Anti-Trichomonas vaginalis activity and chemical analysis of metabolites produced by marine-associated fungi

Trichomoniasis is the most common non-viral sexually transmitted infection worldwide and it may have serious consequences, especially for women. Currently, 5-nitroimidazole drugs are the treatment of choice for trichomoniasis, although presenting adverse effects and reported cases of drug resistance. Metabolites isolated from marine fungi have attracted considerable attention due to their unique chemical structures with diverse biological activities, including antiprotozoal activity. In this study, we showed the anti-Trichomonas vaginalis activity of fractions obtained from marine fungi and the chemical composition of the most active fraction was determined. Ethyl acetate fractions of the fungus Aspergillus niger (EAE03) and Trichoderma harzianum/Hypocrea lixii complex (EAE09) were active against T vaginalis. These samples, EAE03 and EAE09, were also effective against the fresh clinical isolate metronidazole-resistant TV-LACM2R, presenting MIC values of 2.0 mg/mL and 1.0 mg/mL, respectively. The same MIC values were found against ATCC 30,236 T. vaginalis isolate. In vitro cytotoxicity revealed only the fraction named EAE03 with no cytotoxic effect; however, the active fractions did not promote a significant hemolytic effect after 1-h incubation. Already, the in vivo toxicity evaluation using Galleria mellonella larvae demonstrated that none of the tested samples caused a reduction in animal survival. The fraction EAE03 was followed for purification steps and analyzed by LC-DAD-MS. Eleven compounds were annotated, including butyrolactone, butanolide, and atromentin. Overall, the range of activities reported confirms the potential of marine fungi to produce bioactive molecules.

Automated summary

This study demonstrated the anti-Trichomonas vaginalis activity of fractions obtained from marine fungi, identifying the chemical composition of the most active fraction. The samples tested showed significant activity against both T. vaginalis and metronidazole-resistant strains. These findings indicate the potential of marine fungi in producing bioactive compounds for the treatment of trichomoniasis.