Volume 149, Issue 3, 7 October 2013, Pages 750–771
Ethnopharmacological in vitro studies on Austria's folk medicine—An unexplored lore in vitro anti-inflammatory activities of 71 Austrian traditional herbal drugs
- Open Access funded by Austrian Science Fund (FWF)
- Under a Creative Commons license
Open Access
Abstract
Ethnopharmacological relevance
In
Austria, like in most Western countries, knowledge about traditional
medicinal plants is becoming scarce. Searching the literature concerning
Austria's ethnomedicine reveals its scant scientific exploration.
Aiming
to substantiate the potential of medicinal plants traditionally used in
Austria, 63 plant species or genera with claimed anti-inflammatory
properties listed in the VOLKSMED database were assessed for their in vitro anti-inflammatory activity.
Material and methods
71
herbal drugs from 63 plant species or genera were extracted using
solvents of varying polarities and subsequently depleted from the bulk
constituents, chlorophylls and tannins to avoid possible interferences
with the assays. The obtained 257 extracts were assessed for their in vitro
anti-inflammatory activity. The expression of the inflammatory
mediators E-selectin and interleukin-8 (IL-8), induced by the
inflammatory stimuli tumor necrosis factor alpha (TNF-α) and the
bacterial product lipopolysaccharide (LPS) was measured in endothelial
cells. The potential of the extracts to activate the nuclear factors
PPARα and PPARγ and to inhibit TNF-α-induced activation of the nuclear
factor-kappa B (NF-κB) in HEK293 cells was determined by luciferase
reporter gene assays.
Results
In total, extracts from 67 of the 71 assessed herbal drugs revealed anti-inflammatory activity in the applied in vitro
test systems. Thereby, 30 could downregulate E-selectin or IL-8 gene
expression, 28 were strong activators of PPARα or PPARγ (inducing
activation of more than 2-fold at a concentration of 10 µg/mL) and 21
evoked a strong inhibition of NF-κB (inhibition of more than 80% at
10 µg/mL).
Conclusion
Our
research supports the efficacy of herbal drugs reported in Austrian folk
medicine used for ailments associated with inflammatory processes.
Hence, an ethnopharmacological screening approach is a useful tool for
the discovery of new drug leads.
Graphical abstract
Keywords
- Traditional European medicine (TEM);
- Austria;
- Inflammation;
- PPAR;
- NF-ĸB;
- IL-8;
- E-selectin
1. Introduction
In
contrast to traditional Chinese medicine (TCM), traditional European
medicine (TEM), including Austria's ethnomedicine, has been barely
scientifically explored (Adams et al., 2009).
Although the advance of Western medicine and the loss of knowledge in
the medical profession and in wide sections of the Austrian population
concerning TEM led to repression of the use of traditional preparations,
Austria and its adjacent regions have a rich history in traditional
folk medicine. In order to conserve this knowledge, the so-called
VOLKSMED database was generated by gathering information about
traditionally used medicines in Austria and the immediate vicinity (Gerlach et al., 2006 and Saric-Kundalic and Dobes, 2010).
It refers to knowledge that had been passed on from generation to
generation and does not lean on any existing literature. Besides an
exact identification of the medicinal product, it contains information
about the plant/animal parts or products used, preparation and
application methods, internal or external use, and indications. The
whole database comprises 43,150 entries, and is based on 67,200
interviews. Regarding inflammatory ailments, the database includes 8457
statements on 226 preparations of 123 plant species or genera and 24
animal products. The VOLKSMED database comprises approximately 700 plant
and fungi species/genera, however, only 196 are mentioned more than 50
times. Hence, this database was the basis for the selection of herbal
drugs to be evaluated on various anti-inflammatory targets, using in vitro cell based assays.
Inflammation is part of various pathological conditions e.g.
arthritis, atherosclerosis, the metabolic syndrome, allergies and other
autoimmune diseases as well as cancer. For most of these conditions no
satisfying treatment of the associated inflammation is available.
General treatment relies on steroidal and non-steroidal
anti-inflammatory drugs (NSAIDs) which have several adverse effects ( McGettigan et al. 2011)
as well as on disease-modifying anti-rheumatic drugs (DMARDs).
Therefore, the search for new anti-inflammatory drugs still represents
an important field in drug discovery.
