%0 Journal Article
%T Polysaccharides of St. John's Wort Herb Stimulate NHDF Proliferation and NEHK Differentiation via Influence on Extracellular Structures and Signal Pathways
%A S. Abakuks
%A A. M. Deters
%J Advances in Pharmacological Sciences
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/304317
%X St. John's Wort herb extracts often contain undesirable or volitional polysaccharides. As polysaccharides exhibit structure-dependent biological functions in the present study water-soluble polysaccharides were extracted from herb material, fractionated by anion exchange chromatography into four main polysaccharide fractions (denominated as Hp1, Hp2, Hp3 and Hp4) and characterized by HPAEC-PAD, CE, IR and GC-MS. Biological activity on human skin keratinocytes and fibroblasts was assessed by investigation of their effect on proliferation, metabolism, cytotoxicity, apoptosis and differentiation. The underlying mechanisms were investigated in gene expression studies. Polysaccharide fraction Hp1 was mainly composed of ¦Â-D-glucose. Hp2, Hp3 and Hp4 contained pectic structures and arabinogalactan proteins varying in composition and quantity. Polysaccharides of Hp1 induced the keratinocyte differentiation by inhibiting the gene expression of the epidermal growth factor and insulin receptor. While the collagen secretion of fibroblasts was stimulated by each polysaccharide fraction only Hp1 stimulated the synthesis. The fibroblast proliferation was reduced by Hp1 and increased by Hp4. This effect was related to the influence on genes that referred to oxidative stress, metabolism, transcription processes and extracellular proteins. In conclusion polysaccharides have been shown as biologically active ingredients of aqueous St. John's Wort extracts with a relation between their structural characteristics and function. 1. Introduction Extracts of St. John¡¯s Wort (Hypericum perforatum L., Hypericaceae) are well investigated and widely used in regard to their effectiveness against moderate depressions. The responsible naphthodianthrones, phloroglucinol derivates, and flavonoids were extensively investigated [1]. Concerning biological activity on the skin the investigations focused on the phototoxicity of lipophilic and aqueous-ethanolic extracts for many years. Beside the ongoing discussion concerning the phototoxicity of St. John¡¯s Wort extracts [2, 3], it has been reported that hyperforin induced keratinocyte differentiation in vitro and the skin hydration in vivo [4, 5]. Nevertheless more information is needed concerning the less investigated side products of extraction. Especially the carbohydrates that conflict with formulation, development, and production of solid dosage forms [6] were mostly seen as nonactive byproducts. There are some reasons for investigation of St. John¡¯s Wort polysaccharides. First of all no information is available concerning composition
%U http://www.hindawi.com/journals/aps/2012/304317/