Avaliação dos efeitos mutagênicos e genotóxicos da droga antimalárica lumefantrina e em combinação com o artemeter em linfócitos humanos

Abstract

The lumefantrine + artemether combination has been used as an alternative treatment of severe malaria chloroquine-resistant. However, the genotoxicity and mutagenicity of these compounds are not known. The aim of this study was to evaluate the in vitro mutagenic, genotoxic and apoptotic effects of lumefantrine and lumefantrine+ artemether in human T lymphocytes. Cells of 8 (4 for testing with lumefantrine and 4 from lumefantrine+ artemether) healthy donors were treated with 100, 80 and 60 µg/ml (C100, C80 and C60) of lumefantrine; to the combined treatment, cells were treated with 80, 60, 30, 9 and 6 µg/ml of lumefantrine plus 13.3, 10, 5, 1.5 and 1 µg/ml of artemether, respectively (C80+, C60+, C30+, C9+, and C6+). Negative control (CN), solvent control (CS, DMSO 2%) and positive control (CP, 0.03 µg/ml of doxorubicin) were evaluated in all experiments. The genotoxicity was assessed by comet assay, the mutagenic effect by the micronucleus assay (MN) and apoptosis by the presence of active caspase 3. C100 (TM = 40.41 ± 2.58), C80 (TM = 28.09 ± 1.34), C60 (TM = 14.99 ± 1.46), C80+ (TM = 30.09 ± 2.54) and C60+ (TM = 14.31 ± 0.84) treatments showed significant (p<0.01) genotoxic effects when compared to CS (TM = 6.23 ± 0.95). Furthermore, C100, C80 and C60 treatments increased significantly (p<0.01) the number of MN (MN = 70.75 ± 6.10, 83.25 ± 7.11 and 36.5 ± 3.7) and nuclear buds (BrN = 26 ± 5.03, 29 ± 8.75, 24 ± 10.23) when compared to CS (MN = 9.25 ± 1.7; BRN = 4.5 ± 1.0), as well as the treatments C80+ (MN = 75.25 ± 8.3; BRN = 25.25 ± 5.85) and C60+ (MN = 31 ± 4.96; BRN = 5.22 ± 5.44) when compared to CS+( MN = 7.25 ± 0.5; BRN = 4.25 ± 1.7). The Nuclear Division Index (IDN) decreased significantly (p <0.05) in C100 (IDN = 1.73), and also in treatments C80+ (IDN = 1.82) and C60+ (IDN = 1.94) compared to CS and CS+ (IDN = 2.25 and 2.06, respectively). All treatments, except C30+, showed a significant increase (p<0.05) in apoptosis at all times evaluated. The results demonstrate that lumefantrine and lumefantrine + artemether have a mutagenic and genotoxic effect (possibly by increasing oxidative stress). In addition, the treatment with lumefantrine and lumefantrine+ artemether elicited apoptosis of the cells in response to DNA damage, and possibly cell cycle arrest (cytostatic effect). However, concentrations of lumefantrine + artemether close to those observed in plasma after treatment for malaria does not show damage in DNA and, therefore, are safe from that standpoint.