Many
inflammatory processes in different cell types are mediated by the
transcription factor nuclear factor kappa-light-chain-enhancer of
activated B-cells (NF-κB). Major target genes of NF-κB include those for
transcription of some pro-inflammatory adhesion molecules (e.g., E-selectin), cytokines (e.g., tumor necrosis factor (TNF)-α), growth factors and enzymes (e.g.,
cyclooxygenase (COX)-2) producing inflammatory mediators. Among the
most prominent mediators of inflammation are cytokines such as TNF-α and
interleukin (IL)-1, as well as components released by bacteria such as
LPS. Important molecular players inhibiting NF-κB responses are nuclear
receptors, like the glucocorticoid receptor, the peroxisome
proliferator-activated receptors (PPARs), the farnesoid X receptor
(FXR), the liver X receptor (LXR) and the orphan nuclear receptors class
4A (NR4A). Nuclear receptors are thought to exert their
anti-inflammatory activities by repressing the activity of other
transcription factors, such as NF-κB, STAT or AP1 proteins, which are
involved in the induction of a variety of pro-inflammatory genes ( Karin et al., 2004, Glass and Ogawa, 2006, Bamborough et al., 2009 and Brasier, 2010).
In
the present study, a panel of functional as well as target-oriented
cell models were used for the identification of active natural products.
Thereby, interference with TNF-α or LPS induced expression of the
adhesion molecule E-selectin or the chemokine IL-8, inhibition of the
NF-κB pathway and activation of nuclear receptors (PPARα and PPARγ) were
investigated, in order to get insight in various steps of the complex
inflammatory process.
Since
there were no data available concerning the interference of bulk
constituents, such as chlorophylls and tannins, with the respective test
systems, separation of those was implemented. However, due to the
possibility of co-separation of active constituents, not only the
purified extracts but also the crude extracts were tested for activity.
2. Materials and methods
2.1. Literature search
In a first step, 123 plant species or genera, reported in the VOLKSMED database as traditionally used anti-inflammatory agents (e.g.,
for colds, rheumatism, gastro-intestinal diseases), were explored in
the databases Chemical Abstracts (CAPLUS) and Medline. The search was
limited to terms concerning inflammation (antiphlogistic,
anti-inflammatory, etc.) in order to avoid re-investigations.
Plant
species/genera with insufficient coverage in the literature and a good
score in the VOLKSMED database were considered as interesting
candidates. Further important points had been the availability of the
herbal drugs on the market or the possibility to collect the material by
wild harvesting. Using these selection criteria, 63 promising plant
species/genera were selected for further investigations.
2.2. Plant material
Part
of the plant material could be purchased from various suppliers (Kottas
Pharma GmbH, Vienna, Austria; Alfred Richter GmbH. & CO. KG,
Kufstein, Austria and Alfred Galke GmbH, Gittelde, Germany). Several
species have been collected in Austria (Table 1)
in most cases at the flowering period. The plant material was
authenticated by one of the authors (J. Saukel). Voucher specimens are
deposited in the Herbarium of the Institute of Pharmacognosy, University
of Vienna (WUP). The material was air dried at room temperature.
- Table 1. Ethnopharmacological uses of traditional Austrian herbal drugs as documented in the VOLKSMED database.
