Comparison of fermented and non-fermented Epilobium angustifolium herb extracts on prostate cells proliferation

Extracts from Epilobium sp. herbs (Onagraceae) have traditionally been used in the treatment of prostate diseases. Epilobium angustifolium L. is one of the species also used fermented in a form of infusion called Ivan tea or Kapor tea. The aim of the study was to investigate the effect of different extracts (hydrophilic-aqueous and lipophilic-ethyl acetate) prepared from E. angustifolium fermented and non-fermented herbs on prostate cell lines (LNCaP, DU 145 and PZ-HPV-7). The extracts were characterized by the HPLC-DAD-MS/MS method. Cells were incubated with increasing concentrations of the extracts (20 – 70 µg/ml). Cell proliferation was measured using bisbenzimide (Hoechst 33258). Non-fermented extracts contained significant amounts of oenothein B, especialy in aqueous extract, as well as flavonoid-glucuronides of quercetin and kaempferol, while fermented ones were deprived of oenothein B and enriched in gallic acid, protocatechuic acid and ellagic acid. Exposure of prostate cancerous cells to the extracts resulted in a significant decrease of cell proliferation in the highest concentration by ˜90% for non-fermented extracts (especialy aqueous one), with the presence of apoptotic cells, and by ˜40% for the fermented ones without significant apoptosis. The non-fermented preparation slightly affected the proliferation of normal prostate epithelium cells (PZ-HPV-7), while fermented extracts were more cytotoxic. Our results partly confirm the usefulness of Epilobium sp. herbs in the treatment of prostate diseases and showed different activity depending of the way of preparation.

Acknowledgements: This study was supported by research grant 2011/01/D/NZ4/01261 from Polish National Science Center.

Keywords: Epilobium angustifolium, Onagraceae, Prostate diseases, Polyphenols, Fermentation