Enhanced Antitumor Activity against Melanoma Cancer Cells by Nitric Oxide Release and Photosensitized Generation of Singlet Oxygen from Ruthenium Complexes. Issue 22 (4th July 2016) - Ramos, Loyanne C. B.
Abstract : We have investigated the synergistic effect of nitric oxide and singlet oxygen originating from stimulated ruthenium complexes and their photodynamic action against a melanoma cancer cell line. In aqueous solution, the photosensitizer [Ru(NH3 )5 pz] 2+ (I ; pz = pyrazine) and the nitrosylruthenium complex trans ‐[RuCl([15]aneN4 )NO] 2+ (II ; [15]aneN4 = 1, 4, 8, 12‐tetrazacyclopentadecane) can produce singlet oxygen and nitric oxide, respectively. The phototoxicity of complexI does not correlate with the singlet oxygen quantum yields unless it is mediated by nitric oxide release from complexII . This effect is around 70 and 50 % higher than the effect prompted by compoundsI andII, respectively, in isolation in the presence of light. It was found that the number of hypodiploid cells in the melanoma cancer cells increased, which indicates that a mixture of compoundsI andII induces apoptosis of tumorigenic cell lines. Both singlet oxygen and nitric oxide produced by the ruthenium complexes enhance the photodynamic efficacy in melanoma cancer cells. Abstract : The synergistic effect of nitric oxide and singlet oxygen originating from Ru complexes has been used to enhance the anticancer activity against B16/F10 cancer cells. The combination of reactive oxygen and nitrogen species (RONS) resulted in a decrease of cell viability up to 40 % compared with their presence in isolation. It seems that RONS activate intracellular molecules associated with cell death.