title: Ecotoxicity and genotoxicity of cyclophosphamide, ifosfamide, their metabolites/transformation products and their mixtures.
abstract: Cyclophosphamide (CP) and ifosfamide (IF) are commonly used cytostatic drugs that repress cell division by interaction with DNA. The present study investigates the ecotoxicity and genotoxicity of CP, IF, their human metabolites/transformation products (TPs) carboxy-cyclophosphamide (CPCOOH), keto-cyclophosphamide (ketoCP) and N-dechloroethyl-cyclophosphamide (NdCP) as individual compounds and as mixture. The two parent compounds (CP and IF), at concentrations up to 320 mg L(-1), were non-toxic towards the alga Pseudokirchneriella subcapitata and cyanobacterium Synecococcus leopoliensis. Further ecotoxicity studies of metabolites/TPs and a mixture of parent compounds and metabolites/TPs performed in cyanobacteria S. leopoliensis, showed that only CPCOOH (EC50 = 17.1 mg L(-1)) was toxic. The measured toxicity (EC50 = 11.5 mg L(-1)) of the mixture was lower from the toxicity predicted by concentration addition model (EC50 = 21.1 mg L(-1)) indicating potentiating effects of the CPCOOH toxicity. The SOS/umuC assay with Salmonella typhimurium revealed genotoxic activity of CP, CPCOOH and the mixture in the presence of S9 metabolic activation. Only CPCOOH was genotoxic also in the absence of metabolic activation indicating that this compound is a direct acting genotoxin. This finding is of particular importance as in the environment such compounds can directly affect DNA of non-target organisms and also explains toxicity of CPCOOH against cyanobacteria S. leopoliensis. The degradation study with UV irradiation of samples containing CP and IF showed efficient degradation of both compounds and remained non-toxic towards S. leopoliensis, suggesting that no stable TPs with adverse effects were formed. To our knowledge, this is the first study describing the ecotoxicity and genotoxicity of the commonly used cytostatics CP and IF, their known metabolites/TPs and their mixture. The results indicate the importance of toxicological evaluation and monitoring of drug metabolites as they may be for certain aquatic species more hazardous than parent compounds.
authors.affiliation: Jožef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova Cesta 39, 1000 Ljubljana, Slovenia.
authors.forename: Marjeta
authors.initials: M
authors.lastname: Česen
authors.affiliation: National Institute of Biology, Večna Pot 111, 1000 Ljubljana, Slovenia.
authors.forename: Tina
authors.initials: T
authors.lastname: Eleršek
authors.affiliation: Jožef Stefan International Postgraduate School, Jamova Cesta 39, 1000 Ljubljana, Slovenia; National Institute of Biology, Večna Pot 111, 1000 Ljubljana, Slovenia.
authors.forename: Matjaž
authors.initials: M
authors.lastname: Novak
authors.affiliation: National Institute of Biology, Večna Pot 111, 1000 Ljubljana, Slovenia.
authors.forename: Bojana
authors.initials: B
authors.lastname: Žegura
authors.affiliation: Jožef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova Cesta 39, 1000 Ljubljana, Slovenia.
authors.forename: Tina
authors.initials: T
authors.lastname: Kosjek
authors.affiliation: National Institute of Biology, Večna Pot 111, 1000 Ljubljana, Slovenia.
authors.forename: Metka
authors.initials: M
authors.lastname: Filipič
authors.affiliation: Jožef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova Cesta 39, 1000 Ljubljana, Slovenia. Electronic address: ester.heath@ijs.si.
authors.forename: Ester
authors.initials: E
authors.lastname: Heath
mesh_terms: D018906:Antineoplastic Agents, Alkylating / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D000460:Chlorophyta / Q000187:drug effects; D003520:Cyclophosphamide / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D004249:DNA Damage; D004785:Environmental Pollutants / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity; D006801:Humans; D007069:Ifosfamide / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D009152:Mutagenicity Tests; D014466:Ultraviolet Rays
chemical_list: D018906:Antineoplastic Agents, Alkylating; D004785:Environmental Pollutants; D003520:Cyclophosphamide; D007069:Ifosfamide
keywords: Aquatic ecotoxicity; Cytostatic; Genotoxicity; Human metabolite; Mixture