Effects of contact sensitizers neomycin sulfate, benzocaine and 2,4-dinitrobenzene 1-sulfonate, sodium salt on viability, membrane integrity and IL-1 alpha mRNA expression of cultured normal human keratinocytes.
The toxic effect of three potential contact sensitization chemicals [the aminoglycosidic antibiotic neomycin sulfate, the local anaesthetic benzocaine and the primary sensitizer 2,4-dinitrobenzene 1-sulfonate, sodium salt (DNBS)], on cultured human keratinocytes was examined. The three chemicals were compared with respect to their cytotoxic potential (determined by crystal violet staining assay), their membrane disruptive potential ([3H]arachidonic acid release assay), and their effects on interleukin 1 alpha (IL-1 alpha) mRNA expression [reverse transcription-polymerase chain reaction (RT-PCR)]. At the concentrations used, neomycin sulfate (0.004-0.32%) and benzocaine (0.0165-0.165%) did not show relevant cytotoxicity or membrane perturbation. On the other hand, DNBS (0.001-1%) caused a significant dose-dependent cytotoxic response at concentrations higher than 0.1%, while the [3H]arachidonic acid release assay indicated absence of membrane perturbation activity in all the range of DNBS concentrations examined. The effects of the three sensitizers on IL-1 alpha mRNA expression were varied; neomycin sulfate caused a dose-dependent induction of IL-1 alpha mRNA, benzocaine did not significantly affect its signal, and DNBS suppressed IL-1 alpha gene expression.
Pastore
S
S
Division of Dermatology, Sunnybrook Health Science Centre, University of Toronto, Ontario, Canada.
Shivji
G M
GM
Kondo
S
S
Kono
T
T
McKenzie
R C
RC
Segal
L
L
Somers
D
D
Sauder
D N
DN
D016718:Arachidonic Acid / Q000378:metabolism; D001345:Autoradiography; D001557:Benzenesulfonates / Q000633:toxicity*; D001566:Benzocaine / Q000633:toxicity*; D002462:Cell Membrane / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003720:Densitometry; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007231:Infant, Newborn; D007375:Interleukin-1 / Q000096:biosynthesis* / Q000235:genetics; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D008297:Male; D009355:Neomycin / Q000633:toxicity*; D010413:Penis; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D014158:Transcription, Genetic
D001557:Benzenesulfonates; D007375:Interleukin-1; D012333:RNA, Messenger; D016718:Arachidonic Acid; C001073:2,4-dinitrobenzenesulfonic acid; D009355:Neomycin; D001566:Benzocaine