Scientific name Part used Family Application form Indications Sample location/source Agrimonia sp., Agrimoniae herba Ph. Eur. Herb Rosaceae Internal as tea Liver and bile, gastrointestinal, respiratory tract Kottas Pharma GmbH, Vienna, Austria Agropyron repens (L.) P. Beauv. Rhizome Poaceae Internal as tea, syrup or cold maceration in water, external as crude drug Fever Kottas Pharma GmbH, Vienna, Austria Ajuga genevensis L. Herb Lamiaceae Internal as tea Respiratory tract Laab im Walde, Lower Austria Ajuga reptans L. Herb Lamiaceae Internal as tea Respiratory tract Laab im Walde, Lower Austria Alnus viridis (Chaix) DC. Leaf Betulaceae Drug internal and external as tea Fever, infections Koenigsalm, Riedingtal, Lungau, Salzburg, Austria Angelica archangelica L. Root Apiaceae Internal as tea or tincture Gastrointestinal tract, respiratory tract, nervous system, fever, infections, flu Kottas Pharma GmbH, Vienna, Austria Angelica sylvestris L. Root Apiaceae Internal as tea or tincture Gastrointestinal tract, respiratory tract, nervous system, fever, infections, flu Alfred Richter GmbH. & CO.KG, Kufstein, Austria Argentina anserina (L.) Rydb. Herb Rosaceae Internal as tea Gastrointestinal tract, gynaecology, spasm Kottas Pharma GmbH, Vienna, Austria Bellis perennis L. Flower Asteraceae Internal as tea, leaves as salad Respiratory tract, gastrointestinal Alfred Galke GmbH, Gittelde, Germany Berberis vulgaris L. Fruit Berberidaceae Internal as tea, jelly or syrup Fever, respiratory tract, infections, colds, flu Kottas Pharma GmbH, Vienna, Austria Beta vulgaris L. Beet Chenopodiaceae Internal drug or juice, external compresses of drug Respiratory tract, fever, infections Alfred Galke GmbH, Gittelde, Germany Betonica officinalis L. Herb Lamiaceae Internal as tea, external as compress or bath Gastrointestinal tract, respiratory tract, nervous system, skin, gynaecology Neustift am Walde, Vienna Austria Calluna vulgaris (L.) Hull Herb Ericaceae Internal as tea Kidney and urinary tract Kottas Pharma GmbH, Vienna, Austria Capsella bursa-pastoris (L.) Medik. Herb Brassicaceae Internal as tea or tincture, external as tincture, tea, ointment, bath or powder Locomotor system, gynaecology, cardiovascular system, hemostasis, skin Kottas Pharma GmbH, Vienna, Austria Circaea lutetiana L. Herb Onograceae Internal as tea, external as cold maceration in ethanol Rheumatism and gout, infections, fever Sagberg, near Purkerdorf, Lower Austria Epilobium angustifolium L. Herb Onograceae Internal as tea Prostate, kidney and urinary tract Kottas Pharma GmbH, Vienna, Austria Epilobium montanum L. Herb Onograceae Internal as tea Prostate, kidney and urinary tract Hochwechsel/ Steyersberger Schwaig, Lower Austria Epilobium parviflorum Schreb. Herb Onograceae Internal as tea Prostate, kidney and urinary tract Kottas Pharma GmbH, Vienna, Austria Equisetum arvense L. Herb Equisetaceae Internal as tea, external as bath and compress Kidney and urinary tract, locomotor system, rheumatism and gout, skin Alfred Richter GmbH. & CO.KG, Kufstein, Austria Equisetum palustre L. Herb Equisetaceae Internal as tea, external as bath and compress Intervertebral disks, lung cancer Oggau, Neusiedlerseeregion, Bgld., Austria Euphrasia rostkoviana Hayne Herb Orobanchaceae Internal as tea, external as compress Eyes, gastrointestinal tract Murtal (near Powerstation Rotgüldensee) Lungau, Salzburg, Austria Euphrasia sp., Euphrasia herba DAC Herb Orobanchaceae Internal as tea, external as compress Eyes, gastrointestinal tract Kottas Pharma GmbH, Vienna, Austria Filipendula ulmaria (L.) Maxim. Flower Rosaceae Internal as tea Rheumatism and gout, infections, fever Kottas Pharma GmbH, Vienna, Austria Filipendula ulmaria (L.) Maxim. Herb Rosaceae Internal as tea Rheumatism and gout, infections, fever Weißpriach, Salzburg; Gontal, near Katschberg, Carinthia, Austria Filipendula vulgaris Moench Flower Rosaceae Internal as tea Rheumatism and gout, infections, fever Neustift am Walde, Vienna Austria