Evaluation of antitrichomonal effect of methanolic extract of Hyssopus officinalis on Trichomonas vaginalis in vitro

Background and Objectives: Trichomonas vaginalis is a flagellate protozoan that is the most common sexually parasitic transmitted infection in the world. Metronidazole is currently used for the treatment of trichomoniasis, which has side effects. In recent years, the use of plants and natural compounds has been considered by researchers. This study was conducted to investigate the anti-trichomonal activity of methanolic extract of Hyssopus officinalis on Trichomonas vaginalis in vitro. Methods: In this experimental study, the extract was prepared by Soxhlet method, and to evaluate the effect of methanolic extract of Hyssopus officinalis on Trichomonas vaginalis parasites, the concentrations of 50, 100, 200, 400, 600, 800, 1,000, 1,200, and 1,400 μg/ml was prepared. Metronidazole and distilled water were considered as positive and negative controls, respectively. Afterward, 105 live parasites were added to all tubes, and all groups were kept at 37°C. Live parasites were counted at 24, 48, and 72 h intervals by Trypan Blue using a neobar slide and light microscope (Hemocytometer). Subsequently, the IC50 value for the above extract was calculated using SigmaPlot ™ software (version 13). It should be noted that all steps of the experiment were performed in triplicate and the results were considered as average. Results: The IC50 of methanolic extract of Hyssopus officinalis on Trichomonas vaginalis parasite was calculated at 965.8, 730.4, and 542.1 μg/ml after 24, 48, and 72 h, respectively. The highest mortality rate (100%) was observed at a concentration of 1,400 μg/ml after 72 h of exposure. Conclusion: Methanolic extract of Hyssopus officinalis in different concentrations had an inhibitory effect on the growth of the Trichomonas vaginalis parasite. Further and more comprehensive studies are suggested to investigate the constituents of this plant and the lethal effect of the parasite in vivo conditions.