title: Cytotoxicity of xanthopterin and isoxanthopterin in MCF-7 cells.
abstract: Human mammary carcinoma MCF-7 cell line responsiveness to the pteridines xanthopterin and isoxanthopterin was studied using the MTS assay for measurement of cell viability. The pteridines were tested at concentrations ranging from 7.8 to 500 microM singly and in 11 isoxanthopterin:xanthopterin ratios. IC50s of xanthopterin and isoxanthopterin were 109+/-13 microM (mean+/-SEM of y estimate) and 103+/-9 microM, respectively. The IC50 values for pteridine mixtures were similar although 3:1 and 4:1 isoxanthopterin:xanthopterin ratios seemed slightly more cytotoxic than other mixtures. However, ANOVA revealed no statistical differences in the cytotoxicity of mixtures.
authors.affiliation: Graduate School of Public Health, San Diego State University, San Diego, CA 92182-4162, USA.
authors.forename: Jean L
authors.initials: JL
authors.lastname: Lord
authors.forename: Ann
authors.initials: A
authors.lastname: de Peyster
authors.forename: P J E
authors.initials: PJ
authors.lastname: Quintana
authors.forename: Robert P
authors.initials: RP
authors.lastname: Metzger
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D001943:Breast Neoplasms; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects*; D004338:Drug Combinations; D004357:Drug Synergism; D006801:Humans; D020128:Inhibitory Concentration 50; D014976:Xanthopterin / Q000494:pharmacology* / Q000633:toxicity
chemical_list: D000970:Antineoplastic Agents; D004338:Drug Combinations; C008217:isoxanthopterin; D014976:Xanthopterin