Dermaseptin S₄ derivative K₄K₂₀S₄: A potential candidate for development of a new microbicide contraceptive agent – an in vitro study

ABSTRACT

Background and objectives Sexually transmitted infections (STIs) and unplanned pregnancies have serious effects on the reproductive health of women. The present study was undertaken with a view to develop an effective means of prevention. The microbicidal and contraceptive potential of cationic peptides from frog's skin, namely, dermaseptin S₄ and its derivatives were investigated in vitro.

Study design Different bacterial and fungal strains were resorted to for determining the antimicrobial activity of the new compounds. The spermicidal activities of the latter were assessed using normal human semen samples, and their toxic effects were identified in a HeLa culture.

Results All S₄ derivatives elicited concentration-dependent spermicidal and antimicrobial activities at microgram concentrations. The highest levels recorded for both types of activity were displayed by K₄K₂₀S₄, and the lowest levels were exhibited by D₄D₂₀S₄ and S₄(5–28). Cytotoxicity assays revealed that some of these compounds were significantly safer than nonoxynol-9 (N-9).

Conclusions The ability of these peptides to instantaneously kill human sperm and STI pathogens at low concentrations indicates that their application as active ingredients in vaginal contraceptive preparations could induce considerably better effects than N-9.

KEYWORDS:

• Dermaseptin S₄
• Spermicide
• Contraceptive
• Antimicrobial activity
• Antimicrobial peptides

ACKNOWLEDGEMENTS

The authors express their sincere gratitude to Mr Anouar Smaoui and Mrs Hanen Ben Salem from the English Language Unit at the Sfax Faculty of Science for the linguistic assistance they kindly provided.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and the writing of the paper.