Antifungal activity of the naphthoquinone beta-lapachone against disseminated infection with Cryptococcus neoformans var. neoformans in dexamethasone-immunosuppressed Swiss mice
Medeiros, C.S.; Pontes-Filho, N.T.; Camara, C.A.; Lima-Filho, J.V.; Oliveira, P.C.; Lemos, S.A.; Leal, A.F.G.; Brandão, J.O.C.; Neves, R.P.
The iin vivo/i antifungal activity of the naphthoquinone beta-lapachone against disseminated infection by iCryptococcus neoformans /iwas investigated. Swiss mice were immunosuppressed daily with dexamethasone (0.5 mg per mouse) intraperitoneally for 3 days, the procedure was repeated 4 days later, and the animals were then challenged intravenously with iC. neoformans/i (10sup6/sup CFU/mL) 1 week later. Seven days after infection, the mice were divided into groups and treated daily with beta-lapachone (10 mg/kg, iiv/i) for 7 (N = 6) and 14 days (N = 10). Amphotericin B (0.5 mg/kg) was used as comparator drug and an additional group received PBS. Treatment with beta-lapachone cleared the yeast from the spleen and liver, and the fungal burden decreased approximately 10sup4/suptimes in the lungs and brain 14 days after infection when compared to the PBS group (P lt; 0.05). This result was similar to that of the amphotericin B-treated group. Protection was suggestively due to iin vivo/i antifungal activity of this drug and apparently not influenced by activation of the immune response, due to similar leukocyte cell counts among all groups. This study highlights the prospective use of beta-lapachone for treatment of disseminated cryptococcosis.
Keywords: Beta-lapachone; Cryptococcus neoformans; Cryptococcosis; Immunesuppression; Experimental infection; Amphotericin B.