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Because plants and their extracts are a potent resource for bioactive substances we developed the plant extract collection Kiel in Schleswig-Holstein (PECKISH) as an open access screening library. PECKISH contains more than 4500 unique aqueous (about 64%), ethanolic (about 32%), and other (about 4%) extracts from > 880 different plant species and 11 different plant tissues. PECKISH represents about 190 plant families. Extracts were obtained from health shops, outdoor cultivated plants, marine algae, herbs from traditional Chinese medicine, African plants and known medicinal plants. Concentrated and sterilized extracts are stored at -80 °C and are available in a 96-well plate format including empty wells for positive and negative controls. The library format allows medium throughput screenings using enzymatic assays, cell-based assays or phenotypic read-outs using model-organisms such asC. elegans or D. melanogaster. Screenings based on PECKISH are useful to develop dietary supplements, functional foods or drugs. The uniqueness of PECKISH lies in its broad diversity of plant extracts and its open access character.

Pancreatic cancer is one of the most aggressive cancer entities, with an extremely poor 5-year survival rate. Therefore, novel therapeutic agents with specific modes of action are urgently needed. Marine organisms represent a promising source to identify new pharmacologically active substances. Secondary metabolites derived from marine algae are of particular interest. The present work describes cellular and molecular mechanisms induced by an HPLC-fractionated, hydrophilic extract derived from the Baltic brown seaweed Fucus vesiculosus (Fv1). Treatment with Fv1 resulted in a strong inhibition of viability in various pancreatic cancer cell lines. This extract inhibited the cell cycle of proliferating cells due to the up-regulation of cell cycle inhibitors, shown on the mRNA (microarray data) and protein level. As a result, cells were dying in a caspase-independent manner. Experiments with non-dividing cells showed that proliferation is a prerequisite for the effectiveness of Fv1. Importantly, Fv1 showed low cytotoxic activity against non-malignant resting T cells and terminally differentiated cells like erythrocytes. Interestingly, accelerated killing effects were observed in combination with inhibitors of autophagy. Our in vitro data suggest that Fv1 may represent a promising new agent that deserves further development towards clinical application.

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