Effect of Solanum nudum Dunal (Solanaceae) steroids on hepatic trophozoites of Plasmodium vivax

Steroids isolated from the plant Solanum nudum showed antiplasmodial activity against the blood stages of Plasmodium falciparum. It has been demonstrated that these steroids are neither mutagenic in vitro nor clastogenic in vivo. This study evaluated the effect of five steroids of S. nudum (SN-1, SN-2, SN-3, SN-4 and SN-5) on hepatic trophozoites of P. vivar, using an experimental design, non-balanced, with blind determination of the effect expressed as the percentage reduction of hepatic trophozoites. The sporozoites used to inoculate human hepatoma cells HepG2-A16 were obtained from gametocytemic blood of volunteers infected only with P. vivar, and passed into laboratory-reared Anopheles albimanus mosquitoes. Steroids were added at three different doses (100, 10 and 1 mu g/mL) just after inoculation of the cells with sporozoites. The effect was determined by indirect immunofluorescence assays using the monoclonal antibodies Pv210 or Pv47E-2E10 and steroid cytotoxicity on HepG2-A16 cells was assessed by the MTT method. All the steroids reduced the number of hepatic P. vivax trophozoites, SN-2 and SN-4 reduced the number of hepatic trophozoites by 47% and 39% (p < 0.05), respectively. Copyright (c) 2006 John Wiley & Sons, Ltd.