In-vitro and in-vivo assessment of the effect of soybean extract on Fasciola gigantica infection in comparison with triclabendazole

Objective The aim of this study was to assess the effect of genistein (soybean extract) on fascioliasis. Background Continued use of triclabendazole (TBZ) as the major antifascioliasis drug has resulted in resistance. Genistein, a major isoflavone in soybean extract, shows activity against different parasites. Materials and methods This was an in-vivo study that included 28 male New Zealand rabbits grouped as follows: GI, infected and nontreated; GII, infected and treated with TBZ; GIII, infected and treated with soybean extract; GIV, normal control group; GV1, not infected and treated with TBZ; and GV2, not infected and treated with soybean extract. Treatment started on the 80th day postinfection (d.p.i.) Stool examination by formol ether concentration and egg count per gram of feces were performed on day 0 of treatment, 3rd and 7th day post treatment (d.p.t.) Cure rate and fecal egg count reduction of TBZ and soybean extract were compared. Rabbits were killed on the 95th d.p.i. Liver sections were stained with hematoxylin & eosin (HE GII, TBZ exposed; GIII, soybean extract exposed; and GIV, incubated with DMSO (soybean solvent). Adult Fasciola DNA was extracted for electrophoresis. Results Fecal egg count reduction of soybean extract was 41.6% on the 3rd d.p.t. and 95.8% on the 7th d.p.t. compared with 100% of TBZ on the 3rd and 7th d.p.t. The cure rate of this extract was 0% on the 3rd d.p.t. and 83.3% on the 7th d.p.t compared with 100% of TBZ on the 3rd and 7th d.p.t. Soybean extract improved most hepatic lesions shown by H&E staining and decreased the apoptotic changes detected by caspase-3 immunostaining. It also induced apoptotic damage of Fasciola gigantica DNA. Conclusion Soybean extract can be used in the treatment of fascioliasis to decrease the emergence of TBZ resistance.