Safety of herbal medicine use during chemotherapy in patients with ovarian cancer: a "bedside-to-bench" approach.

In this study, we explored herbal supplements used by patients during chemotherapy and test for herb-drug interactions and response of cancer cells to treatment. Patients with gynecological cancer referred to a complementary and integrative medicine (CIM) service were asked about their use of herbal medicine during chemotherapy. The leading five clinically relevant herbs selected for cytotoxicity analysis included the following: wheatgrass (Triticum aestivum), European mistletoe (Viscum album), ginger (Zingiber officinale), Ephedra (Ephedra campylopoda), and Oriental mistletoe (Viscum cruciatum). Cytotoxicity was examined using XTT assays in cisplatin-sensitive and resistant ovarian cancer cell lines (A2780, A2780CisR), and non-cancer kidney cells (HEK-293). The effect of the selected herbs on carboplatin and paclitaxel cytotoxicity was tested as well. Pro-apoptotic effects were tested using Poly(ADP-ribose) polymerase (PARP) cleavage. Of 98 patients referred to the CIM service, 42 (42.9%) reported using/intending to use herbal products during chemotherapy. European mistletoe and ginger exhibited significant anti-cancer activity in cisplatin-sensitive and resistant ovarian cells. Wheatgrass and ephedra reduced cytotoxicity of carboplatin on cisplatin-sensitive ovarian cancer cells, while ginger, European and Oriental mistletoe increased chemosensitivity in both cancer cell lines. Wheatgrass, European mistletoe, and ginger increased sensitivity to cisplatin-resistant cells treated with carboplatin and paclitaxel. No effect was observed with the addition of any of the herbs on non-cancerous embryonic kidney cells (HEK-293). Herbal medicine use by patients with ovarian cancer may influence anti-cancer activity of chemotherapy. Integrative physicians can provide "bedside-to-bench" guidance on the safety of these products.