Pentatrichomonas hominis, a parasitic protozoan often detected in human diarrheic stools, is the cause of severe morbidity in newborns and children, particularly in tropical zones. The flagellate is resistant to many disinfectants and anti-protozoan drugs. Therefore in this study we have synthesized three novel 4,5,6,7-tetrabromobenzimidazole (TBBI) derivatives carrying a polyfluoroalkyl substituent in position 2 of the benzimidazole scaffold, namely 2-trifluoromethyl-TBBI (CF3-TBBI), 2-nonafluorobutyl-TBBI (C4F9-TBBI), and 2-nonadecafluorononyl-TBBI (C9F19-TBBI), that next we tested for their in vitro activity against P. hominis.Widely applied anti-protozoal drug, metronidazole as a reference was used. All the investigated agents were added to 24 h P. hominis cultures; each of them was administered at three different concentrations. Number of the moving trichomonads was determined and compared with the control cultures. Different anti-trichomonal activity occurred depending on a kind of compound and its concentration. C4F9-TBBI was the most effective TBBI derivative tested: the agent, at the highest concentration 24.2 μg/ml, after 72 h reduced the number of viable trichomonads to 44.3%; C9F19-TBBI, at the concentration 24 μg/ml reduced the number of the flagellates to 58.5%. Paradoxically, metronidazole after the same time given at the highest concentration increased trophozoite counts by 464.6% in comparison with the control cultures (100%).
The objective of the present study that has been carried out in the Institute of Chemistry, Warsaw University of Life Sciences, was to investigate antimicrobial activity of a number of sweet marjoram extracts. Raw (fresh or dried) plant material from culinary or medicinal herbs may contain varying amounts of bacteria or protozoa, including some known human pathogens. The isolates, which are prepared by procedures involving the use of elevated temperature and/or organic solvents or other chemicals are expected to have considerably less or no such potentially harmful burden. Four sweet marjoram (Origanum majorana L.) fractions obtained by steam distillation, Soxhlet n-hexane extraction, extraction with aqueous ethanol, and with ethanolic ammonia solution were evaluated in vitro for activity against twenty Gram-positive or Gram-negative bacterial strains, six Candida sp. yeast strains and a single protozoan species Pentatrichomonas hominis. The n-hexane extract showed the highest antibacterial activity and inhibited growth of eight out of nine Staphylococcus aureus strains used. The other bacteria showed no substantial susceptibility to the extracts, except that Acinetobacter baumannii showed some inhibition by the aqueous ethanol extract. The isolates were also active against three out of six Candida sp. strains used, and the ethanolic ammonia extract reduced the number of viable P. hominis trophozoites by 50% at 160 µg·ml-1 concentration in 24 h cultures; the remaining extracts were considerably less or but marginally effective. These data warrant further study on identifying the components of the extracts with the highest activities.