In vitro antischistosomal activity of Artemisia species

Praziquantel is currently the only effective treatment for schistosomiasis, but several limitations underscore the need for new therapeutic agents. Recent promising in vitro results with Artemisia species and the success of A. annua and its active compound artemisinin in treating parasitic infections warrant the need for further studies. Here we evaluate the in vitro activity of nine Artemisia species, including previously untested species, against newly transformed schistosomula (NTS) and adult Schistosoma mansoni. Three extracts were prepared: an aqueous infusion, a dichloromethane (DCM) fraction of the aqueous infusion, and a DCM extract. All samples were tested for activity at concentrations ranging from 1-25 μg/ml against NTS and the most promising against the adult S. mansoni. All aqueous infusions showed inferior activity against NTS as opposed to the DCM fractions of the infusions and DCM extracts of A. abrotanum, A. arborescens, A. afra, and A. scoparia which displayed superior activity as compared to the positive control praziquantel. The DCM fraction infusions of A. afra (BB) were the most active with IC₅₀ values of 0.35 μg/ml against NTS and 4.5 μg/ml against adult worms. Chemical fingerprinting using High-performance liquid chromatography (HPLC) analysis of the samples revealed some phytochemical similarities and significant differences between the species tested. This study provides supporting evidence of the antischistosomal potential of Artemisia spp. and warrants more in-depth research to identify potential novel therapeutic agents for the treatment of schistosomiasis.