Gentiana punctata L. Leaf, root Gentianaceae Internal and external as liqueur and tea Gastrointestinal tract, skin, locomotor system, liver and bile, paediatrics, fever, flu, rheumatism and gout Pöllatal (east of the Grosser Hafner), Carinthia, Austria Glechoma hederacea L. Herb Lamiaceae Internal as salad and tea Liver and bile, gastrointestinal tract, respiratory tract, food, kidney and urinary tract, fever, flu Kottas Pharma GmbH, Vienna, Austria Geum montanum L. Root Rosaceae Internal as tea Rheumatism and gout, infections, fever Schattneralm, near Krakaudorf, Styria, Austria Geum urbanum L. Herb Rosaceae Internal as tea Rheumatism and gout, infections, fever Alfred Galke GmbH, Gittelde, Germany Geum urbanum L. Root Rosaceae Internal as tea Rheumatism and gout, infections, fever Alfred Galke GmbH, Gittelde, Germany Hippophae rhamnoides L. Fruit Elaeagnaceae Internal as tea, juice or syrup Infections, colds, flu Alfred Galke GmbH, Gittelde, Germany Hypericum maculatum Crantz Herb Hypericaceae Internal as oil and tea, external as oil, ointment or cold maceration in ethanol Skin, locomotor system, nervous system, gastrointestinal tract, respiratory tract, kidney and urinary tract, cardiovascular system, infections, rheumatism and gout Gontal, near Katschberg, Carinthia, Austria Linum usitatissimum L. Seeds Linaceae Internal soaked or as tea, external as compress or oil Respiratory tract, eyes, infections, colds, flu, fever, rheumatism and gout Alfred Richter GmbH. & CO.KG, Kufstein, Austria Lycopodium sp., Lycopodii herba Herb Lycopodiaceae External as compress, internal as tea Locomotor system, skin, liver and bile, kidney and urinary tract, infections, rheumatism and gout Kottas Pharma GmbH, Vienna, Austria, Saukel Majorana hortensis Moench Herb Lamiaceae Internal as herb Gastrointestinal tract, infections Alfred Richter GmbH. & CO.KG, Kufstein, Austria Malva neglecta Herb Malvaceae Internal as tea, external as bath Skin, gastrointestinal tract, respiratory tract Nodendorf, near Ernstbrunn, Lower Austria Malva sp., Malvae folium Ph. Eur. Leaf Malvaceae Internal as tea, external as bath Skin, gastrointestinal tract, respiratory tract Kottas Pharma GmbH, Vienna, Austria Melampyrum pratense L. Herb Orobanchaceae Internal as tea, external as pillow Calcification blood vessels, rheumatism Neustift am Walde, Vienna Austria Melissa officinalis L. Leaf Lamiaceae Internal as tea, external essential oil Gastrointestinal tract, nervous system, liver and bile, food Alfred Galke GmbH, Gittelde, Germany Origanum vulgare L. Herb Lamiaceae Internal as tea, external as ointment Gastrointestinal tract, respiratory tract, nervous system Alfred Richter GmbH. & CO.KG, Kufstein, Austria Petasites hybridus (L.) Gaertn., B. Mey. & Scherb. Leaf Asteraceae Internal as tea or cold maceration in ethanol, external as compress or maceration in vinegar Infections, fever, flu, colds Hohe Student, near Halltal, Styria, Austria Peucedanum ostruthium (L.) W.D.J. Koch Root Apiaceae Internal as tea, liqueur and wine, external as fumigation, tincture and incense Gastrointestinal tract, skin, respiratory tract, cardiovascular system, viral infects, infections, fever, flu, colds Kottas Pharma GmbH, Vienna, Austria Peucedanum ostruhtium (L.) W.D.J. Koch Leaf Apiaceae Internal as tea and liqueur, external as fumigation, tincture and incense Gastrointestinal tract, skin, respiratory tract, cardiovascular system, viral infects, infections, fever, flu, colds Hochwechsel/ Steyersberger Schwaig, Lower Austria Picea abies (L.) H. Karst. Shoot tip Piceaceae Internal as syrup, tea, external as resin, bath, inhalation, ointment, tea Respiratory tract, skin, locomotor system, viral infects, gastrointestinal tract Wechsel, Mariensee, Lower Austria Pimpinella major (L.) Hudson Root Apiaceae Internal as drug, tea, in milk, liqueur Respiratory tract, fever, infections, colds, flu Kienstein, Ebenwaldhöhe, near Kleinzell, Lower Austria Plantago lanceolata L. Leaf Plantaginaceae