Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 8 1 2013 03 15 167 170 EN A Farahnak Department of Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. A Golestani Department of Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Mr Eshraghian Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran,.Iran 2015 10 14   Background: The aim of this study was to compare superoxide dismutase (SOD) activity in Fasciola hepatica and Fasciola gigantica parasites. Materials: F. gigantica and F. hepatica helminths were collected from abattoir and cultured in buffer media for 4 h at 37 °C. Excretory-Secretory (ES) products were collected, centrifuged and stored at - 20◦C. E-S protein concentration was measured by Bradford method and SOD activity was detected using RANSOD kit (Randox Lab. Crumlin, UK). Statistical t-test was conducted for analysis of re-sults. Results: Protein concentration for F. hepatica and F. gigantica were obtained 7.293 ug/ml and 19.65 ug/ml respectively and SOD activity as 0.721 U/ml and 1.189 U/ml , in that order. ES protein con-centration of two species was significantly different (P<0.05), however the difference of SOD activi-ty of two species was not significant. Conclusion: Two species of Fasciola have comparable SOD biochemical defense enzyme and can help us explain the parasite survival in host tissue. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/511 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/511/413