comparative assay of glutathione s- transferase (gsts) activity of excretory-secretory materials and somatic extract of fasciola spp parasites

fascioliasis is a worldwide parasitic disease in human and domestic animals. the causative agents of fascioliasis are fasciola hepatica and fasciola gigantica. in the recent years, fasciola resistance to drugs has been reported in the many of publications. fasciola spp has detoxification system including gst enzyme which may be responsible for its resistance. therefore , the aim of the study was to assay of gst enzyme activity in fasciola parasites. fasciola gigantica and fasciola hepatica helminths were collected from abattoir as a live and cultured in buffer media for 4 h at 37 °c. excretory-secretory products were collected and stored in -80◦c. f. gigantica and fasciola hepatica were homogenized with homogenizing buffer in a glass homogenizer to prepare of somatic extract. suspension was then centrifuged and supernatant was stored at -80°c. in order to assay the enzyme activity, excretory-secretory and somatic extracts in the form of cocktails (potassium phosphate buffer, reduced glutathione and 1-chloro-2,4-dinitrobenzene substrates) were prepared and their absorbance recorded for 5 minutes at 340 nm. the total and specific gst activity of f. gigantica somatic and es products were obtained as 2916.00, 272.01 micromole/minute and 1.33, 1.70 micromole/minute/mg protein, respectively. fasciola hepatica also showed 2705.00, 276.86 micromole/minute and 1.33, 1.52 micromole/minute/mg protein, respectively. these results are important for analysis of parasite survival / resistance to drugs which use for treatment of fascioliasis.