Trichomonas vaginalis is a flagellated parasite that causes trichomonosis, the most common non-
viral sexually transmitted disease (STD) in the world. Worryingly, trichomonosis is associated to increased transmission of HIV. Due to high frequency of the
infection during pregnancy and the development of
metronidazole-resistant isolates, therapeutic alternatives to
5-nitroimidazole are being searched.
Triterpenes are natural products presenting several
biological activities such as anti-protozoal activity. The aim of this study was to evaluate the in vitro
anti-T. vaginalis activity from betulinic and ursolic
acids, as well as semisynthetic derivatives obtained. Compounds obtained from
betulinic acid presented better activity than those from
ursolic acid.
Piperazine derivatived from
betulinic acid presented minimum inhibitory concentration (MIC) value of 91.2 μM, and the kinetic growth curve performed with parasites treated with this most active compound revealed complete inhibition of trophozoite proliferation at 2 h of incubation and total abolition of trophozoite growth in 24 h, revealing that the
piperazine derivative is an efficient trichomonacidal molecule. The same compound promoted total erythrocyte lysis and
lactate dehydrogenase (LDH) liberation of 83 and 100% (at 45.6 and 91.2 μM, respectively), indicating parasite membrane damage. The
piperazine derivative demonstrated cytotoxic effect against the HMVII and HeLa cell lineages at the MIC value. This is the first report of semisynthetic
triterpenoid derivatives with
anti-T. vaginalis activity, revealing the high potential of these compounds as trichomonacidal agents.