Anoplin is a recently discovered
antimicrobial peptide (
AMP) isolated from the
venom sac of the spider wasp Anoplius samariensis, and it is one of the shortest α-helical
AMP found naturally to date consisting of only ten
amino acids. Previous results showed that
anoplin exhibits potent antimicrobial activity but little hemolytic activity. In this study, we synthesized
anoplin, studied its cytotoxicity in Friend virus-induced
leukemia cells [murine
erythroleukemia (MEL) cells], and proposed its possible mechanism. Our results showed that
anoplin could inhibit the proliferation of MEL cells in a dose-dependent and time-dependent manner via disrupting the integrity of cell membrane, which indicated that
anoplin exerts its cytotoxicity efficacy. In addition, the cell cycle distribution of MEL cells was arrested in the G₀/G₁ phase significantly. However,
anoplin could not induce obvious apoptosis in MEL cells, as well as
anoplin could not induce visible changes on morphology and quantity in the bone marrow cells isolated from normal mice. All of these results indicate that
anoplin, as generally believed, is a selective
AMP, a value characteristic in the design of safe therapeutic agents. The cytotoxicity of
anoplin on MEL cells was mainly attributable to the plasma membrane perturbation and also to the intracellular events such as the arrest of cell cycle. Although this is an initial study that explored the activity of
anoplin in vitro rather than in vivo, with the increasing resistance of conventional
chemotherapy, there is no doubt that
anoplin has desirable feature to be developed as a novel and selective
anticancer agent.