344 JOURNAL OF COSMETIC SCIENCE J/m 2 UVB resulted in significant induction of cyclobutane pyrimidine dimers, as indi- cated by the quantified fluorescence due to binding of the antibody (Figure 2). In Figure 3 the mean fluorescence is given for the skin samples (two skin samples per time point), of which approximately 400 cells were measured. Fluorescence in non-irradiated samples was around 26 arbitrary units and was not affected by application of Unipertan © VEG- 2002 (data not shown). Background fluorescence is accounted for by non-specific bind- ing of the antibody preparations, and also by the noise of the laserscan microscope. Application ofUnipertan © VEG-2002 before exposure to UV did not result in a decrease of UV-induced CPD and, therefore, it does not act as a sunscreen creme. Figure 2. Section of human skin stained with the antibody against UV-DNA damage (cyclobutane py- rimidine dimers).

DNA DAMAGE AND REPAIR 345 250 200 g 150 o -• lOO E 5O 0 F • donor 1 donor 2 donor 3 Figure 3. Mean fluorescence due to antibody binding, measured in nuclei from epidermal cells. Human skin organ cultures were used from three donors. Treatments: 3000 J/m 2 UVB (black bar) and Unipertan © VEG-2002 followed by 3000 J/m 2 UVB (hatched bar). No reduction in the level of CPD at 24 h after exposure was observed in skin samples obtained from donor 1 in donors 2 and 3, however, reduction was 20% and 44%, respectively, at 24 h after exposure. When Unipertan © VEG-2002 was applied before irradiation, an additional reduction in the level of CPD was observed after 6 and 24 h. The reduction in the level of CPD increased to 12%, 41%, and 79% at 24 h after exposure in the three donors, respectively. Results are presented in Figure 4. CLINICAL TRIAL After the demonstration of enhancement of removal of UVB-DNA damage in ex vivo human skin samples, a preliminary clinical trial was performed with three volunteers. Unipertan © VEG-2002 was applied to the forearms at 1 h before exposure to 3 MED UVB. The punch biopsies taken at t = 0 and t = 24 h were processed for immuno- staining, analogous to the in vitro experiments. No reduction in the level of CPD at 24 h was found in one volunteer in another volunteer reduction was intermediate (43%), and almost complete (90%) in the third. Application of Unipertan © VEG-2002 reduced the 24-h level of DNA damage in the first two volunteers, resulting in a reduction of 34% and 77%, respectively. In the third volunteer the level of CPD after Unipertan © application was comparable to that of the control. This volunteer had already removed all of the initially induced DNA damage within 24 h, and no further reduction in CPD was expected. The results are summarized in Figure 5. DISCUSSION Two important facts are made clear by the present study: (a) the in vitro data are