16α-bromoepiandrosterone, a dehydroepiandrosterone (DHEA) analogue, inhibits Plasmodium falciparum and Plasmodium berghei growth

Dehydroepiandrosterone (DHEA) and its analogue, 16 alpha -bromoepiandrosterone (alpha -epi-Br), may have activity against viral and parasitic infections, including human immunodeficiency virus (HIV) and Cryptosporidium parvum. Therefore, we evaluated its antimalarial effects on Plasmodium falciparum and Plasmodium berghei. In vitro, chloroquine (CQ)-sensitive and resistant strains of P. falciparum parasitized red blood cells were incubated with escalating doses of alpha -epi-Br or CQ. In vivo, 62 rats were infected with P. berghei and treated with CQ or alpha -epi-Br. At the highest doses tested against a CQ-sensitive strain, parasitemias decreased from 25.4% in the saline control group to 4.3% and 4.8% in the alpha -epi-Br and CQ groups, respectively (P < 0.05). Against two CQ-resistant strains, parasitemias decreased from 22.3-28.8% and 24.8-30% in the CQ and saline groups, respectively, to 2.5-2.7% in the <alpha>-epi-Br groups (P = 0.003). In vivo, on Day 4, parasitemias decreased from 23% in the saline group to 9-12% and 12% in the in alpha -epi-Br and CQ groups, respectively (P < 0.05). These data demonstrate that <alpha>-epi-Br shows activity against CQ-sensitive and resistant strains of P. falciparum in vitro. At the doses tested against P. berghei in vivo in rats, alpha -epi-Br is comparable to CQ.