Anthroposophic research in dermatology is mainly dedicated to the investigation of beneficial effects of plant extracts on the skin. There are many hints of Rudolf Steiner’s on the therapeutic value of plants for the skin, i.e. Hypericum perforatum (St. John’s wort), Betula alba (birch bark), Potentilla officinalis (tormentil), or essential oils. The plants contain a variety of natural compounds with therapeutic relevance, such as free radical scavenging, antiinflammatory and antimicrobial substances. The dermatologic usability of most of these compounds is only partly explored.
The research centre skinitial™ at the University of Freiburg is integrated into the clinical divisions of the Department of Dermatology. It performs its tasks in cooperation with the other institutions of the Medical Center, University of Freiburg, allowing for close connection to clinical research. The integrative approach of skinitial™ is expressed by interdisciplinary research projects with natural sciences such as allergology, pharmacy and biology, as well as complementary research and therapies. A wide range of molecular and clinical test systems is used to elucidate the mode of action of selected natural products and drugs.
Bitter taste receptors and the skin
Almost 90 years ago Steiner postulated that “every organ has its own specific taste experience”. He also said that tasting is not restricted to the tongue and throat, but is continued unconsciously throughout the body. Only during the last years it was discovered that bitter taste receptors (T2Rs) are not only present on the tongue and upper gastrointestinal tract but also in the lung. The binding of bitter substances to T2R receptors in the lung induces bronchodilation which may be of therapeutic use in the treatment of asthma bronchiale. The research centre skinitial could show that the skin also possesses bitter taste receptors. (1)
Plant derived bitter agents from gentian (amarogentin) or willow bark (salicin) bind to the receptors in the skin and induce calcium influx into the keratinocytes, eventually leading to the synthesis of lipids and proteins. Thus the binding of bitter taste receptor ligands to T2Rs stimulates the regeneration of the skin barrier. Moreover, bitter agents display antiallergic effects on immunocompetent cells of the skin. (2)
Tannins in the treatment of skin inflammation
Tannins represent another group of plant polyphenols with prominent antioxidative properties. Moreover, tannins chemically react with proteins and have therefore been used for the tanning of leather. In the molecular range tannins are highly effective immune modulators and anticancer agents. Today, plant dervived tannins are mainly used in anthroposophic medicine as therapeutics that regulate increased cell proliferation, edema and atopic diseases. Skinitial has performed clinical and experimental research on tannin containing plants such as oak bark and tormentil (Potentilla officinalis, PO). It could be shown, that PO displays anti-inflammatory and vasoconstrictory effects and is effective in the treatment of atopic dermatitis. (3,4,5)
Effects of birch bark extract on the skin
There are hints of Steiner’s that birch may be a remedy for the treatment of “exudative skin disorders”. Interdisciplinary research of the last years has explored the effects of birch bark extract and betulin on the skin and on wound healing. It has been shown that betulin induces skin differentiation and is effective in the treatment of skin conditions with an impaired skin barrier such as burns and superficial wounds. (6,7,8)
Prof. Dr. med. dipl. biol. Christoph Schempp,
Research Centre skinitial™,
University of Freiburg, Germany
Expression and functional activity of the bitter taste receptors TAS2R1 and TAS2R38 in human keratinocytes. Ski Pharmacol Physiol 2015; 28, pp. 137–146
Amarogentin displays immunomodulatory effects in human mast cells and keratinocytes. Med Inflamm 2015;
Potentilla officinalis displays antiinflammatory effects in the UV erythema test and on atopic skin. J Dtsch Dermatol Ges 2016; 14, pp. 917-922
Anti-inflammatory effects of agrimoniin-enriched Potentilla erecta fractions. Molecules 2016; 21, pp. 792
Anti-inflammatory and vasoconstrictive properties of Potentilla erecta : a traditional medicinal plant from the northern hemisphere. J Ethnopharmacol 2017; 204, pp. 86-94
Triterpenes promote keratinocyte differentiation in vitro, ex vivo and in vivo : A role for the transient receptor potential canonical 6. J Invest Dermatol 2010; 130, pp. 113-23
From a traditional medicinal plant to a rational drug : understanding the clinically proven wound healing efficacy of birch bark extract. PLoS One 2014; 22(1), pp. e86147.
Accelerated reepithelialization of partial-thickness skin wounds by a topical betulin gel : Results of a randomized phase III clinical trials program. BURNS 2017;