Submitted to: Parasitology Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/14/2011
Publication Date: 5/12/2011
Citation: Ferreira, J.F., Peaden, P., Keiser, J. 2011. In vitro trematocidal effects of crude alcoholic extracts of Artemisia annua, A. absinthium, Asimina triloba, and Fumaria officinalis. Parasitology Research. DOI: 10.1007/s00436-011-2418-0. Interpretive Summary: Liver and blood fluke worm (trematodes) infections are of great public concern due to their negative effect on the health of humans and livestock and to global food safety. There are only two approved anthelmintic drugs for their treatment, with no alternative drugs in sight. In this work, we tested six crude plant extracts in the laboratory against adult worms that cause Schistosomiasis (blood fluke) and fascioliasis (liver fluke) in humans and small ruminants, respectively. Worm mortality was best achieved by aqueous ethanol extracts of sweet wormwood, paw-paw, and wormwood, while no anthelmintic effect was obtained for the boiled aqueous extract of sweet wormwood or for an ethanol extract of fumitory. Sweet wormwood, paw-paw, and wormwood extracts killed all trematodes at low concentrations, while some extracts were inactive. Although there is no report of anthelmintic activity for sweet wormwood or paw-paw extracts, published work of others points to the anthelmintic activity of artemisinin-derived drugs against blood and liver flukes and of wormwood against the barberpole worm of sheep and goats. The anthelmintic activity of these extracts at low concentrations indicated their potential for animal testing as natural alternative controls of internal parasites in both animals and humans. In the light of the high costs and growing loss of activity of commercial anthelmintics, crude plant extracts may offer a natural alternative control method of internal parasites to be used by populations of limited income, such as small farmers.
Technical Abstract: Trematode infections negatively affect human and livestock health, and threaten global food safety. The only approved human anthelmintics for trematodiasis are triclabendazole and praziquantel with no alternative drugs in sight. We tested six crude plant extracts against adult Schistosoma mansoni, Fasciola hepatica and Echinostoma caproni in vitro. Mortality was best achieved by ethanolic extracts of Artemisia annua (sweet Annie), Asimina triloba (paw-paw), and Artemisia absinthium (wormwood) which, at 2 mg/mL, killed S. mansoni and E. caproni in 20 h or less (except for wormwood), F. hepatica between 16-23 h (sweet Annie) or 40 h (paw-paw). Some extracts were active at 0.2 mg/mL and 20 ug/mL, although more time was required to kill trematodes. However, aqueous A. annua and methanol extracts of Fumaria officinalis had no activity. Chromatographic analysis of the three best extracts established that Artemisia annua and Asimina triloba extracts contained bioactive artemisinin and acetogenins (asimicin and bullatacin), respectively. The anthelmintic activity of our extracts at such low doses indicates that their anthelmintic activity deserve further animal testing as natural alternative control of parasites of both animals and humans. Our results also support recent evidence that synergistic effects of multiple bioactive compounds present in crude plant extracts is worth exploring.