Inhibitory effects of Melia azedarach L. extracts on the growth of Trichomonas vaginalis : Ultrastructural changes of Trichomonas vaginalis treated by Melia azedarach L

Meliae cortex (Melia azedarach Linne. var. japonica Makino, M. toosendan Siebold & Zucc) is one of the herbs used in oriental medicine for the treatment of various types of vaginitis. The present study was performed to examine the effects of Meliae cortex extracts on the growth and fine structure of Trichomonas vaginalis (T. vaginalis). Meliae cortex dose-dependently reduced the viability of T. vaginalis. In the electron microscopy study, we also observed the ultrastructural changes of T. vaginalis following the treatment with Meliae cortex. One to two hours after the addition of the extract of Meliae cortex, the movement of flagella and axostyle decreased, but the cell death did not occur. The fine structure of the cytoplasm was changed 30 min to 2 hour after the treatment of the extract of Meliae cortex. The number of polyribosome decreased, whereas the number of single ribosomes in the cytoplasm increased. These results indicate that Meliae cortex has the antiprotozoal effects on T. vaginalis cells through the inhibition of cell multiplication as well as the impairment of protein synthesis.