Antimalarial Activity of Tetracycline and a De‐novo Synthesized Quinolone Derivative Against Plasmodium berghei in Mice

This report presents the results of studies of the anti-malarial activity of a de-novo synthesized quinolone (Q/1) and the antibiotic tetracycline in mice infected with Plasmodium berghei. P. berghei-infected mice received either Q/1 2-4-diamino-10-methyl-pyrimido[4,5-b]quinolin-5(10H)-one (125 mg kg−1, i.m.), tetracycline (250 mg kg−1, i.m.) or a combination of the drugs (Q/1 125 mg kg−1 + tetracycline 250 mg kg−1, i.m.) in 0.1 mL vols. Parasitaemias from tail blood were determined over 17 days. Mice receiving Q/1 only, did not have a parasitaemia significantly different from the control group, but the Q/1-treated mice had a longer survival time (15 vs 10 days). Mice receiving tetracycline showed similar results to the Q/1 group. However, the animals treated with the Q/1 + tetracycline combination showed a significant decrease in the mean parasitaemias compared with the control and had a longer survival time (17 days). These results show the potential for de-novo synthesized quinolone derivatives, associated with other drugs, in the treatment of human malaria.