mentioned in URs by the interviewees. In Bavaria, medicinal plants are actively used by farmers to treat their livestock with a high level of satisfaction. The knowledge is not passed on from generation to generation in a purely static way, but is dynamically developed by the users in almost one fifth of the URs. Ethnoveterinary research combined with data from regional historical textbooks may facilitate pharmacological and clinical studies in veterinary medicine, and the discussion about a simplified registration for traditional herbal veterinary medicinal products.
Complementary Medicine Research, 2014
Planta Medica, 2020
A blinded placebo-controlled multi-center on-farm trial was conducted in dairy cows with subclini... more A blinded placebo-controlled multi-center on-farm trial was conducted in dairy cows with subclinical ketosis to investigate effects of a multicomponent herbal extract. Blood ketone levels were measured weekly in early lactating cows from 16 Swiss herds. Cows were subclassified based on their initial blood-β-hydroxybutyrate levels (≥ 1.0 [KET-low, 84 cows] and > 1.2 mmol/L [KET-high, 39 cows]) and randomly distributed to 3 groups treated orally with herbal extract containing Camellia sinensis, Cichcorium intybus, Gentiana lutea, Glycyrrhiza glabra, Taraxacum officinale, Trigonella foenum-graecum, and Zingiber officinale, sodium propionate, or placebo twice a day for 5 days. Milk yield, milk acetone, blood-β-hydroxybutyrate, glucose, nonesterified fatty acids, gamma-glutamyl transferase, and glutamate dehydrogenase were analyzed over 2 wk. Linear mixed effect models were used for data analysis. No effects were found for nonesterifed fatty acids, gamma-glutamyl transferase, and gluc...
Molecules, 2020
A screening of Sudanese medicinal plants for antiprotozoal activities revealed that the chlorofor... more A screening of Sudanese medicinal plants for antiprotozoal activities revealed that the chloroform and water fractions of the ethanolic root extract of Haplophyllum tuberculatum exhibited appreciable bioactivity against Leishmania donovani. The antileishmanial activity was tracked by HPLC-based activity profiling, and eight compounds were isolated from the chloroform fraction. These included lignans tetrahydrofuroguaiacin B (1), nectandrin B (2), furoguaiaoxidin (7), and 3,3′-dimethoxy-4,4′-dihydroxylignan-9-ol (10), and four cinnamoylphenethyl amides, namely dihydro-feruloyltyramine (5), (E)-N-feruloyltyramine (6), N,N′-diferuloylputrescine (8), and 7′-ethoxy-feruloyltyramine (9). The water fraction yielded steroid saponins 11–13. Compounds 1, 2, and 5–13 are reported for the first time from Haplophyllum species and the family Rutaceae. The antiprotozoal activity of the compounds plus two stereoisomeric tetrahydrofuran lignans—fragransin B2 (3) and fragransin B1 (4)—was determined ...
Journal of Animal Physiology and Animal Nutrition, 2020
In contrast to natural and historical diets of wild and domesticated ruminants, the diversity of ... more In contrast to natural and historical diets of wild and domesticated ruminants, the diversity of plant species is limited in diets of modern dairy cows. Are "production diseases" linked to this? We conducted a trial to test the effects of a multicomponent herbal feed additive (HFA) on health, performance and fertility traits. A dose
Journal of Ethnopharmacology, 2019
In the pre-antibiotic era, a broad spectrum of medicinal plants was used to treat livestock. This... more In the pre-antibiotic era, a broad spectrum of medicinal plants was used to treat livestock. This knowledge was neglected in European veterinary medicine for decades but kept alive by farmers. Emergence of multidrug resistant bacterial strains requires a severely restricted use of antibiotics in veterinary medicine. We conducted a survey on the ethnoveterinary knowledge of farmers in the bilingual (French and German speaking) Western region of Switzerland, namely the cantons of Fribourg, Neuchâtel and Jura, and in the French speaking part of the canton of Bern. Aim of the study: To find out whether differences exist in plants used by farmers in French speaking and bilingual regions of Switzerland as compared to our earlier studies conducted in Switzerland. Additional focus was on plants that are used in diseases which commonly are treated with antimicrobials, on plants used in skin afflictions, and on plants used in animal species such as horses, for which the range of veterinary medicinal products is limited. Material and methods: We conducted in 2015 semistructured interviews with 62 dialog partners, mainly cattle keeping farmers but also 18 horse keeping farmers. Of these, 41 were native French (FNS) and 21 native German speakers (GNS). Detailed information about homemade herbal remedies (plant species, plant part, manufacturing process) and the corresponding use reports (target animal species, category of use, route of administration, dosage, source of knowledge, frequency of use, last time of use and farmers satisfaction) were collected. Results: A total of 345 homemade remedies were reported, of which 240 contained only one plant species (Homemade Single Species Herbal Remedy Reports; HSHR). A total of 289 use reports (UR) were mentioned for the 240 HSHR, and they comprised 77 plant species belonging to 41 botanical families. Of these, 35 plant species were solely reported from FNS, 20 from GNS, and 22 from both. Taking into account earlier ethnoveterinary studies conducted in Switzerland only 10 (FNS) and 6 (GNS) plant species connected with 7% of FNS and GNS UR respectively were "unique" to the respective language group. The majority of the UR (219) was for treatment of cattle, while 38 UR were intended to treat horses. The most UR were for treatment of gastrointestinal and skin diseases. The most frequently mentioned plants were Linum usitatissimum L., Coffea L., Matricaria chamomilla L., Camellia sinensis (L.) Kuntze, and Quercus robur L. for gastrointestinal diseases, and Calendula officinalis L., Hypericum perforatum L. and Sanicula europaea L. for skin afflictions. Conclusion: No clear differences were found between the medicinal plants used by French native speakers and German native speakers. Several of the reported plants seem to be justified to widen the spectrum of veterinary
Journal of Natural Products, 2019
Natural Product Communications, 2006
In continuation of our search for anti-inflammatory constituents in lipophilic extracts of Isatis... more In continuation of our search for anti-inflammatory constituents in lipophilic extracts of Isatis tinctoria, an HPLC-based profiling for inhibitors of human neutrophil elastase was performed. Using a linear gradient profile, fractions with significant activity (>50%) appeared in the second half of the chromatogram and corresponded to moderately to highly lipophilic constituents. The active fractions of intermediate polarity were further analyzed by HPLC, TLC and GC. They contained mainly α-linolenic, linoleic, cis-11-octadecenoic acid, oleic and palmitic acids.
Planta Medica, 2019
A phytochemical investigation of extracts from flowers and aerial parts of Tanacetum sonbolii aff... more A phytochemical investigation of extracts from flowers and aerial parts of Tanacetum sonbolii afforded 7 new germacranolide sesquiterpene lactones. The structures were established by a combination of 1- and 2-dimensional nuclear magnetic resonance spectroscopy, high-resolution mass spectrometry, and electronic circular dichroism. The in vitro antiprotozoal activity of the compounds against Trypanosoma brucei rhodesiense and cytotoxicity against rat myoblast (L6) cells were determined. Compounds 4 and 5 showed IC50 values of 5.1 and 10.2 µM and selectivity indices of 3.9 and 4.0, respectively.
Journal of Ethnopharmacology, 2018
Ethnoveterinary contemporary knowledge of farmers in pre-alpine and alpine regions of the Swiss c... more Ethnoveterinary contemporary knowledge of farmers in pre-alpine and alpine regions of the Swiss cantons of Bern and Lucerne compared to ancient and recent literature-is there a tradition?
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Papers by Matthias Hamburger