Protection from ultraviolet damage and photocarcinogenesis by vitamin d compounds

© Springer Nature Switzerland AG 2020. Exposure of skin cells to UV radiation results in DNA damage, which if inadequately repaired, may cause mutations. UV-induced DNA damage and reactive oxygen and nitrogen species also cause local and systemic suppression of the adaptive immune system. Together, these changes underpin the development of skin tumours. The hormone derived from vitamin D, calcitriol (1,25-dihydroxyvitamin D3) and other related compounds, working via the vitamin D receptor and at least in part through endoplasmic reticulum protein 57 (ERp57), reduce cyclobutane pyrimidine dimers and oxidative DNA damage in keratinocytes and other skin cell types after UV. Calcitriol and related compounds enhance DNA repair in keratinocytes, in part through decreased reactive oxygen species, increased p53 expression and/or activation, increased repair proteins and increased energy availability in the cell when calcitriol is present after UV exposure. There is mitochondrial damage in keratinocytes after UV. In the presence of calcitriol, but not vehicle, glycolysis is increased after UV, along with increased energy-conserving autophagy and changes consistent with enhanced mitophagy. Reduced DNA damage and reduced ROS/RNS should help reduce UV-induced immune suppression. Reduced UV immune suppression is observed after topical treatment with calcitriol and related compounds in hairless mice. These protective effects of calcitriol and related compounds presumably contribute to the observed reduction in skin tumour formation in mice after chronic exposure to UV followed by topical post-irradiation treatment with calcitriol and some, though not all, related compounds

Aloysia citriodora Palau

Aloysia citriodora Palau, cedron or lemon verbena, is a South American aromatic species widespread in North America, Eurasia, and Africa. It is appreciated because it therapeutic and food (condiment, flavoring) uses. Also is valued as ornamental, insect repellent, and sometimes in perfumery. Its popular culinary and medicinal uses have been expanded from Latin America to the rest of the Western world. Its main active constituents are essential oils, to which owes its aroma and flavor similar to lemon, but also contain flavonoids, verbascosides, iridoids heterosides, and others. It most disseminated uses in folk medicine include those to treat gastrointestinal disorders (digestive, antispasmodic, carminative, antidiarrheal), mild sedative, cardiotonic, febrifuge, analgesic, and antiseptic. Various experimental studies validate different effects, as eupeptic, spasmolytic, antimicrobial, anti-inflammatory, analgesic, hypotensive, among others. Its sedative/anxiolytic activity requires deeper further studies. Of particular interest are its cancer-related effects analyzed to date (antimutagenic, antigenotoxic, and antiangiogenic), and its antioxidant activity linked in various ways to our health.Fil: Hurrell, Julio Alberto. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Etnobotánica y Botánica Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin