The efficacy of two electron transport inhibitors (720C80 and 993C76) on murine strongyloidiasis: a comparison with albendazole.

The clinical efficacy of albendazole (ABZ) in the treatment of chronic uncomplicated strongyloidiasis has been reported to be highly variable. In our murine model of strongyloidiasis a single oral dose of 5 and 10 mg kg-1 ABZ reduced (at day 4 post infection) the faecal larval count (FLC) by 54.2 +/- 12.5% and 81.5 +/- 10.2%, respectively. 100 mg kg-1 ABZ reduced the FLC by 100%. Two inhibitors of protozoan and filarial electron transport (720C80 and 993C76) inhibited the endogenous O2 consumption of intact infective (L3) larvae of S. ratti by > 50% at 2 x 10(-5) M in vitro, and reduced the FLC by 72 +/- 9.3% and 62.0 +/- 10.3% respectively in vivo, at a dose of 70 mg kg-1. These results suggest that compounds designed as selective inhibitors of protozoan electron transport have significant efficacy against murine strongyloidiasis and may prove useful in the management of human strongyloidiasis.