Surfactants as microbicides and contraceptive agents: a systematic in vitro study.
BACKGROUND
The urgent need for cheap and easy-to-use protection against both unwanted pregnancies and sexually transmitted diseases has stimulated considerable interest in the use of surfactants as microbicides, anti-viral, and contraceptive agents in recent years. In the present study we report a systematic in vitro evaluation of the microbicidal, anti-viral and contraceptive potential of cationic, anionic, zwitterionic, and non-ionic surfactants.


RESULTS
Toxicity was evaluated in mammalian columnar epithelial (MDCK) cells, human sperm cells, Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Neisseria gonorrhoeae, Streptococcus agalactiae and Enterococcus faecalis. The inhibition of adenovirus and lentivirus infection of MDCK cells was also tested. A homologous series of cationic surfactants, alkyl-N,N,N-trimethylammonium bromides (C(n)TAB), with varying alkyl chains were shown to be bactericidal and fungicidal at doses that were related to the surfactant critical micelle concentrations (CMC), all of them at concentrations significantly below the CMC. In general, bacteria were more susceptible to this surfactant group than C. albicans and this organism, in turn, was more susceptible than MDCK cells. This suggests that the C(n)TAB may be useful as vaginal disinfectants only in so far as bacterial and fungal infections are concerned. None of the surfactants examined, including those that have been used in pre-clinical studies, showed inhibition of adenovirus or lentivirus infection of MDCK cells or spermicidal activity at doses that were sub-toxic to MDCK cells.


CONCLUSIONS
The results of this study lead us to propose that systematic analysis of surfactant toxicity, such as we report in the present work, be made a mandatory pre-condition for the use of these substances in pre-clinical animal and/or human studies.
Vieira
Otilia V
OV
Centre for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal. vieira@cnc.cj.uc.pt
Hartmann
Diego O
DO
Cardoso
Carla M P
CM
Oberdoerfer
Daniel
D
Baptista
Marta
M
Santos
Manuel A S
MA
Almeida
Luis
L
Ramalho-Santos
João
J
Vaz
Winchil L C
WL
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology; D000998:Antiviral Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D002175:Candida / Q000187:drug effects; D002460:Cell Line; D003270:Contraceptive Agents / Q000494:pharmacology*; D004285:Dogs; D004847:Epithelial Cells / Q000187:drug effects / Q000502:physiology; D005260:Female; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006801:Humans; D007668:Kidney; D008297:Male; D012749:Sexually Transmitted Diseases / Q000188:drug therapy / Q000517:prevention & control*; D013501:Surface-Active Agents / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D000998:Antiviral Agents; D003270:Contraceptive Agents; D013501:Surface-Active Agents