Apigenin prevents ultraviolet-B radiation induced cyclobutane pyrimidine dimers formation in human dermal fibroblasts

- UVB-exposure induces dose-dependent cyclobutane pyrimidine dimers (CPDs) formation in human dermal fibroblasts (HDFa).
- UVB-induced CPDs consequently affects nucleotide excision repair (NER) proteins and increases apoptotic signaling in HDFa cells.
- Apigenin pre- and post-treatment significantly prevents UVB-induced CPDs formation.
- Further, apigenin restores UVB-mediated loss of NER proteins and prevents apoptosis.
- This preventive effect may be due to its ability to absorb UVB photons, as this compound exhibit SPF value of 10.08.

Exposure to solar ultraviolet-B (UVB) radiation leads to the formation of cyclobutane pyrimidine dimers (CPDs). We investigated the protective effect of apigenin against UVB-induced CPDs formation in human dermal fibroblasts cells (HDFa). For this purpose, HDFa cells were treated with apigenin (15 μM) prior to UVB irradiation (20 mJ/cm2); DNA damage and subsequent molecular end points were observed. Exposure to UVB radiation increased significant CPDs formation in HDFa cells and the frequencies of CPDs were reduced by treatment with apigenin (15 μM). UVB-induced CPDs downregulates the expression of nucleotide excision repair (NER) genes such as xeroderma pigmentosum complementation group C, B, G and F (XPC, XPB, XPG and XPF), transcription factor II human (TFIIH) and excision repair cross-complementation group 1 (ERCC1) in HDFa cells. Conversely, apigenin treatment restored UVB-induced loss of NER proteins in HDFa cells, which indicates its preventive effect against CPDs formation. Besides, single low dose UVB-exposure induced nuclear fragmentation, apoptotic frequency and apoptotic proteins expression (Bax and Caspase-3) have been prevented by the apigenin pretreatment. Furthermore, apigenin exhibits strong UV absorbance property and showed 10.08 SPF value. Thus, apigenin can protect skin cells against UVB-induced CPDs formation probably through its sunscreen effect. Hence, apigenin can be considered as an effective protective agent against UV induced skin damages.