The escalating demand for natural ingredients with health-enhancing properties has driven research into plant-derived compounds for use in nutricosmetics and cosmeceuticals. A significant concern in skin health is oxidative stress induced by environmental factors such as UVA irradiation, which contributes to premature aging and various skin disorders by generating damaging free radicals. While Rosa rubiginosa L. is traditionally recognized for its medicinal and cosmetic benefits, its leaf extract remains relatively understudied, particularly regarding its antioxidant mechanisms in human skin cells. This study addresses this gap by investigating the in vitro biological properties of Rosa rubiginosa L. leaf extract on human primary keratinocytes and fibroblasts under photo-oxidative stress, aiming to evaluate its potential as a bio-functional ingredient. The rationale for considering this extract stems from its known antioxidant and anti-inflammatory properties and its rich phytochemical profile, suggesting a promising avenue for combating oxidative damage and promoting skin health.
Rosa rubiginosa L. leaves were collected, and the extract was prepared using maceration with a water-ethanol solvent. The antioxidant potential of the extract was assessed using DPPH and Folin–Ciocalteu assays, as well as a DNA protection assay. In vitro assessments involved culturing human dermal fibroblasts (NHDF) and epidermal keratinocytes (NHEK), treating them with the extract, and exposing them to UVA irradiation. Cell viability was determined by ATP level measurements, and the expression of 20 genes related to antioxidant and inflammation pathways was analyzed using RT-qPCR.
Key Findings
•The Rosa rubiginosa L. leaf extract exhibited strong DPPH radical scavenging activity (IC50 = 11.97 ± 0.42 µg/mL) and a high total phenolic content (633.93 ± 0.14 µg GAE/mg DW), indicating significant antioxidant potential.
•The extract effectively inhibited peroxyl radical-induced DNA strand breakage in a concentration-dependent manner, with the highest concentration (135 µg/mL) showing 98.39% protection.
•Treatment with the Rosa rubiginosa L. leaf extract increased intracellular ATP levels in both NHDF and NHEK cells, even under UVA irradiation, suggesting enhanced cell viability and energy metabolism.
•In NHEK cells under UVA irradiation, the extract downregulated the gene expression of pro-inflammatory cytokines (IL1A, IL1B, IL6, IL8, TNFa) and upregulated the expression of an antimicrobial peptide (DEFB4).
•In NHDF cells under UVA irradiation, the extract upregulated the gene expression of key antioxidant enzymes (GPX1, GPX4, SOD1, CAT) and a transcription factor (NRF2), as well as collagen type III alpha 1 chain (COL3A1).
This study provides compelling evidence for the bio-functional potential of Rosa rubiginosa L. leaf extract. The research is novel in its comprehensive in vitro evaluation of this specific extract’s biological activities on human skin cells under photo-oxidative stress, elucidating its strong antioxidant capabilities and its ability to protect DNA. Furthermore, the study reveals the extract’s dual protective effects: mitigating inflammation and promoting antimicrobial responses in keratinocytes and enhancing the antioxidant defense system and collagen production in fibroblasts under UVA irradiation. These findings underscore the potential of Rosa rubiginosa L. leaf extract as a promising ingredient for the next generation of cosmeceuticals and nutraceuticals aimed at combating skin aging and damage caused by oxidative stress. Future research should focus on elucidating the precise molecular mechanisms underlying these effects and evaluating the extract’s efficacy and safety in in vivo and clinical settings to fully realize its translational potential.
Link to the study: https://www.mdpi.com/2079-9284/12/2/62
