effect of the fasciolicidal drug: bithionol, on the B6-dependent kynurenine metabolizing enzymes: kynurenine

ABSTRACT

The present study deals with the effect of the fasciolicidal drug 2,2- thiobis, 4, 6-dichlorophenol [bithionol], on the B[6]-dependent kynurenine metabolizing enzymes kynurenine hydrolase [KH], and kynurenine aminotransferase [KATE]. This investigation was carried out on the liver homogenates of normal and Fasciola gigantica [F. gigantica]-infected rabbits. It was found that bithionol induced an inhibitory effect on the KH. In contrast, the infection with F. gigantica an activating effect on the same enzyme in the host. The latter effect was attributed to a metabolic byproduct excreted from F.gigantica. Therefore, the normalizing effect on the activity of KH which was encountered when the drug was applied to F.gigantica-infected rabbits, was attributed to the antagonistic action of the drug to that of the metabolic byproduct from the flukes. However, neither bithionol, nor infection with F.gigantica have any detectable effect on the KATE in the host. Therefore, it was concluded that Treatment of Fasciola gigantica infected rabbits with bithionol retains or restores the kynurenine hydrolase activity to the normal level and has no effect on the kynurenine transaminase