Triclosan: cytotoxicity, mode of action, and induction of apoptosis in human gingival cells in vitro.
The in vitro cytotoxicology of triclosan, the active ingredient in some mouthrinses and dentifrices used in the prevention and treatment of gingivitis and plaque, was studied using the Smulow-Glickman (S-G) human gingival epithelial cell line. The 24 h midpoint cytotoxicity value was 0.05-0.06 mM triclosan as assessed with the neutral red (NR) assay. Triclosan is used in dentifrices in combination with either zinc citrate or sodium fluoride (NaF). The sequence of potencies of these test agents, as assessed with the NR assay, was triclosan>zinc citrate>>NaF; combinations of triclosan + zinc citrate and triclosan + NaF were additive in their toxicities. Damage to the integrity of the plasma membrane, as assessed by the leakage of lactic acid dehydrogenase during a 3-h exposure, was initially evident with 0.1 mM triclosan. When exposed to triclosan for 3 d, a lag in the growth kinetics of the S-G cells was first observed at 0.01 mM triclosan. A reduction in attachment of S-G cells to dentin chips, previously exposed to triclosan for 1 h, was noted at 0.25 mM triclosan and greater. Triclosan-induced cell death was apparently by apoptosis, as noted by fluorescence microscopy and DNA agarose gel electrophoresis of extracted oligonucleosomal fragments.
Zuckerbraun
H L
HL
Department of Biology, Stern College for Women, Yeshiva University, New York, NY 10016, USA.
Babich
H
H
May
R
R
Sinensky
M C
MC
D000891:Anti-Infective Agents, Local / Q000633:toxicity*; D017209:Apoptosis; D002448:Cell Adhesion / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects; D053938:DNA Fragmentation; D003802:Dentifrices / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004847:Epithelial Cells / Q000187:drug effects*; D005460:Fluorides, Topical / Q000633:toxicity; D005881:Gingiva / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D012969:Sodium Fluoride / Q000633:toxicity; D014260:Triclosan / Q000633:toxicity*; D017967:Zinc Compounds / Q000633:toxicity
D000891:Anti-Infective Agents, Local; D003802:Dentifrices; D004338:Drug Combinations; D005460:Fluorides, Topical; D017967:Zinc Compounds; D014260:Triclosan; D012969:Sodium Fluoride