G. Valacchi et al., Effect of benzoyl peroxide on antioxidant status, NF-kappa B activity and interleukin-1 alpha gene expression in human keratinocytes, TOXICOLOGY, 165(2-3), 2001, pp. 225-234
Benzoyl peroxide (BP) is used as a topical treatment for acne. Besides its
anti-bacterial activity, the exact molecular mechanisms underlying its mode
of action are not fully understood. In the current study, the effects of B
P on cell viability, antioxidant status and, IL-1 and IL-8 gene expression
were investigated in HaCaT keratinocytes. Keratinocytes incubated for 24 h
with BP exhibited a dose-dependent cytotoxicity at concentrations above 250
muM. Furthermore, in the presence of 300 muM BP about 50% of the cellular
vitamin E was depleted within the first 30 min. The intracellular ratio of
oxidized to reduced glutathione (GSSG/GSH) was increased significantly star
ting 6 h after BP treatments indicating that BP reacts rapidly with targets
in the cell membrane and more slowly with those in the cytosol. NF-kappaB
transactivation was not significantly affected by BP. However, BP treatment
of HaCaT keratinocytes resulted in a dose-dependent increase in IL-1 alpha
gene expression whereas no changes in IL-8 mRNA levels were observed. Thes
e results demonstrate that BP induces an inflammatory reaction mediated by
oxidative stress by a pathway independent of the redox-sensitive transcript
ion factor NF-kappaB. (C) 2001 Elsevier Science Ireland Ltd. All rights res
erved.