Xyloses containing polysaccharides of Ispaghula seed husk (Plantago ovata, Forssk, Plantaginaceae, P1) and tamarind (Tamarindus indica, L., Fabaceae, TSw) significantly increase the proliferation of human skin keratinocytes (NHEK, HaCaT) and fibroblasts (NHDF) independent of the used concentration. To determine if these polysaccharides share the effectiveness gene expression studies as well as fluorescence based methods were carried out. As detected by confocal fluorescence laser scan microscopy both polysaccharides were internalized by NHDF and HaCaT-keratinocytes. Quantification of internalized polysaccharides by flow cytometry revealed that P1, an acidic arabinoxylan, was entirely up-taken already after 3h by NHDF and HaCaTs while the xyloglycan TSw was completely internalized not before 12h of incubation. Gene expression studies showed that these polysaccharides act upon different intra and extra cellular targets dependent of the used cells and incubation time. Within 6h P1 significantly increased the gene expression of NHDF and NHEK whereas the gene expression was reduced after 24h. While incubation with P1 mostly resulted in an up-regulation of genes TSw predominantly repressed the genes expression. Especially the genes referring to the extracellular matrix, cell cycle, metabolism, membrane proteins, intermediate filaments as well as DNA replication were differenzially regulated by P1 in NHEK and NHDF. So the results show that a different effectiveness results in a similar biologic activity.