Internal as syrup or tea, external as fresh stumped leaves Respiratory tract, skin, insect bites, viral infects Kottas Pharma GmbH, Vienna, Austria Prunella vulgaris L. Herb Lamiaceae Internal as tea Respiratory tract, infections Neustift am Walde, Vienna, Austria Ribes nigrum L. Fruit Grossulariaceae Internal as food or syrup Gastrointestinal tract, viral infects, locomotor system, respiratory tract, cardiovascular system Alfred Richter GmbH. & CO.KG, Kufstein, Austria Rosa canina L. Fruit Rosaceae Internal as tea Kidney and urinary tract, viral infects, food Kottas Pharma GmbH, Vienna, Austria Rumex alpinus L. Leaf, root Polygonaceae Internal as drug Viral infects Hohe Student, near Halltal, Styria, Austria Salvia officinalis L. Herb Lamiaceae Internal as tea or chewed Respiratory tract, mouth, gastrointestinal tract, skin Alfred Richter GmbH. & CO.KG, Kufstein, Austria Sambucus ebulus L. Fruit Adoxaceae Fever, respiratory tract Laab im Walde, Lower Austria Sambucus nigra L. Fruit Adoxaceae Internal as tea, jelly, juice or syrup Viral infects, fever, flu, colds, respiratory tract, mouth, gastrointestinal tract, skin Kottas Pharma GmbH, Vienna, Austria Sambucus nigra L. Flowers Adoxaceae Internal as tea or syrup Viral infects, fever, flu, colds, respiratory tract, mouth, gastrointestinal tract, skin Sagberg, near Purkersdorf, Lower Austria Sanicula europaea L. Root Apiaceae Internal as tea, external as ointment Skin, respiratory tract, locomotor system, gastrointestinal tract, infections Jubilaeumswarte, Vienna, Austria Sorbus aucuparia L. Fruit Rosaceae Internal as tea, syrup, jelly or liqueur Respiratory tract, fever, infections, colds, flu, rheumatism and gout Kottas Pharma GmbH, Vienna, Austria Symphytum officinale L. Root Boraginaceae Internal as tea or tincture, external as ointment, compress or alcoholic digestion Locomotor system, gastrointestinal tract Kottas Pharma GmbH, Vienna, Austria Symphytum officinale L. Leaf stem Boraginaceae External as ointment, compress, or alcoholic digestion, internal as tea or tincture Locomotor system, gastrointestinal tract, rheumatism and gout Oggau, Neusiedlersee- region, Bgld., Austria Tilia sp., Tiliae flos Ph. Eur. Flowers Malvaceae Internal as tea Fever, flu, viral infects, respiratory tract Kottas Pharma GmbH, Vienna, Austria Tussilago farfara L. Leaf Asteraceae Internal as tea or syrup, external direct or stumped Respiratory tract, skin, locomotor system, viral infects, flu, colds, fever, rheumatism and gout Alfred Richter GmbH. & CO.KG, Kufstein, Austria Urtica dioica L. Herb Urticaceae Internal as tea or fresh leaves Kidney and urinary tract, gastrointestinal tract, locomotor system, skin, hemorrhage, cardio-vascular system, rheumatism and gout, flu Alfred Richter GmbH. & CO.KG, Kufstein, Austria Vaccinium myrtillus L. Fruit Ericaceae Internal as fresh food, liqueur or tea Gastrointestinal tract, diabetes Alfred Richter GmbH. & CO.KG, Kufstein, Austria Vaccinium vitis-idaea L. Fruit Ericaceae Internal as jelly or syrup Fever, gastrointestinal tract, kidney and urinary tract, food Hochwechsel/ Steyersberger Schwaig, Lower Austria Verbascum sp.,Verbasci flos Ph. Eur. Flower Scrophulariaceae Internal as tea, external as ointment, tea, bath or compress Respiratory tract, skin, veins, gastrointestinal tract, locomotor system Alfred Richter GmbH. & CO.KG, Kufstein, Austria Verbena officinalis L. Herb Verbenaceae Internal as tea or liqueur Fever, infections Kottas Pharma GmbH, Vienna, Austria Veronica chamaedrys L. Herb Plantaginaceae Internal as tea Nervous system, respiratory tract, cardiovascular system, metabolism Neustift am Walde, Vienna, Austria Veronica officinalis L. Herb Plantaginaceae Internal as tea Nervous system, respiratory tract, cardiovascular system, metabolism Neustift am Walde, Vienna, Austria Veronica sp., Veronica herba DAC Herb Plantaginaceae Internal as tea Nervous system, respiratory tract, cardiovascular system, metabolism Kottas Pharma GmbH, Vienna, Austria