Apoptosis or programmed cell death is the most common
form of eukaryotic cell death. With the kit that was used,
necrotic cells fluoresce in red color, living cells fluoresce
in yellow green and apoptotic cells fluoresce in yellow
green and red simultaneously (Perez-Arriaga et al.,
2006). F. septica extract induced apoptotic-like changes
to T. vaginalis trophozoites after 72 h exposure.
Moreover, red surrounded by yellow signals were also
observed in F. septica and S. foetida against E.
histolytica (Figure 4). Cells in all cases showed a clear
loss of normal morphology. On the other hand, the negative
control (with ethanol) and the control without any
extract or solvent gave a green color. This signified the
presence of viable cells.
Apoptosis induced by antiparasitic drugs has been
barely studied in protozoan parasites (Perez-Arriaga et
al., 2006). In the method that was used, the effects are
attributable to the plant extracts since the kit preferentially
and specifically labels DNA strand breaks generated
during apoptosis. It allows the discrimination of apoptosis
from necrosis and from primary DNA strand breaks
induced by cytostatic drugs or irradiation. These effects
might be consequences of the activation of apoptotic
mechanisms that may be exclusive for microorganisms
lacking mitochondria (Perez-Arriaga et al., 2006).
Antiprotozoal and cytotoxicity assays are rarely done in
antimicrobial studies. Thus, the assays performed in
these two plants play an essential role in discovering
various capabilities of these plants which are seldom
investigated. Moreover, this discovery offers great
possibilities in the discovery of new drugs.