FLICKR, VOX EFXIt has long been known that extremely dilute bleach baths—0.005 percent—can be used as a successful accessory treatment for eczema, but until now, no one understood how it worked. Researchers from Stanford University have shown that hypochlorite (HOCl)—bleach’s active ingredient—effectively blocks the function of nuclear factor κB (NF-κB), which activates genes involved in inflammation and aging. Their work was published in the Journal of Clinical Investigation last week (November 15).
“Originally it was thought that bleach may serve an antimicrobial function, killing bacteria and viruses on the skin,” coauthor Thomas Leung said in a statement. “But the concentrations used in clinic are not high enough for this to be the sole reason,” he continued, “so we wondered if there could be something else going on.”
The team treated human keratinocytes with 0.005 percent HOCl and found that they were unable to activate NF-κB until 24 hours later. The researchers showed that HOCl oxidized and inactivated inhibitor of NF-κB kinase (IKK), which is necessary for NF-κB activation, both in vitro and in vivo. The researchers also put mice in a shallow HOCl bath 30 minutes before exposing them to radiation, finding that the mice that had a bleach bath developed fewer and less severe skin lesions from the radiation than mice that had a water bath. Further, the scientists showed that HOCl reduced thinning in the skin of 18-month-old mice by increasing proliferation, but that the effect was reversible within a few weeks.
“This research opens up the potential for new clinical treatments in the future,” Graham Johnson of the British Association of Dermatologists told BBC News. “However, it is worth noting that this research is just the beginning,” he added. “And although the science is sound, there are yet to be human clinical trials.”