Background: Previous in vivo studies performed in our laboratories demonstrated that anti-malarial drugs may or enhance or slow down Ehrlich's ascites tumour progression in infected mice. In the light of these observations, an in vitro study was undertaken to assess the response of human tumour cells to various anti-malarial drugs and consequently the safety of the anti-malarial therapy.
Materials and methods: MCF-7 cells and Vero cells (control line) were cultured in Eagle's minimum Essential medium (EMEM) and then subjected to graded concentrations of different anti-malarial drugs. Trypan-blue exclusion, MTT and Western blotting tests were performed.
Results: The findings showed that pyrimethamine (12.5 mg/L), chloroquine (12.5 mg/L) and primaquine (1.56 mg/L) stimulated MCF-7 cell growth. The proliferative effect was inhibited by doxorubicin only in cultures treated with chloroquine and primaquine. These results might indicate that some anti-malarial drugs have a worrying tumour-promoting effect which should not be underestimated when undertaking anti-malarial prophylactic measures.