Marina Weizenmann

Lycorine induces cell death in the amitochondriate parasite, Trichomonas vaginalis, via an alternative non-apoptotic death pathway

In this study, the mechanism of action of the pro-apoptotic alkaloid lycorine on an amitochondriate cell, the parasite Trichomonas vaginalis, was investigated. The cytotoxicity of lycorine against T. vaginalis was studied from 2.5 to 1000μM and several important ultrastructural alterations were observed by electron microscopy. Lycorine arrested the T. vaginalis cell cycle, although no hallmarks of apoptosis, such as apoptotic bodies, were observed. Consequently, the underlying mechanism of action fails to completely fulfill the criteria for apoptosis. However, some similarities to paraptotic cell death were observed.

Candimine-induced cell death of the amitochondriate parasite Trichomonas vaginalis.

Candimine (1), an alkaloid from the bulbs of Hippeastrum morelianum, was found to be cytotoxic for the amitochondriate parasite Trichomonas vaginalis. Candimine (1) induced cell death with an unprecedented group of effects that failed to fulfill the criteria for apoptosis and apoptosis-like death already reported in trichomonads. Arrest of the parasite cell cycle, and morphologic and ultrastructural alterations, including marked cytoplasmic vacuolization, were induced by 1. The present findings suggest some similarities to paraptotic cell death, described for multicellular organisms. This study contributes to both a better understanding of the biological effects of 1 and T. vaginalis cell biology.