title: Protective effect of tropical highland blackberry juice (Rubus adenotrichos Schltdl.) against UVB-mediated damage in human epidermal keratinocytes and in a reconstituted skin equivalent model.
abstract: Solar ultraviolet (UV) radiation, particularly its UVB (280-320 nm) spectrum, is the primary environmental stimulus leading to skin carcinogenesis. Several botanical species with antioxidant properties have shown photochemopreventive effects against UVB damage. Costa Rica's tropical highland blackberry (Rubus adenotrichos) contains important levels of phenolic compounds, mainly ellagitannins and anthocyanins, with strong antioxidant properties. In this study, we examined the photochemopreventive effect of R. adenotrichos blackberry juice (BBJ) on UVB-mediated responses in human epidermal keratinocytes and in a three-dimensional (3D) reconstituted normal human skin equivalent (SE). Pretreatment (2 h) and posttreatment (24 h) of normal human epidermal keratinocytes (NHEKs) with BBJ reduced UVB (25 mJ cm(-2))-mediated (1) cyclobutane pyrimidine dimers (CPDs) and (2) 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation. Furthermore, treatment of NHEKs with BBJ increased UVB-mediated (1) poly(ADP-ribose) polymerase cleavage and (2) activation of caspases 3, 8 and 9. Thus, BBJ seems to alleviate UVB-induced effects by reducing DNA damage and increasing apoptosis of damaged cells. To establish the in vivo significance of these findings to human skin, immunohistochemistry studies were performed in a 3D SE model, where BBJ was also found to decrease CPDs formation. These data suggest that BBJ may be developed as an agent to ameliorate UV-induced skin damage.
authors.affiliation: Centro de Investigación en Biotecnología, Instituto Tecnológico de Costa Rica, Cartago, Costa Rica; Centro de Investigación en Estructuras Microscópicas, Universidad de Costa Rica, San José, Costa Rica.
authors.forename: Laura
authors.initials: L
authors.lastname: Calvo-Castro
authors.forename: Deeba N
authors.initials: DN
authors.lastname: Syed
authors.forename: Jean C
authors.initials: JC
authors.lastname: Chamcheu
authors.forename: Fernanda M P
authors.initials: FM
authors.lastname: Vilela
authors.forename: Ana M
authors.initials: AM
authors.lastname: Pérez
authors.forename: Fabrice
authors.initials: F
authors.lastname: Vaillant
authors.forename: Miguel
authors.initials: M
authors.lastname: Rojas
authors.forename: Hasan
authors.initials: H
authors.lastname: Mukhtar
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002478:Cells, Cultured; D004249:DNA Damage; D005638:Fruit / Q000737:chemistry*; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects* / Q000528:radiation effects*; D018384:Oxidative Stress; D010936:Plant Extracts / Q000494:pharmacology*; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D012867:Skin / Q000166:cytology / Q000187:drug effects* / Q000528:radiation effects*; D014329:Tropical Climate; D014466:Ultraviolet Rays
chemical_list: D010936:Plant Extracts; D011837:Radiation-Protective Agents