Induction of different reactive oxygen species in the skin during various laser therapies and their inhibition by fullerene

Abstract

The production of reactive oxygen species (ROS) is one of the mechanisms of laser irradiation in the skin, and there are beneficial and detrimental aspects to this reaction. Detrimental side effects after laser treatments, such as redness and pigmentation, can be reduced by using anti-oxidants. Electron spin resonance (ESR) analysis using a free radical trapping agent revealed that different free radicals, including hydroxyl ((·) OH) and superoxide anion (O 2-) radicals, were generated in the skin of hairless mice by irradiation with intense pulsed light (IPL), plasma, and radio frequency lasers. Generation of O 2- and (·) OH radicals was significantly inhibited in a dose-dependent fashion by fullerene and fullerene did not have any pro-oxidant effects as no radical adduct signal was detected. Although ROS can increase expression of COX-2 mRNA, an inflammatory marker, laser-induced COX-2 expression was significantly suppressed by the antioxidant activity of fullerene. In addition, imaging analysis of human skin has shown that erythema-associated redness caused by laser-induced inflammation is inhibited by fullerene gel. These data suggest that laser-induced inflammation is suppressed by the ROS-scavenging activity of fullerene and that application of fullerene is effective against oxidative skin damage caused by laser irradiation. Thus, fullerene has potential as an after-care therapy following laser irradiation of the skin.