Iranian J Parasitol: Vol. 7, No.1, 2012, pp.92-96 Iranian J Parasitol Open access Journal at http:// ijpa.tums.ac.ir Iranian Society of Parasitology http:// isp.tums.ac.ir Tehran University of Medical Sciences Publication http:// tums.ac.ir Original Article Novel in Vitro Efficiency of Chitosan Biomolecule against Trichomonas gallinae *M Tavassoli1, A Imani1, H Tajik 2, M Moradi2, SH Pourseyed1 1Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran 2Department of Food Science and Technology, Ahar Faculty of Agriculture, University of Tabriz, Tabriz, Iran *Corresponding author: Fax: ++98-441- 2771926, E-mail: mtavassoli2000@yahoo.com (Received 11 Sep 2011; accepted 19 Nov 2011) ABSTRACT Background: Development of new natural agents for parasitic diseases treatment has unexpec- tedly increased to overcome effectively against emergence and re-emergence of parasitic diseases, the appearance of drug resistant organisms and toxic side effects of current agents. The aim of the study was to evaluate antiprotozoal activities of chitosan biomolecule on trophozoites of Trichomonas gallinae. Methods: The antitrichomonal activity of various low molecular weight chitosan concentrations including 125, 250, 500 and 1250 μg ml-1 against T. gallinae trophozoites cultured in trypticase- yeast extract-maltose medium supplemented with heat-inactivated cold horse serum was eva- luated in vitro. Samples containing medium without chitosan were also assayed as controls. Results: The mortality rates at 0, 3 and 6 h post treatment with all concentrations were signifi- cantly different from control group (P<0.05). Treated trophozoites showed more susceptibility to the highest concentration reaching mortality rate of 100% at 3h post inoculation. However, at this time, results for 125, 250 and 500 μg ml-1 were 93%, 95% and 96.7%, respectively. Conclusion: The results demonstrate that the application of chitosan biomolecule is a promising option for treatment of trichomoniasis in pigeons. Keywords: Trichomonas gallinae, Chitosan, Antiparasitic drugs, Trophozoite, In Vitro 92 Available at: http://ijpa.tums.ac.ir