The effects of anti-schistosome drugs on schistosomes and the immune responses of their hosts

Sharaf, Osama Fathy (2004) The effects of anti-schistosome drugs on schistosomes and the immune responses of their hosts. PhD thesis, University of Glasgow.

Abstract

The effects of Mirazid® (MZD), an extract of myrrh, on Schistosoma mansoni were investigated and compared to those of praziquantel (PZQ). The effects of both drugs on the soluble proteome and the immune responses to schistosome infections were also investigated. In vitro studies showed that MZD was more effective than PZQ against the schistosomula stage. However, its effects against adult worms were less than those of PZQ. Lengthy exposures to high concentrations of MZD were required for the drug to be effective. In vivo studies showed that MZD had no anti-schistosomal activity against S. mansoni in mice.

In vitro exposure of adult worms to either PZQ or MZD caused significant changes in the expression of some proteins. Interestingly, some vaccine candidates including paramyosin and actin were among the proteins that showed differential expression.

Treatment of human S. haematobium infection with PZQ favoured the development of protective immune responses that render the individuals resistant to reinfection. Sera from putatively resistant individuals showed distinct recognition patterns of soluble worm antigen, after exposure to reinfection, compared to sera from susceptible individuals. Interestingly, many putative vaccine candidate antigens were recognised by antibody isotypes that are found in individuals with some degree of resistance to infection.

In conclusion, although the in vitro studies revealed some promising effects of MZD, the results of the in vivo studies do not support the use of this drug in the treatment of schistosome infections.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: Q Science > QR Microbiology > QR180 Immunology; Q Science > QL Zoology
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Infection & Immunity
• Supervisor's Name: Hagan, Prof. Paul and Kusel, Prof. John
• Date of Award: 2004
• Depositing User: Elaine Ballantyne
• Unique ID: glathesis:2004-1797
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 13 May 2010
• Last Modified: 10 Dec 2012 13:46
• URI: https://theses.gla.ac.uk/id/eprint/1797