In Vitro culture studies of FlorEssence on human tumor cell lines.

FlorEssence (FE) is an herbal tea widely used by patients to treat chronic conditions in North America, particularly cancer patients during chemo- and radiation therapy. Although individual components of FE have antioxidant, antiestrogenic, immunostimulant and antitumor properties, in vitro evidence of anticancer activity for the herbal tea itself is still lacking. We studied the antiproliferative effect of FE on MCF7 and MDA-MB-468 human breast cancer, and Jurkat and K562 leukemia cell lines. We found that FE significantly inhibited the proliferation of both breast and leukemia cells in vitro only at high concentrations, with 50% inhibition of MDA-MB-468 cells at about 1[sol ]20 dilution, Jurkat cells at about 1[sol ]10 dilution and MCF7 and K562 cells at less than 1[sol ]10 dilution. Flow cytometry analysis showed that treatment with a high concentration of FE induced G2[sol ]M arrest in MCF7 and Jurkat cells, with also an increased SubG0[sol ]G1 fraction in MCF7 cells. MDA-MB-468 cells showed a significantly increased Sub G0[sol ]G1 fraction after treatment with 1[sol ]10 dilution of FE while the cell cycle of K562 was unaffected. When MCF7 and MDA-MB-468 breast cancer cells were treated with a combination of FE with either paclitaxel or cisplatin, results showed that only the combination of 1[sol ]20 dilution of FE with 0.5 microM cisplatin resulted in a small but significantly higher MCF7 cell survival than 0.5 microM cisplatin treatment alone. FE at 1[sol ]20 and 1[sol ]50 dilutions did not affect the antiproliferative properties of these two commonly used chemotherapeutic agents. The results suggest that FE at high concentrations show differential inhibitory effect on different human cancer cell lines. Further studies are needed to assess the biological activities of FE.