In Vitro Activity of Foeniculum vulgare and Its Main Essential Oil Component Trans-Anethole on Trichomonas vaginalis

Background: Trichomoniasis is one of the most common nonviral sexually transmitted infections worldwide which drug-resistant cases of the infection are rising. The aim of the study was to assessment the in vitro activity of Foeniculum vulgare and its main essential oil component on Trichomonas vaginalis. Also phytochemical investigation of F. vulgare essential oil was performed. Methods: Five T. vaginalis isolates subjected to susceptibility testing against essential oil and extracts of F. vulgare and anethole using microtiter plate method. The minimum lethal concentration (MLC) of the natural products was assessed in comparison with metronidazole. Gas chromatography-mass spectrometry and gas chromatography-flame ionization detector was applied for chemical investigation of the essential oil. Results: After 48 hours incubation, the most potent antitrichomonal agents were the methanolic and hexanic extract with MLC of 360 µg/ml and followed by the essential oil and anethole (1600 µg/ml). The isolates were sensitive to metronidazole with a mean MLC of 13.7 µg/ml. E-Anethole (88.41 %) was the major constituent of F. vulgare essential oil. Conclusion: The results suggested in vitro antiprotozoal properties of F. vulgare and anethole against T. vaginalis. Therefore further studies are needed to evaluate their in vivo effects and toxicity.