Background: Trichomoniasis is the most common sexually transmitted parasite in the world. The mainstay treatment for trichomoniasis is metronidazole, but some resistant strains to this treatment have also been detected. Considering the therapeutic properties of Pelarqonium roseum in traditional medicine, this study aimed to examine the antitrichomonal effects of Pelarqonium in vitro.

Materials and Methods: In this experimental study, 1203 persons referred to Kashan Medical Centers randomly tested for Trichomonas vaginalis. Of them, 23 persons were infected with T. vaginalis. Three T. vaginalis isolates were cultured in a TYI-S-33 medium and were used to study the effect of Pelarqonium extract. Different concentrations (12.5, 25, 50,100,200,400,800, 1000µg/ml) of Pelarqonium extracts were tested in three different times (24, 48 and 72h) on T. vaginalis trophozoeites. Also the effect of metronidazole (0.025, 0.05, 0.1, 0.2, 0.4 µg/ml) was investigated as the drug control. In all tests the numbers of live and dead parasites were counted by trypan blue staining.

Results: Result showed that the alcoholic and aqueous extracts of Pelarqonium had the inhibitory effects on the growth of T. vaginalis trophozoeites. The IC50 of the aqueous and alcoholic extracts of Pelarqonium and metronidazole after 24h were 54.67, 27.63 and 0.0326, respectively.

Conclusion: While the alcoholic and aqueous extract of Pelarqonium have anti-Trichomonas effect, the anti-Trichomonas properties of alcoholic extract is more than its aqueous extract. Since Pelarqonium is a herbal drug, it can be tested in vivo.