Mutagenic activity of rhodamine dyes and their impurities as detected by mutation induction in Salmonella and DNA damage in Chinese hamster ovary cells

• Published in: Cancer research (Chicago, Ill.) Ill.), 1979-11, Vol.39 (11), p.4412
• Main Authors: Nestmann, E R, Douglas, G R, Matula, T I, Grant, C E, Kowbel, D J
• Format: Article
• Language: English
• Subjects: Animals; Cell Survival - drug effects; Cells, Cultured; Cricetinae; DNA, Single-Stranded - metabolism; Female; Mutagens; Mutation - drug effects; Ovary; Rhodamines - pharmacology; Salmonella typhimurium - drug effects; Xanthenes - pharmacology
• ISSN: 0008-5472

Commercial rhodamine dyes 6G and B induce His+ reversion mutations in Salmonella and single-strand breaks in Chinese hamster ovary cells, as detected by alkaline sucrose sedimentation. Aroclor 1254-induced rat liver homogenate (S9) is required for production of genetic activity by these dyes. Rhodamine 6G induces both frameshift and base substitution mutations, whereas rhodamine B induces only frameshift mutations. Rhodamine 6G is genetically more active and more toxic than is rhodamine B in both the bacterial and mammalian assays. Rhodamine 6G and B induce doublings of His+ revertants in Salmonella at the doses of 0.02 and 0.52 mumol/plate and shifts in the molecular weight of Chinese hamster ovary DNA at concentrations of 9 x 10(-5) and 9 x 10(-4) M, respectively. All genetic effects assayed demonstrate dose-related increases. Further testing of the pure dyes in Salmonella revealed that rhodamine B loses most of its mutagenicity with purification, whereas rhodamine 6G does not. Impurities from commercial rhodamine B demonstrate the same extent of mutagenicity as the commercial dye.