Immunological and histological effects of combined treatment with praziquantel and thymic hormones during murine Schistosomiasis mansoni infection

Abstract

Granuloma formed in the liver or lung of man and experimental animals infected with schistosomiasis and common manifestation of an inflammatory delayed hypersensitivity reaction. Therefore, our aim in this work was to study the effect of thymosin a 1 (Tal) treatment on Schistosomiasis mansoni-infected mice. Ta 1 was given in one dose level either alone or in combination with praziquantel (PZQ), the drug of choice for the treatment of shistosomiasis. Three aspects of drug action were investigated, the effect on Schistosoma mansoni infection, the effect on liver function and the worm distribution. When PZQ was given alone, it reduced the granuloma diameter markedly and the number of S. mansoni worms in the liver. When Ta1 was administered in

combination with PZQ, the most prominent effect was a further lowering in the dead worms and ova number over that produced by PZQ alone. In addition, administration of Ta 1 in combination with PZQ succeeded partially to correct the biochemical changes in the liver function. Concerning the histological distribution of apoptotic cells, combined treatment of Ta 1 and PZQ produced a pronounced elevation in the level of apoptosis in the liver and thymus of S. mansoni-infected mice. These changes were accompanied with an alteration in the levels of IFN-y and TNF-a. Collectively, our results suggest that Ta1 may play a great role against the alteration caused by S. mansoni infection, an effect which may be induced partly by improving the immunological host system and to some extent with its pharmacological effect.