A polyphenol enriched fraction of rose oil distillation water inhibits proliferation in HaCaT cells and induces apoptosis

Water steam distillation of rose flowers (Rosa damascena) separates the essential oil from the polyphenol containing rose oil distillation waste water (RODW). While the essential oil represents the desired liquid for the cosmetic industry, the polyphenol containing RODW is in the center of our interest. Recently, a strategy was developed to separate RODW into a polyphenol depleted water fraction and a polyphenol enriched fraction [RF20-(SP-207)]. Polyphenols are known to have a wide spectrum of biochemical and pharmacological effects. In the present study, it was of interest to investigate possible antiproliferative effects of RF20-(SP-207) and fractions thereof F(I)-(IV) in immortalized human keratinocytes (HaCaT). The BrdU cell proliferation assay was used to measure cell proliferation. Cell migration was elucidated by time lapse microscopy. The data demonstrated that from all tested fractions only F(IV) revealed a dose dependent antiproliferative effect which is comparable to RF20-(SP-207) (IC₅₀ of approx. 10 µg/mL). This effect is similar to both positive controls LY294002 (PI3K-inhibitor, 30% inhibition) and NVP-BEZ235 (dual PI3K/mTOR-inhibitor, 30% inhibition) and clearly exceeds the anti-proliferative action of quercetin (approx. 20% inhibition). Time lapse microscopy revealed that cell migration was dramatically decreased under influence of RF20-(SP-207) and F(IV). This effect was comparable to LY294002 and NVP-BEZ235. Fluorescence microscopy images confirm the qualitative increase of apoptosis under influence of RF20-(SP-207) and (IV).