Acerola-Derived Photorepair System for Eliminating Ultraviolet-Induced Pyrimidine Dimers in Human Cells

Background/Objectives: Ultraviolet B (UV-B) is a significant risk factor for skin damage, as it induces cyclobutane pyrimidine dimers (CPD), which suppress DNA replication and transcription. Photolyase (PHR) is a blue light-dependent enzyme that repairs DNA damage caused by UV irradiation. While it is absent in human, it plays a crucial role in repairing CPD in other organisms. Acerola (Malpighia emarginata DC), a fruit with high antioxidant content, is widely consumed for health benefits. This study aimed to identify a novel PHR in acerola and evaluate its photorepair activity. Methods: Using RNA-seq data, we cloned the full-length sequence of the acerola PHR gene and constructed an expression vector. A stable transfected HEK293 cell line (HEK293/acPHR) was established. CPD repair activity was analyzed under blue light in these cells, as well as in normal human dermal fibroblasts (NHDFs) supplemented with extracellular vesicles (EVs) from HEK293/acPHR cells and extracellular vesicle-like nanoparticles derived from acerola extract. Results: Blue light-dependent CPD reduction was observed in HEK293/acPHR cells compared to control cells following UV-B irradiation. Additionally, CPD repair activity was demonstrated in NHDFs and HEK293 cells treated with EVs from HEK293/acPHR cells and nanoparticles from acerola extract. Conclusions: Acerola-derived PHR exhibits the potential to repair UV-induced DNA damage in human cells. Furthermore, EV-mediated delivery of PHR provides a promising avenue for extending photorepair capabilities to other cells. These findings highlight the potential applications of acerola PHR in the prevention and treatment of UV-induced skin damage and related conditions.