title: Cytogenetic and oxidative status of human lymphocytes after exposure to clinically relevant concentrations of antimalarial drugs atovaquone and proguanil hydrochloride in vitro.
abstract: Atovaquone (ATO) and proguanil hydrochloride (PROG) is the fixed combination for the prevention and treatment of Plasmodium falciparum malaria. As safe and effective antimalarial drugs are needed in both the treatment and the prophylaxis of malaria, this study was performed to investigate their possible cyto/genotoxic potential towards human lymphocytes and the possible mechanism responsible for it. Two different concentrations of ATO and PROG were used with and without S9 metabolic activation. The concentrations used were those found in human plasma when a fixed-dose combination of ATO and PROG was used: 2950/130 ng/mL after prophylactic treatment and 11 800/520 ng/mL after treatment of malaria, respectively. Possible cellular and DNA-damaging effects were evaluated by cell viability and alkaline comet assays, while oxidative stress potential was evaluated by formamidopyrimidine-DNA glycosylase (Fpg)-modified comet assay, in addition to measuring malondialdehyde and glutathione levels. According to our results, the ATO/PROG combination displayed only weak cyto/genotoxic potential towards human lymphocytes with no impact on oxidative stress parameters, suggesting that oxidative stress is not implicated in their mechanism of action towards human lymphocytes. Given that the key portion of the damaging effects was induced after S9 metabolic activation, it is to presume that the principal metabolite of PROG, cycloguanil, had the greatest impact. The obtained results indicate that the ATO/PROG combination is relatively safe for the consumption from the aspect of cyto/genotoxicity, especially if used for prophylactic treatment. Nevertheless, further cytogenetic research and regular patient monitoring are needed to minimize the risk of adverse events especially among frequent travellers.
authors.affiliation: Oral Solid Forms, Pliva Croatia Ltd., Prilaz baruna Filipovića 25, 10000, Zagreb, Croatia.
authors.forename: Domagoj
authors.initials: D
authors.lastname: Dinter
authors.affiliation: Mutagenesis Unit, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, 10000, Zagreb, Croatia.
authors.forename: Goran
authors.initials: G
authors.lastname: Gajski
authors.affiliation: Faculty of Pharmacy and Biochemistry, University of Zagreb, A. Kovačića 1, 10000, Zagreb, Croatia.
authors.forename: Ana-Marija
authors.initials: AM
authors.lastname: Domijan
authors.affiliation: Mutagenesis Unit, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, 10000, Zagreb, Croatia.
authors.forename: Vera
authors.initials: V
authors.lastname: Garaj-Vrhovac
mesh_terms: D000328:Adult; D000962:Antimalarials / Q000009:adverse effects* / Q000627:therapeutic use*; D053626:Atovaquone / Q000009:adverse effects* / Q000627:therapeutic use*; D002470:Cell Survival / Q000187:drug effects; D003582:Cytogenetics / Q000379:methods; D004249:DNA Damage / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D016778:Malaria, Falciparum / Q000188:drug therapy; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D010963:Plasmodium falciparum / Q000187:drug effects; D002727:Proguanil / Q000009:adverse effects* / Q000627:therapeutic use*; D014227:Triazines / Q000627:therapeutic use
chemical_list: D000962:Antimalarials; D004338:Drug Combinations; D014227:Triazines; C026009:cycloguanil; D008315:Malondialdehyde; D005978:Glutathione; D002727:Proguanil; D053626:Atovaquone
keywords: atovaquone; cycloguanil; cyto/genotoxicity; human lymphocytes; oxidative stress; proguanil hydrochloride