Shahrekord University of Medical Sciences Journal of Herbmed Pharmacology 2345-5004 7 2 2018 04 01 In vitro anti-parasitic activities of Pulicaria dysenterica and Lycopus europaeus methanolic extracts against Trichomonas gallinae 112 118 10.15171/jhp.2018.19 EN Ali Nikpay Maryam Soltani https://orcid.org/0000-0001-6733-1435 Journal Article 10.15171/jhp.2018.19 2017 08 09 2018 03 20 Introduction: Trichomonas gallinae is the causative agent of trichomoniasis in birds. Although metronidazole is now the drug of choice for treatment of this infection, several studies reported metronidazole-resistant strains of T. gallinae. So it is important to explore for effective alternative compounds such as herbal extracts for treatment of avian trichomoniasis. This study was carried out to investigate the effects of methanolic extracts of Pulicaria dysenteric and Lycopus europaeus on the growth of T. gallinae trophozoites. Methods: The methanolic extracts were obtained from aerial parts of plants. The anti-trichomonas activities of P. dysenterica at the concentrations of 200, 100, 50, 25, 12.5 and 6.25 mg/mL and L. europaeus at the concentrations of 227, 113.5, 56.75, 28.37, 14.1 and 7.09 mg/mL after 0, 1, 3, and 6 hours exposure time were evaluated. Results: The results showed that both extracts decreased the viability of T. gallinae. The methanolic extract of P. dysenteric and L. europaeus showed 10% and 60% growth inhibition (GI %) at the highest concentration immediately after exposure. P. dysenteric methanolic extract at a concentration of 6.25 mg/mL completely inhibited the growth of parasite after 6 hours which was the minimum inhibitory concentration, while the lowest concentration of L. europaeus extract that showed 100% GI was 28.37 mg/mL that affected trophozoites after 6 hours. Conclusion: Based on the results, both extracts revealed significant growth inhibitory effect on T. gallinae, suggesting the potential use of these plants in preparation of new anti-trichomonas compounds.