Fluorescence microscopic visualization of a DNA-cationic fullerene complex

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

BACKGROUND AND OBJECTIVES

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

The co-application effects of fullerene and ascorbic acid on UV-B irradiated mouse skin

The role of fullerene as a pro-oxidant or anti-oxidant in Ultraviolet B ray (UV-B)-induced disorders in mouse skin was investigated. Fullerene gave no photo-toxic effect to UV-B-irradiated mouse skin. Since erythema was concentrated at the pore circumference in a UV-B irradiation experiment in mouse skin, the sebaceous gland pairs was strongly implicated as a site for the generation of reactive oxygen species (ROS). In a histological evaluation of the skin stained with CH(3)MDFDA (ROS index) and YO-Pro-1 (apoptosis index), the fluorescence intensity of a sebaceous gland significantly increased with UV-B irradiation. With the application of fullerene to UV-irradiated mouse skin, no toxicity was recognized in comparison with the control, and erythema, the ROS index, and the apoptosis index decrease with the application of fullerene. Ascorbyl radical (AA*) increased with the application of ascorbate (AA) to UV-B-irradiated mouse skin, and AA* decreased with the application of fullerene. The co-application of AA and fullerene, which suppressed AA* in vitro, significantly suppressed erythema, and also suppressed both the ROS index and apoptosis index in mouse skin after UV-B irradiation. In both mouse skin at 48 h after UV-B irradiation and in an attempt to reproduce this phenomenon artificially in vitro, a similar high AA* peak (AA*/H*>4) was observed in electron spin resonance (ESR) charts. The binding of fullerene with AA impairs the Fenton reaction between AA and Fe-protein based on the observation of ascorbate-specific UV absorption and a linear equation for the calibration curve. Therefore, fullerene may impair the intercalation of AA to a heme pocket by binding with AA. These results suggest that the co-application of AA and fullerene is effective against oxidative skin damage caused by UV-B irradiation, and the development of an AA* inhibitor such as fullerene should be useful for reducing organ damage associated with Fe-protein oxidation.