Rosemary Diterpenes and Flavanone Aglycones Provide Improved Genoprotection against UV-Induced DNA Damage in a Human Skin Cell Model

Abstract

Overexposure to solar ultraviolet (UV) radiation is the major cause of a variety of cutaneous disorders, including sunburn, photoaging, and skin cancers. UVB radiation (290–320 nm) causes multiple forms of DNA damage, p53 induction, protein and lipid oxidation, and the generation of harmful reactive oxygen species (ROS). In recent years, botanicals containing polyphenols with antioxidant and anti-inflammatory properties as skin photoprotective agents have emerged. This study evaluated the protective effects of two formulations against UVB-induced damage in a skin cell model. One of the formulations (F2) contained a combination of citrus and olive extracts and the other one (F1) also contained a rosemary extract. The antioxidant capacity of both formulations was estimated by different in vitro methods, and the cell viability, intracellular ROS generation, mitochondrial depolarization, and DNA damage were studied in UVB-irradiated human keratinocytes. Both formulations exerted photoprotective effects on skin cells and decreased mitochondrial depolarization and DNA damage. F1 which contained iridoids, rosemary diterpenes, glycosides and aglycones of citrus flavanones, and monohydroxylated flavones exhibited higher cellular photoprotective effects and mitochondrial membrane potential restoration, as well as an enhanced capacity to decrease DNA double strand breaks and the DNA damage response. In contrast, F2, which contained mostly iridoids, citrus flavanone aglycones, and mono- and dihydroxylated flavones, exhibited a higher capacity to decrease intracellular ROS generation and radical scavenging capacity related to metal ion chelation. Both formulations showed a similar capability to decrease the number of apoptotic cells upon UVB radiation. Based on our results and those of others, we postulate that the stronger capacity of F1 to protect against UVB-induced DNA damage in human keratinocytes is related to the presence of rosemary diterpenes and citrus flavanone aglycones. Nevertheless, the presence of the dihydroxylated flavones in F2 may contribute to inhibiting the generation of metal-related free radicals. To confirm the efficacy of these formulations as potential candidates for oral/topical photoprotection, human trials are required to circumvent the limitations of the cellular model.

Sweet Cherry Byproducts Processed by Green Extraction Techniques as a Source of Bioactive Compounds with Antiaging Properties

“…However, weaker effects were obtained after 1200 J/m 2 of UVB irradiation, with 3.51% and 13.99% photoprotection, respectively, compared to control as shown in Table S1. Similar results with other natural extracts, such as citrus, rosemary, and lemon balm extracts, have been obtained using the same technique, with protection levels ranging from 10% to 80% [22,23,66].…”

Changes in Hepatic Phospholipid Metabolism in Rats under UV Irradiation and Topically Treated with Cannabidiol

“…Moreover, UV radiation is quite commonly used in phototherapy to treat skin diseases, such as psoriasis [18]. Earlier studies on the effects of UV radiation on living organisms have focused on metabolic changes in the skin and skin cells after in vivo or in vitro irradiation [40][41][42]. It is known that UVA/UVB radiation intensifies the production of ROS and reduces the level/activity of antioxidants, both in the skin and internal tissues, including blood and liver, which contributes to the formation of oxidative stress, inflammation and consequent metabolic disturbances [15,16].…”

Insight into Polyphenol and Gut Microbiota Crosstalk: Are Their Metabolites the Key to Understand Protective Effects against Metabolic Disorders?

“…Moreover, phenolic compounds can display genoprotective effects, thereby preventing/reversing the progression of various CMD diseases [ 167 ]. Through the protection of DNA against OxS damages, some types of polyphenols can promote metabolic health [ 168 , 169 , 170 , 171 ]. For example, epigallocatechin gallate and resveratrol exhibit high capacity to decrease DNA double strand breaks, chromosome loss, and DNA deterioration response in H 2 O 2 -induced genotoxicity in cells [ 172 , 173 ].…”