Planta Med 2009; 75 - PD34
DOI: 10.1055/s-0029-1234513

Antitrypanosomal and antileishmanial activities of organic and aqueous extracts of Artemisia annua

AR Bilia 1, M Kaiser 2, D Tasdemir 3
  • 1Department of Pharmaceutical Sciences, University of Florence, 50019 Sesto Fiorentino, Florence, Italy
  • 2Department of Medical Parasitology, Swiss Tropical Institute, 4002 Basel, Switzerland
  • 3Centre for Pharmacognosy and Phytotherapy, School of Pharmacy, University of London, London WC1N 1AX, UK

Artemisia annua is a herbal drug with profound antimalarial activity, which is ascribed to the unique sesquiterpene lactone artemisinin. Recently, artemisinin has been reported to show efficacy against other parasitic protozoan sp., such as Trypanosoma and Leishmania [1,2], however trypanocidal and leishmanicidal effects of A. annua extracts have remained unstudied. In the current study, we evaluated the in vitro growth inhibitory activity of a number of organic and aqueous extracts of a selected high-yield Brazilian cultivar of A. annua against three infectious parasitic protozoa, T. brucei rhodesiense, T. cruzi and L. donovani. Artemisinin was also evaluated for its antiparasitic activity for comparison. Artemisinin content of these extracts (obtained by evaporation of the organic solvent or freeze-dried aqueous solutions) was determined by HPLC/DAD/MS. The hexane extract was found to be the richest in artemisinin (3.68%), whereas the toluene extract was the poorest (0.57%) [3]. Among the tested extracts, the acetone- and the n-hexane-solubles of A. annua were the most potent against T. b. rhodesiense with IC50 values of 0.30 and 0.455µg/ml, respectively, whereas the other extracts were ten- to fifty-fold less potent. None of the extracts or artemisinin had trypanocidal activity against T. cruzi (IC50>30µg/ml). Only the organic extracts of A. annua arrested the growth of L. donovani with modest IC50 values (5.1 to 9.0µg/ml) comparable to that of artemisinin (IC50 8.8µg/ml). This study highlights significant variations in the artemisinin content of A. annua extracts and underlines the potential of A. annua extracts and artemisinin in the treatment of trypanosomal and leishmanial infections.

Notes: Percentages are given on the dried extracts obtained by evaporation of the organic solvent or freeze-dried aqueous solutions, and do not reflect the content of artemisinin in the dried herbal drug, which is about 0.52%.

References: [1] Mishina, Y.V. et al. (2007) Antimicrob. Agents Chemother. 51:1852–1854.

[2] Sen, R. et al. (2007)J. Med. Microbiol. 56:1213–1218.