Embryotoxicity of magainin-2-amide and its enhancement by cyclodextrin, albumin, hydrogen peroxide and acidification.
BACKGROUND
The channel-forming antimicrobial peptide, magainin-2-amide, interacts preferentially with negatively charged, non cholesterol-containing membranes, including those of sperm, oocytes and cells of pre-implantation embryos. Cyclodextrin and albumin remove membrane cholesterol and together with hydrogen peroxide (H2O2) are potential enhancers of embryotoxicity.


METHODS
Two-cell murine embryos were cultured in vitro with magainin-2-amide at a high effective concentration (250 microg/ml) and at subthreshold concentrations (166 and 200 microg/ml). Embryos treated with sub-threshold concentrations of magainin were additionally treated with cyclodextrin, bovine serum albumin or H2O2 or were cultured under acidified conditions. Cell viability was verified with propidium iodide and fluorescein diacetate.


RESULTS
The embryotoxic effect of magainin and H2O2 was dose- and time-dependent. Cyclodextrin, H2O2, acidification of the medium, and to a lesser extent albumin, enhanced the embryotoxicity of magainin at sub-threshold concentrations.


CONCLUSIONS
Magainin on its own is highly embryotoxic. Its embryotoxicity is enhanced by cyclodextrin, albumin, H2O2 and acidification. Thus, magainin which has antibacterial, antifungal and antiprotozoal activity may also have a potential role as a contraceptive agent. The harmful effects of various concentrations of the exogenous H2O2 on 2-cell stage mouse embryos are reported here, to the best of our knowledge, for the first time.
Mystkowska
E T
ET
Department of Histology and Embryology, Center of Biostructure, Medical Academy, Chalubinski St. 5, 02-004 Warsaw, Poland.
Niemierko
A
A
Komar
A
A
Sawicki
W
W
D000818:Animals; D000890:Anti-Infective Agents / Q000633:toxicity*; D023181:Antimicrobial Cationic Peptides / Q000633:toxicity*; D046508:Culture Techniques; D003505:Cyclodextrins / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004622:Embryo, Mammalian / Q000187:drug effects*; D047108:Embryonic Development; D005260:Female; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D054806:Magainins; D008297:Male; D051379:Mice; D011247:Pregnancy; D012710:Serum Albumin, Bovine / Q000494:pharmacology*; D029867:Xenopus Proteins
D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D003505:Cyclodextrins; D054806:Magainins; D029867:Xenopus Proteins; C053301:magainin 2 peptide, Xenopus; D012710:Serum Albumin, Bovine; D006861:Hydrogen Peroxide