Preventive effect of chemical peeling on ultraviolet induced skin tumor formation

Abstract Background Chemical peeling is one of the dermatological treatments available for certain cutaneous diseases and conditions or improvement of cosmetic appearance of photoaged skin. Objectives We assessed the photochemopreventive effect of several clinically used chemical peeling agents on the ultraviolet (UV)-irradiated skin of hairless mice. Methods Chemical peeling was done using 35% glycolic acid dissolved in distilled water, 30% salicylic acid in ethanol, 10% or 35% trichloroacetic acid (TCA) in distilled water at the right back of UV-irradiated hairless mice every 2 weeks in case of glycolic acid, salicylic acid, and 10% TCA and every 4 weeks in case of 35% TCA for totally 18 weeks after the establishment of photoaged mice by irradiation with UVA + B range light three times a week for 10 weeks at a total dose of 420 J/cm2 at UVA and 9.6 J/cm2 at UVB. Tumor formation was assessed every week. Skin specimens were taken from treated and non-treated area for evaluation under microscopy, evaluation of P53 expression, and mRNA expression of cyclooxygenase (COX)-2. Serum level of prostaglandin E2 was also evaluated. Results All types of chemical peeling reduced tumor formation in treated mice, mostly in the treated area but also non-treated area. Peeling suppressed clonal retention of p53 positive abnormal cells and reduced mRNA expression of COX-2 in treated skin. Further, serum prostaglandin E2 level was decreased in chemical peeling treated mice. Conclusions These results indicate that chemical peeling with glycolic acid, salicylic acid, and TCA could serve tumor prevention by removing photodamaged cells.