Novel insights to the anti-proliferative activity of rosemary (Rosmarinus officinalis L.) co-treatment

Abstract

The aim of this study was to characterize volatile and non-volatile compounds of rosemary from the North Adriatic region and to determine its antiproliferative activity, alone or in combination with radiomimetic bleomycin (BLM) on three malignant and one non-transformed human cell line. Chemical analysis of the volatile compounds revealed the presence of monoterpenes (93.8%), in which 1.8-cineol (32.9%) and camphor (15.5%) were the dominant compounds. Also, obtained results showed that the major polyphenolic constituents in rosemary extract were phenolic acids (rosmarinic acid and its derivatives up to 69.2 mg 100 g-1), as well as flavones and flavonols in the following order: luteolin>isorhamnetin>quercetin>kaempferol>apigenin. Cell growth test showed that rosemary extract alone exerted moderate antiproliferative activity, as well as a synergistic antiproliferative effect with bleomycin (EC50 344.3-461.5 µg mL-1 and 58.6-292 µg mL-1, respectively). The anti-tumor effect of rosemary extract in combination with BLM was much stronger, compared to BLM itself on the breast cancer cells. Through their proposed sensitizing effect, rosemary extracts, in combination with the standard chemotherapeutics, could be used for the investigations of possible therapeutic modalities.