Parasitology

Original Articles

Physiological and morphological effects of genistein against the liver fluke, Fasciola hepatica

E. TONERa1, G. P. BRENNANa1, K. WELLSa1, J. G. McGEOWNa2 and I. FAIRWEATHERa1 c1

a1 Parasite Proteomics and Therapeutics Research Group, School of Biological Sciences

a2 Basic Medical Sciences, School of Medicine and Dentistry, Medical Biology Centre, The Queen's University of Belfast, 97 Lisburn Road, Belfast, Northern IrelandBT9 7BL

SUMMARY

A study has been carried out to determine the activity of genistein against adult liver fluke, Fasciola hepatica. Flukes were incubated in vitro in genistein at a concentration of 0·27 mg/ml (=1 mm). They ceased to move after 3 h, at which point the experiment was terminated and the specimens prepared for examination by scanning and transmission electron microscopy. Surface changes to the flukes comprised swelling and blebbing, especially in the posterior region of the flukes, and there was particular disruption to the spines, accompanied by some spine loss. Fine structural changes to the tegumental syncytium indicated an accelerated release of secretory bodies at the surface, but a reduction in their production within the cell bodies. Autophagic activity was evident in the tegumental cells, a phenomenon that was also observed in the gastrodermal cells. Disruption to the testis and vitelline follicles was severe, with an apparent block in the normal developmental sequence of the spermatogenic and vitelline cells, respectively. Shell protein production by the vitelline cells was also disrupted. In separate experiments, somatic muscle strips were exposed to concentrations of genistein ranging from 1 μm to 1 mm. There were statistically significant increases in the frequency and/or amplitude of muscle contractions at concentrations of 10 μm, 100 μm and 1 mm. The results suggest that genistein is capable of causing severe morphological and neuromuscular disruption to adult flukes in vitro over a short time-span.

(Received February 28 2008)

(Revised April 30 2008)

(Accepted April 30 2008)

Correspondence:

c1 Corresponding author: School of Biological Sciences, Medical Biology Centre, The Queen's University of Belfast, 97 Lisburn Road, Belfast, Northern Ireland BT9 7BL. Tel: +44-28-90972298. Fax: +44-28-90975877. E-mail: i.fairweather@qub.ac.uk

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