Resumen
- Solar ultraviolet (UV) radiation, particularly its UVB (280–320 nm) spectrum, is the primary environmental stimulusleading to skin carcinogenesis. Several botanical species withantioxidant properties have shown photochemopreventiveeffects against UVB damage. Costa Rica’s tropical highlandblackberry (Rubus adenotrichos) contains important levels ofphenolic compounds, mainly ellagitannins and anthocyanins,with strong antioxidant properties. In this study, we exam-ined the photochemopreventive effect of R. adenotrichosblackberry juice (BBJ) on UVB-mediated responses inhuman epidermal keratinocytes and in a three-dimensional(3D) reconstituted normal human skin equivalent (SE). Pre-treatment (2 h) and posttreatment (24 h) of normal humanepidermal keratinocytes (NHEKs) with BBJ reduced UVB(25 mJ cm2)-mediated (1) cyclobutane pyrimidine dimers(CPDs) and (2) 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-ox-odG) formation. Furthermore, treatment of NHEKs withBBJ increased UVB-mediated (1) poly(ADP-ribose) polymer-ase cleavage and (2) activation of caspases 3, 8 and 9. Thus,BBJ seems to alleviate UVB-induced effects by reducingDNA damage and increasing apoptosis of damaged cells. Toestablish the in vivo significance of these findings to humanskin, immunohistochemistry studies were performed in a 3DSE model, where BBJ was also found to decrease CPDs for-mation. These data suggest that BBJ may be developed as anagent to ameliorate UV-induced skin damage.